[Nitric oxide in supernatants of leukocytes and the serum of patients with B-CLL].

Progression of B-cell chronic lymphocytic leukemia (B-CLL) is linked to an abnormal immune system in the host. Recent studies have suggested that polymorphonuclear neutrophils (PMN) play a role in the malignancy process through release of a wide range of mediators, involving nitric oxide (NO). The aim of this study was to examine NO production by PMN and, for comparison of peripheral blood mononuclear cell (PBMC) confronted with the expression and concentration of inducible NO synthase (iNOS) in these cells derived from patients with B-CLL. Results obtained were analyzed according to Rai' staging systems. Our results have shown impaired production of NO by human neutrophils and mononuclear cells. Furthermore, higher expression of iNOS detected by western blot as well as increased concentrations iNOS estimated by ELISA in these cells were observed. We also found higher expression and concentration of iNOS in PMN and PBMC patients in III stage in comparison with patients in I stage of the disease. Additionally we demonstrated a lower production of superoxide anion by neutrophils of patients with B-CLL. Results obtained suggest that impaired NO production, despite of enhanced expression of iNOS, may have a favorable effect on anti-tumor response in patients with B-cell chronic lymphocytic leukemia.