Clinical utility of serum Galactin-9 in evaluation of systemic lupus erythematosus patients

Abstract

Aim of the work

To evaluate the levels of serum Galactin-9 (Gal-9) in systemic lupus erythematosus (SLE) patients and to assess its association with disease activity, severity, and renal affection.

Patients and methods

The study included 50 SLE patients and 50 matched controls. SLE disease activity index (SLEDAI) was assessed and patients subdivided into active (SLEDAI > 4) and inactive (SLEDAI ≤ 4). Renal affection in SLE patients was assessed by rSLEDAI. Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR-DI) was assessed.Serum Gal-9 levels were measuredby Enzyme-Linked Immunosorbent Assay (ELISA).

Results

The mean age of SLE patients was 31.1 ± 8.7 years and the majority of studied groups were females. Gal-9 was significantly higher in SLE patients in comparison to healthy control (890.1 ± 1740.4 vs. 266.8 ± 37.9 ng/L); p < 0.0001) and in active compared to inactive LN patients (1377.9 ± 2273.8 vs. 317.6 ± 40.4, P < 0.001) was detected. Serum Gal-9 correlated with anti-dsDNA positivity (r = 0.29, p = 0.04), SLEDAI (r = 0.61, p ≤ 0.0001), and rSLEDAI (r = 0.61, p ≤ 0.0001). At a cut-off value of 299 ng/l Gal-9 can significantly differentiate SLE patients from controls (AUC 0.97; p < 0.0001) at a sensitivity of 88 %, specificity of 75 %, and accuracy of 83.3 %. Gal-9 at a cut-off value 335 ng/l can significantly differentiate active from inactive SLE patients (AUC 0.94; p < 0.0001) at a sensitivity of 90 %, specificity of 84.2 %, and accuracy of 88 %. Gal-9 was significant predictor for SLE activity.

Conclusion

The serum Gal-9 levels were significantly high in SLE patients compared to healthy controls and these high levels were associated with disease activityand renal affection in SLE patients.