Diversity and complexity of mouse allergens in allergenic products assessed with an immuno‐allergomic approach: 64

Abstract

S A T U R D A Y Sue L. Dong, Tamar A. Smith-Norowitz, PhD, Margaret R. Hammerschlag, MD, Rauno Joks, MD, and Stephan A. Kohlhoff, MD; SUNY Downstate Medical Center, Brooklyn, NY, SUNY Downstate Medical Center, Dept of Pediatrics, Brooklyn, NY, SUNY Downstate Medical Center, Dept of Medicine, Brooklyn, NY. RATIONALE: C. pneumoniae is a common cause of upper and lower respiratory tract infections in both children and adults and can cause asthma exacerbations. Our laboratory has previously demonstrated that T-lymphocyte memory responses of PBMC infected withC. pneumoniae in vitrowas increased in asthmatics compared to healthy subjects without asthma. However, there were both Th1 and Th2 responses present in the asthmatic population. In this investigation, we studied differences in the Th response (Th1 versus Th2) to C. pneumoniae infection of PBMC between pediatric and adult patients with asthma. METHODS: PBMC (1x10/ml) from pediatric (<18y) (n515) and adult (>518y) (n59) asthmatics were infected or mock infected with C. pneumoniae CM-1 and cultured for 48h. Levels of IL-4 and IFN-gamma in supernatants were measured by ELISA. Cytokine levels of mock infected sampleswere subtracted from those of infected samples for each study subject. Differences between age groups were determined by Mann-Whitney Test. RESULTS: PBMC from asthmatic adults produced more IL-4 in response toC. pneumoniae stimulation than those from asthmatic children (p<0.01). There was no significant difference in IFN-gamma production after C. pneumoniae infection between the two study groups (p50.9). CONCLUSIONS: We found that a C. pneumoniae-induced Th2 immune profile was prevalent in adult asthmatics, but not in pediatric asthmatics. Repeated or persistent infections with C. pneumoniae can occur and repeat exposure may lead to change in Th response with increasing age in predisposed individuals. Whether this age-specific response to C. pneumoniae contributes to the symptomatology of asthma remains to be further elucidated.