Longterm ultraviolet-A1 irradiation therapy in systemic lupus erythematosus

In a recent series of short term studies ultraviolet-A1 (UV-A1; 340-400 nm) dermal irradiation proved effective in reducing signs and symptoms of disease activity in patients with systemic lupus erythematosus (SLE). To determine if the effectiveness persisted with longterm therapy, we followed the progress of 6 of these patients for an average of 3.4 (range 2.4-4.5) yrs. The 6 had had significant decreases in signs and symptoms of disease activity during the first 12 weeks of the earlier studies while receiving 3 to 5 low dose UV-A1 irradiations weekly and were asked to continue into longterm therapy.

Longterm therapy consisted of 1 or 2 irradiations of 6-15 J/m2 (15-30 min, or about 1/8-1/4 minimal erythema dose) per week. We assessed their progress every 3 mo with the systemic lupus activity measures.

Despite the smaller number of weekly treatments, the gains achieved during the initial 12 weeks of the early studies not only persisted but increased slightly. Tanning was moderate to absent, the therapy was well tolerated, and there was no apparent toxicity.

UV-A1 radiation induced remissions in SLE persist with longterm therapy; 1 or 2 weekly exposures suffice; there appears to be no significant toxicity.