ROLE AND RELEVANCE OF THE EUROFLOW ANTIBODY PANEL IN IMMUNOPHENOTYPING OF CHRONIC LYMPHOPROLIFERATIVE DISORDERS

Detection of phenotypically aberrant and clonal mature lymphocytes is the diagnostic hallmark of chronic lymphoproliferative disorders (CLPD). B-CLPD is the commonest of all the CLPD. In this study we evaluated the role of CD200 and CD43 new markers that have been introduced in the Euroflow panel in the separation between chronic lymphocytic leukemia (CLL) and all other mature B cell malignancies .These markers were also correlated with the markers used in the Matutes score like FMC7 and Surface membrane Immunoglobulin. Patient samples between October 2017-February 2018, peripheral blood or bone marrow aspirates of patients with suspected B-cell lymphoproliferative disorders were subjected to evaluation by flow cytometry. After washing, samples were stained by antibodies targeting the antigens CD45, CD19, CD5, CD10, CD20, CD23, CD43, CD79b, CD200, FMC7, CD25,CD103 ,CD11c ,sIgM, kappa and lambda . Immunophenotyping was performed using a BD FACS Canto flow cytometer. There were a total of 108 cases of B CLPD that were analysed by flow cytometry . Mean age (SD ) was 65 years. There were 68 males and 40 female patients . There were 71 cases of typical CLL , 7 cases of atypical CLL , 3 cases of Mantle cell lymphoma (MCL) , 5 cases of Follicular lymphoma ( FCL ) , 8 cases of Splenic lymphoma with villous lymphocytes (SLVL) , 6 cases of Hairy cell leukemia ( HCL) , 6 cases of unclassifiable B-NHL and 2 cases of lymphoplasmacytic lymphoma. All our cases of typical CLL showed bright expression of CD200 .It was also brightly expressed in all our atypical cases of CLL . CD43 was brightly positive in all our cases of typical CLL . The expression of this marker along with CD200 negativity was helpful in diagnosing of MCL.There were diagnostic difficulties in differentiating atypical CLL from B-NHL unclassifiable. The lack or dim expression FMC7 expression in all these cases along with absent or dim expression of sIgM were informative. Their use along with the panel by Euroflow is suggested to provide an accurate diagnosis.