Free light chains a novel biomarker of cardiovascular disease. A pilot study.

OBJECTIVE: Atherosclerosis and ischemic heart disease (IHD) are the major cause of morbidity and mortality but their inflammatory pathogenesis is still unclear. In this scenario, the role of serum free light chains (sFLC) has never been fully evaluated. The aim of the present study is to assess the clinical and pathogenetic role of sFLC in patients with IHD and to propose their use as a new biomarker for cardiovascular disease. PATIENTS AND METHODS: We enrolled 117 patients, divided into 5 cohorts: 15 healthy controls, non-diabetic and without ischemic heart disease; 19 patients with type 2 diabetes (T2DM), without ischemic heart disease at recruitment; 39 patients with stable chronic angina; 27 patients with NSTEMI, 17 patients with acute STEMI. Serum sFLC and high-sensitive C-reactive protein (hs-CRP) were measured. Patients also underwent a transthoracic echocardiographic study. RESULTS: sFLC were higher in patients with IHD and T2DM. However, we did not find statistically significant differences in sFLC concentration among subgroups. No correlation resulted between sFLC and hs-CRP levels. The median value of the sFLC κ/λ ratio in the population was 0.63, therefore stratifying it into two groups according to their levels. We found that an increase in left ventricular ejection fraction at 12 months was detected in 77% of patients with κ/λ ratio higher than 0.63 and 25% of patients with κ/λ ratio lower of 0.63 (p=0.016, OR=10.0 [1.8-55.6]). CONCLUSIONS: Our study suggests that the sFLC, produced by the B-lymphocytes in the context of generalized immune activation, could play a pathogenetic role in acute coronary syndromes and that they could represent a novel risk biomarker of cardiovascular disease.