Scleroderma renal crisis in mixed connective tissue disease.

Scleroderma renal crisis is a serious vascular complication most commonly associated with systemic sclerosis. Its occurrence in mixed connective tissue disease is very rare, with 10 cases reported to date. Scleroderma renal crisis pathogenesis involves endothelial injury, intimal proliferation, and arteriolar constriction leading to malignant hypertension and, in many cases, microangiopathic hemolytic anemia. Management focuses on prompt initiation of angiotensin-converting enzyme inhibitors, particularly captopril, to control blood pressure and prevent irreversible renal injury. Despite advances in therapy, many patients progress to end-stage renal disease, necessitating dialysis or kidney transplantation. Emerging therapies, including endothelin receptor antagonists and complement inhibitors, may offer benefit in refractory cases. Awareness of scleroderma renal crisis in mixed connective tissue disease is crucial for early recognition and timely intervention to improve outcomes.