calca-protein--human and Pneumonia--Pneumococcal

The role of procalcitonin (PCT) as a biomarker for sepsis in adults is well documented, while its role in infections affecting neonatal children remains controversial. Among these infections, Community-Acquired pneumonia (CAP) has been studied extensively, because it's the second cause of death in children in developing countries, and one of the most frequent causes of hospitalization in industrialized countries. The PubMed database and the Cochrane Library were used to search for the following keywords: CAP, procalcitonin, and children. Thirteen articles were studied to determine the role of PCT in CAP management, specifically its usefulness for distinguishing pneumococcal infections from viral and unknown infections, for predicting severity and the correct antibiotic treatment. This paper focuses on the studies performed to identify the best inflammatory biomarker for CAP management. Although there is an increase in studies confirming the usefulness of PCT in CAP management in children, further studies are needed to have better understanding of its role for pediatric CAP management.

Topics: Anti-Bacterial Agents; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child; Community-Acquired Infections; Humans; Pneumonia, Pneumococcal; Protein Precursors

Current diagnostic tests lack sensitivity for the identification of the bacterial etiology of pneumonia. Attempts during the past 2 decades to improve sensitivity of detection of bacterial constituents in blood by use of antibody-antigen complexes and polymerase chain reaction have been disappointing. Recent data using pneumococcal conjugate vaccines as probes suggest that increased levels of both C-reactive protein and procalcitonin may be useful adjuncts to chest radiographs in the selection of patients with presumed bacterial pneumonia for inclusion in clinical trials. Among pneumococcal diagnostics currently under investigation, quantitative real-time polymerase chain reaction of respiratory secretions, as well as urinary antigen detection and pneumococcal surface adhesin A serological analysis for adults, are candidates for use in future clinical trials of antibiotics.

Topics: Adult; Antigens, Bacterial; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Clinical Trials as Topic; Community-Acquired Infections; Humans; Lung; Pneumonia, Pneumococcal; Polymerase Chain Reaction; Protein Precursors; Radiography, Thoracic; Streptococcus pneumoniae

To determine the value of C-reactive protein (CRP) and procalcitonin in the evaluation of the efficacy of a pneumococcal conjugate vaccine in Gambian children.. The investigation was done as a substudy of a phase III pneumococcal conjugate vaccine trial. A pilot study (n = 120) to compare CRP and procalcitonin concentrations in children with pneumonia was undertaken, followed by a larger study of CRP concentrations (n = 1868) obtained from a subsample of children with clinical pneumonia seen during the trial.. In the pilot study, CRP had a higher sensitivity and specificity for the detection of primary endpoint (radiographic) pneumonia than procalcitonin. In the subsequent study of 1868 episodes of clinical pneumonia, CRP showed moderate sensitivity but poor positive predictive value in identifying primary endpoint pneumonia or pneumococcal bacteraemia. Addition of CRP thresholds of 40, 60 or 120 mg/l to the diagnosis of clinical pneumonia did not give higher estimates of vaccine efficacy or vaccine attributable reduction in incidence than primary endpoint pneumonia.. A combination of a raised CRP concentration with a clinical diagnosis of pneumonia is a more specific endpoint than clinical pneumonia alone but less appropriate than primary endpoint pneumonia as a measure of the impact of a pneumococcal vaccine in a Gambian setting.

Topics: Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child, Preschool; Double-Blind Method; Gambia; Humans; Infant; Pilot Projects; Pneumococcal Vaccines; Pneumonia, Pneumococcal; Protein Precursors; Sensitivity and Specificity; Streptococcus pneumoniae; Treatment Outcome; Vaccines, Conjugate

This study explored whether C-reactive protein (CRP) and/or procalcitonin levels were useful to measure vaccine efficacy (VE) and impact against the burden of pneumonia of a 9-valent pneumococcal conjugate vaccine (PCV), compared with chest radiograph-confirmed alveolar consolidation (CXR-AC) as an outcome. Sera obtained from children participating in a phase 3 PCV efficacy trial who were hospitalized for treatment of clinically diagnosed lower respiratory tract infection (C-LRTI) were retrospectively analyzed for CRP and procalcitonin measurements.. For non-human immunodeficiency virus (HIV)-infected children, the VE estimates for C-LRTI with CRP levels of > or =40 mg/dL (VE 26.3%; P = 0.003) or CRP levels of > or =120 mg/dL (VE 41.0%; P = 0.003) were 1.7-fold (P = 0.002) and 2.7-fold (P < 0.0001) greater, respectively, than that for CXR-AC (VE 15.1%; P= 0.15). The sensitivity of CXR-AC as an outcome to detect the burden of pneumonia prevented by PCV was 44% (95% confidence interval, 36-55%) in comparison with C-LRTI with CRP levels of > or =40 mg/dL and 73% (95% confidence interval, 58-92%) in comparison with C-LRTI with CRP levels of > or =120 mg/dL. CRP also helped to measure the PCV efficacy for children with C-LRTI but the absence of CXR-AC, for whom the outcome of C-LRTI with CRP levels of > or =40 mg/dL (VE 31.5%; P = 0.007) increased the VE estimate 19.8-fold (P < 0.0001) in comparison with C-LRTI alone (VE 1.6%; P = 0.78) and 3.2-fold (P = 0.005) in comparison with WHO-defined severe pneumonia (VE 10.0%; P = 0.17). Although there was a significant correlation between CRP and procalcitonin levels (Spearman's rho = 0.45; P < 0.0001), the use of procalcitonin levels did not improve either the specificity or sensitivity of measuring the effect of PCV against pneumonia for non-HIV-infected children. The observations were similar for HIV-infected children.. CRP levels of > or =40 mg/dL provide a better measure than chest radiographs to assess the effect of PCV in preventing pneumonia.

Topics: C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; HIV Infections; Humans; Infant; Infant, Newborn; Lung; Pneumococcal Vaccines; Pneumonia, Pneumococcal; Protein Precursors; Radiography; Sensitivity and Specificity; Vaccines, Conjugate

Pneumonia remains the leading cause of death in young children. The poor specificity of chest radiographs (CXRs) to diagnose pneumococcal pneumonia may underestimate the efficacy of pneumococcal conjugate vaccine in preventing pneumococcal pneumonia.. The efficacy of nine-valent pneumococcal conjugate vaccine among children not infected with HIV (21%; 95% confidence interval, 1%-37%) increased when CXR-confirmed pneumonia was associated with serum C-reactive protein of 120 mg/l (12 mg/dl) or more and procalcitonin of 5.0 ng/ml or more (64%; 95% confidence interval, 23%-83%). Similar results were observed in children infected with HIV.. C-reactive protein and procalcitonin improve the specificity of CXR to diagnose pneumococcal pneumonia and may be useful for the future evaluation of the effectiveness of pneumococcal conjugate vaccine in preventing pneumococcal pneumonia.

Topics: Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Double-Blind Method; HIV Infections; Humans; Placebos; Pneumococcal Vaccines; Pneumonia, Pneumococcal; Protein Precursors; Radiography, Thoracic; Sensitivity and Specificity

Distinguishing between bacterial and viral lower respiratory tract infection (LRTI) remains challenging. Transcriptional profiling is a promising tool for improving diagnosis in LRTI.. We performed whole blood transcriptional analysis in 118 patients (median age [interquartile range], 61 [50-76] years) hospitalized with LRTI and 40 age-matched healthy controls (median age, 60 [46-70] years). We applied class comparisons, modular analysis, and class prediction algorithms to identify and validate diagnostic biosignatures for bacterial and viral LRTI.. Patients were classified as having bacterial (n = 22), viral (n = 71), or bacterial-viral LRTI (n = 25) based on comprehensive microbiologic testing. Compared with healthy controls, statistical group comparisons (P < .01; multiple-test corrections) identified 3376 differentially expressed genes in patients with bacterial LRTI, 2391 in viral LRTI, and 2628 in bacterial-viral LRTI. Patients with bacterial LRTI showed significant overexpression of inflammation and neutrophil genes (bacterial > bacterial-viral > viral), and those with viral LRTI displayed significantly greater overexpression of interferon genes (viral > bacterial-viral > bacterial). The K-nearest neighbors algorithm identified 10 classifier genes that discriminated between bacterial and viral LRTI with a 95% sensitivity (95% confidence interval, 77%-100%) and 92% specificity (77%-98%), compared with a sensitivity of 38% (18%-62%) and a specificity of 91% (76%-98%) for procalcitonin.. Transcriptional profiling is a helpful tool for diagnosis of LRTI.

Topics: Adult; Aged; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Case-Control Studies; Diagnosis, Differential; Female; Gene Expression Profiling; Hospitalization; Humans; Influenza, Human; Male; Middle Aged; Pneumonia, Pneumococcal; Prospective Studies; Protein Precursors; Sensitivity and Specificity; Transcriptome

To analyze the usefulness and ability of procalcitonin (PCT) to predict the presence of bacteremia in patients with community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae (S. pneumoniae) or other bacteria.. This is an observational, prospective and descriptive study involving patients who were diagnosed with CAP in our Emergency Department. Data collected included socio-demographic and comorbidity variables, Charlson index, stage in the Pneumonia Severity Index and criteria of severe NAC, microbiologic studies and biomarker determinations (PCT and C reactive protein). The follow-up was carried out during 30 days to calculate the predictive power and the diagnostic performance for bacteremia caused or not by S. pneumoniae.. Four hundred and seventy-four patients were finally included in the study. Blood cultures were positive in 85 individuals (17.9%) and S. pneumoniae was identified as the responsible pathogen in 75 of them (88.4%) (in 5 cases together with another agent). The area under the Receiver Operating Characteristic curve for PCT to predict bacteremia (caused by S. pneumoniae or not) was 0.988 (95% confidence interval 0.908-0.995; P<.001) and, considering a cut-off value≥0.95ng/mL, the negative predictive value and the positive likelihood ratio were>98% and>10, respectively. The most frequently isolated serotypes of S. pneumoniae were 19A, 7F, 1 and 3. The highest mean levels of PCT were found in serotypes 7F, 19A, 3 and 1, which showed statistically significant differences with regard to the others serotypes considered (P=.008). Serotypes associated with the highest percentage of severe sepsis-septic shock, 30-days mortality and multi-lobe or bilateral affection were 3, 1 and 19A; 1, 3 and 19A; and 3, 19A and 6A, respectively.. PCT had a remarkable diagnostic ability to discard or suspect bacteremia and to guide the etiology of CAP caused by S. pneumoniae. Serotypes 1, 3, 19A and 7F showed greater frequency, systemic inflammatory response and clinical severity.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteremia; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Female; Follow-Up Studies; Humans; Male; Middle Aged; Pneumonia, Bacterial; Pneumonia, Pneumococcal; Prospective Studies; Protein Precursors; ROC Curve; Young Adult

Procalcitonin (PCT), a calcitonin precursor, is commonly measured in the setting of community-acquired pneumonia (CAP). However, the clinical significance of serial PCT changes has not been established. We conducted a prospective observational study of 122 patients with CAP. Thirty-day mortality was the primary endpoint. Secondary endpoints included: (1) initial treatment failure, (2) 30-day mortality and/or initial treatment failure, and (3) intensive care unit (ICU) admission. In subgroup analysis, we classified patients into pneumococcal pneumonia and non-pneumococcal pneumonia groups. The baseline frequency of 30-day mortality was 10.7%. Increases in serum PCT levels from admission to Day 3 were observed with statistically higher frequency in patients with 30-day mortality (P = 0.002). For secondary endpoints, only the 30-day mortality and/or initial treatment failure group was statistically significant (P = 0.007). Subgroup analysis revealed statistically significant changes in the non-pneumococcal pneumonia group (N = 85) across several endpoints, including 30-day mortality (P = 0.001), initial treatment failure (P = 0.013), and 30-day mortality and/or initial treatment failure (P < 0.001). No significant changes in endpoint measurements were found in the pneumococcal pneumonia group (N = 28). Interestingly, serum PCT levels at the time of diagnosis were higher in patients with pneumococcal pneumonia than those with non-pneumococcal pneumonia (P = 0.006), and this positively correlated with disease severity scores for all patients (PCT vs. PSI: R = 0.380, P < 0.001; PCT vs.. R = 0.422, P < 0.001) and for non-pneumococcal pneumonia (PCT vs. PSI: R = 0.468, P < 0.001; PCT vs.. R = 0.448, P < 0.001), but not for pneumococcal pneumonia. In conclusion, serial quantification of PCT can predict clinical outcomes for patients with CAP.

Topics: Aged; Aged, 80 and over; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Female; Humans; Male; Middle Aged; Pneumonia, Pneumococcal; Prognosis; Prospective Studies; Protein Precursors; Treatment Outcome

A high genomic load of Pneumococcus from blood or cerebrospinal fluid has been associated with increased mortality. We aimed to analyse whether nasopharyngeal colonisation density in HIV-infected patients with community-acquired pneumonia (CAP) is associated with markers of disease severity or poor outcome.. Quantitative lytA real-time PCR was performed on nasopharyngeal swabs in HIV-infected South African adults hospitalised for acute CAP at Chris Hani Baragwanath Hospital, Soweto, South Africa. Pneumonia aetiology was considered pneumococcal if any sputum culture or Gram stain, urinary pneumococcal C-polysaccharide-based antigen, blood culture or whole blood lytA real-time PCR revealed pneumococci.. There was a moderate correlation between the mean nasopharyngeal colonisation densities and increasing CURB65 scores among all-cause patients with pneumonia (Spearman correlation coefficient r=0.15, p=0.06) or with the Pitt bacteraemia score among patients with pneumococcal bacteraemia (p=0.63). In patients with pneumococcal pneumonia, nasopharyngeal pneumococcal colonisation density was higher among non-survivors than survivors (7.7 vs 6.1 log10 copies/mL, respectively, p=0.02) and among those who had pneumococci identified from blood cultures and/or by whole blood lytA real-time PCR than those with non-bacteraemic pneumococcal pneumonia (6.6 vs 5.6 log10 copies/mL, p=0.03). Nasopharyngeal colonisation density correlated positively with the biomarkers procalcitonin (Spearman correlation coefficient r=0.37, p<0.0001), proadrenomedullin (r=0.39, p=0.008) and copeptin (r=0.30, p=0.01).. In addition to its previously reported role as a diagnostic tool for pneumococcal pneumonia, quantitative nasopharyngeal colonisation density also correlates with mortality and prognostic biomarkers. It may also be useful as a severity marker for pneumococcal pneumonia in HIV-infected adults.

Topics: Adolescent; Adrenomedullin; Adult; Bacteremia; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; HIV Infections; Hospitalization; Humans; Nasopharynx; Pneumonia; Pneumonia, Pneumococcal; Protein Precursors; Real-Time Polymerase Chain Reaction; Severity of Illness Index; South Africa; Streptococcus pneumoniae

Our objective was to evaluate procalcitonin (PCT) and C-reactive protein (CRP) as predictors of a pneumococcal etiology in community-acquired pneumonia (CAP) in hospitalized children.. Children requiring hospitalization for CAP were prospectively enrolled. The following indices were determined: antibodies against pneumococcal surface proteins (anti-PLY, pneumococcal histidine triad D, pneumococcal histidine triad E, LytB and pneumococcal choline-binding protein A), viral serology, nasopharyngeal cultures and polymerase chain reaction for 13 respiratory viruses, blood pneumococcal polymerase chain reaction, pneumococcal urinary antigen, PCT and CRP. Presumed pneumococcal CAP (P-CAP) was defined as a positive blood culture or polymerase chain reaction for Streptococcus pneumoniae or as a pneumococcal surface protein seroresponse (≥2-fold increase).. Seventy-five patients were included from which 37 (49%) met the criteria of P-CAP. Elevated PCT and CRP values were strongly associated with P-CAP with odds ratios of 23 (95% confidence interval: 5-117) for PCT and 19 (95% confidence interval: 5-75) for CRP in multivariate analysis. The sensitivity was 94.4% for PCT (cutoff: 1.5 ng/mL) and 91.9% for CRP (cutoff: 100 mg/L). A value≤0.5 ng/mL of PCT ruled out P-CAP in >90% of cases (negative likelihood ratio: 0.08). Conversely, a PCT value≥1.5 ng/mL associated with a positive pneumococcal urinary antigen had a diagnostic probability for P-CAP of almost 80% (positive likelihood ratio: 4.59).. PCT and CRP are reliable predictors of P-CAP. Low cutoff values of PCT allow identification of children at low risk of P-CAP. The association of elevated PCT or CRP with a positive pneumococcal urinary antigen is a strong predictor of P-CAP.

Topics: Antigens, Bacterial; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Chi-Square Distribution; Child; Child, Preschool; Cohort Studies; Community-Acquired Infections; Female; Hospitalization; Humans; Infant; Male; Pneumonia, Pneumococcal; Prospective Studies; Protein Precursors; Streptococcus pneumoniae

This study aimed to evaluate the role of biomarkers as markers of pneumococcal bacteremia in severe community-acquired pneumonia (SCAP).. A prospective, single-center, observational cohort study of 108 patients with SCAP admitted to the intensive care department of a university hospital in Portugal was conducted. Leucocytes, C-reactive protein (CRP), lactate, procalcitonin (PCT), d-dimer, brain natriuretic peptide (BNP), and cortisol were measured within 12 hours after the first antibiotic dose.. Fifteen patients (14%) had bacteremic pneumococcal pneumonia (BPP). They had significantly higher levels of median CRP (301 [interquartile range, or IQR], 230-350] mg/L vs 201 [IQR, 103-299] mg/L; P = .023), PCT (40 [IQR, 25-102] ng/mL vs 8 [IQR, 2-26] ng/mL; P < .001), BNP (568 [IQR, 478-2841] pg/mL vs 407 [IQR, 175-989] pg/mL; P = .027), and lactate (5.5 [IQR, 4.5-9.8] mmol/L vs 3.1 [IQR, 1.9-6.2] mmol/L; P = .009) than did patients without BPP. The discriminatory power evaluated by the area under the receiver operating characteristic curve (aROC) for PCT (aROC, 0.79) was superior to lactate (aROC, 0.71), BNP (aROC, 0.67), and CRP (aROC, 0.70). At a cutoff point of 17 ng/mL, PCT showed a sensitivity of 87%, a specificity of 67%, a positive predictive value of 30% and a negative predictive value of 97%, as a marker of pneumococcal bacteremia.. In this cohort, significantly higher PCT, BNP, lactate, and CRP levels were found in BPP, and PCT presented the best ability to identify pneumococcal bacteremia. A PCT serum level lower than 17 ng/mL could identify patients with SCAP unlikely to have pneumococcal bacteremia.

Topics: Bacteremia; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Female; Health Status Indicators; Humans; Lactates; Male; Middle Aged; Natriuretic Peptide, Brain; Pneumonia, Pneumococcal; Portugal; Predictive Value of Tests; Prospective Studies; Protein Precursors; Severity of Illness Index

The value of measuring procalcitonin (PCT) in patients with community-acquired pneumonia (CAP) is unclear. The aim of this study was to determine the value of PCT as a marker for microbial etiology and a predictor of outcome in CAP patients.. A single-center observational study was conducted with CAP patients. On admission, their leukocyte count, serum C-reactive protein level, and serum PCT level were determined, and microbiological tests were performed. Patients were classified into 4 groups according to the A-DROP scoring system, which assesses the severity of CAP.. A total of 102 patients were enrolled. The pathogen was identified in 60 patients, and 31 patients had streptococcal pneumonia. The PCT levels were significantly higher in those patients with pneumococcal pneumonia than in those patients with other bacterial pneumonias (P < 0.0001). Multivariate regression analysis revealed that high PCT levels were associated with a pneumococcal etiology [odds ratio, 1.68; 95% confidence interval (CI): 1.02-2.81; P = 0.04] after adjustment for disease severity and demographic factors. The PCT levels were correlated with the A-DROP score (r = 0.49; P < 0.0001). The area under the curve for predicting mortality was highest for the A-DROP score (0.97; 95% CI: 0.92-0.99), followed by the area under the curve for PCT (0.82; 95% CI: 0.74-0.89) and C-reactive protein (0.77; 95% CI: 0.67-0.84).. High PCT levels indicate that pneumococcal pneumonia and PCT levels depend on the severity of pneumonia. PCT measurements may provide important diagnostic and prognostic information for patients with CAP.

Topics: Aged; Aged, 80 and over; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Female; Humans; Japan; Logistic Models; Male; Pneumonia, Pneumococcal; Prospective Studies; Protein Precursors

Invasive pneumococcal diseases were reduced after introduction of pneumococcal conjugate vaccine, but infections due to non-vaccine serotypes persisted. The pneumococcal origin of community-acquired pneumonia remains difficult to affirm, but high procalcitonin and C-reactive protein blood levels and duration of fever 48 h or less after initial antibiotic treatment are excellent predictors of pneumococci. Among 259 patients under 7 years of age hospitalized from 2003 to 2008 for community-acquired pneumonia, 47 met these criteria, including 27 of 141 hospitalized between 2006 (date of vaccine generalization) and 2008. Of these 27, 21 had previously received pneumococcal conjugate vaccine and 19 of 21 were attendees of nursery school or day care centers versus only 2 in 2003-2006. These data show that pneumococcal pneumonias are possible in immunized children cared for in-group settings.

Topics: C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child Day Care Centers; Child, Preschool; Community-Acquired Infections; Female; France; Hospitalization; Humans; Infant; Male; Pneumococcal Vaccines; Pneumonia, Pneumococcal; Protein Precursors; Risk Factors; Schools, Nursery; Serotyping

We retrospectively analyzed the records of 61 hospitalized patients with community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae or Legionella pneumophila. We found that serum procalcitonin and sodium concentrations were significantly lower, and ferritin levels were significantly higher, in patients infected with L. pneumophila than in those infected with S. pneumoniae. The ratio of C-reactive protein to procalcitonin significantly distinguished between the groups. High procalcitonin levels were associated with an adverse clinical course.

Topics: Aged; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Diagnosis, Differential; Female; Ferritins; Hospitalization; Humans; Legionnaires' Disease; Male; Middle Aged; Pneumonia, Pneumococcal; Predictive Value of Tests; Protein Precursors; Retrospective Studies; Sensitivity and Specificity; Serum

To evaluate the value of clinical features in differentiating between viral, pneumococcal and atypical bacterial pneumonia in children.. A retrospective analysis of clinical signs and symptoms, supplemented with chest radiograph and serum procalcitonin data, in 101 children with community-acquired pneumonia. Viral and bacterial aetiology was studied prospectively by antibody assays, and pneumococcal infection was found in 18, atypical bacterial infection in 28 and viral infection alone in 22 cases.. Chest radiographs and serum procalcitonin were studied in all cases. Data on clinical signs and symptoms were retrospectively collected from the medical cards of the patients.. Among symptoms, cough was present in 89% and fever (>37.5 degrees C) in 88% of the cases. Among physical signs, crackles were present in 49% and decreased breath sounds in 58%. No significant associations were found between any of the clinical signs or symptoms and the aetiology of pneumonia. In multivariate analyses, age over 5 years and serum procalcitonin over 1.0 ng/mL were the only independent predictors of bacterial aetiology, but no finding was able to screen between pneumococcal and atypical bacterial aetiology of infection.. No clinical or radiological characteristic was helpful in the separation between viral, pneumococcal and atypical bacterial aetiology of community-acquired pneumonia (CAP) in children.

Topics: Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child, Preschool; Community-Acquired Infections; Diagnosis, Differential; Humans; Infant; Pneumonia, Bacterial; Pneumonia, Pneumococcal; Pneumonia, Viral; Protein Precursors

Pulmonary tuberculosis (PTB) and pneumococcal community-acquired pneumonia (PCAP) are common causes of lower respiratory tract infections in HIV-seropositive patients and may have similar clinical and radiological features. This study aimed to assess the value of serum procalcitonin (PCT) and C-reactive protein (CRP) levels in HIV-seropositive patients with pneumonia, and to investigate their potential role in differentiating pneumococcal from mycobacterial infections. HIV-seropositive patients admitted with pneumonia were evaluated prospectively, 34 with PTB and 33 with PCAP. All 33 patients in the PCAP group and 20 of 34 patients in the PTB group had elevated PCT levels (>0.1 ng x mL(-1)). All patients in both groups had elevated CRP levels (>10 mg x L(-1)). The PTB group had significantly lower CD4 T-lymphocyte counts, lower CRP levels, lower white cell counts, and lower PCT levels than the PCAP group. Receiver operating characteristic analysis showed that optimal discrimination between PTB and PCAP could be performed at a cut-off point of 3 ng x mL(-1) for PCT (sensitivity 81.8%; specificity 82.35%) and 246 mg x L(-1) for CRP (sensitivity 78.8%; specificity 82.3%). In conclusion, HIV-seropositive patients with pneumococcal community-acquired pneumonia had significantly higher procalcitonin and C-reactive protein levels than those with pulmonary tuberculosis. A procalcitonin level >3 ng x mL(-1) and a C-reactive protein level >246 mg x L(-1) were both highly predictive of pneumococcal infection.

Topics: Adult; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Diagnosis, Differential; Female; HIV Seropositivity; Humans; Male; Pneumonia, Pneumococcal; Prospective Studies; Protein Precursors; Tuberculosis, Pulmonary

Serum C-reactive protein (CRP), blood white cell count (WBC), serum procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) were measured in 132 children hospitalized for community-acquired pneumonia. Serological evidence for viral infection was found in 38 cases and for pneumococcal infection in 41 cases, and the infiltrate was alveolar in 46 cases and interstitial in 86 cases. The aim of the present paper was to determine if there is a combination of these four host response markers and chest radiograph findings suitable for differentiating pneumococcal from viral etiology of pneumonia.. The 50th, 75th and 90th percentiles of CRP, WBC, ESR and PCT in the total group of 132 patients were calculated. By using these cut-off limits, the likelihood ratios of a positive test result were calculated for the possible combinations of CRP, WBC, ESR and PCT, and the likelihood ratio was 1.50 or more for six combinations.. The highest likelihood ratio (1.74) was achieved with the combination CRP > 90th (80 mg/L) or WBC > 75th (17.0 x 10(9)/L) or PCT > 75th (0.84 microg/L) or ESR > 90th (63 mm/h) percentile. For this combination, the sensitivity was 61% and the specificity 65%. When the 90th percentile cut-off limit was applied also for WBC (>22 x 10(9)/L) and PCT (>1.8 microg/L), the specificity increased to 76%, but the sensitivity decreased to 37%. When the presence of an alveolar infiltration was included in the combination, the likelihood ratio was 1.89; the specificity was as high as 82% and the sensitivity as low as 34%.. CRP, PCT, WBC and ESR have only limited value in differentiating pneumococcal or other bacterial pneumonia from viral pneumonia. If there was a high value in at least one of the markers (CRP > 80 mg/L, PCT > 1.8 microg/L, WBC > 22 x 10(9)/L or ESR > 60 mm/h), viral infections were rare. There was no combination of these markers which was sufficiently sensitive and specific to be used in clinical pediatric practice.

Topics: Biomarkers; Blood Sedimentation; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Diagnosis, Differential; Humans; Infant; Leukocyte Count; Pneumonia, Pneumococcal; Pneumonia, Viral; Protein Precursors; Sensitivity and Specificity

A microbe-specific diagnosis in community-acquired pneumonia (CAP) is difficult in children, and studies on nonspecific chest radiographic and host response markers have been inconsistent. Serum procalcitonin (PCT) is a newly recognized, promising marker for differentiating between bacterial and viral infections. Serum PCT was measured by a luminometric assay in 190 children with CAP diagnosed in the primary healthcare setting during a population-based study in a geographically defined population. The pneumococcal, mycoplasma, chlamydia, and viral etiology of infections was studied by an extensive serologic test panel. The median PCT concentrations were 0.47, 0.46, and 0.35 ng/mL in children aged <5 years, 5-9 years, and >/=10 years (P = 0.004). An elevated PCT >1.0 ng/mL was seen in 12.1% and >2.0 ng/mL in only 2.1% of the children. No association was seen between severity (inpatient vs. outpatient care) and etiology of CAP (evidence for pneumococcal, mycoplasma, or chlamydia, vs. viral infection). We conclude that serum PCT measurements have no role in the diagnosis of bacterial CAP in children in primary healthcare settings.

Topics: Adolescent; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Chlamydia Infections; Chlamydophila pneumoniae; Community-Acquired Infections; Diagnosis, Differential; Female; Glycoproteins; Humans; Male; Pneumonia, Bacterial; Pneumonia, Mycoplasma; Pneumonia, Pneumococcal; Pneumonia, Viral; Prospective Studies; Protein Precursors; Radiography; Regression Analysis

To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in differentiating bacterial and viral causes of pneumonia.. A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15, Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration.. PCT concentration was greater than 2 microg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 microg/l in 86% of patients with bacterial infection (including Mycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40% v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration.. PCT concentration, with a threshold of 1 microg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for differentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases.

Topics: Adolescent; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Community-Acquired Infections; Diagnosis, Differential; Humans; Infant; Interleukin-6; Leukocyte Count; Pneumonia, Bacterial; Pneumonia, Pneumococcal; Pneumonia, Viral; Predictive Value of Tests; Protein Precursors; Sensitivity and Specificity

Serum procalcitonin (PCT), a marker of bacterial infection, was measured in children with pneumonia to examine whether PCT can be used to screen pneumococcal (PNC) from viral pneumonia. The number of patients was 132; mean age 3.0 yrs, and 64% were males. In all cases, pneumonia was radiologically confirmed, being alveolar in 46 and interstitial in 86 cases. The aetiology of infection was studied by a panel of serological tests for PNC, for five other respiratory bacteria and for seven common respiratory viruses. PNC infection was found in 25, mixed viral-PNC infections in 13 and viral infection in 17 cases. In general, serum PCT was not associated with the type or aetiology of pneumonia. PCT values were >1.0 mg.L(-1) in 40% of PNC cases, as compared to 12-15% in viral or mixed cases, respectively (p<0.05). PCT values were significantly higher in >2 yrs old children than in younger ones. The cut-off limits of 0.5 ng.mL(-1), 1.0 ng.mL(-1) and 2.0 ng.mL(-1) were tested for screening between PNC and viral pneumonia. The highest sensitivity of 55% was found at the 0.5 ng.mL(-1) cut-off level, whereas the highest specificity of 88% was reached at the level of 1.0 ng.mL(-1). The likelihood ratios, however, were far from optimal for both the positive and negative results. Although marginally higher in pneumococcal pneumonia than in viral pneumonia, serum procalcitonin cannot be used to discriminate between these two types of pneumonia.

Topics: Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Child, Preschool; Diagnosis, Differential; Female; Humans; Male; Pneumonia, Pneumococcal; Pneumonia, Viral; Prospective Studies; Protein Precursors; Sensitivity and Specificity