Biological Significance of Ss (Serum Soluble) HLA-Class I Antigens in Bone Marrow Transplantation

: Ss (serum soluble) HLA-class I antigens were investigated in 10 cases of bone marrow transplantation and the relationships among Ss HLA antigens, lymphocyte counts, GvHD and the clinical course were compared. Cs (cell surface) HLA antigens were typed by the NIH standard microcytotoxicity test. Measurement of Ss HLA antigens was performed by both the lymphocytotoxicity inhibition test and solid phase RIA. A good correlation was found between the cytotoxicity inhibition test and solid phase RIA. No correlation was observed between lymphocyte counts and changes in the Ss HLA antigens in the presence of GvHD. In cases with GvHD, Ss HLA antigens were found to correlate with the GvHD. Ss HLA antigens also correlated with levels of lymphocyte counts in cases without GvHD. Ss HLA antigens are an important marker of biological significance in GvHD following bone marrow transplantation.