Detection of human histocompatibility (HLA) antigens with an indirect rosette microassay.

An indirect rosette assay which utilizes erythrocytes coupled with purified antiimmunoglobulin (Ig) antibodies was modified into a microassay for detecting HLA allo-and xenoantibodies. The test, which is performed in microtiter plates, is specific, reproducible and can handle large numbers of samples. As an inhibition assay the test can detect HLA antibodies even if mixed with antibodies to other cell surface structures. The rosette microassay is at least 10 times more sensitive than the complement-dependent microcytotoxic test and can use target cells which exhibit low viability or abnormal susceptibility to lysis.