Increased serum BAFF (B-cell activating factor of the TNF family) level is a peculiar feature associated with familial chronic lymphocytic leukemia

Abstract

In a series of 84 chronic lymphocytic leukemia (CLL) patients we sought to establish whether BAFF (B-cell activating factor of the TNF family) circulating levels correlated with clinical characteristics of disease. BAFF serum levels were significantly higher in 20 healthy controls (i.e., median 695 ng/mL, range 389–1040) in comparison to the whole population of CLL patients (median 376, range 93–8914; P < 0.0001). After setting a cut-off at the median value observed in healthy controls (i.e., 695 ng/mL) we found that 6 out of 15 (40%) patients with familial CLL had increased BAFF levels while the same occurred only in 5 out of 64 (7.2%) patients with sporadic CLL ( P = 0.0007). No significant difference in age ( P = 0.82), sex ( P = 0.97), Binet clinical stage ( P = 0.20), incidence of autoimmune hemolytic anemia (AIHA) or immune thrombocytopenia (ITP) ( P = 0.47), mutational status of IgVH ( P = 1.00), CD38 ( P = 0.34) and ZAP-70 expression ( P = 0.16) could be detected between patients with sporadic and familial CLL, respectively. The only feature characterizing familial CLL patients was a higher serum BAFF level ( sporadic CLL 336 ng/mL, range 93–925; familial CLL 601 ng/mL, range 138–8914; P = 0.002). Our data suggest that BAFF levels are elevated in patients with familial CLL. The small cohort of patients used implies that a larger study is needed to reinforce the observation.