Increased serum levels of Galectin-9 in patients with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults. Despite improvements in treatment, CLL is still considered an incurable disease. The aim of the present study was to evaluate galectin-1, -3 and -9 (Gal-1, -3 and -9) and Gal-3 binding protein (Gal-3BP) as prognostic and predictive factors in patients with CLL. Serum concentrations of Gal-1, -3 and -9 and Gal-3BP were measured in 48 patients with CLL and 30 control patients, using multiplex bead arrays. In patients with CLL, galectin concentrations were assessed prior to, during and following treatment. In patients with CLL who were untreated, galectin concentrations were measured twice with a 6-month interval. The serum level of Gal-9 was significantly increased (P<0.0001) in patients with CLL compared with the control group, and was associated with the clinical stage according to Binet classification, as well as poor cytogenetic and serum CLL prognostic factors. In addition, patients with CLL, who exhibited treatment failure, exhibited higher concentrations of Gal-9 (P=0.06) and Gal-3BP (P=0.009) at the end of the treatment when compared with patients under complete remission or stabilization of the disease. The serum level of Gal-3 was significantly decreased (P=0.012) in patients with CLL compared with the control group. These results suggest that Gal-9 is a potential prognostic factor in patients with CLL. The predictive value of Gal-9 requires further study in larger cohorts of patients.