Correlation of monoclonal antibody phenotyping and cellular DNA content in non‐Hodgkin's lymphoma. The southeastern cancer study group experience

Flow cytometric measurements of DNA ploidy and synthetic (S) fractions are quantitative parameters that can aid in the diagnosis and classification of non‐Hodgkin's lymphomas (NHL). Although the S‐fraction correlates with histologic classification, the relationship between specific immunologic phenotypes and DNA ploidy is less well known. We investigated this relationship in 106 cases of NHL. Samples from 17 SEG institutions were sent for flow cytometry and for frozen section immunoperoxidase phenotyping. DNA histograms were analyzed for ploidy changes and cases classified by degree of abnormality. Ninety‐eight cases were B‐cell and eight were T‐cell. B‐cell tumors were subdivided by expression of antigens CD24, CD10, CD5, HB31, CD22, CD20, and transferrin receptor. Among B‐cell tumors there was no correlation between degree of aneuploidy and phenotype, but B‐cell tumors displayed a higher degree of aneuploidy than T‐cell tumors (P < 0.02). There was no difference between the S‐fractions of B‐cell and T‐cell lymphomas. However, the transferrin receptor was more often expressed when the S‐fraction was higher than 5%. Cases with S‐fractions higher than 5% were more likely to lack any of the Pan‐B antigens CD19, CD22 or CD20, and also were more frequently CD24 negative. We conclude that T‐cell and B‐cell NHL differ in degree of aneuploidy, and that monoclonal antibody phenotyping and DNA ploidy analysis independently define subgroups of B‐cell NHL. Within B‐cell lymphomas phenotype also correlates with grade of NHL as defined by the S‐fraction.