Rh negativity seems to predispose to a milder COVID-19 course

Introduction: Infection with the SARS-CoV-2 virus can lead to the development of COVID-19. Currently, more than 700 million people worldwide have been diagnosed with COVID-19, of which nearly 7 million have died from the severe course of the disease. Recent reports suggest that patients with blood group A are most at risk of developing COVID-19, and people with natural anti-A antibodies (especially those with blood type 0) have a milder course of the disease. This study aimed to assess the humoral response to infection with SARS-CoV-2 depending on the patient’s blood type. Material and methods: The study group consisted of 147 patients with confirmed previous COVID-19 (convalescents) and 147 individuals who declared no previous infection with SARS-CoV-2. All enrolled subjects were blood donors registered at Regional Blood Center. The concentration of SARS-CoV-2 anti-nucleocapsid antibodies was determined in the serum of the patients using the Elecsys Anti-SARS-CoV-2 test. The blood group was determined by a manual method using anti-A, anti-B, and anti-D monoclonal sera and A, B, and 0 standard red blood cells (RBC). Results and conclusions: Based on anti-SARS-CoV-2 detection 68 people who denied contact with SARS-CoV-2 had previous asymptomatic infection. Blood type distribution differed between the asymptomatic convalescents and the declared convalescents, p = 0.0013. People with Arh–, BRh+, BRh–, and 0Rh– blood type were more often asymptomatically infected. Moreover, the Rh- subjects more often didn’t know about the previous infection than those with Rh+, p = 0.0012. It seems that subjects with Rh– blood type have a significantly milder course of disease than Rh+.