Antibodies to granulocytes in patients infected with human immunodeficiency virus

Individuals who are infected with human immunodeficiency virus (HIV) are known to have a high incidence of autoantibodies. In this study, serum samples from 100 individuals with HIV infection were tested for granulocyte antibodies (red cell antibodies, lymphocytotoxic antibodies, circulating immune complexes, and serum immunoglobulin G levels) by granulocyte agglutination (GA) and granulocyte immunofluorescence (GIF) assays. Granulocyte antibodies were detected in 66% of serum samples by GIF and in 21% of serum samples by GA. None of the positive sera reacted with granulocyte antigens of known specificity. Antibodies that reacted with red cell antigens other than ABO were detected in only three serum samples, but lymphocytotoxic antibodies were detected in 62% of patients. All serum samples were tested by immunoblotting with granulocyte plasma membranes. Only two samples were found to be positive; one sample reacted with a 58 kd protein and one reacted with a 55 kd protein, but neither serum sample immunoprecipitated any protein from granulocytes that were labeled at the cell surface with iodine 125. Since immune complexes that are bound to granulocyte membranes can be detected by GIF, circulating immune complex levels were measured in all 100 samples. Immune complexes were increased in GIF-reactive serum samples compared with GIF-nonreactive serum samples (23.3 +/- 19.5 micrograms Eq/ml [mean +/- SD] vs 9.6 +/- 8.1 micrograms Eq/ml, p less than 0.001) but not in GA-reactive serum samples compared with GA-nonreactive sera (24.4 +/- 21.3 micrograms Eq/ml versus 16.9 +/- 16.0 micrograms Eq/ml, p = 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)