Severe Arterial Thrombosis Revealing Underlying Nephrotic Syndrome

A man in his 30s with hypertension presented with acute left lower limb pain and numbness for one week. Imaging revealed a thrombus at the left iliac bifurcation, following which he underwent urgent thromboembolectomy. Despite repeated interventions and anticoagulation, re-occlusion occurred the following day, ultimately requiring an above-knee amputation. Persistent hypoalbuminaemia and proteinuria prompted further evaluation, revealing nephrotic syndrome. Due to heparin resistance from severe hypoalbuminaemia, anticoagulation was switched from unfractionated heparin to argatroban. Immunosuppression with high-dose steroids and rituximab was initiated, chosen to cover potential causes including minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS). A renal biopsy could not be performed due to continuous anticoagulation. The second rituximab dose was delayed due to stump infection of the amputated limb. The patient's albumin and proteinuria improved significantly following the treatment. This case highlights the need for early urine protein testing in unexplained hypoalbuminaemia or arterial thrombosis, to investigate nephrotic syndrome as a potential cause. Prompt treatment is key to preserve kidney function and reduce the chance of limb loss.