Ultraviolet-A1 phototherapy modulates Th1/Th2 and Tc1/Tc2 balance in patients with systemic lupus erythematosus

Objective. Ultraviolet-A1 (UVA1) phototherapy is effective for a variety of dermatological diseases. We examined the effectiveness and reliability of low-dose UVA1 phototherapy (60 kJ/m(2)/treatment) in patients suffering from systemic lupus erythematosus (SLE). We studied the changes in immunological parameters. Methods. The patients received a 9-week course of phototherapy according to the following regimen: five times a week during the first 3 weeks, three times a week during the second 3 weeks and twice during the last 3 weeks. Among other things, we analysed the proportions of T helper 1 (Th1), Th2, T cytotoxic (Tc1) and Tc2 cell populations in the peripheral blood of patients by flow cytometric detection of intracytoplasmic interferon gamma (IFN-gamma) and interleukin 4 (IL-4). Results. Our study showed the improvement of clinical symptoms determined by the subjective clinical disease activity scoring and the SLE Disease Activity Index (SLEDAI). By the end of UVA1 phototherapy, the mean value of SLEDAI had decreased from 7.2 +/- 5.6 to 0.9 +/- 1.8, which was significant (P = 0.005). Immunological investigations detected a decrease in the frequency of IFN-gamma-producing Th1 and Tc1 cells and a decrease in the Th1/Th2 and Tc1/Tc2 ratios after UVA1 therapy. Conclusion. According to the literature, IFN-gamma has a pathogenic role in the development of SLE. We observed a decreased proportion of IFN-gamma-secreting cells, which we think is presumably one of the beneficial effects of UVA1 therapy. On the basis of our study, UVA1 phototherapy does seem to be an effective adjuvant in the treatment of SLE patients.