Granulocyte-rosette assay for detection of anti-lymphocyte antibodies.

It is well known that the serum of SLE patients contain anti-lymphocyte antibodies (ALA). In this paper we present a new rosette-forming assay for investigation of ALA. The method is based on the first step of antibody dependent cellular cytotoxicity (ADCC): the adherence of Fc-receptor bearing effector cells to the lymphocytes coated by antibodies. SLE serum samples were tested simultaneously by the new method (the rosette-test, RT) and the microcytotoxicity test (MCT) based on the complement mediated lysis. The results obtained by use of MCT and RT showed that the latter is suitable for investigation of ALA, indeed its diagnostic parameters are better than those of MCT. Moreover these results suggest that the two tests may differ in the antibody class detected. The new method is simple, time saving and demands no 51Cr-isotope as other ADCC tests do.