Antibody-dependent lymphocyte-mediated granulocytotoxicity (ADLG) for the detection of granulocyte antibodies

An antibody-dependent cell-mediated granulocytotoxic assay (ADLG) has been developed to detect antibodies to human granulocytes. This study examines some possible variables in this assay, the ADLG activity in serum from normal individuals, the contribution of ABO isohemagglutinins and the sensitivity and specificity of this technique. Significant differences in percentage cytotoxicity of ABO compatible and incompatible cell/serum combinations were detected in the normal population. Human serum with antibodies to the neutrophil specific antigens NA1 and NB1 gave positive results in the ADLG assay. However, differences in sensitivity and specificity were observed among various sera. ADLG activity was dependent on the source of effector cells. Effector and target cells stored in vitro were unsatisfactory in this assay. The ADLG assay may be a valuable addition to existing granulocyte serological methods and provide useful clinical information on mechanisms of immune neutropenias.