The relationship between serum iron levels and AChR-Ab and IL-6 in patients with myasthenia gravis.

Abstract

To investigate the correlation between serum iron (SI) levels and acetylcholine receptor antibodies (AChR-Ab) and interleukin 6 (IL-6) in patients with myasthenia gravis (MG). A total of 76 patients with myasthenia gravis (MG group) between July 2015 to March 2018, and another 50 healthy subjects during the same period were selected for this study. SI levels in the peripheral blood serum of all participants were measured using the colorimetric method (a SI level of < 8.95 umol/L was considered the standard for SI deficiency). Enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA) were used to detect the expression and levels of IL-6 and AChR-Ab in the peripheral blood of all participants. The presence and levels of IL-6 and AChR-Ab in the serum of MG patients and normal healthy subjects were compared. The levels of IL-6 and AChR-Ab in MG patients with normal SI levels and those with SI deficiency were analyzed. The SI deficiency rate, AChR-Ab positivity rate, AChR-Ab levels, and IL-6 levels in the MG group were significantly higher than those in the control group (73.68% vs. 26.00%, 81.58% vs. 0.00%, 1.05 ± 0.40 nmol/L vs. 0.21 ± 0.09 nmol/L, and 183.54 ± 35.26 ng/mL vs. 121.43 ± 28.45 ng/mL, respectively; all p-values were < 0.01). In MG patients, the levels of AChR-AB and IL-6 in the SI deficiency group were significantly higher than those in the normal SI group (1.15 ± 0.34 nmol/L vs. 0.81 ± 0.45 nmol/L and 193.12 ± 31.70 ng/mL vs. 156.74 ± 31.19 ng/mL, respectively; all p-values were < 0.01). The correlation analysis showed that SI levels were negatively correlated with AChR-AB and IL-6 levels in MG patients (r = -0.776, r = -0.663, both p-values were < 0.01). Iron deficiency in MG patients and SI levels are negatively correlated with AChR-Ab and IL-6 levels in MG patients.