Background and objective: T1DM and asthma are mediated by opposite arms of the cellular immune system namely T helper (Th)1 and Th2 CD4(+) cells, respectively. Our aim was to characterize the Th1/Th2 cytokine balance in patients with both T1DM and asthma.
Methods: Forty-four patients, mean age 19 years were matched by gender and age, to 4 paired groups: T1DM and asthma, asthma only, T1DM only and healthy controls. Peripheral blood mononuclear cells (PBMC) were stimulated in vitro with disease-specific recombinant antigens; glutamic acid decarboxylase and house dust mite (Der p1 antigen) for T1DM and asthma, respectively, and non-specific mitogens; phytohemaglutinin (PHA), tetanus toxin and anti-CD3 mAb. ELISPOT and ELISA technique were used to determine INF-gamma, IL-2, IL-4, IL-13 and IL-10 expression.
Results: Patients with T1DM and asthma demonstrated a similar cytokine pattern but lower Th1/Th2 ratio compared to patients with T1DM only. The Th2 cytokines response to Der p1 was enhanced in patients with both diseases compared to controls. The IL-10 overall secretion was higher in patients with both diseases compared to one disease only.
Conclusion: The Th1 and Th2 secretory pattern of patients with T1DM and asthma combines features of both diseases suggesting a unique Th1/Th2 balance.