Clearance of severe psoriasis after allogenic bone marrow transplantation.

Case report A 36 year old white man had a 20 year history of severe intractable psoriasis that required numerous admissions to hospital for inpatient treatment. He had long periods of erythrodermic psoriasis and underwent many forms of treatment, including psoralens and ultraviolet A, methotrexate, razoxane, and etretinate, in an attempt to control his psoriasis. In November 1984 he developed acute myelomonocytic leukaemia; remission was speedily induced using combined chemotherapy with cytarabine, daunorubicin, and thioguanine. His leukaemia remitted, but he continued to suffer severe psoriasis requiring treatment with methotrexate. In August 1985 he was conditioned for an allogenic bone marrow transplant with cyclophosphamide 60 mg/kg twice and total body irradiation with 14 Gy given in seven fractions. He received a bone marrow transplant from his brother, who did not suffer from psoriasis. The bone marrow T cells in this transplant were depleted using monoclonal antibodies MBG6 and RFT8, and depletion was greater than 99%. Immediately after the bone marrow transplantation his psoriasis disappeared entirely, and he remained free of it despite cessation of cytotoxic and immunosuppressive therapy. In October 1986 he suffered a relapse of acute myelomonocytic leukaemia. He received a further bone marrow transplant from his brother (this time without depletion of T cells) without induction of remission after chemotherapy with cytarabine and cyclophosphamide. He received cyclosporin at a dose of 400 mg/day after the transplant; the dose was tapered gradually and stopped after 10 months. Since the initial bone marrow transplant he has remained completely free of psoriasis, and he has had no further relapse of his myelomonocytic leukaemia. DNA tvping performed on peripheral lymphocvtes confirmed chimerism, with the DNA type being that of donor.