Assessment of IgG N-Glycan patterns in adult patients with immune thrombocytopenia and healthy individuals.

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by a platelet count less than 100,000/μL caused by increased immune-mediated destruction of platelets and, in some cases, impaired platelet production in the bone marrow. Previous studies have shown that in various pathological conditions, such as inflammatory and autoimmune diseases, changes in the composition of glycans occur, and that these differences have a significant impact on the progression of various diseases. We examined changes in the glycosylation of immunoglobulin G (IgG) in ITP in a prospective study that was conducted in the Division of Hematology at the University Hospital Centre Zagreb from 2015 to 2021. The study included 56 adult patients with ITP and 26 healthy controls. Liquid chromatography based on hydrophilic interactions was used for glycan analysis. Patients with ITP had a statistically significantly lower proportion of sialylated glycans and an increased proportion of agalactosylated structures. This could be associated with reduced anti-inflammatory activity of IgG and increased complement activation, all of which result in increased destruction of platelets. Analysis of IgG glycosylation in patients with ITP could have significant implications for understanding the pathophysiology of the disease and potentially become a useful biomarker for the diagnosis of ITP.