Immunoglobulin E Sensitization to Mammalian Oligosaccharide Galactose-alpha-1,3 (alpha-Gal) Is Associated With Noncalcified Plaque, Obstructive Coronary Artery Disease, and ST-Segment-Elevated Myocardial Infarction

BACKGROUND: Treating known risk factors for coronary artery disease (CAD) has substantially reduced CAD morbidity and mortality. However, a significant burden of CAD remains unexplained. Immunoglobulin E sensitization to mammalian oligosaccharide galactose-alpha-1,3-galactose (alpha-Gal) was recently associated with CAD in a small observational study. We sought to confirm that alpha-Gal sensitization is associated with CAD burden, in particular noncalcified plaque. Additionally, we sort to assess whether that alpha-Gal sensitization is associated with ST-segment-elevated myocardial infarction (STEMI) METHODS: We performed a cross-sectional analysis of participants enrolled in the BioHEART cohort study. We measured alpha-Gal specific-immunoglobulin E antibodies in serum of 1056 patients referred for CT coronary angiography for suspected CAD and 100 selected patients presenting with STEMI, enriched for patients without standard modifiable risk factors. CT coronary angiograms were assessed using coronary artery calcium scores and segmental plaque scores. RESULTS: alpha-Gal sensitization was associated with presence of noncalcified plaque (odds ratio, 1.62 [95% CI, 1.04-2.53], P=0.03) and obstructive CAD (odds ratio, 2.05 [95% CI, 1.29-3.25], P=0.002), independent of age, sex, and traditional risk factors. The alpha-Gal sensitization rate was 12.8-fold higher in patients with STEMI compared with matched healthy controls and 2.2-fold higher in the patients with STEMI compared with matched stable CAD patients (17% versus 1.3%, P=0.01 and 20% versus 9%, P=0.03, respectively). CONCLUSIONS: alpha-Gal sensitization is independently associated with noncalcified plaque burden and obstructive CAD and occurs at higher frequency in patients with STEMI than those with stable or no CAD. These findings may have implications for individuals exposed to ticks, as well as public health policy. REGISTRATION: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001322224.