Investigation of circulating lncRNAs as potential biomarkers in chronic respiratory diseases.

BACKGROUND: In the present study the blood expression level of inflammatory response and autoimmunity associated long non-coding RNAs (lncRNAs) were compared in patients with different chronic respiratory diseases and investigated whether they could be used as biomarkers in these diseases. METHODS: In the discovery cohort, the gene expression level of 84 lncRNAs were measured in the blood of 24 adult patients including healthy controls and patients with asthma and COPD. In the replication cohort the expression of 6 selected lncRNAs were measured in 163 subjects including healthy controls and adults with allergic rhinitis, asthma, COPD and children with asthma. It was evaluated whether these lncRNAs can be used as diagnostic biomarkers for any studied disease. With systems biology analysis the biological functions of the selected lncRNAs were predicted. RESULTS: In the discovery cohort, the mean expression of 27 lncRNAs showed nominally significant differences in at least one comparison. OIP5-AS1, HNRNPU, RP11-325K4.3, JPX, RP11-282O18.3, MZF1-AS1 were selected for measurement in the replication cohort. Three lncRNAs (HNRNPU, RP11-325K4.3, JPX) expressed significantly higher in healthy children than in adult controls. All the mean expression level of the 6 lncRNAs differed significantly between adult allergic rhinitis patients and controls. RP11-325K4.3, HNRNPU and OIP5-AS1 expressed higher in allergic asthma than in non-allergic asthma. COPD and asthma differed in the expression of RP11-325K4.3 from each other. In examining of the lncRNAs as biomarkers the weighted accuracy (WA) values were especially high in the comparison of healthy controls and patients with allergic rhinitis. OIP5-AS1 and JPX achieved 0.98 and 0.9 WA values, respectively, and the combination of the selected lncRNAs also resulted in a high performance (WA = 0.98). Altogether, OIP5-AS1 had the highest discriminative power in case of three out of six comparisons. CONCLUSION: Differences were detected in the expression of circulating lncRNAs in chronic respiratory diseases. Some of these differences might be utilized as biomarkers and also suggest a possible role of these lncRNAs in the pathomechanism of these diseases. The lncRNAs and the associated pathways are potential therapeutic targets in these diseases, but naturally additional studies are needed for the confirmation of these results.

Implication of BIRC5 in asthma pathogenesis.

In the last few years, it has been recognized that the unbalanced regulation of survival and apoptosis of bronchial inflammatory cells is a key component in the development of asthma. Baculoviral IAP repeat containing 5 (BIRC5) (also known as survivin) is an important anti-apoptotic protein that has been implicated in many cancer types, and recent studies provide evidence for its role in controlling inflammatory disorders as well. Our aim was to investigate at both genetic and transcriptional levels if BIRC5 has an impact on asthma development. We found that induced sputum samples of patients with bronchial asthma contained elevated levels of BIRC5 mRNA compared with healthy subjects and its level was in correlation with sputum eosinophil percentages. Furthermore, in a case-control study examining single nucleotide polymorphisms (SNPs) in the BIRC5 regulatory regions, the minor alleles of rs8073903 and rs8073069 were found to be significantly associated with asthma and especially non-allergic asthma phenotypes, which associations were more prominent among women. Two marker haplotype analyses further strengthen the impact of these two polymorphisms on both asthma and non-allergic asthma. In the female cohort, rs1508147 was also significantly associated with increased risk of non-allergic asthma. Additionally, with linear regression analysis, we showed that rs9904341 was significantly correlated with both absolute and relative serum eosinophil levels. In conclusion, our results suggest that possibly by inhibition of the eosinophil apoptosis, BIRC5 might be an important regulator of the asthmatic processes and we provide some evidence that its effect might be affected by SNPs located in the gene regulatory regions.

Role of anti-polyethylene glycol (PEG) antibodies in the allergic reactions to PEG-containing Covid-19 vaccines: Evidence for immunogenicity of PEG.

A small fraction of recipients who receive polyethylene-glycol (PEG)-containing COVID-19 mRNA-LNP vaccines (Comirnaty and Spikevax) develop hypersensitivity reactions (HSRs) or anaphylaxis. A causal role of anti-PEG antibodies (Abs) has been proposed, but not yet been proven in humans.We used ELISA for serial measurements of SARS-CoV-2 neutralizing Ab (anti-S) and anti-PEG IgG/IgM Ab levels before and after the first and subsequent booster vaccinations with mRNA-LNP vaccines in a total of 291 blood donors. The HSRs in 15 subjects were graded and correlated with anti-PEG IgG/IgM, just as the anti-S and anti-PEG Ab levels with each other. The impacts of gender, allergy, mastocytosis and use of cosmetics were also analyzed. Serial testing of two or more plasma samples showed substantial individual variation of anti-S Ab levels after repeated vaccinations, just as the levels of anti-PEG IgG and IgM, which were over baseline in 98-99 % of unvaccinated individuals. About 3-4 % of subjects in the strongly left-skewed distribution had 15-45-fold higher values than the median, referred to as anti-PEG Ab supercarriers. Both vaccines caused significant rises of anti-PEG IgG/IgM with >10-fold rises in about âˆ¼10 % of Comirnaty, and all Spikevax recipients. The anti-PEG IgG and/or IgM levels in the 15 vaccine reactors (3 anaphylaxis) were significantly higher compared to nonreactors. Serial testing of plasma showed significant correlation between the booster injection-induced rises of anti-S and anti-PEG IgGs, suggesting coupled anti-S and anti-PEG immunogenicity.Conclusions: The small percentage of people who have extremelevels of anti-PEG Ab in their blood may be at increased risk for HSRs/anaphylaxis to PEGylated vaccines and other PEGylated injectables. This risk might be further increased by the anti-PEG immunogenicity of these vaccines. Screening for anti-PEG Ab "supercarriers" may help predicting reactors and thus preventing these adverse phenomena.

Asthma endophenotypes and polymorphisms in the histamine receptor HRH4 gene.

BACKGROUND: Histamine as an inflammatory mediator plays an important role in chronic allergic and asthmatic conditions. However, the role of genetic polymorphisms of the histamine receptor HRH4 (histamine receptor H4) gene in asthma susceptibility and endophenotypes has not been studied yet. Our aim was to investigate the possible association between single nucleotide polymorphisms (SNPs) in the HRH4 gene and asthma or some endophenotypes of asthma. METHODS: Twenty-one SNPs of the HRH4 gene were genotyped in 313 asthmatic patients and 360 controls using Sequenom® iPLEX® Gold Genotyping Technology. RESULTS: Genotype distribution of three HRH4 SNPs, namely rs17187619 [p = 0.002; odds ratio, OR (95% confidence interval, CI) = 2.4 (4.1-1.4)], rs527790 [p = 0.0002; OR (95% CI) = 3.3 (6.1-1.8)] and rs487202 [p = 0.00007; OR (95% CI) = 3.5 (6.6-1.9)] differed significantly between patients with or without infection-induced asthma. Haplotypes, which included the rs4800573-rs527790 CC allele combination, were found to be associated with infection-induced asthma [p = 0.0009, OR (95% CI) = 0.5 (0.4-0.8)]. The rs487202-rs574913 CA haplotype was more frequent among patients with infection-induced asthma [p = 0.0006, OR (95% CI) = 1.9 (1.3-2.6)]. None of the SNPs contributed directly to the risk of asthma. CONCLUSIONS: Our results suggest that genetic variation in the HRH4 gene might influence the pathogenesis of infection-induced asthma.

Review of Novel Oral Amphotericin B Formulations for the Treatment of Parasitic Infections.

Amphotericin B (AmpB) is a polyene macrolide antibiotic used in the treatment of blood-borne parasitic and fungal infections. However, its use, particularly in the developing world, has been limited by dose-dependent kidney toxicity, other systemic-related toxicity issues following injection, the inconvenience of parenteral administration, and accessibility. Oral formulation approaches have focused on the dual problem of solubility and permeability of AmpB, which is poorly water soluble, amphoteric and has extremely low oral bioavailability. Therefore, to enhance oral absorption, researchers have employed micellar formulations, polymeric nanoparticles, cochleates, pro-drugs, and self-emulsifying drug delivery systems (SEDDS). This paper will highlight current uses of AmpB against parasitic infections such as leishmaniasis, preclinical and clinical formulation strategies, applications in veterinary medicine and the importance of developing a cost-effective and safe oral AmpB formulation.

Corrigendum: Investigation of the Possible Role of Tie2 Pathway and TEK Gene in Asthma and Allergic Conjunctivitis.

[This corrects the article DOI: 10.3389/fgene.2020.00128.].

Author Correction: Plasma neutrophil extracellular trap level is modified by disease severity and inhaled corticosteroids in chronic inflammatory lung diseases.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Investigation of the Possible Role of Tie2 Pathway and TEK Gene in Asthma and Allergic Conjunctivitis.

Tie2, coded by the TEK gene, is a tyrosine kinase receptor and plays a central role in vascular stability. It was suggested that variations in the TEK gene might influence the susceptibility to asthma and allergic conjunctivitis. The aim of this study was to further investigate these suggestions, involving different populations and to study the Tie2 related pathway on a mouse model of asthma. The discovery, stage I cohort involved 306 patients with moderate and severe allergic rhinitis, the stage II study consisted of four cohorts, namely, adult and pediatric asthmatics and corresponding controls. Altogether, there were 1,258 unrelated individuals in these cohorts, out of which 63.9% were children and 36.1% were adults. In stage I, 112 SNPs were screened in the TEK gene of the patients in order to search for associations with asthma and allergic conjunctivitis. The top associated SNPs were selected for association studies on the replication cohorts. The rs3824410 SNP was nominally associated with a reduced risk of asthma in the stage I cohort and with severe asthma within the asthmatic population (p=0.009; OR=0.48) in the replication cohort. In the stage I study, 5 SNPs were selected in conjunctivitis. Due to the low number of adult patients with conjunctivitis, only children were involved in stage II. Within the asthmatic children, the rs622232 SNP was associated with conjunctivitis in boys in the dominant model (p=0.004; OR=4.76), while the rs7034505 showed association to conjunctivitis in girls (p=0.012; OR=2.42). In the lung of a mouse model of asthma, expression changes of 10 Tie2 pathway-related genes were evaluated at three points in time. Eighty percent of the selected genes showed significant changes in their expressions at least at one time point during the process, leading from sensitization to allergic airway inflammation. The expressions of both the Tek gene and its ligands showed a reduced level at all time points. In conclusion, our results provide additional proof that the Tie2 pathway, the TEK gene and its variations might have a role in asthma and allergic conjunctivitis. The gene and its associated pathways can be potential therapeutic targets in both diseases.

Plasma neutrophil extracellular trap level is modified by disease severity and inhaled corticosteroids in chronic inflammatory lung diseases.

A flow cytometry-based method was developed to quantify in vivo circulating neutrophil extracellular trap (NET) levels in plasma and compare them in patients with different chronic inflammatory lung diseases. Seventeen asthmatic and 11 control children, 12 adult controls, 46 asthmatic, 6 COPD and 6 adult patients with asthma-COPD overlap syndrome (ACOS) were recruited in the study. The presence of NETs in unstimulated cell-free plasma was confirmed and visualized by confocal laser-scanning microscopy. No significant differences were found in plasma NET levels between children and adults, children with or without asthma and adults with or without asthma, COPD or ACOS. When asthmatic patients were stratified according to their disease severity the average plasma NET level was significantly higher in asthmatic patients with more serious symptoms (adjusted p = 0.027). Patients with poorer pulmonary functions had higher plasma NET levels which negatively correlated with the FEV1 values (r = -0.39, p = 0.002). Patients who were medicated daily with inhaled corticosteroids (ICS) had significantly lower average plasma NET level than patients who did not or just occasionally used ICS (p = 0.027). If further studies confirm the NET-lowering effect of ICS in the circulation, it can be utilized in diseases where NETosis contributes to the pathogenesis.

Investigation of the Possible Role of the Hippo/YAP1 Pathway in Asthma and Allergy.

PURPOSE: Several lines of evidence indicate that the Hippo/Yes-associated protein 1 (YAP1) pathways might play a role in the pathogenesis of asthma. To investigate the possible role of the Hippo/YAP1 pathway in the pathogenesis of asthma or its phenotypes. METHODS: The levels of gene expressions of the members of the Hippo/YAP1 were compared. The presence of the proteins of the YAP1 and FRMD6 were analyzed with Western blot in induced sputum of 18 asthmatic subjects and 10 control subjects. Fourteen single nucleotide polymorphisms (SNPs) in the YAP1 gene were genotyped in 522 asthmatic subjects and 711 healthy controls. The results were evaluated with traditional frequentist methods and with Bayesian network-based Bayesian multilevel analysis of relevance (BN-BMLA). RESULTS: The mRNA of all the members of the Hippo/YAP1 pathway could be detected in the induced sputum of both controls and cases. A correlation was found between YAP1 mRNA levels and sputum bronchial epithelial cells (r=0.575, P=0.003). The signal for the FRMD6 protein could be detected in all sputum samples while the YAP1 protein could not be detected in the sputum samples, of the healthy controls and severe asthmatics, but it was detectable in mild asthmatics. The rs2846836 SNP of the YAP1 gene was significantly associated with exercise-induced asthma (odds ratio [OR]=2.1 [1.3-3.4]; P=0.004). The distribution of genotypes of rs11225138 and certain haplotypes of the YAP1 gene showed significant differences between different asthma severity statuses. With BN-BMLA, 2 SNPs, genetic variations in the FRMD6 gene proved to be the most relevant to exercise-induced asthma and allergic rhinitis. These 2 SNPs through allergic rhinitis and exercise-induced asthma were in epistatic interaction with each other. CONCLUSIONS: Our results provided additional evidence that the FRMD6/Hippo/YAP1 pathway plays a role in the pathogenesis of asthma. If additional studies can confirm these findings, this pathway can be a potential novel therapeutic target in asthma and other inflammatory airway diseases.

From genomes to diaries: a 3-year prospective, real-life study of ragweed-specific sublingual immunotherapy.

During the last decades, the prevalence of allergy has dramatically increased. Allergen-specific immunotherapy is the only currently available medical intervention that has the potential to affect the natural course of the disease, but there are still many questions and unmet needs hindering its widespread use to fulfill its treatment potential and maximize its benefits for the society. To provide a comprehensive phenome-wide overview in sublingual immunotherapy, using ragweed allergy as a target, we planned and carried out a longitudinal, prospective, observational, open-label study (DesensIT). In this paper we present challenges of using deep and comprehensive phenotypes embracing biological, clinical and patient-reported outcomes in allergen-specific immunotherapy and show how we designed the DesensIT project to optimize data collection, processing and evaluation.

[Pharmacogenomics of asthma: present and perspective]. / Az asthma farmakogenomikája: jelen es perspektíva.

One main area of pharmacogenomics is the discovery of new drugs and drug targets with molecular genetic or genomic methods; the other is the study of how genomic differences influence the variability in patients responses to drugs. In this review the authors summarise the most important results of this latter issue. Despite the availability of three major classes of therapeutic agents for asthma, it has been estimated that as many as half of asthmatic patients do not respond to treatment with beta2-agonists, leukotriene modifiers or inhaled corticosteroids. Moreover, in some individuals asthma therapy has been associated with serious adverse drug reactions. An estimated 60 to 80% of variability in individual responses to therapy may have genetic bases. All of the currently available data on asthma pharmacogenomics originated from genetic variations in genes of the drug treatment target or target pathways. Results of genetic association studies that investigate responses to beta2-agonist, leukotriene modifier and corticosteroid therapy will be summarised and recent findings in the literature highlighted. Although, at present pharmacogenomics can explain only a fraction of the adverse drug responses, hopefully these results mark the clinical use of genotyping at an individual level as adjunct to pharmacotherapy for asthma and many other diseases.

[Genomic approach to allergic diseases: present and future perspectives]. / Az allergiás megbetegedések genomikai megközelítése; lehetóségek és távlatok.

The rapid advances in genomic research have a major impact on biomedical sciences. In this review the authors summarize the current results of the genomic investigation of allergic diseases. From a genetic point of view allergy is multifactorial, which means that the susceptibility to the disease is determined by interactions between multiple genes, and involve important nongenetic factors such as the environment for their expression. There are two widespread methods for searching for disease susceptibility genes in allergy: (1) genome-wide search and (2) candidate gene association studies. Until now five groups have completed genome-wide searches for asthma, and almost 500 genetic linkage and association studies have reported more than 500 atopy and asthma loci throughout the genome. In this review we selected those results, which were consistently confirmed by several independent studies, or appeared particularly important, or interesting. On the basis of this, 9 chromosome regions can be associated with the susceptibility to allergic diseases: 2q, 5q31-q33, 6p21.3, 7q31, 11q13, 12q14.3-q24.31, 14q11.2-q13, 16p21, 17q11.2. According to the results of the human genome programs, and association studies, the authors discuss the possible roles of candidate genes found in these loci in the pathomechanism of allergy. Besides, the authors summarize briefly the results of pharmacogenomics, and animal linkage and genetics studies related to allergy.

Novel genes in Human Asthma Based on a Mouse Model of Allergic Airway Inflammation and Human Investigations.

PURPOSE: Based on a previous gene expression study in a mouse model of asthma, we selected 60 candidate genes and investigated their possible roles in human asthma. METHODS: In these candidate genes, 90 SNPs were genotyped using MassARRAY technology from 311 asthmatic children and 360 healthy controls of the Hungarian (Caucasian) population. Moreover, gene expression levels were measured by RT PCR in the induced sputum of 13 asthmatics and 10 control individuals. t-tests, chi-square tests, and logistic regression were carried out in order to assess associations of SNP frequency and expression level with asthma. Permutation tests were performed to account for multiple hypothesis testing. RESULTS: The frequency of 4 SNPs in 2 genes differed significantly between asthmatic and control subjects: SNPs rs2240572, rs2240571, rs3735222 in gene SCIN, and rs32588 in gene PPARGC1B. Carriers of the minor alleles had reduced risk of asthma with an odds ratio of 0.64 (0.51-0.80; P=7×10(-5)) in SCIN and 0.56 (0.42-0.76; P=1.2×10(-4)) in PPARGC1B. The expression levels of SCIN, PPARGC1B and ITLN1 genes were significantly lower in the sputum of asthmatics. CONCLUSIONS: Three potentially novel asthma-associated genes were identified based on mouse experiments and human studies.

Relationship between air pollution, NFE2L2 gene polymorphisms and childhood asthma in a Hungarian population.

Air pollution and subsequent increased oxidative stress have long been recognized as contributing factors for asthma phenotypes. Individual susceptibility to oxidative stress is determined by genetic variations of the antioxidant defence system. In this study, we analysed the association between environmental nitrogen dioxide (NO(2)) exposure and single nucleotide polymorphisms (SNP) in NFE2L2 and KEAP1 genes and their common impact on asthma risk. We genotyped 12 SNPs in a case-control study of 307 patients diagnosed with asthma and 344 controls. NO(2) concentration was collected from the period preceding the development of asthma symptoms. Multiple logistic regression was applied to evaluate the effects of the studied genetic variations on asthma outcomes in interaction with NO(2) exposure. Our data showed that genotypes of rs2588882 and rs6721961 in the regulatory regions of the NFE2L2 gene were inversely associated with infection-induced asthma (odds ratio (OR) = 0.290, p = 0.0015, and OR = 0.437, p = 0.007, respectively). Furthermore, case-only analyses revealed significant differences for these SNPs between asthma patients that lived in modestly or highly polluted environment (OR = 0.43 (0.23-0.82), p = 0.01, and OR = 0.51, p = 0.02, respectively, in a dominant model). In conclusion, our results throw some new light upon the impact of NFE2L2 polymorphisms on infection-induced asthma risk and their effect in gene-environment interactions.

Evaluation of a partial genome screening of two asthma susceptibility regions using bayesian network based bayesian multilevel analysis of relevance.

Genetic studies indicate high number of potential factors related to asthma. Based on earlier linkage analyses we selected the 11q13 and 14q22 asthma susceptibility regions, for which we designed a partial genome screening study using 145 SNPs in 1201 individuals (436 asthmatic children and 765 controls). The results were evaluated with traditional frequentist methods and we applied a new statistical method, called bayesian network based bayesian multilevel analysis of relevance (BN-BMLA). This method uses bayesian network representation to provide detailed characterization of the relevance of factors, such as joint significance, the type of dependency, and multi-target aspects. We estimated posteriors for these relations within the bayesian statistical framework, in order to estimate the posteriors whether a variable is directly relevant or its association is only mediated.With frequentist methods one SNP (rs3751464 in the FRMD6 gene) provided evidence for an association with asthma (OR = 1.43(1.2-1.8); p = 3×10(-4)). The possible role of the FRMD6 gene in asthma was also confirmed in an animal model and human asthmatics.In the BN-BMLA analysis altogether 5 SNPs in 4 genes were found relevant in connection with asthma phenotype: PRPF19 on chromosome 11, and FRMD6, PTGER2 and PTGDR on chromosome 14. In a subsequent step a partial dataset containing rhinitis and further clinical parameters was used, which allowed the analysis of relevance of SNPs for asthma and multiple targets. These analyses suggested that SNPs in the AHNAK and MS4A2 genes were indirectly associated with asthma. This paper indicates that BN-BMLA explores the relevant factors more comprehensively than traditional statistical methods and extends the scope of strong relevance based methods to include partial relevance, global characterization of relevance and multi-target relevance.

Chlamydophila pneumoniae infection status is dependent on the subtypes of asthma and allergy.

This study was undertaken to investigate the association of Chlamydophila pneumoniae infection (CPI) with asthma and allergy. One hundred forty-one patients with asthma aged 3-21 years, 125 healthy controls aged 3-21 years, and 62 allergic but nonasthmatic patients aged 4-20 years participated in this study. C. pneumoniae-specific antibodies were measured by ELISA. There were no significant differences in the percentage of patients positive for C. pneumoniae-specific antibodies between the three groups. Significantly more allergic asthmatic patients were positive for C. pneumoniae-specific IgA and IgA + IgG than nonallergic asthmatic patients, and this difference remained significant after adjustment for age and gender: adjusted odds ratio (OR) = 5.9 (1.7-26.2) and p = 0.01 for IgA, and OR = 5.2 (1.6-25.8) and p = 0.02 for IgA + IgG. The prevalence of the C. pneumoniae-specific IgA and the IgA + IgG positivity also was significantly lower in the nonallergic asthmatic group than in the allergic and control groups (p < 0.005). No food/drug-allergic patient was positive for C. pneumoniae-specific IgA, whereas 41.6% of the inhalative-allergic patients were positive for this antibody (p = 0.002). In our population CPI does not associate directly with asthma and allergy, but chronic or recurrent infection is associated with allergic asthma and inhalative allergy as opposed to nonallergic asthma and noninhalative allergy.

Pediatric asthmatic patients have low serum levels of monocyte chemoattractant protein-1.

Serum levels of MCP-1 were measured in children with and without asthma in order to determine a possible correlation between the MCP-1-2518A/G polymorphism, serum levels of MCP-1 and asthma. Two groups of subjects -160 children with asthma and 158 healthy children were screened with a PCR-based genotyping assay. Serum MCP-1 level was measured by ELISA. The -2518G allele occurred at a significantly higher frequency in asthmatic children than in controls. The mean serum MCP-1 level was significantly lower in the asthmatic than in the control children. There was no significant association between the MCP-1 genotypes and the serum MCP-1 levels.

Involvement of TNFalpha -308A promoter polymorphism in the development of asthma in children infected with Chlamydophila pneumoniae.

Several data indicate a connection between Chlamydophila pneumoniae infection and asthma. Although C. pneumoniae is a common cause of infection, not all infected patients develop asthma. This suggests that certain individuals may be genetically predisposed to the chronic effects of C. pneumoniae infection on airway functions. We investigated the possible modifying effect of different polymorphisms on C. pneumoniae infection and on the susceptibility to asthma in 318 children, among those 144 had asthma and 174 had no asthmatic symptoms. C. pneumoniae-specific antibodies were measured by ELISA. Tumor necrosis factor-alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), and RANTES (regulated on activation normal T cell expressed and secreted) genotypes were determined by PCR-restriction fragment length polymorphism (RFLP). There were no significant differences in the percentage of children positive for C. pneumoniae-specific antibodies between cases and controls. None of the genotypes was associated with altered susceptibility to C. pneumoniae infection. Among asthmatic children carrying the TNFalpha -308A allele, there were significantly more patients positive for C. pneumoniae-specific IgG, than among control children carrying the same allele (20.1% versus 9.2% of asthmatic versus control children, respectively; p = 0.002; odds ratio = 3.52 (1.52-7.53); p = 0.005). This study indicates the possible roles of polymorphisms in the immune system in the susceptibility to asthma in children infected with C. pneumoniae.

The development of asthma in children infected with Chlamydia pneumoniae is dependent on the modifying effect of mannose-binding lectin.

BACKGROUND: Although several studies found associations between infection with Chlamydia pneumoniae and asthma, these were mainly restricted to the exacerbation of the symptoms in adults with known asthma. Data about the role of C pneumoniae in the initiation and development of asthma in children are controversial. OBJECTIVE: We investigated the role of C pneumoniae infection in 139 children with asthma, comparing them with 174 healthy control subjects. Furthermore, we studied the modifying effect of mannose-binding lectin (MBL) variant alleles on the susceptibility to asthma in children infected with C pneumoniae. METHODS: C pneumoniae-specific antibodies were measured by means of ELISA, and MBL genotypes were determined by means of PCR-RFLP. RESULTS: There were no significant differences in the percentage of children with positive results for C pneumoniae-specific antibodies between patients and control subjects. Among asthmatic children carrying variant MBL alleles, there were significantly more patients with positive results for C pneumoniae-specific IgG than among control children with variant MBL genotypes (63.7% vs 40.7% of asthmatic vs control children, respectively; odds ratio adjusted for age and sex, 2.21; 95% CI, 1.10-4.41; P =.02). Infected children with variant MBL alleles were found to have a higher risk of asthma development than infected children with normal MBL genotype. This risk was especially high in children with chronic or recurrent infection (positive results for both IgA and IgG; adjusted odds ratio, 5.38; 95% CI, 1.75-14.36; P =.01), but no increased risk was seen in children with current C pneumoniae infection (positive results for IgM). CONCLUSION: This study indicates the important role of variant MBL alleles in the susceptibility to asthma in children infected with C pneumoniae.