Diffuse alveolar haemorrhage in a case with anti-RNA polymerase III antibody-positive systemic sclerosis successfully treated with plasma exchange and corticosteroid therapy

A 63-year-old woman was admitted because of diffuse alveolar haemorrhage complicated with systemic sclerosis. High anti-RNA polymerase III (RNAP III) antibody titre was detected despite normal blood pressure and renal function. Antibodies other than anti-RNAP III antibody were negative. After initiation of methyl-prednisolone pulse therapy, the patient developed thrombotic microangiopathy (TMA) with exacerbation of respiratory failure, which required mechanical ventilation. However, renal function was preserved. We immediately started the patient on plasma exchange; subsequently, her diffuse alveolar haemorrhage and TMA dramatically improved. Diffuse alveolar haemorrhage with systemic sclerosis is generally occurred as pulmonary renal syndrome, and positive anti-RNAP III antibody is recognised as a predictive marker of scleroderma renal crisis. However, this case suggests that high anti-RNAP III antibody titre may play a role in the development of diffuse alveolar haemorrhage without scleroderma renal crisis.