Associations of specific histocompatibility antigens with certain human diseases may elucidate basic mechanisms of disease. Since there is evidence for a disordered immune response in MLNS, HLA antigens were evaluated by NIGH standard technique in 27 patients (3 Oriental, 1 black) fulfilling CDC criteria for MLNS. In contrast to previous Japanese studies, we found no incidence of HLA-Bw22. We did, however, find a significant increase in HLA-Bw51: CHANCES OF DISTRIBUTION OF HLA PHENOTYPES IN CAUCASIANS To our knowledge, this is only the second disease associated with HLA-B5 specificity. In preliminary studies, 10/17 Caucasian patients with MLNS were DR-2 (frequency in control population 23%, p