Quantification of Complement Receptor 1 on Erythrocytes: Follow‐Up of HIV‐1‐Infected Patients with AIDS‐Related Complex/Walter‐Reed 5 under Treatment with Intravenous Immunoglobulin

摘要

Abstract.A sensitive flow‐cytometric method was established to quantify the number of complement receptor 1 (CR1, C3b/C4b receptor, CD35) on the surface of purified erythrocytes of 12 patients infected by HIV‐1 and showing two clinical AIDS‐related complex/Walter‐Reed 5 criteria. Erythrocytes were incubated with biotinylated monoclonal anti‐CR1 antibody followed by phycoerythrin‐streptavidin before analysis on a flow cytometer. As few as 50 binding sites/cell could be detected, making this method as sensitive as a radioimmunoassay with125I anti‐CR1. Seven of the patients studied received an imunoglobulin preparation suitable for intravenous use during the first 6 months of the study, 5 got an equal amount of a placebo preparation consisting of human serum albumin. For a year, erythrocytes were collected and purified every 3 months, frozen and stored at ‐70°C until the end of the study, when the number of CR1 was determined. No difference between the two groups of patients was found. In 8 patients, small fluctuations of the amount of CR1/ erythrocyte were seen during the period of observation, whereas in 4 of the patients a drop of the number of CR1 was observed towards the end of the study. No correlation was found between CR1 numbers on erythrocytes and circulating immune complexes, CH50, C3 and C4 concentrations or CD4‐po