title: Prediction of the pathogens that are the cause of pneumonia by the battlefield hypothesis.
abstract: Commensal organisms are frequent causes of pneumonia. However, the detection of these organisms in the airway does not mean that they are the causative pathogens; they may exist merely as colonizers. In up to 50% cases of pneumonia, the causative pathogens remain unidentified, thereby hampering targeting therapies. In speculating on the role of a commensal organism in pneumonia, we devised the battlefield hypothesis. In the "pneumonia battlefield," the organism-to-human cell number ratio may be an index for the pathogenic role of the organism. Using real-time PCR reactions for sputum samples, we tested whether the hypothesis predicts the results of bacteriological clinical tests for 4 representative commensal organisms: Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas spp., and Moraxella catarrhalis. The cutoff value for the organism-to-human cell number ratio, above which the pathogenic role of the organism was suspected, was set up for each organism using 224 sputum samples. The validity of the cutoff value was then tested in a prospective study that included 153 samples; the samples were classified into 3 groups, and each group contained 93%, 7%, and 0% of the samples from pneumonia, in which the pathogenic role of Streptococcus pneumoniae was suggested by the clinical tests. The results for Haemophilus influenzae, Pseudomonas spp., and Moraxella catarrhalis were 100%, 0%, and 0%, respectively. The battlefield hypothesis enabled legitimate interpretation of the PCR results and predicted pneumonia in which the pathogenic role of the organism was suggested by the clinical test. The PCR reactions based on the battlefield hypothesis may help to promote targeted therapies for pneumonia. The prospective observatory study described in the current report had been registered to the University Hospital Medical Information Network (UMIN) registry before its initiation, where the UMIN is a registry approved by the International Committee of Medical Journal Editors (ICMJE). The UMIN registry number was UMIN000001118: A prospective study for the investigation of the validity of cutoff values established for the HIRA-TAN system (April 9, 2008).
authors: Department of Respiratory Medicine, Saitama Medical University, Moroyama, Saitama, Japan.
authors: Takashi
authors: T
authors: Hirama
authors: Takefumi
authors: T
authors: Yamaguchi
authors: Hitoshi
authors: H
authors: Miyazawa
authors: Tomoaki
authors: T
authors: Tanaka
authors: Giichi
authors: G
authors: Hashikita
authors: Etsuko
authors: E
authors: Kishi
authors: Yoshimi
authors: Y
authors: Tachi
authors: Shun
authors: S
authors: Takahashi
authors: Keiji
authors: K
authors: Kodama
authors: Hiroshi
authors: H
authors: Egashira
authors: Akemi
authors: A
authors: Yokote
authors: Kunihiko
authors: K
authors: Kobayashi
authors: Makoto
authors: M
authors: Nagata
authors: Toshiaki
authors: T
authors: Ishii
authors: Manabu
authors: M
authors: Nemoto
authors: Masahiko
authors: M
authors: Tanaka
authors: Koichi
authors: K
authors: Fukunaga
authors: Satoshi
authors: S
authors: Morita
authors: Minoru
authors: M
authors: Kanazawa
authors: Koichi
authors: K
authors: Hagiwara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011014:Pneumonia / Q000382:microbiology*; D011446:Prospective Studies; D055815:Young Adult