[Relationship between anti-ENO1 antibody and systemic lupus erythematosus patients with retinopathy]

To build bridges between anti-α enolase antibody (anti-enolase 1 antibody, anti-ENO1 antibody) and common clinical and laboratory characteristics of systemic lupus erythematosus (SLE) and to analyze the role of anti-ENO1 antibody in the evaluation of SLE disease activity.

The SLE patients with retinopathy and without retinopathy were enrolled in the study, as well as healthy individuals whose gender and age matched with those of the SLE patients. Serum anti-ENO1 antibodies were measured using enzyme-linked immunosorbent assay (ELISA), presenting as intra-group positive rate and arbitrary units (AU) value. Clinical and laboratory data were obtained from medical records.

The SLE retinopathy patients represented various fundus abnormalities. Ranked by percentage, the top three retinopathies were retinal hemorrhage (14/32, 43.75%), cotton-wool spots (8/32, 25.00%) and retinal vein occlusion (3/32, 9.38%). Among the 32 SLE retinopathy patients, 13 (40.63%) suffered from two or more fundus abnormalities. The positive rate and AU value of the SLE patients were higher than of the SLE patients without retinopathy (68.75% vs. 46.00%, P=0.043; 16.11%±10.35% vs. 12.06%±6.47%, P=0.045). Besides, the positive rate and AU value of the two SLE groups were both significantly higher than those of the healthy control group (P < 0.001). Compared with the SLE-without-retinopathy group, the systemic lupus erythematosus disease activity index (SLEDAI)-2000 of the SLE retinopathy patients were significantly higher than those of the SLE patients without retinopathy (17.41±4.25 vs. 9.48±5.35, P < 0.001). Dividing all the SLE patients into an anti-ENO1-positive group and an anti-ENO1-negative group, we found that anti-ENO1-positive was more likely to be correlated to developing fever and positive result of urine occult blood (P=0.011, P=0.042). Comparing with the patients with negative anti-ENO1 antibodies, the patients with positive anti-ENO1 antibodies had significantly higher erythrocyte sedimentation rate (ESR) [the median (range) was 29.50 (1.52-110.00) mg/L vs. 12.00 (4.00-101.00) mg/L, P=0.001], higher immunoglobulin G (IgG) [the median (range) was 14.30 (4.02-37.80) g/L vs. 10.46 (2.50-25.73) g/L, P=0.000 3], and higher blood platelet count (PLT) [(205.87×10⁹±67.98×10⁹) /L vs. (164.57×10⁹±69.57×10⁹) /L, P=0.008], as well as higher immunoglobulin A (IgA) [the median (range) was 2.85 (0.07-27.00) g/L vs. 2.05 (0.42-4.36) g/L, P=0.014].

The positive rate and AU value of anti-ENO1 antibody suggested higher SLE disease activity and they were elevated in SLE and SLE retinopathy.