New study links IgG immunoglobulin's glycan coating with cardiovascular health

The glycan sugar coating on IgG immunoglobulin plays a crucial role in modulating immune responses and maintaining overall health. This coating, consisting of complex sugar molecules attached to the protein structure of IgG, influences various aspects of immune function, including antibody stability, binding affinity, and interaction with immune cells. Alterations in the glycan composition of IgG have been linked to various diseases, including autoimmune disorders, infectious diseases, and cancer.

The researchers studied the sugar coatings on an antibody known as immunoglobulin G (IgG), which is implicated in the immune responses associated with chronic inflammation among participants in two case-control studies.Using conditional logistic regression, they investigated the association of future CVD with baseline IgG N-glycans and a glycan score adjusting for clinical risk factors such as statin treatment, age, sex, race, lipids, hypertension, and smoking. Using least absolute shrinkage and selection operator regression, an IgG glycan score was derived as a linear combination of selected IgG N-glycans.

The study found that specific IgG N-glycans were linked to cardiovascular disease (CVD) in both case-control studies. One agalactosylated glycan (IgG-GP4) showed a positive association, whereas three digalactosylated glycans (IgG glycan peaks 12, 13, 14) and two monosialylated glycans (IgG glycan peaks 18, 20) exhibited negative associations with CVD. These findings suggest that the sugar coatings on IgG directly influence CVD risk, likely through inflammatory mechanisms. Additionally, an IgG glycan score was identified as a predictor of future cardiovascular events, independent of other risk factors.

"IgG N-glycans which are the sugar coatings that modify the IgG immunoglobulins might not be only novel biomarkers for cardiometabolic health, but also potential new drug targets," said Samia Mora, MD, MHS, of Brigham's Divisions of Preventative and Cardiovascular Medicine. "Our results represent a promising and underappreciated novel biomarker that has great potential for risk stratification, CVD prevention, diagnostics and treatment purposes."

References: https://doi.org/10.1161/CIRCRESAHA.123.323623