calca-protein--human and Virus-Diseases

Respiratory infections remain the most common reason why patients seek medical care in ambulatory and hospital settings, and they are the most frequent precursor of sepsis. In light of the limitations of clinical signs and symptoms and traditional microbiologic diagnostics for respiratory infections, blood biomarkers that correlate with the presence and extent of bacterial infections may provide additional useful information to improve diagnostic and prognostic efforts and help with therapeutic decisions in individual patients. A growing body of evidence supports the use of procalcitonin (PCT) to differentiate bacterial from viral respiratory diagnoses, to help risk stratify patients, and to guide antibiotic therapy decisions about initial need for, and optimal duration of, therapy. Although still relatively new on the clinical frontier, a series of randomized controlled trials have evaluated PCT protocols for antibiotic-related decision making and have included patients from different clinical settings and with different severities of respiratory infection. In these trials, initial PCT levels were effective in guiding decisions about the initiation of antibiotic therapy in lower-acuity patients, and subsequent measurements were effective for guiding duration of therapy in higher-acuity patients, without apparent harmful effects. Recent European respiratory infection guidelines now also recognize this concept. As with any other laboratory test, PCT should not be used on a stand-alone basis. Rather, it must be integrated into clinical protocols, together with clinical, microbiologic data and with results from clinical risk scores. The aim of this review is to summarize recent evidence about the usefulness of PCT in patients with lower respiratory tract infections and to discuss the potential benefits and limitations of this marker when used for clinical decision making.

Topics: Anti-Bacterial Agents; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Cost-Benefit Analysis; Costs and Cost Analysis; Humans; Prognosis; Protein Precursors; Respiratory Tract Infections; Virus Diseases

Sepsis is one of the most cost-intensive conditions of critically ill patients in intensive care medicine. Furthermore, sepsis is known to be the leading cause of morbidity and of mortality in intensive care patients. Early initiation of antibiotic therapy can significantly reduce mortality. The development of resistance of bacterial species against antibiotics is a compelling issue to reconsider indications and administration of antibiotic treatment. Adequate indications and duration of therapy are particularly important for the use of highly potent substances in the intensive care setting. Until recently no laboratory marker has been available to distinguish bacterial infections from viral or non-infectious inflammatory responses. However, procalcitonin (PCT) appears to be the first among a large array of inflammatory markers that offers this possibility. Regular procalcitonin measurements can significantly shorten the length of antibiotic therapy, show positive influence on antibiotic costs and have no adverse affects on patient outcome.

Topics: Adult; Algorithms; Anti-Bacterial Agents; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child; Critical Care; Critical Illness; Humans; Protein Precursors; Sepsis; Virus Diseases

Sepsis, an innate immunological response of systemic inflammation to infection, is a growing problem worldwide with a relatively high mortality rate. Immediate treatment is required, necessitating quick, early and accurate diagnosis. Rapid molecular-based tests have been developed to address this need, but still suffer some disadvantages. The most commonly studied biomarkers of sepsis are reviewed for their current uses and diagnostic accuracies, including C-reactive protein, procalcitonin, serum amyloid A, mannan and IFN-γ-inducible protein 10, as well as other potentially useful biomarkers. A singular ideal biomarker has not yet been identified; an alternative approach is to shift research focus to determine the diagnostic relevancy of multiple biomarkers when used in concert. Challenges facing biomarker research, including lack of methodology standardization and assays with better detection limits, are discussed. The ongoing efforts in the development of a multiplex point-of-care testing kit, enabling quick and reliable detection of serum biomarkers, may have great potential for early diagnosis of sepsis.

Topics: Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Chemokine CXCL10; Early Diagnosis; Humans; Mannans; Mycoses; Protein Precursors; Sensitivity and Specificity; Sepsis; Serum Amyloid A Protein; Virus Diseases

A short-cut review was performed to evaluate whether inflammatory markers such as C reactive protein (CRP), erythrocyte sedimentation rate (ESR), white cell count (WCC) and procalcitonin (PCT) are able to discriminate between streptococcal and viral tonsillitis, enabling a reduction in the overuse of antibiotics. Eight studies with a total of 1031 participants were found. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line is that WCC, CRP and PCT levels are higher in patients with streptococcal tonsillitis compared to patients with tonsillitis or pharyngitis without group A streptococcus isolated from a throat swab. Which of these markers has the best test performance characteristics requires further study.

Topics: Biomarkers; Blood Sedimentation; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Evidence-Based Medicine; Humans; Leukocyte Count; Protein Precursors; Streptococcal Infections; Tonsillitis; Virus Diseases

Procalcitonin (PCT) is synthesized by a large number of tissues and organs in response to invasion by pathogenic bacteria, fungi, and some parasites. Current PCT assays are rapid, specific, and of sufficient sensitivity to detect increases in PCT serum levels within 4 to 6 h of initiation of infection. Clinically, PCT levels may help in decisions regarding the need for empirical antibiotic therapy, "source control" of infection, and duration of antibiotic therapy. The addition of PCT levels to bacterial culture and viral detection results can assist with the separation of colonization and invasion by pathogenic bacteria.

Topics: Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Humans; Microbiological Techniques; Protein Precursors; Virus Diseases

For decades, many investigators have attempted to identify clinical or laboratory markers that can accurately differentiate severe bacterial from self-limiting viral infections in young children with fever without source. Unfortunately, no perfect marker has been discovered so far. Many guidelines recommend white blood cell count as a screening marker in fever without source, whereas compelling evidence in the literature emphasizes the superior characteristics of C-reactive protein and procalcitonin. One way to improve predictive value is the combination of prediction rules of different tests for clinical and laboratory markers. Several clinical decision rules, reviewed in this article, have been suggested but seem to be difficult to implement in practice due to their complexity. Recently, procalcitonin, C-reactive protein and urinary dipstick were combined in a simple risk index score that displayed promising predictive value in severe bacterial infections in children. Ultimately, impact analyses still have to be performed to show improved quality of care in this setting.

Topics: Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child, Preschool; Clinical Trials as Topic; Diagnosis, Differential; Fever of Unknown Origin; Humans; Infant; Infant, Newborn; Leukocyte Count; Protein Precursors; Sensitivity and Specificity; Sepsis; Virus Diseases

This article reviews the production, metabolism, and clinical application of procalcitonin (PCT). PCT is a useful indicator to differentiate bacterial infection and virus infection. Also, it can be used to determine the infection severity and prognosis.

Topics: Animals; Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Humans; Protein Precursors; Virus Diseases

Topics: Anti-Bacterial Agents; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Humans; Leukocyte Count; Predictive Value of Tests; Protein Precursors; Respiratory Tract Infections; Virus Diseases

Procalcitonin, a propeptide of calcitonin, is normally produced in the C-cells of the thyroid gland, but it's plasma level markedly increases, mostly due to extra-thyroidal production in cases of severe infections (bacterial, parasitic and fungal) with systemic manifestations, especially in the presence of septic shock. Since noninfectious inflammatory reaction, viral infection and localized bacterial infections manifest only small to modest increases of procalcitonin in plasma, procalcitonin levels may be useful in differentiating between these diseases and sepsis. In addition, it has been suggested that procalcitonin is an early and good marker of elevated cytokines in patients with sepsis, and that it's plasma level is correlated with Sepsis-related Organ Failure Assessment (SOFA) score. Since plasma procalcitonin is measured easily, quickly and accurately by immunoluminometric assay, it is useful for early diagnosis of sepsis in patients with severe systemic inflammatory response syndrome and as an indicator of severity of sepsis in such patients.

Topics: Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Humans; Infections; Protein Precursors; Sepsis; Virus Diseases

In febrile children and adults, it is frequently difficult, based on the sole clinical examination, to differentiate a bacterial illness from systemic inflammatory syndromes or severe viral infections. However, the positive and rapid diagnosis of a severe bacterial infection or a sepsis is essential to initiate lifesaving therapies. Among the numerous infectious biomarkers that have recently been investigated, procalcitonin has the best diagnostic yield. Plasma levels below 0.5 microg/l usually rule out a severe bacterial disease, whereas values above 2 microg/l are strongly indicative of a bacterial sepsis. The usefulness and the limitations of the measurement of procalcitonin as a diagnostic and a prognostic tool during severe bacterial infections are discussed in this paper.

Topics: Adult; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child; Diagnosis, Differential; Fever; Glycoproteins; Humans; Inflammation; Protein Precursors; Sepsis; Syndrome; Virus Diseases

Procalcytonin (PCT) is a prohormon of calcitonin. It is made in thyroid structures. Level of procalcitonin is related from actual calcium concentration in blood. It is shown that procalcitonin level increases in bacterial, fungus and parasite infections, in systematic inflammatory response syndrome (SIRS), burn and multiple organ dysfunction syndrome (MODS). We wanted to conclude the actual knowledge about the role of procalcitonin used in acute infection. Level of PCT is compatible with the etiology of infection. The procalcitonin is a fast infection marker with a longer semi-loose time than CRP. A mechanism of secretion of procalcitonin to blood circulation is still enigmatic. The determination method (immunoluminometric assay) is easy and inexpensive and results are credible and can be used to differentiating and moni-toring of disease.. It is possible that PCT could be an important marker in fast diagnosis and differentiating of bacterial infections, also could be used in treatment monitoring and prognosis.

Topics: Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Humans; Immunoassay; Luminescent Measurements; Parasitic Diseases; Protein Precursors; Sensitivity and Specificity; Virus Diseases

A meta-analysis was performed to evaluate the accuracy of determination of procalcitonin (PCT) and C-reactive protein (CRP) levels for the diagnosis of bacterial infection. The analysis included published studies that evaluated these markers for the diagnosis of bacterial infections in hospitalized patients. PCT level was more sensitive (88% [95% confidence interval [CI], 80%-93%] vs. 75% [95% CI, 62%-84%]) and more specific (81% [95% CI, 67%-90%] vs. 67% [95% CI, 56%-77%]) than CRP level for differentiating bacterial from noninfective causes of inflammation. The Q value for PCT markers was higher (0.82 vs. 0.73). The sensitivity for differentiating bacterial from viral infections was also higher for PCT markers (92% [95% CI, 86%-95%] vs. 86% [95% CI, 65%-95%]); the specificities were comparable (73% [95% CI, 42%-91%] vs. 70% [95% CI, 19%-96%]). The Q value was higher for PCT markers (0.89 vs. 0.83). PCT markers also had a higher positive likelihood ratio and lower negative likelihood ratio than did CRP markers in both groups. On the basis of this analysis, the diagnostic accuracy of PCT markers was higher than that of CRP markers among patients hospitalized for suspected bacterial infections.

Topics: Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Humans; Inflammation; Likelihood Functions; Protein Precursors; Sensitivity and Specificity; Virus Diseases

Procalcitonin (PCT), the precursor protein of calcitonin, has proved to be a good marker of "acute phase" response in bacterial infections, particularly in severe and generalized one. The diagnostic utility of PCT in community-acquired respiratory tract infections is discussed in the article, particularly with regard to community-acquired pneumonia and the utilization of PCT as a monitoring and prognostic tool in the course of disease. Our review of the available literature on the subject enables us to state the following: (1) Serum PCT levels increased significantly only in bacterial respiratory tract infections. (2) Increases in serum PCT concentrations were related to the intensity of systemic inflammatory response in the course of disease; very high PCT levels were associated with poor prognosis. (3) Measurements of PCT concentrations were useful in clinical decision making as to antimicrobial treatment. (4) Testing the serum PCT level not only supplements the range of available markers of "acute phase" response, but also provides some additional information about ongoing systemic inflammation.

Topics: Acute-Phase Proteins; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Diagnosis, Differential; Humans; Inflammation; Prognosis; Protein Precursors; Respiratory Tract Infections; Virus Diseases

Data on the origin and biological function of procalcitonin, the pro-hormone of calcitonin, are scarce. Since this peptide can be induced in bacterial invasive infections, serum procalcitonin levels may be useful in differential diagnosis of systemic inflammatory response syndrome. This review will focus on the clinical significance of changes in serum procalcitonin levels in patients with connective tissue diseases and other rheumatic disorders.

Topics: Arthritis, Rheumatoid; Autoimmune Diseases; Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Connective Tissue Diseases; Diagnosis, Differential; Granulomatosis with Polyangiitis; Humans; Lupus Erythematosus, Systemic; Mycoses; Protein Precursors; Rheumatic Diseases; Virus Diseases

Topics: Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Female; Humans; Infant; Male; Protein Precursors; Reproducibility of Results; Sensitivity and Specificity; Virus Diseases

Viral lower respiratory tract illness (LRTI) frequently causes adult hospitalization and is linked to antibiotic overuse. European studies suggest that the serum procalcitonin (PCT) level may be used to guide antibiotic therapy. We conducted a trial assessing the feasibility of using PCT algorithms with viral testing to guide antibiotic use in a US hospital.. Three hundred patients hospitalized with nonpneumonic LRTI during October 2013-April 2014 were randomly assigned at a ratio of 1:1 to receive standard care or PCT-guided care and viral PCR testing. The primary outcome was antibiotic exposure, and safety was assessed at 1 and 3 months.. Among the 151 patients in the intervention group, viruses were identified in 42% (63), and 83% (126) had PCT values of <0.25 µg/mL. There were no significant differences in antibiotic use or adverse events between intervention patients and those in the nonintervention group. Subgroup analyses revealed fewer subjects with positive results of viral testing and low PCT values who were discharged receiving antibiotics (20% vs 45%; P = .002) and shorter antibiotic durations among algorithm-adherent intervention patients versus nonintervention patients (2.0 vs 4.0 days; P = .004). Compared with historical controls (from 2008-2011), antibiotic duration in nonintervention patients decreased by 2 days (6.0 vs 4.0 days; P < .001), suggesting a study effect.. Although antibiotic use was similar in the 2 arms, subgroup analyses of intervention patients suggest that physicians responded to viral and biomarker data. These data can inform the design of future US studies.. NCT01907659.

Topics: Aged; Anti-Bacterial Agents; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Female; Hospitalization; Humans; Male; Middle Aged; New York; Prescription Drug Overuse; Protein Precursors; Respiratory Tract Infections; Virus Diseases

Procalcitonin concentration increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable making it a potentially useful marker for distinguishing between bacterial and viral infections.. Procalcitonin (PCT) was determined with an immunoluminometric assay on plasma collected at admission in 436 infants and children hospitalized for bacterial or viral infection. It was compared with C reactive protein, interleukin-6 and interferon-alpha measured on the same sample.. PCT was 41.3 +/- 77.4 micrograms/l in children with septicemia or bacterial meningitis (n = 53), 0.39 +/- 0.57 microgram/l in children with viral infection (n = 274) and 3.9 +/- 5.9 micrograms/l in children with a localized bacterial infection who had a negative blood culture (n = 109). PCT was > 1 microgram/l in 126 children with a localized or systemic bacterial infection (sensitivity 78%). PCT was < 1 microgram/l in 258 children with a viral infection (specificity 94%). For differenciation between viral and bacterial infections, CRP value > or = 20 mg/l, IL-6 > 100 pg/ml and interferon-alpha > 0 Ul/ml have 85, 48 and 76% sensitivity and 73, 85 and 92% specificity respectively.. In this study, a PCT value of 1 microgram/l or greater had better specificity, sensitivity and predictive value than CRP, IL-6 and interferon-alpha in children for distinguishing between viral and bacterial infections. PCT may be useful in pediatric emergency room for making decision about antibiotic treatments.

Topics: Adolescent; Bacterial Infections; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Emergencies; Glycoproteins; Humans; Infant; Inflammation; Interferon-alpha; Interleukin-6; Protein Precursors; Virus Diseases

Poor targeting of antimicrobial drugs contributes to the millions of deaths each year from malaria, pneumonia, and other tropical infectious diseases. While malaria rapid diagnostic tests have improved use of antimalarial drugs, there are no similar tests to guide the use of antibiotics in undifferentiated fevers. In this study we estimate the diagnostic accuracy of two well established biomarkers of bacterial infection, procalcitonin and C-reactive protein (CRP) in discriminating between common viral and bacterial infections in malaria endemic settings of Southeast Asia.. Serum procalcitonin and CRP levels were measured in stored serum samples from febrile patients enrolled in three prospective studies conducted in Cambodia, Laos and, Thailand. Of the 1372 patients with a microbiologically confirmed diagnosis, 1105 had a single viral, bacterial or malarial infection. Procalcitonin and CRP levels were compared amongst these aetiological groups and their sensitivity and specificity in distinguishing bacterial infections and bacteraemias from viral infections were estimated using standard thresholds.. Serum concentrations of both biomarkers were significantly higher in bacterial infections and malaria than in viral infections. The AUROC for CRP in discriminating between bacterial and viral infections was 0.83 (0.81-0.86) compared with 0.74 (0.71-0.77) for procalcitonin (p < 0.0001). This relative advantage was evident in all sites and when stratifying patients by age and admission status. For CRP at a threshold of 10 mg/L, the sensitivity of detecting bacterial infections was 95% with a specificity of 49%. At a threshold of 20 mg/L sensitivity was 86% with a specificity of 67%. For procalcitonin at a low threshold of 0.1 ng/mL the sensitivity was 90% with a specificity of 39%. At a higher threshold of 0.5 ng/ul sensitivity was 60% with a specificity of 76%.. In samples from febrile patients with mono-infections from rural settings in Southeast Asia, CRP was a highly sensitive and moderately specific biomarker for discriminating between viral and bacterial infections. Use of a CRP rapid test in peripheral health settings could potentially be a simple and affordable measure to better identify patients in need of antibacterial treatment and part of a global strategy to combat the emergence of antibiotic resistance.

Topics: Adolescent; Adult; Asia, Southeastern; Bacteremia; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Cambodia; Child; Child, Preschool; Female; Fever; Humans; Laos; Malaria; Male; Pneumonia; Prospective Studies; Protein Precursors; Sensitivity and Specificity; Thailand; Virus Diseases; Young Adult

Respiratory viral infections precipitate exacerbations of chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease though similar data in non-cystic fibrosis (CF) bronchiectasis are missing. Our study aimed to determine the point prevalence of viruses associated with exacerbations and evaluate clinical and investigational differences between virus-positive and -negative exacerbations in children with bronchiectasis.. A cohort of 69 children (median age 7 years) with non-CF bronchiectasis was prospectively followed for 900 child-months. PCR for 16 respiratory viruses was performed on nasopharyngeal aspirates collected during 77 paediatric pulmonologist-defined exacerbations. Clinical data, systemic (C reactive protein (CRP), IL-6, procalcitonin, amyloid-A, fibrinogen) and lung function parameters were also collected.. Respiratory viruses were detected during 37 (48%) exacerbations: human rhinovirus (HRV) in 20; an enterovirus or bocavirus in four each; adenoviruses, metapneumovirus, influenza A virus, respiratory syncytial virus, parainfluenza virus 3 or 4 in two each; coronavirus or parainfluenza virus 1 and 2 in one each. Viral codetections occurred in 6 (8%) exacerbations. HRV-As (n=9) were more likely to be present than HRV-Cs (n=2). Children with virus-positive exacerbations were more likely to require hospitalisation (59% vs 32.5% (p=0.02)) and have fever (OR 3.1, 95% CI 1.2 to 11.1), hypoxia (OR 25.5, 95% CI 2.0 to 322.6), chest signs (OR 3.3, 95% CI 1.1 to 10.2) and raised CRP (OR 4.7, 95% CI 1.7 to 13.1) when compared with virus-negative exacerbations.. Respiratory viruses are commonly detected during pulmonary exacerbations of children with bronchiectasis. HRV-As were the most frequently detected viruses with viral codetection being rare. Time-sequenced cohort studies are needed to determine the role of viral-bacterial interactions in exacerbations of bronchiectasis.

Topics: Bronchiectasis; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Cohort Studies; Cystic Fibrosis; DNA, Viral; Female; Fibrinogen; Follow-Up Studies; Humans; Infant; Interleukin-6; Male; Polymerase Chain Reaction; Prevalence; Prospective Studies; Protein Precursors; Respiratory Tract Infections; Serum Amyloid A Protein; Virus Diseases; Viruses

The diagnostic performance of procalcitonin and neopterin as markers for bacterial and viral causes of fever was evaluated in a cohort of 69 febrile travellers with known etiological agents. Our aim was to establish a decision rule to minimize empirical antibiotic treatment. Compared with C-reactive protein (CRP) and leukocyte (differential) counts, procalcitonin and neopterin had a disappointing diagnostic accuracy. Refraining from antibiotics in case of combined presence of lymphocytosis and/or CRP ≤10 mg/l would result in an 85% reduction in unwanted antibiotic treatment in patients with viral disease but in adequate antibiotic coverage of all patients with bacterial disease.

Topics: Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Cohort Studies; Diagnosis, Differential; Female; Fever; Humans; Male; Neopterin; Pilot Projects; Predictive Value of Tests; Protein Precursors; Sensitivity and Specificity; Travel; Virus Diseases

Serum procalcitonin levels have been used as a biomarker of invasive bacterial infection and recently have been advocated to guide antibiotic therapy in patients with chronic obstructive pulmonary disease (COPD). However, rigorous studies correlating procalcitonin levels with microbiologic data are lacking. Acute exacerbations of COPD (AECOPD) have been linked to viral and bacterial infection as well as noninfectious causes. Therefore, we evaluated procalcitonin as a predictor of viral versus bacterial infection in patients hospitalized with AECOPD with and without evidence of pneumonia.. Adults hospitalized during the winter with symptoms consistent with AECOPD underwent extensive testing for viral, bacterial, and atypical pathogens. Serum procalcitonin levels were measured on day 1 (admission), day 2, and at one month. Clinical and laboratory features of subjects with viral and bacterial diagnoses were compared.. In total, 224 subjects with COPD were admitted for 240 respiratory illnesses. Of these, 56 had pneumonia and 184 had AECOPD alone. A microbiologic diagnosis was made in 76 (56%) of 134 illnesses with reliable bacteriology (26 viral infection, 29 bacterial infection, and 21 mixed viral bacterial infection). Mean procalcitonin levels were significantly higher in patients with pneumonia compared with AECOPD. However, discrimination between viral and bacterial infection using a 0.25 ng/mL threshold for bacterial infection in patients with AECOPD was poor.. Procalcitonin is useful in COPD patients for alerting clinicians to invasive bacterial infections such as pneumonia but it does not distinguish bacterial from viral and noninfectious causes of AECOPD.

Topics: Aged; Aged, 80 and over; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Disease Progression; Female; Humans; Logistic Models; Male; Middle Aged; Multivariate Analysis; New York; Pneumonia; Pneumonia, Bacterial; Predictive Value of Tests; Protein Precursors; Pulmonary Disease, Chronic Obstructive; Risk Assessment; Risk Factors; Time Factors; Up-Regulation; Virus Diseases

During the 2009 influenza A H1N1 pandemic, it became difficult to differentiate viral infections from other conditions in patients admitted to the intensive care unit. We sought to evaluate the behavior and diagnostic utility of procalcitonin, C-reactive protein and four other molecules in patients with suspected 2009 Influenza A H1N1 infection.. The serum levels of procalcitonin, C-reactive protein, tumor necrosis factor α, interferon γ, interleukin 1β, and interleukin 10 were tested on admission and on days 3, 5, and 7 in 35 patients with suspected 2009 H1N1 infection who were admitted to two ICUs.. Twelve patients had confirmed 2009 influenza A H1N1 infections, 6 had seasonal influenza infections, and 17 patients had negative swabs. The procalcitonin levels at inclusion and on day 3, and the C-reactive protein levels on day 3 were higher among subjects with 2009 influenza A H1N1 infections. The baseline levels of interleukin 1b were higher among the 2009 influenza A H1N1 patients compared with the other groups. The C-reactive protein levels on days 3, 5, and 7 and procalcitonin on days 5 and 7 were greater in non-surviving patients.. Higher levels of procalcitonin, C-reactive protein and interleukin-1β might occur in critically ill patients who had a 2009 H1N1 infection. Neither procalcitonin nor CRP were useful in discriminating severe 2009 H1N1 pneumonia. Higher levels of CRP and procalcitonin appeared to identify patients with worse outcomes.

Topics: Adolescent; Adult; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Critical Illness; Diagnosis, Differential; Female; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Interleukin-1beta; Male; Prospective Studies; Protein Precursors; Real-Time Polymerase Chain Reaction; Respiratory Distress Syndrome; Virus Diseases; Young Adult

Timely knowledge of the bacterial etiology and localization of infection are important for empirical antibiotic therapy. Thus, the goal of this study was to evaluate routinely used biomarkers together with novel laboratory parameters in the diagnosis of infection.. In this prospective study, 54 adult patients with bacterial infections admitted to the Department of Infectious Diseases were included. For comparison, 27 patients with viral infections were enrolled. In these patients, white blood cell (WBC) counts, differential blood counts, serum levels of procalcitonin (PCT), IL-1β, IL-6, IL-8, IL-10, IL-12, TNF-α, IFN-γ, soluble CD14 (sCD14), heparin-binding protein (HBP), cortisol (Cort), and monocyte surface expression of TLR2, TLR4, HLA-DR, and CD14 were analyzed. Also, these biomarkers were evaluated in 21 patients with acute community-acquired bacterial pneumonia (CABP), as well as in 21 patients with pyelonephritis and urosepsis.. The highest sensitivity and specificity (expressed as the area under the curve [AUC]) for bacterial infection were observed in serum concentration of PCT (0.952), neutrophil and lymphocyte counts (0.852 and 0.841, respectively), and serum levels of HBP (0.837), IL-6 (0.830), and Cort (0.817). In addition, the serum levels of IFN-γ and Cort were significantly higher and IL-8 levels were lower in CABP when compared to pyelonephritis or urosepsis.. From the novel potential biomarkers, only PCT demonstrated superiority over the routine parameters in the differentiation of bacterial from viral infections. However, some of the novel parameters should be further evaluated in larger and better characterized cohorts of patients in order to find their clinical applications.

Topics: Adult; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Czech Republic; Female; Humans; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Protein Precursors; Pyelonephritis; Sensitivity and Specificity; Sepsis; Severity of Illness Index; Urinary Tract; Virus Diseases

The differential diagnosis between viral and bacterial infections can be challenging in children. Procalcitonin (PCT) has been investigated as an early marker for bacterial infections. The aim of this study was to assess the usefulness of procalcitonin (PCT) compared to C-reactive protein (CRP), white cell blood count (WBC), and absolute neutrophil count (ANC) for differentiating bacterial from viral infections in a third level pediatric hospital.. Children admitted for a clinically suspected infection to the Pediatric Clinic from January 1, 2005 to December 31, 2008, who had concurrent evaluation of PCT, CRP, WCB, and ANC were included in the study. According to the diagnosis at discharge based on the ICD-9 codes, patients were classified into two groups: children with certain bacterial infections (CBI) and children with certain viral infections (CVI). PCT concentrations were determined by semiquantitative PCT-Q strips. The diagnostic performance of the markers were studied by receiver operating characteristic (ROC) analysis. Logistic regression analysis was used to evaluate the risk of bacterial infection in relation to all the study markers.. Among the 165 children included in the study PCT sensitivity was the same as CRP (60.56% vs 66.19%; p = 0.646) while PCT specificity was lower (77.27% vs 88.18%; p = 0.050) in the detection of bacterial infections.. The PCT semiquantitative test is not sufficiently sensitive to be used alone as a marker of bacterial infection.

Topics: Adolescent; Bacterial Infections; Biomarkers; Blood; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Diagnosis, Differential; Female; Hospitals, Pediatric; Humans; Infant; Infant, Newborn; Leukocyte Count; Male; Neutrophils; Organ Specificity; Predictive Value of Tests; Protein Precursors; Reagent Strips; Retrospective Studies; Risk; ROC Curve; Sensitivity and Specificity; Virus Diseases

Topics: Acute Disease; Anti-Bacterial Agents; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Female; Humans; Male; Protein Precursors; Respiratory Tract Infections; Risk Assessment; Sensitivity and Specificity; Treatment Outcome; Virus Diseases

Topics: Acute Disease; Anti-Bacterial Agents; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Female; Humans; Male; Primary Health Care; Protein Precursors; Respiratory Tract Infections; Sensitivity and Specificity; Treatment Outcome; Virus Diseases

Antibiotics are recommended for severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) admitted to intensive care units (ICU). Serum procalcitonin (PCT) could be a useful tool for selecting patients with a lower probability of developing bacterial infection, but its measurement has not been investigated in this population.. We conducted a single center prospective cohort study in consecutive COPD patients admitted to the ICU for AECOPD between September 2005 and September 2006. Sputum samples or tracheal aspirates were tested for the presence of bacteria and viruses. PCT levels were measured at the time of admittance, six hours, and 24 hours using a sensitive immunoassay.. Thirty nine AECOPD patients were included, 31 of which (79%) required a ventilator support at admission. The median [25%-75% interquartile range] PCT level, assessed in 35/39 patients, was: 0.096 microg/L [IQR, 0.065 to 0.178] at the time of admission, 0.113 microg/L [IQR, 0.074 to 0.548] at six hours, and 0.137 microg/L [IQR, 0.088 to 0.252] at 24 hours. The highest PCT (PCTmax) levels were less than 0.1 microg/L in 14/35 (40%) patients and more than 0.25 microg/L in 10/35 (29%) patients, suggesting low and high probability of bacterial infection, respectively. Five species of bacteria and nine species of viruses were detected in 12/39 (31%) patients. Among the four patients positive for Pseudomonas aeruginosa, one had a PCTmax less than 0.25 microg/L and three had a PCTmax less than 0.1 microg/L. The one patient positive for Haemophilus influenzae had a PCTmax more than 0.25 microg/L. The presence or absence of viruses did not influence PCT at time of admission (0.068 vs 0.098 microg/L respectively, P = 0.80).. The likelihood of bacterial infection is low among COPD patients admitted to ICU for AECOPD (40% with PCT < 0.1 microg/L) suggesting a possible inappropriate use of antibiotics. Further studies are necessary to assess the impact of a procalcitonin-based therapeutic strategy in critically ill COPD patients.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Female; Humans; Intensive Care Units; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Protein Precursors; Pulmonary Disease, Chronic Obstructive; Sputum; Virus Diseases

The values of procalcitonin (PCT), neopterin, and C-reactive protein (CRP) alone and in combination to differentiate bacterial from viral etiology in patients with lower respiratory tract infections (LRTIs) were evaluated. Sera obtained on the day of hospitalization for LRTI from 139 patients with confirmed bacterial etiology and 128 patients with viral etiology were examined. A further 146 sera from healthy Chinese subjects with no infection were included as controls. The area under the receiver operating characteristic (ROC) curve (area under curve [AUC]) for distinguishing bacterial from viral infections was 0.838 for CRP and 0.770 for PCT (P < 0.05). The AUC for distinguishing viral from bacterial infections was 0.832 for neopterin (P < 0.05). When the markers were used in combination, AUC of ROC (CRP/neopterin) was 0.857, whereas (CRP x PCT)/neopterin was 0.856. Combination of 2 or all 3 of the biomarkers may improve the discriminatory power in delineating bacterial versus viral etiology in LRTI.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Female; Humans; Male; Middle Aged; Neopterin; Protein Precursors; Respiratory Tract Infections; ROC Curve; Sensitivity and Specificity; Virus Diseases

Serum procalcitonin was measured in 58 children with symptoms and signs of hepatic disease. According to mechanism responsible for liver injury, children were assigned to one of 4 categories: 1, invasive bacterial infection; 2, acute viral infection; 3, toxic liver injury; and 4, autoimmune disease. Procalcitonin concentrations exceeded normal values in all children with invasive bacterial infection. It was low in viral infection and toxic liver injury. Moderately elevated procalcitonin concentrations were present in 50% of children with an autoimmune process.

Topics: Adolescent; Autoimmune Diseases; Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Chemical and Drug Induced Liver Injury; Child; Child, Preschool; Humans; Infant; Liver Diseases; Protein Precursors; Virus Diseases

Procalcitonin (PCT) is a new parameter of inflammation, the clinical usefulness of which is currently being evaluated.. We determined simultaneously the serum concentrations of PCT and C-reactive protein (CRP) as well as the white blood cell (WBC) count in 25 patients with Kawasaki disease (KD), 17 with bacterial infections, 10 with systemic autoimmune diseases, 17 with viral infections and 18 healthy children. The optimal cut-off value of each parameter for predicting coronary aneurysms was determined using receiver operating characteristic curves.. Significantly higher serum concentrations of PCT were observed in patients with KD (2.3 +/- 3.0 ng/ml) and bacterial infections (2.2 +/- 2.9 ng/ml) than in patients with autoimmune diseases (0.4 +/- 0.4 ng/ml) or viral infections (0.4 +/- 0.3 ng/ml), or in healthy children (0.2 +/- 0.1 ng/ml). The serum PCT but not the WBC count or CRP, differentiated the KD patients from the patients with autoimmune diseases. The optimal cut-off value of 3.0 ng/ml of PCT increased the prediction rate of coronary aneurysms that subsequently occurred in 4 (16%) patients with KD.. The serum PCT may be clinically useful for determining the severity of KD and for narrowing the differential diagnosis of patients with inflammatory diseases.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Autoimmune Diseases; Bacterial Infections; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; gamma-Globulins; Humans; Leukocyte Count; Mucocutaneous Lymph Node Syndrome; Protein Precursors; Statistics, Nonparametric; Virus Diseases

The flogosis markers currently in use show both low sensitivity and specificity, particularly in neoplastic and degenerative diseases. Procalcitonin (PCT) is a pro-peptide of calcitonin produced mainly but not only in the C-cells of the thyroid glands and, as several studies show, PCT levels in plasma increase during infections. Bacterial infections are also the main cause of death in oncological patients. Furthermore, in patients with leukaemia in chemotherapy recovery, infections often induce relapses. The aim of the present study is to detect PCT levels in plasma in oncohaematologic patients with and without infections.. The study was carried out on 54 patients by a quantitative automated immunoassay.. PCT plasma levels > or =0.5 ng were detected in 27 out of 30 patients (90,0%) with bacterial infections; 8 out of 9 patients (88,9%) with viral infections and in 12 out of 15 patients in the control group without statistically significant differences.. The results, which differ from those in the literature, are discussed.

Topics: Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Humans; Immunoassay; Leukemia; Lymphoma; Protein Precursors; Virus Diseases

To study the levels of procalcitonin (PCT) in various inflammatory states seen in an internal medicine department and to evaluate the possible discriminative role of PCT in differentiating bacterial infection from other inflammatory processes.. PCT, C reactive protein (CRP), and white blood cell count (WBC) were measured in patients admitted to the department for fever or biological inflammatory syndrome, or both. The serum of 173 consecutive patients was analysed according to the aetiological diagnosis. The patients were divided into two groups: group I (n=60) with documented bacterial or fungal infection; group II (n=113) with abacterial inflammatory disease.. PCT levels were >0.5 ng/ml in 39/60 (65%) patients in group I. In group II, three patients with a viral infection had slightly increased PCT levels (0.7, 0.8, and 1.1 ng/ml) as did two others, one with crystal arthritis and the other with vasculitis (0.7 ng/ml in both cases). All other patients in group II had PCT levels <0.5 ng/ml. In this study a value of PCT >0.5 ng/ml was taken as the marker of bacterial infection (sensitivity 65%, specificity 96%). PCT values were more discriminative than WBC and CRP in distinguishing a bacterial infection from another inflammatory process.. PCT levels only rose significantly during bacterial infections. In this study PCT levels >1.2 ng/ml were always evidence of bacterial infection and the cue for starting antibiotic treatment.

Topics: Aged; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Female; Fever; Glycoproteins; Humans; Inflammation; Leukocyte Count; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Protein Precursors; ROC Curve; Sensitivity and Specificity; Virus Diseases

Topics: Adolescent; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Emergency Service, Hospital; Female; Humans; Infant; Predictive Value of Tests; Prospective Studies; Protein Precursors; ROC Curve; Sensitivity and Specificity; Virus Diseases

Since it is of great importance to distinguish between a systemic inflammatory response syndrome (SIRS) and an infection caused by microbes especially after heart transplantation (HTX), we examined patients following heart surgery by determining procalcitonin (PCT), because PCT is said to be secreted only in patients with microbial infections.. Sixty patients undergoing coronary artery bypass grafting (CABG) and 14 patients after heart transplantation were included in this prospective study. In the CABG group we had 30 patients without any postoperative complications (group A). Furthermore we took samples of 30 patients who suffered postoperatively from a sepsis (group B, n=15) or a systemic inflammatory response syndrome (C, n=15). In addition we measured the PCT-levels in 65 blood samples of 14 patients after heart transplantation (Group I: rejection > IIa, II: viral infection (CMV), III: bacterial/fungal infection, IV: controls).. In all patients of group A the pre- and intraoperative PCT-values and the measurement at arrival on intensive care unit (ICU) were less than 0.2 ng/ml. On the second postoperative day the PCT-value was 0.33+/-0.15 ng/ml in the control group. At the same time it was 19.6+/-6.2 ng/ml in sepsis and 0.7+/-0.4 ng/ml in systemic inflammatory response syndrome patients (P<0.05). In transplanted patients we could find the following PCT-values: Gr.I: 0.18+/-0.06 II: 0.30+/-0.09 III: 1.63+/-1.16 IV: 0.21+/-0.09 ng/ml (P<0.05 comparing group III with I, II and IV).. These results show that extracorporeal circulation (ECC) and systemic inflammatory response syndrome do not initiate a PCT-secretion. Septic conditions cause a significant increase of PCT. In addition, PCT is a reliable indicator concerning the essential differentiation of bacterial or fungal--not viral--infection and rejection after heart transplantation.

Topics: Aged; Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Extracorporeal Circulation; Female; Glycoproteins; Graft Rejection; Heart Transplantation; Humans; Male; Middle Aged; Mycoses; Prospective Studies; Protein Precursors; Sepsis; Systemic Inflammatory Response Syndrome; Virus Diseases

Procalcitonin (PCT) concentration increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable, making it a potentially useful marker for distinguishing between bacterial and viral infections.. PCT concentration was determined with an immunoluminometric assay on plasma collected at admission in 360 infants and children hospitalized for bacterial or viral infection. It was compared with C-reactive protein (CRP), interleukin 6 and interferon-alpha measured on the same sample.. The mean PCT concentration was 46 microg/l (median, 17.8) in 46 children with septicemia or bacterial meningitis. PCT concentration was > 1 microg/l in 44 of 46 in this group and in 59 of 78 children with a localized bacterial infection who had a negative blood culture (sensitivity, 83%). PCT concentration was > 1 microg/l in 16 of 236 children with a viral infection (specificity, 93%). PCT concentration was low in 9 of 10 patients with inflammatory disease and fever. A CRP value > or =20 mg/l was observed in 61 of 236 patients (26%) with viral infection and in 105 of 124 patients (86%) with bacterial infection. IL-6 was > 100 pg/ml in 14% of patients infected with virus and in 53% with bacteria. A secretion of interferon-alpha was found in serum in 77% of viral infected patients and in 8.6% of bacterial infected patients.. In this study a PCT value of 1 microg/l or greater had better specificity, sensitivity and predictive value than CRP, interleukin 6 and interferon-alpha in children for distinguishing between viral and bacterial infections. PCT values are higher in invasive bacterial infections, but the cutoff value of 1 microg/l indicates the severity of the disease in localized bacterial infection and helps to decide antibiotic treatment in emergency room. PCT may be useful in an emergency room for differentiation of bacterial vs. viral infections in children and for making decisions about antibiotic treatments.

Topics: Adolescent; Bacterial Infections; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Emergency Service, Hospital; Humans; Immunoassay; Infant; Interferon-alpha; Interleukin-6; Luminescent Measurements; Predictive Value of Tests; Protein Precursors; ROC Curve; Sensitivity and Specificity; Virus Diseases

Serum procalcitonin was determined in newborn infants at the time of admission to the pediatrics or obstetrics unit. Increased levels were found in all neonates with bacterial sepsis. Neonates with viral infection, bacterial colonization, or neonatal distress had normal or slightly increased levels. These data suggest that procalcitonin might be of value in diagnosing neonatal sepsis.

Topics: Bacterial Infections; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Glycoproteins; Humans; Infant, Newborn; Prospective Studies; Protein Precursors; Sepsis; Virus Diseases

High concentrations of calcitonin-like immunoreactivity have been found in the blood of patients with various extrathyroid diseases. By means of a monoclonal immunoradiometric assay for calcitonin precursors, we have measured serum concentrations of procalcitonin in patients with various bacterial and viral infections. 79 children (newborn to age 12 years) in hospital with suspected infections were investigated prospectively. 19 patients with severe bacterial infections had very high serum concentrations of procalcitonin at diagnosis (range 6-53 ng/mL) in comparison with 21 children found to have no signs of infection (baseline concentrations < 0.1 ng/mL). Serum procalcitonin values decreased rapidly during antibiotic therapy. 11 patients with peripheral bacterial colonisation or local infections without invasive sepsis and 18 (86%) of 21 patients with viral infections had concentrations within or slightly above the normal range (0.1-1.5 ng/mL). Among 9 severely burned patients studied in an intensive care unit, the post-traumatic course of procalcitonin concentrations (range 0.1-120 ng/mL) was closely related to infectious complications and acute septic episodes. Concentrations of mature calcitonin were normal in all subjects, whatever procalcitonin concentrations were found. Concentrations of a substance immunologically identical to procalcitonin are raised during septic conditions. Serum concentrations seem to be correlated with the severity of microbial invasion.

Topics: Bacterial Infections; Burns; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Chromatography, High Pressure Liquid; Glycoproteins; Humans; Infant; Infant, Newborn; Protein Precursors; Virus Diseases