ABSTRACT
Introduction: Vaccination against SARS-Cov-2 infection has significantly reduced the incidence of severe cases. However, safety concerns have increased as possibly related side effects have been described. It is postulated that vaccination could induce different autoimmune diseases, probably due to cross-reactivity between SARS-Cov-2 proteins and human proteins. To date, more than 20 cases of post-vaccination autoimmune hepatitis (AIH) have been described in the literature. Aims & Methods: The aim of this study was to collect cases of AIH that were detected after vaccination for SARS-Cov-2 in our hospital, and to analyse their characteristics and the possible causality of the vaccine. Cases of probable or definitive autoimmune hepatitis according to the simplified criteria of the International Autoimmune Hepatitis Group that presented less than 90 days after COVID-19 vaccination were collected. All cases had to have a compatible liver biopsy and response to corticosteroids in order to be included. The following data were collected: age, sex, type of vaccine, latency, transaminase and bilirubin (BT) levels at diagnosis, liver biopsy, autoantibodies and IgG, predisposing HLA and treatment received. Result(s): Since the start of vaccination, 5 cases of altered liver biochemistry after vaccination have been detected (Table 1). Four patients were female and one male, with a mean age of 62 years. Sixty percent received Pfizer and 40% Astrazeneca. The mean time from vaccination to detection of laboratory abnormalities was 26 days. No patients showed evidence of liver failure, although there was one case of severe acute hepatitis. ANAs were positive together with elevated IgG levels in all patients. Liver biopsy was performed in 4 cases, which were compatible with AIH. Four patients were treated with systemic corticosteroids with good outcome, and three of them were prescribed azathioprine as maintenance therapy (in one patient it was contraindicated due to a concomitant diagnosis of endometrial neoplasia). Four of the patients had HLA susceptibility for IAH. The score was calculated based on the simplified diagnostic criteria of the International Autoimmune Hepatitis Group, with all patients who underwent biopsy scoring >7 points (definite autoimmune hepatitis). Four of the patients received a new dose of the vaccine at a later date. The second patient had a slight worsening of transaminases, which was related to the concomitant suspension of azathioprine due to digestive intolerance, with an improvement in blood tests when a new course of corticosteroids was started. Conclusion(s): In all of the cases presented, there is a temporal relationship with onset of the alterations less than 90 days after vaccination. Although controversial, it is postulated that vaccination could be the cause of autoimmunity, or rather play a role as a trigger for latent disease. At least 20 cases of probable AIH following vaccination have been reported in the literature, with characteristics similar to the cases presented in this study. However, at present, it is not possible to say with certainty whether the vaccine is the cause of the debut of IAH or whether it is a casual association in predisposed patients. (Table Presented).