CD71 by flow cytometry as a diagnostic marker to differentiate between aggressive and indolent B-cell lymphomas

Introduction: Flow cytometry is important in diagnosis and classification of mature B-cell neoplasms; however, differentiating indolent and aggressive lymphomas by flow cytometry can be challenging. The transferrin receptor CD71 mediates cellular iron uptake; an essential element of proliferation. This study looks at CD71 expression by flow cytometry in B-cell lymphomas to assess its use in differentiating between aggressive and indolent lymphomas. Methods: From January to October 2018 results from flow cytometry, including CD71, were collected and correlated with the histopathologists’ final diagnosis of 122 clonal B-cell neoplasms. The expression of CD71 by flow cytometry and the median fluorescent index (MFI) was determined. When results of Ki-67 index performed by immunohistochemistry (IHC) on tissue samples were available, these were correlated with CD71 MFI. The mean expression of CD71 for each histological diagnosis was defined. Statistical significance was assessed using the Student t-test, Pearson and Spearman coefficients, and by ROC curve analysis. Results: The expression of CD71 correlated with a histological diagnosis of aggressive lymphomas particularly diffuse large B-cell lymphoma (DLBCL). Correlation between CD71 by flow cytometry and Ki-67 index showed a positive relationship between MFI and a high Ki-67 index. Conclusions: CD71 by flow cytometry has the potential to contribute to the classification of lymphomas with correlations between the expression of CD71 and the diagnosis of aggressive B-cell lymphoma and between CD71 expression and the Ki-67 index.