The immunologic relationship between Th-1 type autoimmune disorders and Th-2 type allergic disorders and the role of T-cell regulation (Treg) in humans in both disorders is as yet unclear. This study examined the production capacity of IL-10 and TGF-beta levels, 2 Treg cytokines, in individuals with concomitant Th-1 autoimmune and allergic rhinitis (AR) diagnoses. Levels were compared to individuals with only AR and with neither diagnosis.

17 case subjects along with age, gender and ethnicity matched controls with only AR diagnoses were recruited from an allergy clinic. Matched normal controls with neither diagnosis were recruited from the general population. Peripheral blood mononuclear cells were obtained and cultured with and without mitogen (phytohemagglutinin) stimulation. Cytokine levels from culture supernatants were measured via ELISA.

Cases had significantly lower unstimulated 3 day IL-10 levels compared to allergic controls and significantly lower stimulated 5 day TGF-beta levels compared to normal controls. Cases had consistently lower Treg capacity compared to both allergic and normal controls as measured by an additive index using both IL-10 and TGF-beta levels.

This study has demonstrated that individuals with concomitant Th-1 type autoimmune disorders and AR have lower immune regulatory capacity when compared to individuals with AR only and with neither diagnosis. The results of this investigation have important implications in tolerance immunology as it suggests a role for Treg in the immune dysregulation seen in allergic and autoimmune diorders.