Anti-Inflammatory Approach in Chronic Dialysis Patients with SARS-CoV-2: ATA or PMMA Dialyzers?

ABSTRACT

BACKGROUND AND AIMS High flux haemodialysis membranes may modulate the cytokine storm of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but their impact in chronic haemodialysis (CHD) patients is not assessed [1, 2]. The aim of the study was the evaluation of asymmetric cellulose triacetate (ATA) and polymethylmethacrylate (PMMA) dialyzers on inflammatory markers in CHD patients with SARS-CoV-2. METHOD A prospective, observational study on CHD patients (age ≥18 years) affected by SARS-CoV-2 was carried out. Patients were enrolled from March 2020 to May 2021 and dialysis was performed at S. Orsola University Hospital (Bologna, Italy) Dialysis Unit. Mechanical ventilation at diagnosis was exclusion criteria. Pre- and post-dialysis C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) were determined at each session and corrected for haemoconcentration during the complete SARS-CoV-2 period. Patients who underwent online haemodiafiltration (OLHDF) with PMMA dialyzer (Filtryzer BG-U™, Toray, surface area 2.1 m2 cut-off 20 kDa, KUF 43 mL/h/mmHg) were compared with those who underwent OLHDF with ATA dialyzer (SolaceaTM Nipro, surface area 2.1 m2 cut-off 45 kDa, KUF 72 mL/h/mmHg). The primary endpoint was to assess the differences in the reduction ratio/session (RR) of CRP, PCT and IL-6. RESULTS A total of 74 patients were enrolled, 48 were treated with ATA and 26 were with PMMA (420 versus 191 dialysis sessions). The main results are shown in Table 1. Median IL-6RR% was higher for ATA [17.08%, interquartile range (IQR) −9.0 to 40.0 versus 2.95%, IQR −34.63 to 27.32]. CRP and PCT showed higher RR with ATA in comparison to PMMA. When IL-6RR > 25% was the dependent variable in the multiple logistic regression analysis only ATA showed a significant correlation [odds ratio (OR) 1.891, 95% confidence interval (95% CI) 1.273–2.840, P = .0018) while higher CRP favoured the risk of lower IL6RR (OR 0.9101, 95% CI 0.868–0.949, P < 0.0001) (Table 2). CONCLUSION In SARS-CoV-2 CHD patients treated with OLHDF, ATA showed a better anti-inflammatory profile than PMMA, in particular regarding IL-6 RR.Table 1. Clinical features and outcomes of ATA versus PMMA. Standard deviation (SD), Interquartile range (IQR)ATA (48)PMMA (26)PAge, years, mean (SD)67.67 (15.48)69.46 (16.37).6421Male, n (%)34 (71)17 (66).7930HD age, months, median (SD)47.00 (13.75–89.75)27.50 (14.25–71.50).3653Charlson Comorbidity Index, median (IQR)4.00 (3.00–5.00)5 (3.00 –7.25).2549Arteriovenous Fistula, n (%)39 (81)14 (54).0166Central venous catheter, n (%)9 (9)12 (46)Interstitial pneumonia, n (%)29 (60)20 (77).2008Pre-HD IL-6 pg/mL, median (IQR)14.50 (5.75–41.43)13.90 (5.80–34.10).6386IL-6 RR%, median (IQR)17.08 (−9.0–40.0)2.95 (−34.63–27.32)<0.001IL-6 RR% based on pre-dialysis IL-6 level (median, IQR) 1st tertile23.55 (−8.96–47.40)3.72 (−51.66–30.08).0013 2nd tertile16.69 (−9.79–39.39)2.18 (−24.03–25.95).0405 3rd tertile12.99 (−8.73–35.75)1.14 (−34.70–31.33).0501CRP RR%, median (IQR)7.77 (2.47–13.77)4.80 (−2.65–11.38).0017PCT RR%, median (IQR)77.38 (70.92–82.97)54.59 (42.62–63.16)<0.0001Variables at diagnosis, median (IQR) IL6 pg/mL20.30 (9.10–62.10)22.60 (9.80–56.35).8763 CRP mg/dL3.88 (0.77–143.70)3.30 (0.33–9.98).4134 PCT pg/mL1.60 (0.72–2.77)0.95 (0.53–1.48).0388Death, n (%)8 (17)5 (19).7604Table 2. Multiple logistic regression with IL-6 RR > 25% as outcome. Odds Ratio (OR), Confidence interval (CI)OR95% CIpATA1.8911.273–2.840.0018IL-6 pre-HD1.0031.001–1.007.0123CRP pre-HD0.91010.8682–0.9496< 0.0001PCT pre-HD0.95280.8644–1.008.2270Ferritin1.0000.9998–1.000.7697