The Clot That Spoke First: Thrombotic Microangiopathy as an Initial Manifestation of Scleroderma Renal Crisis

Introduction: Thrombotic microangiopathy (TMA) is a rare condition marked by microvascular thrombosis and organ ischemia. While typically associated with hemolytic anemia and thrombocytopenia, renal-limited TMA also occurs. We report a case of a healthy young woman initially diagnosed with TMA due to malignant hypertension, later confirmed as scleroderma renal crisis—a rare initial presentation of scleroderma. Case Description: A 33-year-old woman with recently diagnosed hypertension following preeclampsia in last pregnancy presented with chest pain, facial swelling, and elevated blood pressure for two days. Initial evaluation revealed a systolic BP >200 mmHg and nonspecific EKG changes. She was on valsartan-hydrochlorothiazide but was off medications for two months after relocating and not yet establishing primary care. Physical exam was notable for a petechial rash. Laboratory tests showed WBC 11 × 10 /L, hemoglobin 10 g/dL, platelets 130 × 10 /µL, creatinine 6.58 mg/dL. Urinalysis was negative for hematuria and proteinuria. Echocardiogram showed normal ejection fraction; renal ultrasound was unremarkable. Despite blood pressure control, renal function worsened (Cr >7 mg/dL), necessitating hemodialysis.ANA returned positive with a nucleolar pattern; other autoimmune markers including dsDNA, ANCA, anti-GBM, anti-CCP, and RA factor were negative. Given the ANA pattern, anti-Sm/RNP antibodies were checked and returned positive. Skin biopsy of a dorsal rash revealed diminished CD34, consistent with localized scleroderma. Renal biopsy demonstrated acute-on-chronic thrombotic microangiopathy with 60% interstitial fibrosis and tubular atrophy. The constellation of findings led to a diagnosis of scleroderma renal crisis presenting as thrombotic microangiopathy. The patient was started on urgent Eculizumab therapy. She responded well, with improved renal function, allowing discontinuation of dialysis. Discussion: TMAs are defined by microangiopathic hemolytic anemia, thrombocytopenia, and microvascular thrombosis due to endothelial injury. SRC presenting as TMA is a life-threatening complication of systemic sclerosis, with ~20% six-month mortality. Complement activation plays a key role in its pathogenesis. Eculizumab, a C5 inhibitor, blocks early complement activation, serving as a rescue in such cases; while long-term management relies on ACE inhibitor therapy.