ESRD patients on PD face similarly high COVID-19 mortality as those on HD

Patients with end-stage renal disease (ESRD) who are on peritoneal dialysis (PD) face a similarly high rate of COVID-19 mortality as those on haemodialysis (HD), a retrospective analysis of data from six large renal units in Hong Kong has shown.

The analysis included 5,514 patients who were on PD (n=2,526 [45.8 percent]) or HD (n=1,231 [22.3 percent]) or had undergone kidney transplantation (n=1,757 [31.9 percent]). The patients were managed at one of the six large renal units in Hong Kong (ie, Prince of Wales Hospital, Queen Elizabeth Hospital, United Christian Hospital, Caritas Medical Centre, Kwong Wah Hospital, and Alice Ho Miu Ling Nethersole Hospital) during the Omicron fifth wave between 1 October 2021 and 30 April 2022. COVID-19 mortality was evaluated separately for each mode of renal replacement therapy instead of for the infected population. [Hong Kong Med J 2023;doi:10.12809/hkmj2210309]

In this cohort, 90 patients died of COVID-19, including 49 deaths (mean age, 69 years) among PD patients, 27 deaths (mean age, 70 years) among HD patients, and 14 deaths (mean age, 71 years) among kidney transplant recipients. More than 60 percent of the patients who died were unvaccinated against COVID-19.

Notably, COVID-19 mortality was similarly high between PD and HD patients, at 19.4 deaths and 21.9 deaths per 1,000 dialysis population, respectively. Among PD patients who died of COVID-19, 73.5 percent were unvaccinated. In HD patients who succumbed to COVID-19, the proportion of unvaccinated patients was considerably lower, at 48.1 percent.

“[Among patients on renal replacement therapy,] PD patients were perceived to be less vulnerable to SARS-CoV-2 infection because their treatment is home-based with better protection by self-isolation. On the contrary, in-centre HD patients were perceived to have a higher likelihood of infection due to practical challenges in maintaining social distancing within a crowded dialysis unit,” explained the researchers. [J Am Soc Nephrol 2020;31:1815-1323; Am J Kidney Dis 2020;76:690-695; Kidney Med 2021;3:619-634; J Am Soc Nephrol 2021;32:1569-1573]

“A perceived lower risk of infection might have caused a more relaxed attitude among PD patients,” the researchers pointed out. “Potential explanations for the relatively high mortality in the PD cohort are lower adherence to hand hygiene, mask wearing and social distancing, and most significantly, [lower] vaccine uptake. The observation of lower vaccine coverage among death cases in PD patients supports the hypothesis, although we did not have population-level data of vaccination coverage among all dialysis patients.”

“Although we cannot exclude confounding factors such as frailty and age, the result of a high mortality burden among PD patients should caution nephrologists who give advice about vaccination of dialysis patients,” they noted.

According to lead author, Dr Kai-Ming Chow of the Division of Nephrology, Chinese University of Hong Kong, all ESRD patients on dialysis are advised to receive COVID-19 vaccination according to schedule. The patients are also reminded to consider the bivalent vaccine, given their immunocompromised state.