Th2-mediated atopic disease protection in Th1-mediated rheumatoid arthritis

The balance between CD4+ T-helper (h) cell subsets (Th1 and Th2) plays an important role in the pathogenesis of rheumatoid arthritis (RA) and atopy. While RA is believed to be a Th1 mediated disease, Th2 cells predominate in atopic disorders. The purpose of this study was to investigate differences in the occurrence of allergy, hay fever, house dust mite sensitivity and asthma, as well as total serum IgE levels in RA patients and controls.

The case history of atopic disorders was assessed in 134 RA patients and compared to those found in 305 healthy blood donors. RA patients also answered clinical questions concerning disease activity and severity. Total serum IgE levels were measured in both groups, taking into consideration disease modifying therapy.

A significantly lower occurrence of medical history of hay fever (2.3%) and house dust mite sensitivity (3.1%) was found among RA patients compared to controls (24.2% and 12.2%, respectively; p < 0.0001 and p < 0.003 respectively). Moreover, RA patients had significantly lower total serum IgE levels than control subjects (p < 0.0001). RA was less severe in patients with atopy compared to non-atopic RA patients.

These results support the concept that RA and atopy antagonize each other and that a change in the cytokine patterns of Th1 and Th2 cells could provide an indication for curative effects on RA.