title: Clinico-pathological analysis referring hemeoxygenase-1 in acute fibrinous and organizing pneumonia patients.
abstract: Acute fibrinous and organizing pneumonia (AFOP) is a very rare pathological entity of lung injury characterized by intra-alveolar fibrin balls. Hemeoxygenase (HO) -1 is a cytoprotective enzyme against oxidative stress and inflammation. It is known to be expressed in the alveolar macrophages in the healthy adults and overexpressed in other various lung cells of the lung injury patients. We experienced two cases of subacute form AFOP for these 10 years and reviewed clinico-pathological characteristics. The average age was 62 years old and both were male. The etiology of both cases was idiopathic. The average PaO2/FIO2 ratio was 274.5 ± 84.1. The average levels of C-reactive protein and surfactant protein - A of the serum were elevated to 19.8 ± 6.3 mg/dL and 67.6 ± 15.8 ng/mL, respectively. Serum sialylated carbohydrate antigen levels were normal in both cases. The characteristic radiographic findings were bilateral consolidations and ground glass opacities. Lung biopsy specimens revealed fibrin balls and alveolitis with abundant cellular HO-1 expression. Steroid response was excellent and the pulmonary involvements absolutely disappeared for about 3 months.
authors.affiliation: Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, Saitama, Japan ; Respiratory Disease Center, Yokohama City University Medical Center, Kanagawa, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, Saitama, Japan ; Respiratory Disease Center, Yokohama City University Medical Center, Kanagawa, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Shinkai
authors.affiliation: Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, Saitama, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kanoh
authors.affiliation: Division of Infectious Diseases and Pulmonary Medicine, Department of Internal Medicine, National Defense Medical College, Saitama, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kawana
authors.affiliation: Department of Pediatrics, Virginia Commonwealth University, Richmond, USA.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Rubin
authors.affiliation: Departments of Basic Pathology, National Defense Medical College, Saitama, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsubara
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Kanagawa, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
keywords: Acute fibrinous and organizing pneumonia; Corticosteroid; Diffuse alveolar damage; Fibrin balls; Hemeoxygenase-1; Organizing pneumonia; Pulmonary cellular protection