lactoferrin and Respiratory-Tract-Infections

Lactoferrin (Lf) is a glycoprotein present in human and bovine milk with antimicrobial and immune-modulating properties. This review aimed to examine the evidence for the effect of Lf supplementation on inflammation, immune function, and respiratory tract infections (RTIs) in humans. Online databases were searched up to December 2020 to identify relevant, English-language articles that examined the effect of Lf supplementation in human subjects of all ages, on either inflammation, immune cell populations or activity, or the incidence, duration, or severity of respiratory illness or RTIs. Twenty-five studies (n = 20 studies in adults) were included, of which 8 of 13 studies (61%) in adults reported a decrease in at least 1 systemic inflammatory biomarker. Immune function improved in 6 of 8 studies (75%) in adults, with changes in immune cell populations in 2 of 6 studies (33%), and changes in immune cell activity in 2 of 5 studies (40%). RTI outcomes were reduced in 6 of 10 studies (60%) (n = 5 in adults, n = 5 in children), with decreased incidence in 3 of 9 studies (33%), and either decreased frequency (2/4, 50%) or duration (3/6, 50%) in 50% of studies. In adults, Lf reduced IL-6 [mean difference (MD): -24.9 pg/mL; 95% CI: -41.64, -8.08 pg/mL], but not C-reactive protein (CRP) [standardized mean difference: -0.09; 95% CI: -0.82, 0.65], or NK cell cytotoxicity [MD: 4.84%; 95% CI: -3.93, 13.60%]. RTI incidence was reduced in infants and children (OR: 0.78; 95% CI: 0.61, 0.98) but not in adults (OR: 1.00; 95% CI: 0.76, 1.32). Clinical studies on Lf supplementation are limited, although findings show 200 mg Lf/d reduces systemic inflammation, while formulas containing 35-833 mg Lf/d may reduce RTI incidence in infants and children, suggesting improved immune function. Future research is required to determine optimal supplementation strategies and populations most likely to benefit from Lf supplementation. This trial was registered at PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232186) as CRD42021232186.

Topics: Adult; Biomarkers; Child; Dietary Supplements; Glycoproteins; Humans; Immunity; Infant; Inflammation; Interleukin-6; Lactoferrin; Respiratory Tract Infections

Lactoferrin (Lf) is one of the key immunomodulatory substances found naturally in various body fluids, such as saliva, tears, and breast milk, and forms a vital part of the innate defense against invading pathogens. Various studies have demonstrated antibacterial, antifungal, and antiviral properties of Lf and its protective role against respiratory tract infections (RTIs). The present meta-analysis aims to elucidate the association of Lf administration in reducing the risk of RTIs by systematically reviewing the data from randomized controlled trials (RCTs).. We systematically searched PubMed, Cochrane Library, Medline & CINAHL, Turning Research into Practice (TRIP), ProQuest Theses & Dissertations Databases, and China National Knowledge Infrastructure (CNKI) from inception till March 15, 2021. The primary outcome measure was a reduction in respiratory illness; decrease in frequency, symptoms, and duration. Random-effects model was used to estimate the odds ratio (OR) and 95% confidence interval (CI). We used Cochrane's RoB-2 to appraise the risk of bias of included RCTs.. A total of nine RCTs were eligible for this review, of which six were included in the meta-analysis. Overall, two studies demonstrated a high risk of bias. The meta-analysis revealed a significantly reduced odds of developing respiratory infections with the use of Lf relative to the control (pooled odds ratio = 0.57; 95% confidence interval 0.44 to 0.74, n = 1,194), with sufficient evidence against the hypothesis of 'no significant difference' at the current sample size.. The administration of Lf shows promising efficacy in reducing the risk of RTIs. Current evidence also favours Lf fortification of infant formula. Lf may also have a beneficial role in managing symptoms and recovery of patients suffering from RTIs and may have potential for use as an adjunct in COVID-19, however this warrants further evidence from a large well-designed RCT.

Topics: COVID-19; Female; Humans; Lactoferrin; Randomized Controlled Trials as Topic; Respiratory Tract Infections; SARS-CoV-2

The aerobic Gram-negative bacterium Pseudomonas aeruginosa is an opportunistic pathogen responsible for life-threatening acute and chronic infections in humans. As part of chronic infection P. aeruginosa forms biofilms, which shield the encased bacteria from host immune clearance and provide an impermeable and protective barrier against currently available antimicrobial agents. P. aeruginosa has an absolute requirement for iron for infection success. By influencing cell-cell communication (quorum sensing) and virulence factor expression, iron is a powerful regulator of P. aeruginosa behaviour. Consequently, the imposed perturbation of iron acquisition systems has been proposed as a novel therapeutic approach to the treatment of P. aeruginosa biofilm infection. In this review, we explore the influence of iron availability on P. aeruginosa infection in the lungs of the people with the autosomal recessive condition cystic fibrosis as an archetypal model of chronic P. aeruginosa biofilm infection. Novel therapeutics aimed at disrupting P. aeruginosa are discussed, with an emphasis placed on identifying the barriers that need to be overcome in order to translate these promising in vitro agents into effective therapies in human pulmonary infections.

Topics: Anti-Infective Agents; Biofilms; Chelating Agents; Cystic Fibrosis; Gene Expression Regulation, Bacterial; Homeostasis; Humans; Iron; Lactoferrin; Lung; Pseudomonas aeruginosa; Pseudomonas Infections; Quorum Sensing; Respiratory Tract Infections; Thiocyanates

Topics: Bacteriolysis; Ceruloplasmin; Cilia; Complement System Proteins; Cross Infection; Humans; Immunoglobulins; Intensive Care Units; Lactoferrin; Lymphocytes; Macrophages; Mucus; Neutrophils; Opsonin Proteins; Phagocytosis; Postoperative Complications; Respiratory System; Respiratory Tract Infections; Risk

To investigate the effects of lactoferrin (LF) on infectious diseases in Japanese summer.. An intake of placebo, 200 mg, or 600 mg of LF were administered to healthy adults in Kyushu University of Health and Welfare for 12 weeks in a randomized, double-blinded, placebo-controlled parallel-group comparative trial. The primary endpoints were the prevalence and duration of infectious diseases and changes in immune parameters.. Three hundred and ten subjects were randomized (placebo, n = 104; 200 mg, n = 103; 600 mg, n = 103). Twenty subjects were lost to the follow-up, leaving 290 for a full analysis set (n = 99; n = 95; n = 96). The duration (day) of total infectious diseases was shorter in the 200 mg group (2.0, p = 0.045) and 600 mg group (2.0, p = 0.010) than in the placebo group (3.0). The duration of summer colds was shorter in the 600 mg group (2.0, p = 0.036) than in the placebo group (3.0). No significant differences were observed in the prevalence of infectious diseases or changes in immune parameters. In exploratory investigations, changes in the neutrophil phagocytic capacity, cortisol concentrations, and T score of "Vigor/Activity" in the Profile of Mood States 2 were greater in the 600 mg group than in the placebo group, when analysis was done on the lower half groups at the baseline. Adverse events were similar in each group and none had a causal relationship with the intake of the test foods.. In summer, the intake of LF attenuates infectious diseases, including summer colds.

Topics: Adult; Aged; Anti-Infective Agents; Common Cold; Communicable Diseases; Double-Blind Method; Female; Humans; Japan; Lactoferrin; Male; Middle Aged; Respiratory Tract Infections; Seasons; Treatment Outcome; Young Adult

The aim of this study was to explore the dose effect of bovine lactoferrin (bLF) fortification on the morbidity of diarrhea and respiratory tract infections in weaned infants with anemia.. A total of 108 infants with anemia, who were exclusively breast fed at 4 to 6 mo and weaned and formula fed at 6 to 9 mo, were recruited. The eligible infants were randomly assigned to fortified group 0 (FG0), fortified group 1 (FG1), or fortified group 2 (FG2) and were given formula fortified with 0 mg/100 g, 38 mg/100 g, and 76 mg/100 g of bLF, respectively, for 3 mo. The morbidity of diarrhea and respiratory tract infections (RTIs), the duration of respiratory and diarrhea-related illnesses, and the levels of fecal human beta-defensin 2 (HBD-2), cathelicidin LL-37 (LL-37), secretory IgA (sIgA), butyrate, and calprotectin were assessed.. After the exclusion of 12 dropouts, the primary outcome measures, including episodes and duration of diarrhea and RTIs during the intervention, were obtained from 96 infants (35, 33, and 28 in FG0, FG1, and FG2, respectively). Compared with infants in FG0, there was a lower morbidity of rhinorrhea, wheezing, and skin rash among infants in FG1 (P < 0.05) and a lower morbidity of respiratory-related illness and wheezing among infants in FG2 (P < 0.05). Furthermore, a lower morbidity of diarrhea-related illness, diarrhea, vomiting, and nausea was observed among infants in FG2 than those in the other two groups (P < 0.05). In addition, the FG1 infants had a lower morbidity of vomiting and nausea than the FG0 infants (P < 0.05). The HBD-2, LL-37, sIgA, and calprotectin levels were significantly higher whereas the butyrate level was significantly lower in the FG2 infants than in infants in the other two groups after 3 mo of intervention (P < 0.05).. The bLF-fortified formula was effective in reducing the morbidity of diarrhea and RTIs in infants with anemia, with the 76 mg/100 g bLF-fortified formula exhibiting a stronger effect. The bLF fortification could be a new strategy for the prevention of diarrhea and RTIs in infants with anemia.

Topics: Anemia; Diarrhea; Female; Humans; Infant; Lactoferrin; Respiratory Tract Infections; Weaning

Vitamin D insufficiency may be associated with increased risk of upper respiratory tract infection (URTI) in athletes. This study examined the effects of vitamin D₃ supplementation on salivary immune functions and symptoms of URTI in vitamin D-insufficient taekwondo athletes. Twenty-five male taekwondo athletes, aged 19⁻22 years with vitamin D insufficiency [serum 25-hydroxyvitamin-D concentrations (25(OH)D, 31.3 ± 1.39 nmol/L)], participated in this study. They were randomized to receive 5000 IU/day of vitamin D₃ (

Topics: Athletes; Body Composition; Cholecalciferol; Humans; Lactoferrin; Male; Martial Arts; Respiratory Tract Infections; Saliva; Seasons; Vitamin D; Vitamin D Deficiency; Vitamins; Young Adult

The aim of this study was to evaluate the effect of supplementation with bovine lactoferrin (bLf) from iron-fortified formulas on diarrhea and respiratory tract infections (RTIs) in weaned infants.. In this prospective, multicenter, controlled intervention study, 260 infants ages 4 to 6 mo who previously were exclusively breastfed but weaned were randomized into two groups: a lactoferrin-fortified formula milk group (fortified group, FG, containing lactoferrin 38 mg/100 g milk) and a no lactoferrin-fortified milk (control group, CG); breastfed infants were enrolled and served as a reference group (breastfed group, BG). The intervention duration was 3 mo. The morbidity of diarrhea and RTIs were collected during supplementation.. The results of the study demonstrated evidence of a lower incidence rate of respiratory-related illnesses and fewer symptoms of running nose, cough, and wheezing for infants in the FG and BG groups compared with those in the CG (P < 0.05). Despite the undistinguished incidence rate of vomiting, nausea, and colic, the occurrences of diarrhea-related illnesses were significantly lower for children in the FG and BG than for those in CG (P < 0.05).. The beneficial effects on infectious morbidity over 3 mo highlighted the potential of bLF supplementation for previously weaned infants; these findings may be applicable to other infants living in similar socioeconomic districts.

Topics: Breast Feeding; C-Reactive Protein; China; Diarrhea; Female; Food, Fortified; Hemoglobins; Humans; Incidence; Infant; Infant Formula; Iron, Dietary; Lactoferrin; Linear Models; Male; Morbidity; Patient Compliance; Prospective Studies; Respiratory Tract Infections; Treatment Outcome; Weaning

Tears have attracted interest as a minimally-invasive biological fluid from which to assess biomarkers. Lactoferrin (Lf) and lysozyme (Lys) are abundant in the tear fluid and have antimicrobial properties. Since the eye is a portal for infection transmission, assessment of immune status at the ocular surface may be clinically relevant. Therefore, the aim of this series of studies was to investigate the tear fluid antimicrobial proteins (AMPs) Lf and Lys as biomarkers of mucosal immune status. To be considered biomarkers of interest, we would expect tear AMPs to respond to stressors known to perturb immunity but be robust to confounding variables, and to be lower in participants with heightened risk or incidence of illness. We investigated the relationship between tear AMPs and upper respiratory tract infection (URTI; study 1) as well as the response of tear AMPs to prolonged treadmill exercise (study 2) and dehydration (study 3). Study 1 was a prospective cohort study conducted during the common cold season whereas studies 2 and 3 used repeated-measures crossover designs. In study 1, tear Lys concentration (C) as well as tear AMP secretion rates (SRs) were lower in individuals who reported pathogen-confirmed URTI (

Topics: Adolescent; Adult; Biomarkers; Dehydration; Exercise; Female; Humans; Immunity, Mucosal; Immunocompetence; Lactoferrin; Male; Muramidase; Respiratory Tract Infections; Tears; Young Adult

Respiratory infections are common after strenuous exercise, when salivary immunity may be altered. We aim to investigate changes in salivary immunity after a marathon and its relationship with lower respiratory tract infections (LRTI) in healthy non-elite marathon runners.. Forty seven healthy marathon runners (28 males and 19 females) who completed the 42.195 km of the 2016 Barcelona marathon were studied. Saliva and blood samples were collected the day before the marathon and two days after the end of the race. Salivary IgA, antimicrobial proteins (lactoferrin, lysozyme) and chemokines (Groα, Groβ, MCP-1) were determined using ELISA kits in saliva supernatant. Blood biochemistry and haemogram were analyzed in all participants. The presence of LRTI was considered in those runners who reported infectious lower respiratory tract symptoms during a minimum of 3 consecutive days in the 2 weeks after the race.. Eight participants (17%) presented a LRTI during the 2 weeks of follow-up. Higher lysozyme levels were detected after the race in runners with LRTI when compared with those without infection. A decrease in salivary lysozyme, Groα and Groβ levels after the race were observed in those runners who did not develop a LRTI when compared to basal levels. Salivary Groα levels correlated with basophil blood counts, and salivary lysozyme levels correlated with leukocyte blood counts.. LRTI are common after a marathon race in non-elite healthy runners. Changes in salivary antimicrobial proteins and chemokines are related to the presence of LRTI and correlate with systemic defense cells, which suggest an important role of salivary immunity in the development of LRTI in non-elite marathon runners.

Topics: Adult; Chemokines; Female; Humans; Immunoglobulin A; Lactoferrin; Male; Muramidase; Respiratory Tract Infections; Running; Saliva

Bacterial infections of the respiratory tract contribute to exacerbations and disease progression in chronic obstructive pulmonary disease (COPD). There is also an increased risk of invasive pneumococcal disease in COPD. The underlying mechanisms are not fully understood but include impaired mucociliary clearance and structural remodeling of the airways. In addition, antimicrobial proteins that are constitutively expressed or induced during inflammatory conditions are an important part of the airway innate host defense. In the present study, we show that osteopontin (OPN), a multifunctional glycoprotein that is highly upregulated in the airways of COPD patients co-localizes with several antimicrobial proteins expressed in the airways. In vitro, OPN bound lactoferrin, secretory leukocyte peptidase inhibitor (SLPI), midkine, human beta defensin-3 (hBD-3), and thymic stromal lymphopoietin (TSLP) but showed low or no affinity for lysozyme and LL-37. Binding of OPN impaired the antibacterial activity against the important bacterial pathogens Streptococcus pneumoniae and Pseudomonas aeruginosa. Interestingly, OPN reduced lysozyme-induced killing of S. pneumoniae, a finding that could be explained by binding of OPN to the bacterial surface, thereby shielding the bacteria. A fragment of OPN generated by elastase of P. aeruginosa retained some inhibitory effect. Some antimicrobial proteins have additional functions. However, the muramidase-activity of lysozyme and the protease inhibitory function of SLPI were not affected by OPN. Taken together, OPN can contribute to the impairment of innate host defense by interfering with the function of antimicrobial proteins, thus increasing the vulnerability to acquire infections during COPD.

Topics: Bacterial Infections; beta-Defensins; Cytokines; Humans; Lactoferrin; Lung; Midkine; Osteopontin; Protein Binding; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Infections; Secretory Leukocyte Peptidase Inhibitor; Streptococcus pneumoniae; Thymic Stromal Lymphopoietin; Treatment Failure; Up-Regulation

This study reported detailed clinical effects of bovine lactoferrin on 2 canine littermates (1 female and 1 male) with familial neutrophil dysfunction and an investigation of their genetic background. Clinical signs caused by severe upper respiratory bacterial infections were observed in these dogs. Oral administration of bovine lactoferrin for a long duration improved their clinical signs (severe uveitis in the female dog and coughing from pneumonia in the male dog). Their backcross dogs that have the same father didn't show clinical signs of bacterial infection. Neutrophil function tests revealed that the backcross dogs didn't have any disorders. It is likely that abnormal clinical signs are associated with neutrophil dysfunction in the colony, and the mother dog of these cases might be the genetic carrier of this dysfunction.

Topics: Animals; Cattle; Dog Diseases; Dogs; Female; Immune System Diseases; Lactoferrin; Male; Neutrophils; Pedigree; Radiography; Respiratory Tract Infections

To determine the antimicrobial activity of nisin F against Staphylococcus aureus in the respiratory tract.. The respiratory tract of nonimmunosuppressed and immunosuppressed Wistar rats were colonized with 4 x 10(5) viable cells of S. aureus K and then treated by administering 8192 arbitrary units (AU) nisin F intranasal. Symptoms of pneumonia were detected in the trachea and lungs of immunosuppressed rats that had not been treated with nisin F. The trachea and lungs of immunosuppressed rats treated with nisin F were healthy. No significant differences were recorded in blood cell indices. The antimicrobial activity of low concentrations nisin F (80-320 AU ml(-1)) was slightly stimulated by lysozyme and lactoferrin.. Nisin F inhibited the growth of S. aureus K in the respiratory tract of immunocompromised rats. Treatment with nisin F at 8192 AU proofed safe, as the trachea, lungs, bronchi and haematology of the rats appeared normal.. Nisin F is nontoxic and may be used to control respiratory tract infections caused by S. aureus. This is, however, a preliminary study with an animal model and need to be confirmed with studies on humans.

Topics: Administration, Intranasal; Animals; Bronchi; Drug Interactions; Humans; Immunocompromised Host; Lactoferrin; Lung; Male; Muramidase; Nisin; Pneumonia, Bacterial; Rats; Rats, Wistar; Respiratory Tract Infections; Staphylococcal Infections; Staphylococcus aureus; Trachea

Chronic exposure to arsenic, a potent carcinogen and toxicant, via drinking water is a worldwide public health problem. Because little is known about early-life effects of arsenic on immunity, we evaluated the impact of in utero exposure on infant immune parameters and morbidity in a pilot study. Pregnant women were enrolled at 6-10 weeks of gestation in Matlab, a rural area of Bangladesh, extensively affected by arsenic contamination of tubewell water. Women (n=140) delivering at local clinics were included in the study. Anthropometry and morbidity data of the pregnant women and their children, as well as infant thymic size by sonography were collected. Maternal urine and breast milk were collected for immune marker and arsenic assessment. Maternal urinary arsenic during pregnancy showed significant negative correlation with interleukin-7 (IL-7) and lactoferrin (Ltf) in breast milk and child thymic index (TI). Urinary arsenic was also positively associated with fever and diarrhea during pregnancy and acute respiratory infections (ARI) in the infants. The effect of arsenic exposure on ARI was only evident in male children. The findings suggest that in utero arsenic exposure impaired child thymic development and enhanced morbidity, probably via immunosuppression. The effect seemed to be partially gender dependent. Arsenic exposure also affected breast milk content of trophic factors and maternal morbidity.

Topics: Arsenic; Bangladesh; Cohort Studies; Female; Gestational Age; Humans; Immune Tolerance; Infant; Infant, Newborn; Interleukin-7; Lactoferrin; Male; Milk, Human; Morbidity; Organ Size; Pilot Projects; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Tract Infections; Rural Population; Thymus Gland; Water Pollutants, Chemical

Antimicrobial proteins are important in lung defense and are potential therapeutic agents in chronic airways infection such as seen in cystic fibrosis (CF). In preparation for future clinical studies, we sought (1) to determine levels of three antimicrobial proteins [lactoferrin, lysozyme, and secretory leukoprotease inhibitor (SLPI)] in the CF airway and (2) to examine the relationships between these antimicrobial proteins and airway inflammation and infection. We examined bronchoalveolar lavage fluid (BALF) from 45 individuals with CF and 23 disease control individuals. Airway inflammation was measured through BALF neutrophil counts and neutrophil elastase activity. Infection was assessed through quantitative counts of CF-related bacterial pathogens. BALF lysozyme activity and lactoferrin levels were elevated in individuals with CF compared to controls whereas SLPI levels were not different between the groups. Among the CF subjects, lysozyme activity and lactoferrin increased with age while SLPI decreased with age. Lysozyme activity and lactoferrin concentrations correlated positively with neutrophil counts but not with bacterial colony counts. SLPI levels were inversely related to both neutrophil counts and bacterial colony counts. This study provides information concerning the levels of antimicrobial proteins present in the CF airway that are relevant to future clinical trials of these compounds and demonstrates clear relationships between antimicrobial protein-specific levels and airway inflammation and infection.

Topics: Adolescent; Adult; Biomarkers; Bronchitis; Bronchoalveolar Lavage Fluid; Case-Control Studies; Child; Child, Preschool; Cross-Sectional Studies; Cystic Fibrosis; Female; Humans; Immunity, Innate; Infant; Lactoferrin; Leukocyte Count; Leukocyte Elastase; Male; Muramidase; Respiratory Tract Infections; Secretory Leukocyte Peptidase Inhibitor; Young Adult

Bacterial infections of the respiratory tract are a major cause of morbidity and mortality in elderly people. The inflammatory response to such infection is an important protective process and has been suggested to be less effective in elderly patients. To investigate the inflammatory response in respiratory infections acquired in the community by elderly people we studied 52 consecutive patients who met the criteria for either a non-pneumonic chest infection or pneumonia. After exclusion, 41 patients were available for evaluation, with 25 fulfilling the criteria of pneumonia and 16 the criteria of chest infection. Pyrexia was a feature of the patients with pneumonia. Circulating levels of neutrophil elastase-alpha-1-antitrypsin complex and C-reactive protein were greater in the patients with pneumonia than in those with a chest infection and were reduced following antibiotic treatment. No changes occurred in the chest infection group for these markers of inflammation. In both groups, a further neutrophil granule protein, lactoferrin, was unaffected by antibiotic treatment. This study indicates that elderly patients with pneumonia can initiate an appropriate inflammatory response as demonstrated by clinical indicators and circulating mediators of the inflammatory response.

Topics: Age Factors; Aged; Aged, 80 and over; alpha 1-Antitrypsin; Biomarkers; C-Reactive Protein; Female; Humans; Lactoferrin; Leukocyte Elastase; Male; Pancreatic Elastase; Pneumonia, Bacterial; Respiratory Tract Infections

To determine the underlying mechanisms for rhinovirus-induced nasal secretions, nasal lavage fluids were analyzed during experimental rhinovirus infections.. Twenty patients with allergic rhinitis and 18 nonallergic control subjects were inoculated with rhinovirus type 39. Nasal lavage was performed before and on days 2 through 7 after viral inoculation, and the lavage fluids were assayed for proteins and mast cell mediators.. The secretion of total protein and both plasma proteins (albumin and IgG) and glandular proteins (lactoferrin, lysozyme, and secretory IgA) increased after rhinovirus inoculation. Analysis of the specific protein constituents revealed that nasal secretions during the initial response to the rhinovirus infection were predominantly due to increased vascular permeability. Allergic subjects tended to have fewer symptoms and more vascular permeability than control subjects, and increased histamine secretion after rhinovirus inoculation was more frequently seen in the allergy group.. Nasal secretions found early in the course of a viral upper respiratory infection are due to increased vascular permeability, whereas glandular secretions predominate later in the infection.

Topics: Adolescent; Adult; Common Cold; Female; Histamine; Humans; Immunoglobulin A, Secretory; Immunoglobulin G; Lactoferrin; Male; Mucus; Muramidase; Nasal Mucosa; Respiratory Tract Infections; Rhinovirus; Serum Albumin

Serum and salivary total IgA, IgG and IgM as well as salivary innate non-immunoglobulin antimicrobial factors (lysozyme, lactoferrin, salivary and leukocyte peroxidase systems) were measured in 13 children prone to recurrent respiratory infections and compared to their age-matched healthy controls. Serum IgG and IgM levels were significantly elevated and salivary IgA remarkably low in infection-prone children as compared to the controls. However, the levels of secretory piece-bearing IgA were about the same in both groups. There were no significant differences between the two groups in serum IgA levels or in any of the non-immunoglobulin factors. The results indicate that low salivary IgA is associated with recurrent respiratory infections.

Topics: Child, Preschool; Disease Susceptibility; Female; Humans; Immunity, Innate; Immunoglobulin A; Immunoglobulin A, Secretory; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Infant; Lactoferrin; Male; Muramidase; Peroxidases; Respiratory Tract Infections; Saliva

Bronchial secretions obtained during bronchoscopic examination of 60 children suffering from respiratory tract infections were studied for the concentration of immunoglobulins, anti-proteolytic factors, lactoferrin, and lysozyme. Eleven children having bronchial asthma without a history of chronic or recurrent infections of the respiratory tract were designated as a control. The results were analysed in relation to clinical diagnosis (chronic bronchitis, bronchitis, bronchiectasis) or to the local status of bronchial mucosa at the time of bronchoscopy (no inflammation, inflammation, inflammation with documented bacterial infection). The statistical analysis of the results revealed a decrease of lactoferrin and locally produced IgA in the group of children suffering from bronchitis and chronic bronchitis. Samples infected with Haemophilus species had significantly higher concentration of lactoferrin than any other group. Similarly, albumin in this group was higher than in the other group except that other bacteria were present. Samples infected with Haemophilus also had increased concentrations of S-IgA, IgG, and anti-proteolytic factors when compared with the group without local inflammation.

Topics: Bacterial Infections; Bronchi; Bronchitis; Child; Child, Preschool; Humans; Immunoglobulin A; Immunoglobulin A, Secretory; Lactoferrin; Mucus; Muramidase; Respiratory Tract Infections; Serum Albumin

Bronchial secretions from 207 children suffering from various pulmonary diseases and from 15 healthy controls were tested concentration of IgA, IgG, lactoferrin and lysozyme. The results obtained suggest that in many cases of chronic lung diseases in children the levels of lactoferrin and immunoglobulins, especially secretory IgA, are very low. In severe infections (cystic fibrosis, bronchiectases) significant increase of IgG concentration was observed.

Topics: Adolescent; Bronchi; Bronchiectasis; Bronchitis; Child; Child, Preschool; Chronic Disease; Cystic Fibrosis; Humans; Immunoglobulin A; Immunoglobulin A, Secretory; Immunoglobulin G; Lactoferrin; Lactoglobulins; Muramidase; Recurrence; Respiratory Tract Diseases; Respiratory Tract Infections