Interferon Gamma-Induced Protein 10 (IP-10): A Potential Marker for Lupus Nephritis

Background: Lupus nephritis (LN) is the most common cause of kidney injury in patients with systemic lupus erythematosus (SLE). Interferon gamma–induced protein 10 (IP10) has been linked to LN and overall SLE disease activity. Aim and Objectives: To assess serum levels of IP10 in patients with LN and evaluate their relationship to LN activity. Subjects and Methods: 34 female patients with LN were recruited from the inpatient and outpatient clinics of the Rheumatology Department, Maadi Armed Forces Hospital, along with a sex and age matched healthy control group. All participants underwent detailed history taking, clinical examination, laboratory investigations, SLE Disease Activity Index 2000 (SLEDAI2K) scoring, renal SLEDAI2K assessment, and Systemic Lupus International Collaborating Clinics (SLICC) damage index evaluation. Serum IP10 levels were measured and compared between patients and controls. Results: Compared with the matched controls, patients with LN had significantly higher serum IP10 levels (p < 0.001). Among LN patients, those with active disease had significantly higher SLEDAI2K scores and markedly elevated serum IP10 levels compared to inactive cases (p < 0.001). ROC curve analysis demonstrated excellent predictive performance of serum IP10 for active LN >215 pg/ml with sensitivity of 84% and specificity of 100% and AUC of 91%. Conclusion: Serum IP10 are promising biomarkers for identifying active LN and differentiating it from inactive disease. Their strong predictive accuracy supports their potential role in clinical monitoring and early detection of renal flares in SLE.