Neutrophil bactericidal and absorptive function in gout

Aim. To study neutrophil bacterial and absorptive functions and the specific features of their impairments in gout. Subjects and methods. The study included 48 male patients with a valid diagnosis of gout (mean age, 59.7 ± 10.3 years; duration of the disease, 9.2 ± 2.1 years; blood uric acid (UA), 520 ± 80 μmol) (Group 1); 25 apparently healthy volunteers (mean age 55.1 ± 6.2 years; blood UA, 350 μmol/l) (Group 2). Neutrophil functional activity was estimated from the phagocytic-nitroblue tetrazolium reduction (NBT test) and myeloperoxidase (MPO) activity, the determination of non-enzyme cationic proteins (CP) and their spontaneous and induced indices. Neutrophil phagocytic function was also studied. Results. In Group 1, the content of active oxygen forms (AOF) was increased, on average, to 113.3 ± 8.65 conventional units (CI) versus 88.22 ± 5.23 CI in Group 2; p < 0.05). In 34 (70.8%) of the 48 male patients with gout, spontaneous MPO activity was significantly reduced as compared with that in Group 2: 348.4 ± 13.6 and 509.2 ± 12.2 CI, respectively (p < 0.01). In Group 1, the level of CP was noticeably decreased to 60.1 ± 2.06 CI whereas in Group 2, it was 84.91 ± 5.36 CI (p < 0.05). In gouty patients, the CP stimulation index averaged 0.70 ± 0.13; in Group 2, it was significantly higher - 1.2 ± 0.05 (p < 0.05). Conclusion. In the majority of gouty patients, neutrophil functional activity suffers due to its lower phagocytic function, which suppresses the body's antioxidant defense and contributes to the chronic pattern of an inflammatory process.