[A case presenting severe respiratory failure with high antibody titers to Chlamydia pneumoniae]

"HITAZYME C. pneumoniae" is a diagnostic reagent that has been recently developed by adopting an ELISA method for detection of anti-Chlamydia pneumoniae (C. pneumoniae) antibodies. A case presenting bilateral interstitial opacities and severe respiratory failure with high titers of "HITAZYME C. pneumoniae" was described. Sputum, blood, serological, and bronchoalveolar lavage examinations failed to reveal other etiology to explain his severe respiratory illness. Clinicians should be aware that C. pneumoniae may cause severe respiratory failure or ARDS. Further studies are needed to evaluate the role of C. pneumoniae infection in the development of severe pneumonia or ARDS.