COVID-19 em Doentes em Hemodiálise: uma tempestade moderada?

Abstract

Maintenance hemodialysis patients have an expected higher risk of severe COVID-19 due to immune system dysfunction and a high burden of comorbidities. Nevertheless, early reports showed a milder disease course in this group of patients. Therefore, we analyzed 13 case series of maintenance hemodialysis patients diagnosed with SARS-CoV-2 infection in the first five months of 2020. Fever and cough were present in less than 70% of patients and atypical symptoms such as nausea and diarrhea were more prevalent than in other patient groups. Although fatality rate was high - between 10-32% - most reported causes of death were not COVID-19 associated pneumonia. In addition, acute respiratory distress syndrome (ARDS) prevalence - 14% to 48% - was similar to that of patients without end stage kidney disease. The cytokine storm is one of the main mechanisms behind ARDS development in SARS-CoV-2 infection. However, we report decreased cytokine levels in maintenance hemodialysis patients compared to the general COVID-19 population. We propose that the hemodialysis related immune dysfunction, characterized by decreased phagocyte capability, diminished B cell number and impaired T cell activity, is associated with a lower risk of COVID-19 associated cytokine storm development. This differential immune system behavior is associated with an atypical clinical presentation and more favorable prognosis than expected for this group of patients.