Blood-group antigens and antibodies in human brain-tumor cysts.

Cyst fluids from 12 human brain tumors were studied for their blood-group content and compared to autologous saliva, serum, and cerebrospinal fluid (CSF). Lewisa substance, which is a fucolipid, was present in four of 12 cysts studied. Lewisb, which differs from Lewisa by a single fucose, was found in eight of 12 sera and/or saliva and in one CSF specimen; Lewisb substance, however, was not detected in any corresponding cyst fluids. Isohemagglutinins, blood-group antibodies anti-A and/or anti-B, were present in nine of nine cyst fluids studied, were of lower titers as compared to autologous serum, and occurred as either IgG or IgM immunoglobulins. The results further delineate the biochemical requirements necessary for molecular penetration into human brain-tumor cysts.