Anti-α-actinin antibodies in relation to new-onset systemic lupus erythematosus and lupus nephritis

The aim of this study is to investigate the role of anti-α-actinin antibodies in patients with new-onset systemic lupus erythematosus (SLE). Thirty-six patients with SLE, 16 of whom had lupus nephritis (LN), and 53 healthy controls were included. The clinical and laboratory parameters of patients were collected from medical records or by questionnaire. Serum anti-α-actinin Abs was measured by competitive enzyme linked immunosorbent assay (ELISA). Our results show that the OD value of serum anti-α-actinin Abs in SLE patients was significantly lower than that in normal controls (1.212 ± 0.244 vs. 1.364 ± 0.202, P = 0.002); seven of 36 SLE patients were seropositive for anti-α-actinin Abs, which was significantly higher than in normal controls (19.4 vs. 3.8%, P = 0.028). There were no significant differences of clinical parameters between the anti-α-actinin Abs-positive patients and the negative patients. The positive rate of the term urine casts, elevated IgM and IgA in anti-α-actinin Abs-positive patients were higher than that in the negative patients. The OD values of serum anti-α-actinin Abs negatively correlated with disease activity (Rs = −0.352, P = 0.035). Anti-α-actinin Abs may be a useful marker of the disease activity of SLE; in addition, it may be used as a complementary parameter to differentiate LN from SLE without nephritis.