No effect of mycobacterial antigens and immunological memory on the production of cytokines and IgE in response to Dermatophagoides pteronyssinus

INTRODUCTION: Allergic respiratory diseases such as asthma and rhinitis, affecting a high proportion of the Brazilian population. More than 58.000 people have been affected by some of these conditions in Brazil in 2002-2003. Studies in humans and animals suggest that environmental exposure to Mycobacterium tuberculosis or immunization with Mycobacterium bovis (BCG), may be related to protection against allergic diseases. OBJECTIVE: To investigate the influence of Th1 response to mycobacterial antigens on the modulation of Th2-type response to aeroallergen Dermatophagoides pteronyssinus (Derp). METHODS: The study comprised two phases. To evaluate the effect of the response to revaccination with BCG on the modulation of a Th2-type response to Derp, we conducted a randomized intervention study with prospective cohort, and the volunteers composed the Sample 1. To evaluate the effect of latent response to infection with M. tuberculosis on the modulation of a Th2-type response to Derp, a study was made of case-control and the volunteers composed the Sample 2. The population consisted of young adults aged 19 to 33 years. All responded to questionnaire ISAAC modified. Blood sampling was performed for quantification of total IgE, specific IgE to D. pteronyssinus and cytokine responses Th1/Th2/inflamatória. RESULTS: No significant differences in cytokine production or levels of total and specific IgE to Derp between atopic and non-atopic groups of the two samples. CONCLUSIONS: There were no differences regarding cytokine production, total and specific IgE to Derp, between the control group and revaccinated or between infected and uninfected individuals indicating that contact with mycobacteria not seem to affect the allergic response in adults young.