Delivered by Ingenta to: Georgetown University Law Library IP: 95.181.177.126 On: Sat, 11 Jun 2016 01:57:10 Copyright (c) Oceanside Publications, Inc. All rights reserved. For permission to copy go to https://www.oceansidepubl.com/permission.htm Chlamydophila pneumoniae infection status is dependent on the subtypes of asthma and allergy Adrienne Nagy, M.D., Ph.D.,* Ma ´rton Keszei, M.Sc.,# Zolta ´n Kis, Ph.D.,§ Ire ´n Budai, M.D.,¶ Gergely To ¨ lgyesi, M.Sc.,# Ildiko ´ Ungva ´ri, M.Sc.,# Andra ´s Falus, D.Sc.,# and Csaba Szalai, D.Sc.** (Hungary) ABSTRACT 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. (Allergy Asthma Proc 28:58 –63, 2007; doi: 10.2500/aap.2007.28.2957) Key words: Allergic asthma, chlamydia, Chlamydophila pneumoniae, inhalative allergy, nonallergic asthma T he processes of microbial infections are intimately linked to the immune responses of the host in its effort to resolve the infection. Chlamydiae are obligate intracellular bacteria and their ability to persist and elicit chronic immune responses can result in immuno- pathological disease. Murine and human studies sug- gest that Th1 cells and cytokines promote protection from and resolution o, chlamydial infection and dis- ease, whereas Th2 cytokine patterns are associated with persistence and disease. 1,2 Conversely, infection with Chlamydiae also elicits production of special me- diators in the cell that influence its Th1/Th2 balance. 3 Lungs of mice infected intranasally with Chlamydophila (previously Chlamydia) pneumoniae showed prolonged overproduction of interleukin (IL)-4, a Th2 cytokine, one of the main mediators of the allergic diseases. 4 Because of this bidirectional effect between Chlamydiae and the Th1/Th2 balance, and, furthermore, because the predominant Th2-type cytokine response is a char- acteristic feature of allergic diseases, it is a plausible hypothesis that there might be a connection between allergic diseases and chlamydial infection. 3 Asthma is an inflammatory disease of the airways and in the majority of children it also is an allergic disease. 5 C. pneumoniae is a common respiratory patho- gen, and although many infections are believed to be asymptomatic, a growing body of evidence implicates an association between C. pneumoniae infection (CPI) and asthma in some individuals. 8,9 Previously, we have found no direct connection be- tween the disease and C. pneumoniae in children, be- cause the prevalence of the infection was practically the same in children with asthma and in healthy con- trols; however, the difference between the two groups became significant when the subjects were stratified according to their mannose binding lectin genotypes, and C. pneumoniae–specific IgG was considered. Ac- cording to our results CPI may lead to the develop- ment of asthma in genetically predisposed children carrying mannose binding lectin variant alleles. 7 Nev- ertheless, the connection between asthma and C. pneu- moniae usually is not explained by the effect of the infection on allergy but rather by the observations that asthma is a chronic inflammatory disease of the air- From the *Buda Children’s Hospital, Budapest, Hungary, #Department of Genetics, Cell Biology, and Immunobiology, Semmelweis University, Budapest, Hungary, §Na- tional Center of Epidemiology, Budapest, Hungary, ¶Institute of Medical Microbiol- ogy, Semmelweis University, Budapest, Hungary, Immunogenomics Research Group, Hungarian Academy of Sciences, Budapest, Hungary, and **Heim Pa ´l Pediatric Hospital, Budapest, Hungary Supported by grants OTKA (National Scientific Research Fund) T031887, T046372, and TS/2 044707; the Hungarian Ministry of Welfare ETT 134/2001 and 134/2003; and Ja ´nos Bolyai Research Grant. Address correspondence and reprint requests to Csaba Szalai, Heim Pa ´l Pediatric Hospital, P.O. Box 66, Budapest, Hungary H-1958 E-mail address: szalai@heimpalkorhaz.hu Copyright © 2007, OceanSide Publications, Inc., U.S.A. 58 January–February 2007, Vol. 28, No. 1