title: Increased dosage of infliximab is a potential cause of Pneumocystis carinii pneumonia.
abstract: METHODS
  Pneumocystis carinii pneumonia occasionally appears in immunodeficient patients. While several reports have shown that Pneumocystis carinii pneumonia occurred in the early phase of starting infliximab treatment in patients with Crohn's disease (CD), the present case suggests for the first time that an increased dosage of infliximab may also lead to pneumonia.
  
  
  RESULTS
  A 51-year-old male had been taking 5 mg of infliximab for the treatment of CD for 10 years with no adverse events. Beginning in September 2013, the dose of infliximab had to be increased to 10 mg/kg because his status worsened. Thereafter, he complained of a fever and cough, and a CT scan revealed ground-glass opacities in the lower lobes of the bilateral lung with a crazy-paving pattern. Bronchoscopy detected swelling of the tracheal mucosa with obvious dilations of the vessels. A polymerase chain reaction using a bronchoalveolar lavage fluid sample detected specific sequences for Pneumocystis jirovecii; thus he was diagnosed with Pneumocystis carinii (jirovecii) pneumonia. After discontinuing infliximab and starting antibiotic treatment, his symptoms and CT findings were dramatically improved.
  
  
  CONCLUSIONS
  The administration of an increased dosage of infliximab can cause Pneumocystis carinii pneumonia in CD patients.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Iwama
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Sakatani
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Mikihiro
authors.initials: M
authors.lastname: Fujiya
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Shugo
authors.initials: S
authors.lastname: Fujibayashi
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nomura
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ueno
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Kashima
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Gotoh
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Sasajima
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Moriichi
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hematology/Oncology, Asahikawa Medical University, 2-1 Midorigaoka-higashi, Asahikawa, Hokkaido 078-8510 Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ikuta
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