A case of anti-RNA polymerase III antibody-positive systemic scleroderma diagnosed by renal biopsy

Abstract

Scleroderma renal crisis (SRC) is a life-threatening complication of systemic sclerosis (SSc), characterized by new-onset progressive acute renal failure, often with associated microangiopathic hemolytic anemia (MAHA). Here, we report a patient who developed SRC prior to being diagnosed with SSc. A 78-year-old man consulted a family doctor with complaints of general fatigue and epigastralgia. Medical examination revealed progressive renal damage and thoracic esophageal cancer, and he was referred to our hospital. On admission, hypertension, bilateral pleural effusion, anemia, thrombocytopenia, and acute kidney damage were evident. A peripheral blood smear showed schistocytes with evidence of MAHA. Renal biopsy to clarify the diagnosis revealed marked edematous intimal expansion of the interlobular arteries and ischemic change with endothelial damage of the glomeruli, suggesting SRC. Subsequent systemic examination revealed a modified Rodman total skin thickness score (mRSS) of 27 points and positivity for anti-RNA polymerase III (RNAP 3) antibody. On this basis, a diagnosis of anti-RNAP-positive diffuse cutaneous SSc accompanied by SRC was made. Patients with anti-RNAP 3-positive SSc frequently develop SRC and are complicated by malignancies prior to diagnosis of SSc. Prompt diagnosis and appropriate treatment intervention are essential for this disease.