A case of retroperitoneal fibrosis with anti Chlamydophila pneumoniae IgM antibody positive

Abstract

    Idiopathic retroperitoneal fibrosis (RPF) is a rare disorder characterized by chronic nonspecific inflammation of the retroperitoneum, and results of several pathological studies have suggested that idiopathic RPF could be included under the umbrella term chronic periaortitis, along with inflammatory abdominal aortic aneurysms (AAA). A number of previous reports have already suggested that Chlamydophila pneumoniae infection might contribute to the pathogenesis of inflammatory AAA. So Chlamydophila pneumoniae infection might be also the cause of idiopathic RPF. We report here a 37-year-old woman who was diagnosed with idiopathic RPF with anti Chlamydophila pneumoniae IgM antibody positive.　
    She was admitted our hospital because of high fever and polyarthralgia. Neither antinuclear and anti-CCP antibodies were not detected in serum, and her serum anti- Chlamydophila pneumoniae IgM and IgA antibody were positive. She was diagnosed as reactive arthritis and given 200 mg azithromycin, which was effective for fever and arthritis. We also performed CT scanning and found the homogeneous mass surrounding the lower abdominal aorta and iliac arteries and mild hydronephrosis of right kidney. She was diagnosed as idiopathic RPF and treated with 40 mg prednisolone daily, which was proved to be effective. Her serum IgM antibodies to Chlamydophila pneumoniae had been positive for more than 3 years after diagnosis.