Evaluation of Diagnostic Usefulness of CD200 Expression in B-cell Chronic Lymphoproliferative Disorders.

Immunophenotyping by flow cytometry (FCM) is a useful diagnostic tool for the evaluation of mature B-cell neoplasms (MBN). Here, CD200 expression may play a significant role and improve the distinction between various MBNs, but any potential as a prognostic marker is yet to be established. The present prospective study was conducted on all the suspected cases of MBNs. Immunophenotyping was done using a BD FACS Canto FCM using a panel of 4 to 6 color combinations of monoclonal antibodies; CD45, CD34, CD5, CD19, CD20, CD22, CD23, CD79b, FMC7, CD10, CD38, ZAP70, CD200, IgG, IgM, CD25, CD103, CD2, CD3, CD11c as well as κ and λ light chains. CD200 expression was compared in different subgroups. Of the total of 130 cases included in the study, CD200 was positive in 118 cases (90%). CD200 was expressed in 100% of the cases of CLL(86 cases), atypical CLL(06 cases), HCL(14 cases), FL(02 cases), SMZL(04 cases), LPL (01 case), and low-grade NHL (05 cases), with the highest intensity of fluorescence in HCL followed by CLL. All the cases of MCL and PLL were exclusively negative for CD200. In conclusion, the results of the present study support inclusion of this marker in the flow cytometric panels for the differential diagnosis of MBNs.