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.

Asymmetric cellulose triacetate is a safe and effective alternative for online haemodiafiltration. / El triacetato de celulosa asimétrico es una alternativa segura y eficaz para la hemodiafiltración en línea.

BACKGROUND: In post-dilution haemodiafiltration only synthetic membranes have been used to date. Asymmetric cellulose triacetate (ATA™) is now available, whose characteristics are suitable for this technique. OBJECTIVES: To describe the in vivo performance and behaviour of this membrane, to identify its depurative effectiveness, use in clinical practice and its biocompatibility, both acute and after one month of treatment. METHODS: Observational prospective study of 23 patients who were dialysed for 4 weeks using an ATA™ membrane and who maintained their prior regimen. RESULTS: A total of 287 sessions were performed and 264 complete sessions were collected. With an effective time of 243.7 (17.6) min and a mean blood flow of 371.7 (23) ml/min, an average Kt of 56.3 (5.3) l was observed, as well as a convection volume of 27.1 (4.2) l, a filtration fraction of 29.9 (3.7) %, a urea reduction ratio (RR) of 81 (5.2) %, a creatinine RR of 74.7 (4.6) %, a ß2-microglobulin RR of 76.5 (4.8) % and a retinol binding protein RR of 18.6 (7.6) %. There were no technical problems or alarms. Changing the heparin dosage was not necessary. No increases in C3a or C5a concentrations or leukopenia were observed in the first 30min of the session. Neither the monocyte subpopulations nor IL-ß1 or IL-6 were significantly altered after one month of treatment. CONCLUSIONS: The new ATA™ membrane achieves adequate Kt and convection volume, without technical problems and with good biocompatibility and inflammatory profiles. It is therefore a valid option for post-dilution haemodiafiltration, particularly in patients allergic to synthetic membranes.