key: cord-0917679-3mkf0h51
authors: Sasaki, Hironobu; Itoh, Arata; Itoh, Hiroshi
title: Could the development of COVID-19 vaccine-induced type 1 diabetes be explained by a simple mechanism?
date: 2022-03-09
journal: Diabetes Metab
DOI: 10.1016/j.diabet.2022.101338
sha: b57351036aece753686dd400b2061d68ffd6283a
doc_id: 917679
cord_uid: 3mkf0h51

nan

To the editor, We read with great interest the article "Fulminant type 1 diabetes (T1DM) after Covid-19 vaccination" by Tang et al. in this journal [1] . The authors examined islet autoantibodies, HLA alleles, and the capacity for insulin secretion specifically after the treatment of a 50-year-old patient who developed diabetic ketoacidosis following Covid-19 vaccination. The work and efforts of the authors in reporting this valuable case are highly appreciated. Almost simultaneously, cases of acute-onset T1DM in Japanese women induced by Covid-19 vaccination were reported [2, 3] , including the case we presented. In these cases, both patients were administered mRNA vaccines, and the patients' islet autoantibodies were positive, which was different from the type of vaccine and characteristics of T1DM reported in this journal. However, very interestingly, in agreement with this journal's report, both patients had one of the disease-susceptible HLA haplotypes, i.e., DRB1*04:05-DQB1*04:01 [2] and DRB1*09:01-DQB1*03:03 [3] , so we totally agree with the authors' opinion that vaccination of genetically susceptible recipients should be cautious concerning future development of T1DM. Although the authors made little mention about the mechanisms of the development of vaccine-induced T1DM, we would focus on the difference in the time from vaccination to the appearance of hyperglycemic symptoms between this case and the previous reports of Covid-19 vaccine-induced acute-onset T1DM. That is, in the present report [1] , hyperglycemic symptoms occurred within just one week after the first vaccination, whereas these symptoms in new-onset of T1DM with positive for autoantibodies occurred four to seven weeks after the first or second vaccination [2] [3] [4] , indicating a clear difference. Although we cannot exclude the possibility that this discrepancy was attributable to the different types of vaccines, i.e., inactivated vaccine [1] versus mRNA vaccine [2] [3] [4] , such a wide variation in the duration of disease onset suggests that there might be no single mechanism of beta-cell destructions and the development of hyperglycemia associated with Covid-19 vaccination [2] . In the former case, negative autoantibodies and the earlier onset suggested that direct damage to beta cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins or proinflammatory cytokines induced by Covid-19 vaccination might be the primary etiology. Indeed, some researchers suggested that direct infection with SARS-CoV-2 triggers apoptosis and transdifferentiation of beta cells [5] . On the other hand, the latter might require a certain period for the process of cross-immunity [2] . Since the major histocompatibility complex class II molecules of these patients are made from disease-susceptibility genes, vaccination of patients having these genes could easily trigger autoimmunity if the presented viral antigen proteins are similar to beta-cell

Fulminant type 1 diabetes after Covid-19 vaccination

Newly developed type 1 diabetes after coronavirus disease 2019 vaccination: A case report

A Case of new-onset type 1 diabetes after Covid-19 mRNA vaccination

A case of Graves' disease and type 1 diabetes mellitus following SARS-CoV-2 vaccination

Pancreatic β-cell fate in subjects with Covid-19

antigens. We expect that the pathogenesis of new-onset T1DM following Covid-19 vaccination will be clarified by accumulating detailed information on the time from vaccination to the onset, the presence of islet autoantibodies, and genetic background, and investigating their relationships.

The authors declare no conflicts of interest.

No funds were provided for this report.