Acute exercise during hemodialysis prevents the decrease in natural killer cells in patients with chronic kidney disease: a pilot study

Purpose To evaluate the acute response of natural killer (NK) cell subsets of chronic kidney disease patients submitted to intradialytic exercise in a randomized crossover study. Methods Nine patients were submitted to a single bout of 20-min intradialytic exercise and a control hemodialysis (HD) session with an interval of 7 days between them. Peripheral blood sample was collected at baseline, during HD and immediately after HD in each trial to evaluate the peripheral frequency of NK cells and their subsets (CD3-CD56 bright and CD3-CD56 dim ), systemic cortisol concentrations, C-reactive protein (CRP), creatine kinase activity (CK), and urea and creatinine levels. Results HD therapy induced a significant decrease in NK cells frequency ( p = 0.039), NK CD3-CD56 bright cells ( p = 0.04), and CD3-CD56 dim cells ( p = 0.036). On the other hand, no significant alterations were observed in NK cells and NK subsets during and after intradialytic exercise trial ( p > 0.05). Neither trial altered CRP levels or serum CK activity during and after HD therapy ( p > 0.05). However, HD therapy increased cortisol concentrations after HD therapy ( p = 0.034). Conclusions This study suggests the potential role of intradialytic exercise to prevent the decrease in peripheral frequency of NK cell subsets during HD therapy. Moreover, moderate intensity intradialytic exercise did not exacerbate the systemic inflammation or induce muscle damage during HD therapy.