Dynamic assessment of interleukin-6 during hemodialysis and mortality in coronavirus disease-19.

The impact of the newly discovered severe acute respiratory syndrome coronavirus 2 causing coronavirus disease-19 (COVID-19) in hemodialysis patients remains poorly characterized. Some hemodialysis techniques reduce systemic inflammation but their impact on COVID-19 has not been addressed. The aim of this prospective study was to evaluate factors associated with mortality in COVID-19 hemodialysis patients, including the impact of reducing interleukin-6 using a cytokine adsorbent filter. This is a prospective single-center study including 16 hemodialysis patients with COVID-19. All were dialyzed using a polymethyl methacrylate (PMMA) filter. Interleukin-6 levels were obtained before and after the first admission hemodialysis session and at 1 week. Baseline comorbidities, laboratory values, chest X-ray, and treatments were recorded and compared between survivors and non-survivors. Out of 16 patients (13 males, mean age 72 ± 15 years), 4 (25%) died. Factors associated with mortality were dialysis vintage (P = 0.01), chest X-ray infiltrates (P = 0.032), serum C-reactive protein (P = 0.05), and lactate dehydrogenase (P = 0.02) at 1 week, oxygen therapy requirement (P = 0.02) and anticoagulation (P < 0.01). At admission, non-survivors had higher predialysis and postdialysis interleukin-6 levels (P = 0.02 for both) and did not present the reduction of interleukin-6 levels during the dialysis session with PMMA filter that was observed in survivors (survivors vs. non-survivors: 25.0 [17.5-53.2]% vs. -2.8 [-109.4-12.8]% reduction, P = 0.04). A positive balance of interleukin-6 during the admission dialysis was associated with mortality (P = 0.008). In conclusion, in hemodialysis COVID-19 patients, a positive interleukin-6 balance during the admission hemodialysis session was associated with higher mortality.