[Decrease of erythrocyte receptors for the C3b fragment of complement in acquired immunodeficiency syndrome].

The number of C3b receptors (CR1) on erythrocytes (E) was measured, using a newly developed flow cytometry assay and a standard radioimmunoassay, in HIV-infected individuals and in a normal control population. The number of CR1/E was significantly decreased in symptomatic HIV-infected patients with ARC and acquired immunodeficiency syndrome and was normal in asymptomatic carriers of anti-HIV antibodies. Decreased numbers of CR1/E correlated with the clinical severity of the HIV-related disease. A close correlation was found between results obtained with flow cytometry and those obtained with the radioimmuno-assay. Flow cytometric assessment of CR1/E may be of interest in large scale prospective clinical studies of HIV-infected subjects.