Two Cases of Acute Respiratory Distress Syndrome with High Values of Chlamydophila pneumoniae-Specific Antibodies

We herein report two cases of acute respiratory distress syndrome (ARDS) with high values of Chlamydophila pneumoniae-specific antibodies. In the first case (a 65-year-old man), high levels of anti-C. pneumoniae antibodies (IgG and IgA) were detected on admission, and the anti-C. pneumoniae IgA level rose by Day 30. The patient was successfully treated with quinolone and steroids. In the second case (an 85-year-old man), abnormally high levels of anti-C. pneumoniae IgM were detected on admission. The patient did not recover, despite receiving treatment with several antibiotics and anti-inflammatory agents. Neither of the patients displayed other pathogen-specific antigens or antibodies. Chlamydophila pneumonia is usually mild, although it can cause severe interstitial pneumonia and ARDS in reinfected patients and the elderly.