Effect of Aboand Rh Blood Type on Sars-Cov-2 Infection Severity in Patients with Rheumatic Diseases: Data from the National Sar-Covid Registry

ABSTRACT

Objectives: To evaluate the association between the ABO and Rh antigens and the clinical characteristics and evolution of the SARS-CoV-2 infection in patients with rheumatic diseases. Method(s) SAR-COVID is a national, longitudinal, and observational registry. Patients >=18 years of age with a diagnosis of inflammatory or degenerative rheumatic disease, and confirmed SARS-CoV-2 infection (RT-PCR or serology) were included. Data were collected from August 2020 to June 2022. Sociodemographic, clinical data, comorbidities, underlying rheumatic disease, disease activity, and its treatment at the time of infection were recorded, aswell as symptoms, complications and treatments received for COVID-19. The WHO ordinal scale (WHO-OS) was used, and severe COVID-19was defined as WHO-OS>=5. Patients were categorized as follows blood group A or non-A, and Rh factor positive or negative. Result(s) A total of 1356 patients were included, 547 (40,3%) had blood group A and 809 non-A (59,7%). Regarding the Rh factor, 1230 (90,7%)were positive and 126 (9,3%) negative. Age, sex, ethnicity and comorbidities were comparable between both groups. In both cases, the most frequent rheumatic diseases were rheumatoid arthritis (38,9%;p = 0,052), systemic lupus erythematosus (17,4%;p = 0,530) and osteoarthritis (10,1%;p = 0,888). Patients with non-A blood type presented a higher frequency of psoriatic arthritis (group A 5,1% vs non-A 8,7%;p = 0,015). During SARS-CoV-2 infection, more than 90% of patients in both groups were symptomatic (group A 96.0% vs non-A 94,8%;p = 0,384). Non-A blood group patients had a significantly higher frequency of arthralgia and dysgeusia. In A blood group 18.5% of the patients required hospitalization, 41,0% of them were admitted in the intensive care unit and 5.9% presented complications, while in the non-A blood group, were 16,7%, 31,1% and 5,5%, respectively (p > 0,05 in all the cases). The most frequent complications in both groups were respiratory distress syndrome and sepsis (p > 0,05). The outcome of the COVID-19 infection is detailed in Figure 1. In the multivariate analysis, adjusted for poor prognostic factors, patients with A blood type and those with negative Rh factor presented more likely severe COVID-19. (OR 1,75, 95%CI 1,20-2,56, p = 0,003 and OR 2,63, 95%CI 1,45-4,55, p = 0,001, respectively). Conclusion(s) Blood type A and negative Rh factor were associated with worse COVID-19 outcomes in this national cohort of patients with rheumatic diseases.