A victim of the Occam’s razor

Abstract

In November 2011, a 31-year-old man was admitted to our hospital with fever and acute renal failure. Two months before, he had been diagnosed with methicillin-resistant Staphylococcus aureus aortic valve endocarditis requiring valve replacement. Heart surgery was performed without complications, and antibiotic therapy was started. 40 days after surgery, he became febrile and a diagnosis of prosthetic valve endocarditis was suspected. A transesophageal echocardiogram did not reveal new signs of endocarditis. Blood cultures were negative. The initial antibiotic therapy was empirically changed, and gentamicin was administered. After 2 weeks the patient developed acute anuric renal failure. At this time he was transferred to our hospital. On arrival the patient was febrile. Physical examination showed neither new cardiac abnormalities nor signs of systemic embolization. Blood test yielded a leucocytosis, renal failure and mild elevation of procalcitonin levels. CT scan of his head, chest and abdomen were negative for septic emboli. Transesophageal echocardiogram revealed the aortic prosthesis to be functioning normally in the absence of clear vegetations. Blood cultures were negative. Although there was no evidence of sources of infection, fever was considered to be of infectious origin, and the renal failure was attributed to aminoglycoside nephrotoxicity. Gentamicin was discontinued, antibiotic therapy was changed again, and hemodialysis was started. Over the following days, the patient had one episode of severe hemoptysis associated with respiratory failure and blood loss. A CT scan of the chest showed diffuse interstitial and alveolar infiltrates suggestive of alveolar hemorrhage. At this point, a diagnosis of a pulmonary renal syndrome was suspected. Autoimmune tests were performed showing high titers of anti-glomerular basement membrane (anti-GBM) antibodies. A diagnosis of Goodpasture syndrome was made. The patient was administered prednisone and rituximab (preferred to other immunosuppressive drugs to minimize the risk of infection) and underwent a series of 19 plasma-exchange treatments. Clinical conditions improved, no further episodes of hemoptysis occurred, and, at the time of discharge, antiGBM antibodies were undetectable. However, the patient became dependent on chronic hemodialysis. Goodpasture syndrome is an autoimmune disease characterized by pulmonary hemorrhage, glomerulonephritis and the presence of circulating anti-GBM antibodies. Infection may be an initiating event or a precipitating factor for relapse. Identifying Goodpasture syndrome following an infectious event is challenging and high procalcitonin values may be observed even in the absence of infection [1]. In presence of a typical presentation including alveolar hemorrhage and renal failure, the evidence of circulating anti-GBM antibodies may confirm the diagnosis. Life-saving treatment includes plasma-exchange to remove circulating antibodies and immunosuppressive medications to stop the production of the antibodies. F. Elia (&) F. Pagnozzi B. Laface F. Apra High Dependency Unit, San Giovanni Bosco Hospital, Piazza Donatore del Sangue 3, 10154 Turin, Italy e-mail: fabrizioelia@yahoo.it