COVID-19 Pandemic in Dialysis Patients: The Swiss Experience.

Chronic dialysis patients are classified as patients with increased risk for COVID-19. Knowledge about the incidence and survival of chronic dialysis patients infected with SARS-CoV-2 in Switzerland - a high-income country with high density of relatively small dialysis centers - is scarce. We present the findings regarding incidence, survival and regional differences, compared to those of the general population in Switzerland. Information on chronic dialysis patients who tested positive for SARS-CoV-2 between February 24, 2020 and February 28, 2022 were reported to the Swiss dialysis registry by all 94 Swiss dialysis centers. Hereafter, these results were linked with clinical characteristics from the Swiss dialysis registry. Throughout the study period 1,120 out of ~4,700 dialysis patients tested positive for SARS-CoV-2 in Switzerland: 96 cases occurred in the first wave, 472 in the second wave and 5 in between. During the first wave, Italian-speaking Ticino was most severely affected, with a 7-fold higher incidence of dialysis patients compared to the general Swiss population. In the second wave, the majority of cases were found in the French-speaking part of Switzerland, with a 2.5 times higher incidence vs. non-dialysis patients. A total of 123 deaths were recorded in the first two waves, of which COVID-19 was the main cause of death in 100 patients. This corresponds to a highly increased overall mortality rate of 17.5% compared to 1.7% in the general population. Age was identified as the only risk factor for mortality in dialysis patients. During the third, fourth and fifth wave, 61, 43 and 443 cases, respectively, were recorded, resulting in 6 (mortality rate 9.8%), 1 (mortality rate 2.3%) and 13 deaths (mortality rate 2.9%). Chronic dialysis patients in Switzerland were more likely to be infected by SARS-CoV-2 during the first and second wave than the rest of the population, but an inverse trend was observed during the third, fourth and fifth wave, probably thanks to vaccination. In addition, mortality is significantly increased compared to non-dialysis patients. In Swiss dialysis patients, age is the strongest risk factor for death

Sex differences in COVID-19 mortality risk in patients on kidney function replacement therapy

In the general population with COVID-19, the male sex is an established risk factor for mortality, in part due to a more robust immune response to COVID-19 in women. Because patients on kidney function replacement therapy (KFRT) have an impaired immune response, especially kidney transplant recipients due to their use of immunosuppressants, we examined whether the male sex is still a risk factor for mortality among patients on KFRT with COVID-19. From the European Renal Association COVID-19 Database (ERACODA), we examined patients on KFRT with COVID-19 who presented between February 1st, 2020, and April 30th, 2021. 1204 kidney transplant recipients (male 62.0%, mean age 56.4 years) and 3206 dialysis patients (male 61.8%, mean age 67.7 years) were examined. Three-month mortality in kidney transplant recipients was 16.9% in males and 18.6% in females (p = 0.31) and in dialysis patients 27.1% in males and 21.9% in females (p = 0.001). The adjusted HR for the risk of 3-month mortality in males (vs females) was 0.89 (95% CI 65, 1.23, p = 0.49) in kidney transplant recipients and 1.33 (95% CI 1.13, 1.56, p = 0.001) in dialysis patients (p = 0.02). In a fully adjusted model, the aHR for the risk of 3-month mortality in kidney transplant recipients (vs. dialysis patients) was 1.39 (95% CI 1.02, 1.89, p = 0.04) in males and 2.04 (95% CI 1.40, 2.97, p < 0.001) in females (p = 0.02). In patients on KFRT with COVID-19, the male sex is not a risk factor for mortality among kidney transplant recipients but remains a risk factor among dialysis patients. The use of immunosuppressants in kidney transplant recipients, among other factors, may have narrowed the difference in the immune response to COVID-19 between men and women, and therefore reduced the sex difference in COVID-19 mortality risk