#6864 IMMUNE RESPONSES OF PATIENTS ON MAINTENANCE HEMODIALYSIS AFTER INFECTION BY SARS-COV-2: A PROSPECTIVE OBSERVATIONAL COHORT STUDY

Abstract

Abstract Background and Aims We aimed to study the immune response of maintenance hemodialysis (HD) patients to Corona Virus Disease-19 (COVID-19) since it is not fully elucidated. Method In this prospective study, hospitalized HD patients with moderate-to-severe COVID-19 and matched non diseased HD comparators were analyzed for their absolute counts of lymphoid cells (flow cytometry) and circulating inflammatory mediators (ELISA). Blood samples were collected at the start and at of the end of the first in hospital HD session; dialysate samples at the end of the first half hour session. Results 59 HD patients with acute COVID-19 HD and 20 comparators were enrolled. Circulating median (range) of interferon-gamma (IFNγ) at the start of HD was 125 (125-1777) pg/ml in comparators and 810 (125-4000) pg/ml in SARS-CoV-2 (p<0.00001) and 125 (125-1278) pg/ml and 738 (125-4000) pg/ml at the end of HD (p<0.0001). Respective concentrations of platelet derived growth factor-A were 8286 (4600-28150) and 27938 (8285-99256) pg/ml (p<0.0001) and 7779 (5055-28128) and 27410 (6836-87887) pg/ml respectively. Similar increases were found for tumor necrosis factor-alpha (TNFα) only at the start of the HD whereas no differences were found for interleukin (IL)-6, IL-10 and IL-38. Respective mean (SD) CD4-counts were 881.3 (407.6) and 461.6 (365.4) per microliter (p<0.0001) and 839.4 (509.7) and 483.6 (329.9) per microliter (p<0.0001). Respective mean (SD) CD19-counts were 199.0 (154.5) and 76.4 (78.6) per microliter (p<0.0001) and 144.9 (110.3) and 98.3 (70.8) per microliter (p<0.0001). The respective mean (SD) MFI expression of HLA-DR on CD14-monocytes was 97.2 (28.2) and 67.4 (44.7) (p: 0.013) and 87.3 (26.7) and 63.3 (36.3) (p: 0.009). MFI of HLA-DR on CD14-monocytes before the first HD session less than 44 was associated with 100% sensitivity for unfavorable outcome (defined as respiratory failure or death) after 28 days. An absolute CD19-count more than 40 per microliter before the first HD session was associated with 8.70 odds ratio for cure favorable outcome after 28 days. Conclusion HD patients develop an inflammatory reaction to Severe Acute Respiratory Syndrome Coronavirus 2 characterized by increase of the inflammatory mediators IFN-γ, PDGF-A and TNF-a and decrease of circulating T helper lymphocytes. Decreased expression of HLA-DR on CD14-monocytes is a hallmark of unfavorable prognosis.