Prevalence of Antiphospholipid Antibodies in Greek Individuals with Type 1 Diabetes and Their Association with Diabetes-Related Complications

Background/Objectives: Antiphospholipid antibodies (aPL) comprise anticardiolipin antibodies (aCL), antibodies against β2 glycoprotein I (anti-β2GPI) and lupus anticoagulant (LA). LA is an established risk factor for thrombosis and pregnancy morbidity in the general population. In people with type 1 diabetes (T1D), aPL have been proposed as potential predictors of microvascular and macrovascular diabetes-related complications. The aim of the present prospective, observational study was to investigate the prevalence of aPL in a well-defined cohort of adults presenting with uncomplicated T1D compared with healthy controls. In addition, we prospectively examined whether aPL titers or positivity were potentially associated with the subsequent development of diabetes-related complications. Methods: Two hundred (200) adults with T1D and without microvascular or macrovascular complications participated (mean age, 37.9 ± 10.6 years; mean diabetes duration, 21.00 ± 9.20 years). We also included 200 age- and sex-matched healthy controls (mean age, 37.7 ± 10.1 years) without diabetes mellitus or other autoimmune diseases. The aPL panel, including aCL ΙgG/IgM, anti- β2GPI IgG/IgM, and LA, was assessed using standardized laboratory methods. Participants with T1D were re-evaluated after a mean follow-up of 7.6 years. Results: Titers of aCL IgG/IgM and anti-β2GPI IgG, as well as positivity of aCL-IgG and aCL-IgM, were higher in participants with T1D compared with healthy controls, whereas LA positivity was very low in both groups. In the T1D group, aCL-IgG titers significantly correlated with age and diabetes duration. Neither aCL-IgG titers nor positivity was associated with the development of microvascular or macrovascular complications or with all-cause mortality during follow-up. Conclusions: In adults with long-standing, uncomplicated T1D, most aPL titers and positivity rates were higher than those observed in healthy controls. However, aCL-IgG titers and positivity were not associated with the subsequent development of diabetes-related complications. Larger prospective studies are required to determine whether aPL have predictive value for diabetes-related complications and to identify subgroups of people with T1D who may benefit from aPL testing.