Immunological and Clinical Effects of Alphacalcidol in Patients with Psoriatic Arthropathy: Results of an Open, Follow-up Pilot Study

The aim of this study was to describe the effect of systemic alphacalcidol (1 alpha OH vitamin D-3) treatment on clinical and immunological parameters in patients with psoriatic arthropathy. Among the 19 patients investigated, 10 were treated with 0.25 mu g oral alphacalcidol twice daily for 6 months, while 9 other patients served as controls. In the peripheral blood of the treated group but not in the controls, a statistically significant decrease was observed in the percentage of CD3/CD69-positive activated and CD8-positive interferon-gamma-producing T cells and in the serum level of interferon-gamma during the first 3 months and also in the clinical activity of the disease during the whole 6-month follow-up period. Our results show that systemic alphacalcidol treatment has an immunomodulatory effect on patients with psoriatic arthropathy. This effect is manifested by a short-term temporary decrease in type 1 immune responses and a continuous decrease in disease activity.