A Rare Case of Seronegative anti-Glomerular Basement Membrane Disease with Pulmonary Involvement.

Seronegative anti-glomerular basement membrane (GBM) disease with pulmonary involvement is exceedingly rare. Most published cases involve patients with extensive smoking histories, and the prognosis is more favorable than classic, seropositive, anti-GBM disease. Herein, we describe the case of a 62-year-old man with a solitary kidney after right nephrectomy who presented with dyspnea, hemoptysis, and severe acute kidney injury. Kidney biopsy was delayed due to negative serologic evaluation, anchoring to a diagnosis of acute tubular necrosis (ATN), and presence of a solitary kidney; however, progressive kidney injury with microhematuria and proteinuria eventually prompted a biopsy that showed crescentic glomerulonephritis with linear GBM staining. The patient started immunosuppressive treatment and responded very well; he remains stable and off dialysis one year after the diagnosis.