Detection by flow cytometry of antibodies against surface and intracellular granulocyte antigens

A flow cytometric technique was used to detect granulocyte antibodies. with attention to the distinction between antibodies directed against surface a nd intracellularly expressed antigens. Ten serum samples with positive resu lts acid 10 with negative results detected by the granulocyte immunofluores cence test (GIFT), together with 10 positive serum samples detected by an i ndirect immunofluurescence test (IIF) were analyzed against leukocytes from healthy blood donors tested by Row cytometry (FC). Unpermeabilized and per meabilized cells were used to allow identification of surface and intracell ular binding, respectively. The results of testing by GIFT corresponded wit h those by FC, with the exception of the results for four sera: one serum s ample was FC negative, GIFT positive. and three samples were FC positive, G IFT negative. The IIF-positive sera were all FC positive, analyzed against permeabilized granulocytes, and one serum was also positive against non-per meabilized granulocytes. Analysis by FC is a readily performed technique, w hich can be used for the routine detection of antibodies against leukocyte antigens. Screening for granulocyte-specific antibodies can be carried out with pools of granulocytes from three donors. Analysis by FC allows detecti on of both HLA antibodies and granulocyte-specific antibodies and by using both unpermeabilized and permeabilized cells, antibodies against surface an d intracellular antigens. respectively, can be identified.