Spectrum and immunophenotyping of 653 patients with B-cell chronic lymphoproliferative disorders in China: A single-centre analysis

The incidence of B-cell chronic lymphoproliferative disorders (B-CLPDs) is significantly lower in China than that in western countries. There have been studies involving small cohorts with conflicting results regarding the spectrum of B-CLPDs in China, and the types and immunophenotyping of B-CLPDs in China remain largely unexplored. We conducted a retrospective analysis of 653 cases of B-CLPDs seen in our centre from 2011 to 2015. Four-colour flow cytometry was used to determine the expression of each immunological marker, and the diagnostic values of the immunological markers were also investigated. Chronic lymphocytic leukaemia (CLL) was the most common type of B-CLPD, which was consistent with that in west countries. However, the proportions of CLL (55.9%), follicular lymphoma (2.6%), and hairy cell leukaemia (0.2%) were lower, while the proportion of lymphoplasmacytic lymphoma/WaldenstrÖm macroglobulinaemia (5.4%) was higher in China, as compared with western countries. With respect to immunophenotypic characteristics, CD23 (31.7%) was more frequently expressed in mantle cell lymphoma (MCL) in our cohort than that in western countries. Immunophenotyping was useful in differentiating MCL from CLL or B-cell prolymphocytic leukaemia and lymphoplasmacytic lymphoma/WaldenstrÖm macroglobulinaemia from splenic marginal zone lymphoma. CD200 was of better diagnostic performance (accuracy: 94.6%) in differentiating CLL from MCL compared with CD23 (accuracy: 93.3%). Some cases of B-CPLDs, however, had no definite diagnoses, which were diagnosed as CD5⁺ B-CPLDs unclassified (7.7%) and CD5^- B-CPLDs unclassified (15.8%). This is the largest study that systematically explores the spectrum and immunophenotyping of B-CLPDs in Asia, confirming that spectrum of B-CLPDs in China was different from that in western countries. The immunophenotypic features of B-CLPDs were similar between China and western countries, although a few disparities exist. Cases with no definite diagnoses warrant further studies in the future.