Lymphocyte subset counting by immunoperoxidase using an automated routine hematologic analyzer.

Using monoclonal antibodies against CD2, CD4, CD8 and CD19 antigens and an automated biotin-avidin immunoperoxidase technique on whole blood samples, we evaluated the technical performance and clinical usefulness of lymphocyte subset counting by the routine hematology analyzer Technicon H1. Statistical evaluation demonstrated excellent precision and very good correlation with the immunofluorimetric flow cytometer Ortho Spectrum III. Correlation between manual immunofluorescence at the microscope and the H1 method was much poorer, owing to the high intrinsic imprecision of the manual method. Reference ranges obtained with the H1 immunoperoxidase method in 44 healthy subjects closely matched those obtained with the Spectrum III. In 46 subjects with or at risk for HIV infection, we found with the H1 method a significant decrease in CD4+ cells and in the CD4+/CD8+ cell ratio, which was progressively more marked in HIV- negative patients with lymphadenopathic syndrome, AIDS-related complex, and in patients with full-blown AIDS.