Significance of tumor necrosis factor- α and B2 microglobulin in patients having chronic lymphocytic leukemia

Abstract

Background and objectives: Tumor necrosis factor-α (TNF-α) is important for the growth and survival of the leukemic cells in B-cell chronic lymphocytic leukemia (B-CLL). B2 microglobulin (B2MG) is elevated in tumors, it is clinically used for lymphoproliferative diseases, where serum B2MG is related to tumor cell load, prognosis, and disease activity. The aim of this study was to investigate the serum levels of TNF-α and B2MG in B-CLL patients with correlation to relevant haematological data and disease characteristics. Patients, materials and methods: The study included 15 newly diagnosed untreated B-CLL patients obtained from the outpatient clinic at the National Cancer Institute in Cairo and 15 ages and sex matched controls. Venous blood samples were obtained from B-CLL and control groups for complete blood count (CBC). Serum was separated for measurement of TNF-α and B2MG levels by ELISA. Bone marrow (BM) aspiration was done to all B-CLL cases. Results: The studied B- CLL group consisted of 7 females and 8 males with mean ± SD age (54.9 ± 11.6 years). The clinical staging according to Rai classification was: 66.7% cases in stage 0-II and 33.3% cases in stage III-IV. There was highly significant elevation of white blood cell count (WBC), absolute lymphocytes in peripheral blood (PB), serum TNF-α and serum B2MG with high significant reduction of haemoglobin (Hb) in B-CLL group when compared with the control (P<0.001). There was significant reduction of platelets and significant elevation of absolute monocytes in PB in B-CLL group (P<0.01 & P<0.02 respectively). There was significant elevation of TNF- α in B-CLL patients with anaemia and B-CLL patients with thrombocytopenia in comparison with B-CLL patients without anaemia and B-CLL patients without thrombocytopenia (P=0.02 and P<0.05 respectively). There was highly significant positive correlation between TNF-α and both absolute monocytes in PB & serum B2MG with inverse highly significant correlation with Hb. A significant positive correlation was found between TNF- α and: WBC, BM lymphocytes and Rai III-IV disease stage with inverse significant correlation with platelets. A significant positive correlation was detected between B2MG and both WBC and absolute peripheral blood lymphocytes (P=0.01) with highly significant positive correlation with Rai III-IV disease stage (P<0.001), while no correlations were demonstrated with the other parameters. Conclusion: TNF-α and B2MG are important for the process of leukemogenesis and progression and may serve as bad prognostic markers for B- CLL. On the basis of these observations, therapeutic inhibition of TNF-α and B2MG could be a new strategy of importance in the treatment of B-CLL.