A solid phase urease-linked cellular immunosorbent assay for circulating polymorphonuclear binding immunoglobulin

A cellular enzyme linked immunosorbent assay (CELISA) is reported for the detection of circulating polymorphonuclear granulocyte binding immunoglobulin (PBG) in patients' sera. The assay features a solid phase microtiter method in which the enzyme urease is fixed to the antihuman globulin conjugate reagent and uses 0.25 percent glutaraldehyde fixed normal human polymorphonuclear neutrophils (PMNs) as target cells. The assay gave positive results in four of 13 (31 percent) cases of idiopathic neutropenia in which an autoimmune etiology was suspected and one typical case of isoimmune neonatal neutropenia. In a group of 15 patients receiving multiple blood transfusions for chronic anemia, five (33 percent) showed significantly higher levels (p less than 0.001) of PBG than non-transfused normal donors. The PBG-CELISA appears potentially useful for the detection of autoimmune and isoimmune PMN antibodies and PMN binding IgG immune complexes.