Flow cytometric method for the routine follow‐up of red cell populations after bone marrow transplantation

A simple and sensitive flow cytometric method is presented for the quantitation of erythrocyte subpopulations. Cells were indirectly labelled using human antisera (mostly crude) and fluorescein isothiocyanate (FITC)-conjugated anti-human IgG Fab. The method was evaluated by analysing artificial mixtures of blood group antigens A, B, D, E, c, K and Fy(a). Intra-assay coefficients of variation were found to be 7.2% for 1% D-positive mixtures and 2.2% for 10% D-positive mixtures: the inter-assay coefficients of variation were 9.5% and 6.0% respectively. The sensitivity of the method was found to be 0.31%. The method has shown to be suitable for the routine follow-up of patients after allogeneic bone marrow transplantation (BMT).