Abstract
Helicobacter cinaedi is a bacterium in the family Helicobacteraceae that causes mainly enteric and bloodstream infections. A relatively large proportion of patients with chronic kidney disease have H. cinaedi bacteremia, as they are immunocompromised. However, there are a few reports of cyst infection and bacteremia by H. cinaedi in patients with polycystic kidney disease (PKD). A male patient in his 50s with PKD who was receiving hemodialysis developed a high fever and abdominal pain. He had experienced a similar episode 2 years before the current admission, and levofloxacin had effectively improved his symptoms. This time, fluoroquinolone antibiotics did not improve his symptoms, and H. cinaedi was detected in his venous blood after 14 days of culture. Meropenem controlled his infection until neutropenia was induced by it. After other antibiotics failed to show a clear effect, the patient was examined by CT, diffusion-weighted MRI, and Ga-67 scintigraphy; however, no infected cysts could be identified as targets for injection with antibiotics. After drainage, minocycline was percutaneously injected to 3 randomly selected cysts for 1 week, and the symptoms remitted. The characteristics of H. cinaedi include its poor culturability, the need for more than 10 days for its detection, and its tolerance to antibiotics. Primary treatment by fluoroquinolones in accordance with the guidelines of the Japanese Society of Nephrology may not necessarily lead to a favorable response. In the case of refractory cyst infections, H. cinaedi should be considered as a causative pathogen, and a long observation period should be expected for its detection. Furthermore, not only antibiotic therapy but also interventional treatment should be considered in the early phase of its clinical course.
