COVID‑19 in patients requiring renal replacement therapy: an overview of current data and future challenges

Patients with chronic kidney disease, especially those on renal replacement therapy, demonstrate increased incidence and mortality from COVID‑ 19, as compared with the general population. One of the main reasons for this phenomenon is a dysfunction of the immune system associated with its accelerated aging, weakened immune functions, impaired regulation of proinflammatory reactions, chronic inflammation, and immunosuppressive therapy. Most of these patients have a high rate of comorbidities, which may also have a negative impact on the severity of COVID‑ 19 and prognosis. Introduction of COVID 19 vaccines has significantly changed the course of the fight against the pandemic. Due to the very severe disease, in many countries the patients receiving renal replacement therapy were prioritized for vaccination right after health care professionals. Differences in the response to vaccination were noted, which required an individualized approach and modification of the vaccination program in this patient group. Difficulties in assessing these issues are due to the differences in the research methodology used in the available studies and their observational nature. Moreover, response to vaccination varied over time depending on the geographic region and variant of the virus causing the infection. The epidemiology was significantly influenced by the improved prevention methods and treatment of infections as well as the growing percentage of vaccinated and convalescent people. We present the most important differences in the epidemiology of COVID‑ 19, the course of the disease, prognosis, and prevention, as well as the challenges associated with improving the prognosis in patients receiving renal replacement therapy.