IMMUNOPHENOTYPICAL CHARACTERISTICS OF VILLOUS LYMPHOCYTES IN B-CELL LYMPHOPROLIFATIVE DISEASES

Abstract

Objective: the cytological and immunocytochemical features of lymphocytes with villous morphology in some B-cell lymphoproliferative disorders were studied. Object and methods: cytomorphological, cytoche­mical, immunocytochemical methods of investigation were used. The diagnosis of hairy cell leukemia (HCL) in patients with splenomegaly, dissemination of villous cells in the bone marrow (BM) and their presence in periphe­ral blood was established in accordance with the newly revised WHO classification (2016) of lymphoid tumors. Results: neoplastic cells with hairy cell leukemia were determined by the presence of high tartrate-resistant acid phosphatase (TRAP) activity and had an immunophenotype of relatively mature B cells. Cell surface expression of CD19, CD20, and CD22 antigens associated with B lymphocytes detected. Positive was the reaction when detecting CD25, CD103, and CD200.. In some cases, cyclin D1 was determined. Reaction from moAb to CD5, CD10, and CD23 was negative. In the splenic marginal zone lymphoma with villous processes by immunophenotype also corresponded to mature B lymphocytes. Expression of CD19, CD20, and CD22 antigens was observed in all cases; CD11c — in 50% of patients; CD25 or CD5 — in 10% of patients. In pathologic cells of 80% of patients did not show TRAP activity; in 20% of patients it was weak and was stored in 10–15% of cells. TRAP activity was not detected in BM and peripheral blood cells with diffuse red pulp lymphoma. The expression of CD19, CD20, and CD22 antigens was noted. Tumor cells had a negative reaction when CD25 antigens and cyclin D1 were detected. The immunophenotypic features of cells with variant hairy cell leukemia were somewhat diffe­rent from those of classical HCL (CD19⁺ CD20⁺ CD22⁺ CD103⁺ CD11c⁺ CD5^– CD10^– CD23^–). The reaction with moAb to cyclin D1 and CD25 was negative. Conclusions: characterized cytochemical and immunophenoty­pic markers of villous lymphocytes, which have differential diagnostic value in various forms of lymphoid tumors of B cell origin, are important for the choice of treatment methods and prognosis.