Serum level of CXCL 12 in patients with systemic lupus erythematosus: Is it worthy for predilection of lupus nephritis?

Aim of the work: To assess serum level of CXCL12 in systemic lupus erythematosus (SLE) patients and to study its relation to clinical features, disease activity and damage. Patients and methods: Forty SLE patients and 40 controls were included. SLE disease activity index (SLEDAI) and the damage index were assessed. Serum CXCL12 level was measured using ELISA and renal biopsy done. Results: The mean age of the patients was 34.5 +/- 10.4 years, disease duration 5 +/- 5.2 years and were 38 females and 2 males (F:M 19:1). Renal biopsy was performed in 16 patients; 6 had inactive and10 active lupus nephritis (LN); 24 without signs suggestive of LN. Serum level of CXCL12 was significantly higher in patients (30.8 +/- 16.9 ng/ml) than controls (20.2 +/- 15.3 ng/ml) (p = 0.004). CXCL12 in patients with active LN (53.2 +/- 25.3 ng/ml) was significantly elevated than those without LN (27 +/- 12.5 ng/ml)(p < 0.001); and tended to be higher than those with inactive LN (34.2 +/- 8.3 ng/ml)(p = 0.31). Levels were comparable between those with inactive LN and those without LN (p = 0.34). A significant correlation was found between serum CXCL12 and each of platelet count (p = 0.02), ANA titer (p = 0.007) and serum creatinine (p = 0.014). No significant correlations was found between CXCL12 and either SLEDAI (p = 0.59) or the damage index (p = 0.48). Alopecia was inversely associated with CXCL12 (p = 0.02). Conclusion: CXCL12 is a potential key-player for SLE development. Adding this test to ANA, serum creatinine, platelet count and renal biopsy findings may enhance their diagnostic capacity for lupus nephritis and can help in early management and prediction of its prognosis. (C) 2020 Egyptian Society of Rheumatic Diseases. Publishing services provided by Elsevier B.V.