title: [Evaluation of serum KL-6 levels in summer-type hypersensitivity pneumonitis].
abstract: A high level of serum KL-6 is a known feature of active pulmonary fibrosis. Some researchers have suggested that KL-6 is produced and secreted by type II pneumocytes. The present study evaluated serum KL-6 levels in patients with summer-type hypersensitivity pneumonitis (summer-type HP) (n = 6, 7 episodes), Mycoplasma pneumoniae pneumonia (n = 16), Chlamydia psittaci pneumonia (n = 3), Chlamydia pneumoniae pneumonia (n = 9), and bacterial pneumonia (n = 12). In addition, transbronchial lung biopsy (TBLB) specimens were examined pathologically in order to identify the site of production and secretion of KL-6. In patients with summer-type HP, the serum KL-6 levels exceeded 500 U/ml (2.996 +/- 2.016 U/ml), but was below 500 U/ml (302 +/- 126 U/ml, p < 0.001) in the patients with other infectious pneumonias, with the exception of two. One of these two patients with a high serum KL-6 level had adult respiratory distress syndrome due to Mycoplasma pneumoniae. The other had organizing pneumonia due to Chlamydia pneumoniae. TBLB specimens showed proliferative type II pneumocytes in all summer-type HP cases. We believe that the high serum KL-6 levels were produced by type II pneumocytes, and may provide a useful indicating serum marker for HP. Although serum LDH, serum CRP and PaO2 are known as monitoring markers in summer-type HP, our findings demonstrated no manifest correlations among these markers. However, serum KL-6 levels showed a strong positive correlation with serum LDH levels and an inverse correlation with serum CRP levels. These results suggest that serum KL-6 may be a better marker of the degree of disease activity than serum LDH, CRP, or PaO2 in summer-type HP.
authors.affiliation: Department of Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: M
authors.initials: M
authors.lastname: Toshiaki
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Niki
authors.forename: T
authors.initials: T
authors.lastname: Matsushima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000542:Alveolitis, Extrinsic Allergic / Q000097:blood*; D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers / Q000097:blood*; D002690:Chlamydia Infections / Q000097:blood; D016993:Chlamydophila pneumoniae; D005260:Female; D006023:Glycoproteins; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D010446:Peptide Fragments / Q000097:blood*; D018410:Pneumonia, Bacterial / Q000097:blood; D011019:Pneumonia, Mycoplasma / Q000097:blood; D011347:Procollagen / Q000097:blood*; D009956:Psittacosis / Q000097:blood; D012128:Respiratory Distress Syndrome / Q000097:blood; D012621:Seasons
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins; D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide