LADA: A Type of Diabetes in its Own Right?

Autoimmune diabetes mellitus after COVID-19 vaccination in adult population: a systematic review of case reports

BACKGROUND

Autoimmune/type 1 diabetes mellitus (T1DM) is a recently described rare occurrence following the administration of adjuvants such as coronavirus disease 2019 (COVID-19) vaccines. This systematic review aimed to review all available literature on the potential association between COVID-19 vaccines and T1DM.

METHODS

The Directory of Open Access Journals, MEDLINE, Google Scholar, and Scopus were systematically searched for all published studies from inception to July 2022. Articles reporting T1DM development within 8 weeks of administration of COVID-19 vaccine were included. Two reviewers independently performed the risk of bias assessment following the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports.

RESULTS

Eight eligible studies were retrieved, comprising 12 patients diagnosed with T1DM after being vaccinated with a COVID-19 vaccine. Six patients (50%) reported T1DM after receiving the second dose. Five patients (41.7%) presented with diabetic ketoacidosis, of which four presented within the first eight days after vaccination. Five patients (41.7%) had genetic susceptibility, with RNA binding motif protein 45 (RBM45/DRB1) and major histocompatibility complex, class II, DQ beta 1 (HLA-DQB1) mutations being prominent.

INTERPRETATION

In this review, we have shown a small number of new-onset diabetes cases coincidently occurring soon after the COVID-19 vaccine, especially in those with genetic susceptibility. Despite being older, these patients had a similar phenotype to T1DM. While there might be a causal relationship between COVID-19 vaccines and T1DM development, this should not influence decisions regarding vaccination since the overall benefit outweighs the risk. Further larger prospective trials are needed to assess causal relationship and to clarify the potential roles of COVID-19 vaccine-derived antigens in autoimmune disease development.

PROTOCOL REGISTRATION

PROSPERO-CRD42022342093.

Identification and phenotypic characterization of patients with LADA in a population of southeast Mexico

Latent autoimmune diabetes in adults (LADA) has clinical and metabolic features of type 1 and type 2 diabetes. LADA does not have specific features for its diagnosis apart from autoantibody detection; however, these tests are not affordable in clinical settings. In this cross-sectional study, we analyzed clinical criteria, metabolic control, pharmacological treatment, and diabetic complications in two groups of patients with diabetes -LADA and T2D- in order to identify specific characteristic of these clinical entities. Finally, we evaluated if the estimated glucose disposal rate (eGDR) and age at diagnosis of diabetes could be used as a diagnostic criterion for LADA. Demographic, biochemical, clinical and treatment were measured in 377 individuals with diabetes. The diagnostics of LADA were determined using Glutamic acid decarboxylase autoantibodies levels. Chi-square test or t-Student test were used to establish differences between groups. To identify factors associated with LADA, a logistic regression analysis was used. Finally, a ROC curve was plotted to assess the possible variables as diagnostic criteria for LADA. The 377 patients with diabetes were separated into 59 patients with LADA and 318 patients with T2D. Patients with LADA showed lower fasting glucose values, fewer diabetic complications, younger age at diagnosis of diabetes, higher insulin use, and higher eGDR in comparison to patients with T2D. Both groups had a mean BMI classified as overweight. The ROC evaluated the sensitivity and specificity, this analysis indicated that an age younger than 40.5 years and an eGDR value higher than 9.75 mg/kg/min correlated better with LADA. These parameters could be useful to identify patients suspected to have LADA at the first level of medical care in the population of southeastern Mexico and refer them to a second level of care.

Atypical diabetes: a diagnostic challenge

In medical school, we learned how to classify diabetes according to different clinical characteristics. However, at the dawn of the precision medicine era, it is clear that today's clinical reality does not always align well with textbook teachings. The terms juvenile versus elderly-onset diabetes, as well as insulin-dependent versus non-insulin-dependent diabetes, have become obsolete. Contrary to what is often taught severe ketoacidosis may occur in type 2 diabetes. Patients may also suffer from two or more forms of diabetes simultaneously or consecutively. Five authentic cases of diabetes with uncommon characteristics that pose diagnostic challenges are presented here.