Abstract: Ｏｂｊｅｃｔｉｖｅ：To identify risk factors of maintenance hemodialysis (MHD) for severe／critical disease and mortality in waves of coronavirus disease 2019(COVID-19) infections in our hemodialysis center.
Ｍｅｔｈｏｄｏｌｏｇｙ：Include all the MHD patients in our center between 1 December 2022 and 1 February 2023, compare demographic and clinical data, dialysis-specific parameters between severe／critical and mild／moderate, die and survival, identify the risk factors for severe／critical disease and mortality.
Ｒｅｓｕｌｔｓ：A total of 279 MHD patients developed COVID-19 infections of omicron wave among 303 patients, the severity／critical rate is 7.9％,the fatality rate is 4.7％. Compared with the mild and moderate disease, severe／critical disease were older, had higher incidence of diabetes, coronary heart disease,chronic obstructive pulmonary disease (COPD), and lower baseline hemoglobin. Multivariate regression analysis revealed that older age, higher incidence of diabetes, COPD, lower baseline hemoglobin were associated with severe／critical COVID-19 infection. Compared to the survivors, non-survivors were older, had higher incidence of diabetes, coronary heart disease and COPD, diagnosed as anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with renal injury, had lower baseline hemoglobin and albumin. Older age, comorbidities of diabetes, COPD, diagnosed as AAV with renal injury, lower baseline hemoglobin, albumin were associated with mortality.
Ｃｏｎｃｌｕｓｉｏｎ：Older age, higher incidence of diabetes, COPD, lower baseline hemoglobin were more vulnerable of severe／critical COVID-19 infections. Older age, comorbidities of diabetes, COPD, diagnosed as AAV with renal injury, lower baseline hemoglobin, albumin associated with higher mortality.

Key words: COVID-19, maintenance hemodialysis, mortality, risk factors