Quantitation and estimation of lymphocyte subsets in tissue sections. Comparison with flow cytometry.

A quantitation method for lymphocyte subsets in immunoperoxidase-stained frozen tissue sections was compared with flow cytometry in 23 cases of non-Hodgkin's lymphoma. Close correlations were obtained, demonstrating the accuracy of the technic. Weak intensity of fluorescence and fragility of the tumor cells during the fluorescence-activated cell sorter (FACS) analyses were the most likely explanations for a number of the discrepancies observed. The tissue quantitation method was precise, particularly at low values, where it was better than the FACS. A simpler and faster estimation method employing categories within 10 percentage units was also tested in this study; this method correlated as well with the FACS as the quantitation method and gave the best interobserver correlations.