To investigate the relationship between the macrophage M1/M2 proportion and thioredoxin (TRX) levels in the plasma of patients with acute myocardial infarction(AMI) and the coronary tissues of the dead.

A total of 100 patients with acute myocardial infarction from Luoding People's Hospital were collected as the observation group, and 50 healthy people as the control group at the same time. The TRX levels were compared between the two groups, and the macrophage M1/M2 proportion was calculated by flow cytometer. Simultaneously, 21 coronary artery specimens of AMI patients were collected from forensic department of Sun Yat-sen University as the AMI group, and 20 coronary artery specimens of patients without coronary atherosclerotic heart disease (CAD) were collected as the non-CAD group. The macrophage M1/M2 proportion was calculated, and TRX levels were detected by immunohistochemistry (IHC), quantitative polymerase chain reaction (qPCR) and Western-blotting in the specimens respectively. Pearson analysis and simple linear regression were used to study the correlation between M1/M2 proportion and TRX levels.

Compared with the control group, the M1/M2 proportion was much lower [(7.8 ± 1.3) vs. (3.1 ± 0.9), t = 13.672, P < 0.001], and the TRX levels were much higher [(100 ± 22) μg/L vs. (372 ± 17) μg/L, t = 23.654, P < 0.001] in the observation group. The M1/M2 proportion was negatively correlated with the levels of TRX (r = -0.611, P < 0.001), and the regression equation was that TRX = -13.654 × M1/M2 + 414.266 (R² = 0.549, P < 0.001). Meanwhile, the M1/M2 proportion significantly decreased [(5.56 ± 0.44) vs. (2.77 ± 0.14), t = 10.422, P = 0.005], the TRX levels detected by IHC (t = 13.537, P < 0.001), qPCR (t = 14.111, P < 0.001) and Western-blotting (t = 6.153, P < 0.001) all remarkedly increased in the AMI group as compared with the non-CAD group. And the M1/M2 proportion was negatively correlated with the TRX levels by IHC (r = -0.864, P < 0.001), qPCR (r = -0.856, P < 0.001) and Western-blotting (r = -0.868, P < 0.001). The regression equations respectively were that TRX (IHC) = -1.174 × M1/M2 + 8.992 (R² = 0.829, P < 0.001), TRX (qPCR) = -1.214 × M1/M2 + 9.418 (R² = 0.814, P < 0.001), and TRX (Western-blotting) = -0.969 × M1/M2 + 7.392 (R² = 0.837, P < 0.001).

M1/M2 proportion and TRX levels may be involved in the formation of atherosclerosis, and the M1/M2 proportion is negatively correlated with the TRX levels.