Characteristics of Hematopoiesis in Follicular Lymphoma Patients

Abstract

Aim. To assess hematopoiesis in follicular lymphoma (FL) patients at different disease stages with different morphologic structures of tumor and bone marrow microenvironment. Materials & Methods. The trial included 152 FL patients treated from 2006 to 2016. In all of them the diagnosis was based on immunohistochemical analysis of extramedullar tumor as well as the analysis of bone marrow aspirates and core biopsy samples. In cases of bone marrow lesions (n = 33) a detailed morphoimmunophenotypic evaluation of tumor cells was carried out by means of flow cytometry, and lymphocyte subset panel evaluation was performed. Results. Anemia, thrombocytopenia, and monocytosis in blood of FL patients are not associated with bone marrow lesions. In the absence of signs of these lesions anemia was detected in 23 (19 %) patients, thrombocytopenia was identified in 8 (7 %) patients, and 11 (9.1 %) patients showed monocytosis. Among patients with bone marrow lesions 9 (27.2 %) anemia, 11 (33.8 %) thrombocytopenia, and 7 (21 %) monocytosis cases were reported. Depth of cytopenia was determined by the degree of bone marrow tumor infiltration. Based on lymphocyte subset panel evaluation the following types of tumor cells in bone marrow aspirates were characterized: elements with blastic structure of nuclear chromatin, atypical lymphoid cells, and those similar to normal lymphocytes. Immunophenotypic heterogeneity of tumor cells in bone marrow was demonstrated. The trial showed that hemoglobin level, the count of blood thrombocytes and monocytes as well as the count of bone marrow T-cells are not associated with types of tumor cells. Conclusion. Arrest of hematopoiesis and increasing number of monocytes in blood correlate with the degree of bone marrow tumor infiltration and are not affected by morphoimmunological characteristics of FL tumor cells.