Islet autoantibodies as predictors of type 1 diabetes development, a systematic review with public health implications for Africa.

backgroundEarly identification of individuals at high risk of developing type 1 diabetes (T1D) remains a major public health priority. Islet autoantibodies are widely recognised as key biomarkers of autoimmune beta-cell destruction and disease progression; however, their predictive performance across diverse populations, particularly in African settings, has not been comprehensively synthesised. This study systematically reviews and synthesises evidence on the predictive value of islet autoantibodies for T1D development, with particular attention to emerging evidence from Africa.

methodA systematic review was conducted in accordance with PRISMA 2020 guidelines. Literature searches were performed across PubMed, Scopus, Web of Science, and Embase for studies published between 2000 and 2026. Eligible studies included longitudinal and observational investigations assessing the relationship between islet autoantibody positivity and subsequent T1D development. Data were extracted on study characteristics, autoantibody profiles, and effect measures. Qualitative synthesis was conducted for all eligible studies, while a restricted random-effects quantitative synthesis was undertaken for studies reporting sufficiently comparable outcomes. Risk of bias and certainty of evidence were assessed using established frameworks.

resultsForty-seven studies were included in the qualitative synthesis, including eight studies conducted in African populations or specifically addressing African diabetes phenotypes. A restricted subset of studies contributed to the quantitative synthesis. Across these studies, elevated autoantibody titres and multiple-autoantibody positivity were consistently associated with increased risk of progression to T1D. The restricted quantitative synthesis suggested an approximately threefold higher risk among individuals with elevated or multiple-autoantibody profiles (RR = 3.47, 95% CI: 2.57-4.68), although interpretation should be cautious given the limited number of comparable studies. High-affinity autoantibodies measured using advanced assays demonstrated stronger predictive performance. African studies highlighted substantial heterogeneity in disease phenotype, including lower autoantibody prevalence, later age at diagnosis, preserved endogenous insulin secretion, and evidence of non-autoimmune insulin-deficient diabetes, indicating that predictive models developed in high-income settings may not be directly transferable.

conclusionIslet autoantibodies remain important predictors of T1D development, particularly when multiple antibodies are present. However, substantial regional heterogeneity exists, especially in African populations, where atypical diabetes phenotypes are increasingly recognised. These findings support the clinical utility of autoantibody-based risk stratification while underscoring the need for region-specific validation studies, longitudinal African cohorts, and contextually appropriate screening strategies before widespread implementation.