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.