Background: Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disorder characterized by an excessive and chronic inflammatory response which is a result of abnormalities in the immune responses that cause the formation of harmful autoantibodies and inflammatory cells infiltration in target tissues.

Objectives: to investigate the possible role of urinary matrix metalloproteinase 7 (MMP7) as an early predictor of lupus nephritis (LN) flares in SLE cases by comparing the level of urinary MMP7 in SLE cases without LN, SLE cases with LN and control apparent healthy people.

Subjects and methods: This case-control study was subjected to 60 cases, Group I (SLE group): included 20 cases with SLE without nephritis. Group II (LN group): included 20 patients with LN. Group III (control group): included 20 healthy volunteers. All cases were subjected to clinical examination and laboratory tests including CBC, urine analysis, Kidney function tests, 24-hour proteinuria, C3, C4, ANA, and Anti dsDNA antibodies. Urinary and Serum MMP7 levels were detected by ELISA.

Results: A highly remarkable variance was found between the three groups regarding serum and urinary MMP7. Regarding serum MMP7, it was notably higher in both SLE patient (p<0.001) than control group. urinary MMP7, it was markedly elevated in both SLE cases groups (p<0.001) than in group III, also, remarkably higher in SLE cases with LN than in cases without LN (p <0.001).

Conclusion: Our study evaluates the role urinary MMP7 in SLE patients as anon invasive biomarker which can be useful as a marker of prediction of LN flares