1. From Okubo Municipal Hospital, Shinjuku-ku, Tokyo, the Immunology Division, Jichi Medical School, Tochigi-ken, and the Third Department of Internal Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan (address reprint requests to Dr. Makoto Mayumi at the Immunology Division, Jichi Medical School, Tochigi-ken 329–04, Japan).