Association of serum IgG4 and soluble interleukin-2 receptor levels with epicardial adipose tissue and coronary artery calcification

Immunoglobulin G4 (IgG4)-related immuno-inflammation may play a role in the development of coronary artery disease (CAD). We analyzed the association of serum IgG4 and soluble interleukin-2 receptor (sIL-2R) levels with epicardial fat volume (EFV) and coronary artery calcification (CAC). Serum IgG4 and sIL-2R levels were measured in 267 patients who underwent 320-slice cardiac computed tomography. The median serum levels of IgG4 and sIL-2R were higher in patients with CAD than in those without. Serum IgG4 levels were significantly greater in patients with EFV within the second and fourth quartile (≥ 75 mL) than in those with low EFV (< 75 mL) (33.5 mg/dL vs. 22.5 mg/dL). On the other hand, serum sIL-2R levels were significantly higher in patients with CAC than in those without (409 U/mL vs. 345 U/mL). In age- and gender-adjusted logistic regression analysis, the fourth quartile of IgG4 (≥ 56.7 mg/dL) was associated with EFV within the second and fourth quartile (≥ 75 mL) with an odds ratio of 3.13. Serum IgG4 levels were greater in patients with EFV within the second and fourth quartile, whereas serum sIL-2R levels were increased in patients with CAC. These two biomarkers may reflect different mechanisms underlying development of cardiovascular remodeling.