Photopheresis at onset of type 1 diabetes: a randomised, double blind, placebo controlled trial

Background-In recent years photopheresis, an extracorporeal form of photoch emotherapy using psoralen and ultraviolet A irradiation of leucocytes, has been claimed to be an effective form of immunomodulation. Aim-To evaluate its effect in type 1 diabetes we performed a double blind, controlled study using placebo tablets and sham pheresis in the control gro up. Methods-A total of 49 children, aged 10-18 years of age at diagnosis of typ e 1 diabetes were included; 40 fulfilled the study and were followed for th ree years (19 received active treatment with photopheresis and 21 placebo t reatment). Results-The actively treated children secreted significantly more C peptide in urine during follow up than control children. C peptide values in serum showed corresponding differences between the two groups. The insulin dose/ kg body weight needed to achieve satisfactory HbA1c values was always lower in the photopheresis group; there was no difference between the groups reg arding HbA1c values during follow up. The treatment was well accepted excep t for nausea (n = 3) and urticaria (n = 1) in the actively treated group. T here were no differences regarding weight or height, or episodes of infecti on between the two groups during follow up. Conclusion-Photopheresis does have an effect in addition to its possible pl acebo effect, shown as a weak but significant effect on the disease process at the onset of type I diabetes, an effect still noted after three years o f follow up.