Intrarenal Venous Thrombosis as an Initial Presentation of Systemic Lupus Erythematosus in a Young Woman: A Case Report

Introduction: Systemic lupus erythematosus is an autoimmune disease characterized by various clinical presentations, including thrombotic complications associated with antiphospholipid (APS) antibodies. Intra-renal venous thrombosis (IRVT) is a rare clinical entity that requires histopathological examination to establish the diagnosis. It can result in complications such as AKI. We are reporting a case of IRVT as a rare initial presentation of SLE. Case Description: A 22-year-old healthy Hispanic woman presented with a 3-day history of anorexia, nausea, vomiting, and acute, bilateral flank pain. She denied fever, dysuria, or hematuria. Vital signs were normal. AKI (serum creatinine 3.66 mg/dL), hypoalbuminemia (2.9 g/dL), proteinuria (urine protein-to-creatinine ratio 2.0) and microscopic hematuria were present. APS antibodies, lupus anticoagulant, and prothrombin mutation testing were negative; serology revealed antinuclear antibody (1:40, speckled) and anti-double-stranded DNA (12 IU/mL), suggesting SLE. Contrast-free abdominal CT scan revealed bilateral perinephric stranding. Acute tubular necrosis and several intrarenal microthrombi were observed in the renal biopsy. There was no evidence of immune complex glomerulonephritis. She received supportive care along with 60 mg of daily prednisone with rapid tapering. Renal function and proteinuria improved. At 3-month follow-up, the serum creatinine was 0.78mg/dl and urinalysis was negative for proteinuria and hematuria. Discussion: IRVT was reported exclusively in young individuals. Alcohol and non-steroidal drug intake were suggested as risk factors for IRVT in previous cases. Those risk factors were not present in our patient. Our case illustrates that IRVT can be initial presentation of SLE, even in APS-negative patients. A high degree of clinical suspicion, timely biopsy, and serologic testing are essential for early diagnosis and treatment of IRVT.Intra-renal venous microthrombi with neutrophils and endothelial activation, indicating early localized thrombosis.