Interleukin-23 serum level in systemic lupus erythematosus patients: Relation to disease activity and different disease parameters

Aim of the workTo assess serum level of interleukin 23 (IL-23) in systemic lupus erythematosus (SLE) patients and to evaluate its association with disease parameters and activity.Patients and methodsThe study involved 40 SLE patients and 40 controls. The SLE disease activity index (SLEDAI) and damage index (SDI) were assessed. Serum level of IL-23 was measured by enzyme linked immunosorbant assay (ELISA).ResultsPatients were 38 females and 2 males (F:M 19:1),with a mean age of 31.3 ± 7.5 years (17–50 years) and disease duration 4.8 ± 2.9 years (1–13 years). Their mean SLEDAI was 14.3 ± 6.8 (3–32) and SDI 0.4 ± 0.5 (0–2). 85% of patients had photosensitivity, alopecia in 60%, malar rash in 57.5%, oral ulcers 52.5%, arthralgia/arthritis 47.5%, serositis and lupus nephritis in 27.5%, discoid rash in 22.5% and neuropsychiatric in 2.5%. Mean serum level of IL-23 was significantly elevated in patients (107.9 ± 17.3 ng/L; 72.7–165.5 ng/mL) compared to controls (91.6 ± 19.1 ng/L; 57.6–140.3 ng/mL; p < 0.001). IL-23 was significantly elevated in patients with oral ulcers (p = 0.03), arthritis (p < 0.001), lupus nephritis (p = 0.01), alopecia (p = 0.02) and positive anti-dsDNA (p < 0.001). IL-23 significantly correlated with SLEDAI (r = 0.89, p < 0.001), complement C3 (r = -0.55, p < 0.001) and C4 (r = -0.5, p = 0.001). IL-23 could significantly predict SLE at a cut-off 93.1 ng/L (sensitivity 80% and specificity 55%).ConclusionIL-23 may be involved in the pathogenesis of SLE; especially in renal, mucocutaneous and musculoskeletal manifestations and it can be used as a disease activity biomarker. These findings support the possibility of its use as a therapeutic target in SLE.