INTRODUCTION: To the best of our knowledge, only seven cases of endocarditis associated with positive ANCA serologies have been reported. We present a case of Streptococcus oralis endocarditis in a patient found to have positve serine protease-3 antibodies.
CASE PRESENTATION: A 47-year-old male presneted with confusion,fever,dyspnea, and nonproductive cough of two weeks duration. Exam revealed normal breath sounds,no murmur, mild hepatomegaly, and a nonfocal neurologic exam. No stigmata of endocarditis were noted. Chest and abdominal films were unremarkable. Laboratory tests showed a significant transaminitis and a bilirubin of 16. The patient also had severe anemia and a white count of 22K with a left shift. He was noted to be in renal failure with a creatinine of 4.7 and BUN of 64. Urinalysis showed many red cell casts. A renal biopsy performed 2 days later showed necrotizing crescentic glomerulonephritis. Immunoflourescence staining was negative, and electron microscopy showed rare immune complex deposition. Complement levels were low, and ANCA and ANA serologies were reported as negative. MRA of the abdomen showed vascular irregularities consistent with vasculitis. One of 2 blood cultures grew Strep. oralis. The clinical picture was thought to be most consistent with acute renal failure secondary to a systemic vascultis and high dose intravenous steroids and antibiotics were initiated. The patient continued to worsen and was transferred to our institution. Upon transfer, the patient remained febrile and broad spectrum antimicrobials for bacteria and fungus were given. Repeat serologies (ANA, ANCA, and anti-GBM)and blood cultures were sent. High dose solumedrol was continued. Blood cultures were negative and a repeat c-ANCA returned strongly positive. Cytoxan was subsequently added to the patient's regimen. The patient continued to deteriorate, became unresponsive and developed bilateral infiltrates necessitating intubation. Hemodialysis was initiated and a bronchoscopy was performed. Lavage revealed no evidence of alveolar hemorrhage but was positve for Aspergillus. Fungal coverage was changed to Mycafungin. The patient subsequently became bradycardic, developed transient second degree heart block, and required hemodynamic support. Although the patient remained without a murmur, transesophageal echo showed large aortic vegetations with probable aortic ring abscess. Immunosuppression was halted except for stress doses of corticosteroids and cardiothoracic surgery was consulted. The patient was taken to surgery for aortic valve replacement with annuloplasty. Although the patient tolerated the surgery well, his renal and liver failure failed to improve, and he remained encephalopahtic. Repeat echocardiogram showed no recurrence of vegetations. Despite broad spectrum bacterial and fungal antibiotic coverage, the patient developed overwhelming gram negative sepsis with diffuse pulmonary infiltrates and multiorgan system failure. In consultation with the family, care was withdrawn.
DISCUSSIONS: This case illustrates, in an unusual manner, a common medical dilemma: treating for an immune-mediated disease versus treating for infection. In this case, the main differential diagnosis was between a post-infectious glomerulonephritis versus a systemic vasculitis with necrotizing glomerulonephritis. While the immunoflourescence staining was negative and consistent with a non-infectious etiology of renal failure, there were rare immune complex deposits seen on electronmicroscopy and low complement levels (both consistent with post-infectious glomerulonephritis). In retrospect, the profound immunosuppression may have allowed the propagation of the patient's aortic valve vegeatations and ring abscess, despite being on appropriate antibiotic coverage.
CONCLUSION: A literature review revealed only seven prior cases of concomitant positive ANCA serolgies in the setting of endocarditis. This case should remind clinicians that positive serologies do not exclude an infectious cause of vasculitis and/or renal failure.
DISCLOSURE: Louis D'Avignon, None.