Identification of Anti‐Long Chain Saturated Fatty Acid IgG Antibodies in Serum of Patients with Type 2 Diabetes

High levels of serum long chain saturated fatty acids (LCSFAs) have been associated with inflammation in type 2 diabetes. Dietary SFAs can promote inflammation, the secretion of IgG antibodies, and secretion of the proinflammatory cytokine IL‐1β. This study characterizes anti‐LCSFA IgG antibodies from patients with type 2 diabetes. Serum samples from several cohorts with type 2 diabetes were analyzed for the presence of anti‐LCSFA IgG, the cytokine IL‐1β, and nonesterified fatty acids. Anti‐LCSFA IgG was isolated from patient samples and used for in vitro characterization of avidity and specificity. A cohort participating in En Balance, a diabetes health education program that improved diabetes management, tested positive for anti‐LCSFA IgG. Following the 3‐month program, the cohort showed a significant reduction in anti‐LCSFA IgG levels. Anti‐LCSFA antibodies isolated from these patients demonstrated high avidity, were specific for long chain SFAs, and correlated with serum fatty acids in patients with managed type 2 diabetes. Interestingly, anti‐LCSFA IgG neutralized PA‐induced IL‐1β secretion by dendritic cells. Our data shows that nonesterified SFAs are recognized by IgG antibodies present in human blood. The identification of anti‐LCSFA IgG antibodies in human sera establishes a basis for further exploration of lipid induced immune responses in diabetic patients.