Pulmonary-renal syndrome in systemic sclerosis: a report of three cases and review of the literature.

We describe three cases of acute renal failure with diffuse alveolar hemorrhage, which is designated pulmonary-renal syndrome (PRS), in systemic sclerosis (SSc) and review the literature to better define this rare but severe complication of SSc. The clinical course of three SSc patients with acute renal failure and concomitant diffuse alveolar hemorrhage are reported, and the literature published between 1967 and 2005 is reviewed following a PubMed search. Including our cases, a total of 19 SSc patients with acute renal failure and concomitant diffuse alveolar hemorrhage have been reported. Pulmonary-renal syndrome developing in SSc patients can be categorized clinicopathologically into three entities: PRS with thrombotic microangiopathy, PRS with small vessel vasculitides accompanied with SSc, and d-penicillamine-induced Goodpasture-like syndrome. Patients with scleroderma PRS with thrombotic microangiopathy, to which group our all patients belong, often developed diffuse alveolar hemorrhage after receiving high-dose corticosteroid therapy. Pulmonary-renal syndrome is a fatal complication of SSc and results from different pathogenic processes. Prompt differential diagnosis between the subsets is critical, because therapeutic strategy may differ in the use of high-dose corticosteroid and plasma exchange between the subsets of PRS. Clinical courses of the patients with PRS with thrombotic microangiopathy suggest that high-dose corticosteroid therapy is a trigger of diffuse alveolar hemorrhage in patients with diffuse SSc with signs of thrombotic microangiopathy.