Could autoimmune hemolytic anaemia be triggered by SARS-COV- 2 vaccine?-case report

ABSTRACT

Background: Autoimmnue hemolytic anaemia (AIHA) is characterized by the production of autoantibodies against red cells antigens, leading to hemolysis. AIHA can be primary or secondary to rheumatologic and lymphoproliferative diseases, infections, drugs and vaccines. Several immune phenomena were reported after massive SARS-CoV-2 vaccination, including myocarditis, neurological syndormes, immune thrombocytopenia, among others. Aims: We hereby describe an AIHA case possibly related to SARSCoV- 2 vaccination. Methods: Assessment of the clinical evaluation along with the laboratory and immunohematological tests in a symptomatic patient fwe days after receiving the vaccine. Results: A 72-year-old womwn, previously healthy, rceived her first dose of Coronavac (Sinovac, inactivated virus), in January 2021. After 7 days, she was admitted with fatigue and myalgia. Laboratory results revealed haemoglobin 4.9 g/dl, reticulocyte count 31.7%, total bilirubin 9.15 mg/dl, indirect bilirubin 7.88 mg/dl, haptoglobin<6 mg/dl and lactate dehydrogenase 953 U/L. The peripheral blood smear showed spherocytes and polychromasia. The nasopharyngeal PCR test for Covid-19 was negative. Regarding the immunohematological tests, the patient was group O R1K-k+, polyspecific direct antiglobulin test (DAT) was reactive for IgG and C3d, but the monospecific DAT showed only IgG. The eluate was reactive against all test cells. After all adsorptions performed, no alloantibody was detected and the eluate confirmed only the presence of an autoantibody, with no specificity. The patient was successfully managed with steroids, cyclophosphamide and transfusion support (OR1r, K-, antigens S and JKa negative, according with genotyping). No other causes of AIHA were found in the patient's screening and the patient did not have covid prior to vaccination. Summary/Conclusions: In this case, the temporal relationship between the vaccination and the symptoms of AIHA suggests a possible and rare haematological side effect of the vaccine which are able to activate both cellular and humoral immune systems with an important role in the interactions between dendritic cells, B and T cells, and the self-tolerance system. Since there is the increase of the global number of vaccinated people and few of this reports of this phenomenon have described in the literature, we considered it important to disclose this case in our service.