#3255 beta2 microglobulin is an independent parameter related with dysfunction of natural killer cell activity in hemodialysis patients

Abstract Background and Aims End-stage renal disease patients are characterized by immune dysfunction. Natural killer (NK) cells area lymphocytes of innate immune system that play a key role in an immune response towards viral infections and tumors. We aimed to analyze clinical factors related to the NK cell activity in chronic hemodialysis (HD) patients. Method Clinically stable 196 patients who were treated by HD for more than 3 months were enrolled from 4 outpatient HD clinics. NK cell activity was assessed using NK Vue assay (NKMAX, Sungnam, Korea) that uses serum of ex-vivo stimulated whole blood to detect interferon (IFN)-γ secreted from NK cells as an indicator of NK cell activity. All patients were stratified as abnormal (<250 pg/ml) and normal (≥250 pg/ml) groups according to NK cell activity. Results Mean age of the HD patients was 62.7 years [range 31 to 95 years] and mean HD duration was 49.2 months [range 3 to 221 months]. In total, 68 (35%) of HD patients showed abnormal NK cell activity. The abnormal NK cell activity group showed significantly increased age and shorter HD duration compared to the normal NK cell activity group (66.7 ± 11.9 vs. 60.6 ± 13.4 years, p = 0.001; 33.8 ± 33.0 vs. 57.5 ± 48.5 months, p<0.001, respectively). The serum albumin and parathyroid hormone levels were significantly lower in the abnormal NK cell activity group (3.7 ± 0.4 vs. 3.9 ± 0.3 g/dL, p = 0.005 and 176 ± 153 vs. 240 ± 260 pg/mL, respectively). In contrast, hemoglobin, blood urea nitrogen, urea reduction ratio, and C-reactive protein levels were comparable between the two groups. In multivariate regression analysis, old age, short dialysis duration, low serum albumin and high beta2 microglobulin levels were independent risk factors of abnormal NK cell activity in HD patients (adjusted odd ratio [AOR], 1.033; 95% confidence interval [CI], 1.005-1.062, p = 0.02; AOR, 0.981; 95% CI, 0.971-0.992; p<0.001, AOR, 0.395; 95% CI, 0.157-0.995; p = 0.049, and AOR, 1.042; 95% CI, 1.011-1.075; p = 0.008, respectively). Conclusion Our results suggest that young age and good nutrition as well as lower burden of middle molecule uremic toxin is associated with greater NK cell activity in HD patients.