The Association between Peripheral Blood Levels of B-regulatory Lymphocytes and Clinically Unstable Coronary Artery Disease

Objective: Previous studies showed that inflammatory process within atherosclerotic plaque could be implicated in rendering the plaque’s fibrous cap thinner and more prone to rupture, thus influencing plaque’s instability. Several anti-inflammatory lymphocytes have lower levels and diminished activity in patients with unstable coronary artery disease (CAD). The anti-inflammatory role of B-regulatory lymphocytes (B-regs) was demonstrated in several autoimmune diseases. Their role in atherosclerosis was examined in animal models with inconclusive results. Nobody until now examined role of B-regs in clinical course of CAD.

Approach: We examined the levels of several subgroups of B-regs in peripheral blood of patients with acute myocardial infarction (MI) and healthy individuals.

Results: We recruited 24 patients with acute MI and 22 healthy individuals and compared levels of several subgroups of B-regs in their peripheral blood. We also compared the levels of these cells several days following acute MI and several months after the event in nine patients. The levels of CD24+CD38+ B lymphocytes were significantly lower in patients after acute MI than in healthy individuals (24.9±13.3% in patients with MI vs 43.2±9.7% in healthy individuals, p-value<0.001). The levels of B-regs in patients with MI did not change significantly after several months.

Conclusions: This study implies that low level of B-regs can be considered a marker of patients with unstable CAD. It also suggests that lower level of B-regs is a permanent condition, which makes the patients prone to plaque rupture and a less stable clinical course of the CAD.