Characterization of Anti-Insulin Antibodies in Type 1 and Type 2 Diabetes Mellitus: Clinical Relevance

The administration of insulin as a treatment for diabetes frequently leads to the formation of anti-insulin antibodies (IAs). The influence of these antibodies on the efficacy and safety of insulin therapy remains incompletely understood. This study presents a systematic, exploratory, cross-sectional analysis of the quantitative and qualitative properties of IAs in 101 patients with type 1 diabetes (T1D) and 101 patients with type 2 diabetes (T2D). The goal was to identify subpopulations of IAs that might impact glycemic control. We assessed the presence, titer, isotype, subclass, avidity, and in vitro neutralizing capacities of IAs, using glycated hemoglobin A1c (HbA1c) levels as an indicator of the clinical effectiveness of insulin. Our findings showed that 72% of individuals with T1D and 32% with T2D developed IAs, with IgG being the predominant isotype in both groups. Despite the presence of IAs, no in vitro neutralizing effect against insulin was observed, and there was no significant correlation between IA titer or avidity and HbA1c levels in either group. The results from this study demonstrate that while IAs are prevalent in both T1D and T2D, they do not have a significant clinical impact on the outcomes of insulin therapy in our study populations.