Chlamydia pneumoniae enhances the Th2 profile of stimulated peripheral blood mononuclear cells from asthmatic patients.

Chlamydia pneumoniae is a cause of respiratory infection in adults and children. There is evidence for an association between atypical bacterial respiratory pathogens and the pathogenesis of asthma. We compared T helper (Th) responses in C. pneumoniae - infected peripheral blood mononuclear cells (PBMC) in patients with or without asthma. PBMC (1×10(6)/mL) from asthmatic patients (N=11) and non-asthmatic controls (N=12) were infected or mock-infected for 1h +/- C. pneumoniae TW-183 at a multiplicity of infection (MOI)=1 and MOI=0.1, or cultured for 24h +/- Lactobacillus rhamnosus GG (LGG). Interleukin (IL)-4, IL-10, IL-12, Interferon (IFN)-gamma and total IgE levels were measured in supernatants (ELISA). C. pneumoniae infection led to an increase (>50%) of IgE levels in PBMC from asthmatics, compared with mock-infected on day 10; IgE wasn't detected in non-asthmatics. C. pneumoniae - infected PBMC from asthmatics increased levels of IL-4 and IFN-gamma after 24h, compared with PBMC alone; levels of IL-10 and IL-12 were low. When uninfected-PBMC from asthmatics were LGG-stimulated, after 24h, IL-4 was undetectable, but IL-10, IL-12, and IFN-gamma increased, compared with PBMC alone. Thus, C. pneumoniae infection has the ability to induce allergic responses in PBMC of asthmatics, as evidenced by production of Th2 responses and IgE.

Correlation of plasma complement split product levels with allergic respiratory disease activity and relation to allergen immunotherapy.

BACKGROUND: Allergens, including dust mite and grass pollen, and mast cell tryptase are known to generate the complement split products (CSPs) C5a and C3a, which can then trigger allergic inflammation. The relation of these anaphylatoxin levels to clinical allergic disease responses is not known. OBJECTIVE: To evaluate the relationship of plasma CSP levels to allergic respiratory disease variables in an adult cohort. METHODS: A cross-sectional survey was used to assess the association of plasma C5a desArg and C3a desArg levels with clinical allergic respiratory disease variables. Furthermore, a time course of the effect of routine allergen immunotherapy on plasma CSP levels and cutaneous and pulmonary responses was determined. RESULTS: Adult plasma C5a desArg levels correlate with asthma severity as determined by a physician (P = .01) and by Asthma Quality of Life Questionnaire scores (P < .01). Change in plasma C5a desArg levels 1 hour after immunotherapy is associated with baseline rhinoconjunctivitis symptom severity (P = .03), change in total mean wheal diameter (P = .05), and total dust mite dosage (P = .04). Change in plasma C3a desArg levels 3 hours after immunotherapy correlates with change in total mean wheal diameter induced by dust mite (P = .01). Change in plasma CSP levels after immunotherapy did not correlate with change in spirometric outcome. CONCLUSIONS: Plasma C5a desArg levels reflect allergic respiratory disease severity as assessed by physicians and correlate with Asthma Quality of Life Questionnaire scores. Changes in CSP levels after immunotherapy reflect cutaneous allergic responses, especially to dust mite allergen.