RESUMEN
Background/aim: In this study, we aim to investigate the efficacy of convalescent plasma (CP) according to blood groups (BGs) in the treatment of critically ill patients diagnosed with COVID-19. Materials and methods: Twenty-eight critically ill and laboratory-confirmed COVID-19 patients who were admitted to the intensive care unit (ICU) of Sakarya University, Medical Faculty were included in the study. Patients were divided into 2 groups: patients who received anti-A antibody (Ab) containing CP (BG O and B) and those who did not receive CP containing anti-A Ab (BG A and AB). Results: Among the 28 patients, 13 patients received anti-A Ab containing CP (BG; B: 6, O: 7) and 15 patients did not receive anti-A Ab CP (BG; A: 13, AB: 2). Duration in ICU, the rates of mechanical ventilation (MV) support and vasopressor support, the case fatality rate, and the discharge rate were lower in patients who received CP containing anti-A Ab than not containing anti-A Ab CP. However, only the difference in the rate of MV support achieved statistically significance (P = 0.04) Conclusion: In our study, it was observed that the efficiency of CP without anti-A antibody was lower than that of plasma containing anti-A antibody, although it was not statistically significant. This result is thought to be due to the anti-A antibody's ability to block the ACE2 receptor. We believe that this hypothesis should be investigated in controlled studies with higher patient numbers.