الفهرس 
Acknowledgement
Epidemiology of lupus nephritisOnly 14 pages are availabe for public view
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Abstract
Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease characterized by heterogeneous, multisystem involvement and the production of an array of autoantibodies. Renal involvement in SLE remains the strongest predictor of overall patient morbidity and mortality. Despite many years of experience and numerous studies, LN management still remains a challenge for clinicians. The activity of LN cannot be completely estimated by the clinical picture or the laboratory tests – the only possibility is to assess the histopathological pattern of the kidney specimen by renal biopsy. In the previous decade, because the need for newer biomarkers of LN encouraged the researchers to focused on dissecting the pathogenesis of LN in details with a goal to find a genetic or biochemical players of LN that could reflect the disease activity better and have translational significance as biomarkers. TWEAK is a multifunctional cytokine that belongs to the tumor necrosis factor (TNF) superfamily. The expression of TWEAK has been shown to increase dramatically during inflammation and injury of kidney. So there is a growing appreciation for the pathological role of TWEAK pathway in LN .The awareness of this fact, inspired us to investigate urinary TWEAK (uTWEAK) levels in cross section study of SLE patients with active and non active LN and correlate the finding with other disease variables, standard laboratory investigations used to assess renal function and disease activity and damage indices. This study included 42 patients with SLE .All patients fulfilled the SLICC/ACR classification of SLE attended to the outpatient or inpatient unit at physical medicine, Rheumatology and Rehabilitation department, Faculty of Medicine, Assiut University Hospitals. 20 age /sex and ethnic matched healthy volunters subjects were enrolled in the study as control group. The patients were clinically and laboratory evaluated. Activity was assessed using the renal SLEDAI score and the renal damage assessed using SLE renal damage index (SDI). SLE patients were classified into 2 groups (group I=Active LN and group II= Non active LN) based on renal parameters of SLEDAI score. uTWEAK levels were measured using ELISA in SLE patients and controls. Renal biopsy was taken from SLE patients with active LN (group I). uTWEAK levels were significantly higher in SLE patients compared with normal control . Among SLE patients, uTWEAK levels were significantly higher in patients with active LN than non active LN. uTWEAK of the patients with active LN correlated significantly with the renal SLEDAI score, the activity index, the endocapillary hypercellularity, the cellular cresent, the fibrinod necrosis and tubular atrophy . A ROC curve was constructed for the uTWEAK levels and renal disease activity in all SLE patients to quantify the diagnostic utility of this biomarker at cutoff > 4.5. The uTWEAK had a sensitivity of 77.3% and specificity of 90.0% for renal disease activity. Our results support the notion that uTWEAK is an ideal biomarker for identifying LN activity. So, the measurement of uTWEAK in routine follow-up of LN patients may result in earlier diagnosis of LN activity and institution of appropriate treatment. In conclusion, uTWEAK could be a potential biomarker for renal disease activity in adult SLE patients.