Abstract
ReA is a sterile arthritis typically affecting lower limbs, following extra-articular infections such as
gastrointestinal and urogenital infection. It has been suggested that HLA-B27-mediated immune response
and interactions between host cells and disease-triggering pathogens are crucial for pathophysiology of ReA.
However, reports of Japanese children with ReA are rare because of the low positivity for HLA-B27 in Japanese.
Here we report a 13-year-old Japanese girl who was admitted to our hospital because of the arthritis of
her right wrist and elbow. She had fever, abdominal pain and diarrhea 11 days prior to admission. Her fever
persisted despite antibiotics therapy as well as non-steroidal anti-inflammatory drugs, and arthritis became
migratory from her upper limbs to lower limbs. She was diagnosed with ReA because Yersinia enterocolitica
was detected by stool culture. After prednisolone was started, her arthritis gradually were improved.
Subsequently, the positivity of HLA-B27 and increase in titer of serum antibody for Yersinia enterocolitica
were detected.
Gastrointestinal infection is relatively more frequent than urogenital infection as preceding infection
of pediatric ReA. Our patient was diagnosed with ReA because of coincidental detection of Yersinia enterocolitica
in stool culture. However, detection of disease-triggering pathogens by culture tests could be difficult in many
cases. Therefore, pathogen identification by antibody measurements, and HLA-B27 serotyping should be
performed to diagnose ReA.
