Polymerase Chain Reaction Analysis for Diagnosis of Tropheryma whippelii Infective Endocarditis in Two Patients with No Previous Evidence of Whipple's Disease

Blood culture-negative infective endocarditis (IE) is often caused by fastidious organisms that grow poorly or not at all on acellular media, such as Coxiella burnetii, Bartonella species, or Chlamydia [1]. Despite the use of appropriate diagnostic techniques (i.e., serology and cell culture), no microbial agents are identified in a number of definite cases of IE. Polymerase chain reaction (PCR) analysis with primers targeting the eubacterial 16S rRNA gene provide powerful etiologic tools in such cases [2].We report two cases of IE caused by Tropheryma whippelii, the causative agent of Whipple's disease, that were diagnosed by means of PCR analysis of resected heart valve specimens. A 40-year-old man (patient 1) with a 5-year history of ankylosing spondylitis (HLA B27) who was receiving immunosuppressive therapy was admitted to the hospital in June 1995 with a tentative diagnosis of blood culture-negative IE. Severe hemodynamic failure necessitated emergency valve replacement, and an abscess of the aortic ring was found during surgery. Despite 6 weeks of postoperative antibiotic therapy (ofloxacin, 400 mg/d; doxycycline, 200 mg/d), his condition deteriorated again 6 months later, necessitating replacement of both the prosthetic aortic valve (because of paraprosthetic leakage) and the mitral valve (marked mitral insufficiency). He died suddenly the day after surgery.Histological features of the valve specimens removed during the two operations were very similar, with proliferation of fibrous tissue, focal calcification mixed with a few microabscesses containing polymorphonuclear (PMN) cells, and voluminous macrophages (all of which were consistent with the diagnosis of IE).