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

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.