Urinary tissue factor (uTF), tissue factor pathway inhibitor (TFPI) and plasmin as novel biomarkers in early diagnosis of lupus nephritis.

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease, with multi systematic affection. Lupus nephritis (LN) is the most frequent cause of renal damage in SLE patients with variable presentations that may progress to end stage renal failure. Coagulation disorders are frequently reported in SLE and LN with higher mortality rates. Renal biopsy is an invasive process, and the existing indicators for LN diagnosis and activity are unreliable. New urinary biomarkers with significant validity, safety, and accuracy are the current focus of most studies. Our study sought to assess the value of urinary tissue factor (uTF), tissue factor pathway inhibitor (TFPI), and plasmin as biomarkers for the early identification and detection of LN and its activity. This was a cross-sectional study, included 100 subjects (80 SLE patients, and 20 healthy controls), they were recruited from the Internal Medicine department, Rheumatology and Nephrology units and outpatient's clinics at Assiut University hospital between the period of 2020 and 2022. All patients underwent full history taking, clinical evaluation, and activity scoring calculation and laboratory investigations. The results showed that the best diagnostic accuracy of LN was observed with TFPI (90% accuracy, sensitivity 80% and specificity 95% with p <0.001 at cutoff point of >193.2 ng/ml), followed by uTF (75.4% overall accuracy at cut off point of >12.6 ng/ml, sensitivity 90% and specificity 68% with p < 0.001) and plasmin (70.3% accuracy at cut off point of >30.5 ng/ml, sensitivity 55% and specificity 78% with p < 0.001). Urinary TFPI was the best predictor of LN occurrence with odd ratio of 4.34, (p < 0.001). In conclusion urinary TFPI could be used as a diagnostic marker for LN with high accuracy and an early predictor of LN.

Anti-C1q antibodies, sCD40L, TWEAK and CD4/CD8 ratio in systemic lupus erythematosus and their relations to disease activity and renal involvement.

Due to the unpredictable nature of lupus nephritis (LN), it would be clinically valuable to discover a reliable biomarker for disease activity and progression. The aim of this study is to evaluate the role of anti-C1q antibodies, sCD40L and TWEAK in systemic lupus erythematosus (SLE) and their relation to disease activity and kidney involvement. This study included 47 patients with SLE, 28 with LN and 19 without LN, as well as, 20 healthy subjects as controls. All subjects underwent complete history, examination and estimation of disease activity index (SLEDAI) and renal SLEDAI. The following investigations were done for all subjects: anti-C1q antibodies, sCD40L, TWEAK and CD4/CD8 ratio, in addition to complete blood picture, ESR, kidney function tests, ANA, anti-ds DNA antibodies and C3, C4. Anti-C1q antibodies, sCD40L and TWEAK and anti-dsDNA were significantly higher in SLE patients than controls (P < 0.001 for each), while C3, C4 and CD4/CD8 ratio were significantly lower (P < 0.001, 0.05 and 0.001 respectively). In LN patients, anti-C1q antibodies, sCD40L and TWEAK were significantly higher than non LN patients (P < 0.001 for each). Anti-C1q antibodies, sCD40L and TWEAK correlated with traditional disease activity parameters (C3, C4, anti-dsDNA and SLEDAI) as well as rSLEDAI. Levels of serum TWEAK correlated with the development of LN in patients with SLE. We concluded that anti-C1q antibodies, sCD40L and TWEAK may be used as serum biomarkers for the assessment of disease activity and development of LN.