The usefulness of KL-6 and SP-D for the diagnosis and management of chronic hypersensitivity pneumonitis.
BACKGROUND
It is believed that Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) are useful biomarkers for the diagnosis of various types of interstitial lung diseases, including hypersensitivity pneumonitis (HP). The clinical features of chronic HP are similar to those of idiopathic interstitial pneumonias, especially idiopathic pulmonary fibrosis (IPF).


OBJECTIVE
We sought to clarify the usefulness of serum KL-6 and SP-D for the diagnosis and management of chronic HP.


METHODS
We examined serum KL-6 and SP-D levels and retrospectively evaluated the clinical parameters of acute HP (n = 35), chronic HP (n = 57), IPF (n = 54), collagen vascular disease-associated interstitial pneumonia (CVD-IP) (n = 67), and sarcoidosis (n = 47). We analyzed the relations between the two biomarkers and clinical data in chronic HP.


RESULTS
Serum KL-6 and SP-D levels in acute HP (2710 U/ml and 338 ng/ml, median) and chronic HP (1500 U/ml and 264 ng/ml, median) were significantly higher than in IPF, CVD-IP, and sarcoidosis. The area under the curve (AUC) values for serum KL-6 and SP-D between chronic HP and IPF were 0.771 and 0.729, respectively. Serum KL-6 levels in chronic HP were significantly higher during episodes of acute exacerbation than 1 month before acute exacerbation. The serum KL-6 levels had correlations with serum SP-D and the percentage of lymphocytes in bronchoalveolar lavage fluid.


CONCLUSIONS
Serum KL-6 and SP-D levels are useful for the diagnosis and management of chronic HP.
Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: tokamoto.pulm@tmd.ac.jp.
Tsukasa
T
Okamoto
Department of Respiratory Medicine, Soka Municipal Hospital, 2-21-1, Soka, Soka City, Saitama 340-8560, Japan. Electronic address: mayumi-f@fk9.so-net.ne.jp.
Mayumi
M
Fujii
Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: hfurusawa.pulm@tmd.ac.jp.
Haruhiko
H
Furusawa
Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: tsucpulm@tmd.ac.jp.
Kimitake
K
Tsuchiya
Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: miyazaki.pilm@tmd.ac.jp.
Yasunari
Y
Miyazaki
Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: ninase.pulm@tmd.ac.jp.
Naohiko
N
Inase
D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis* / Q000188:drug therapy; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism*; D011239:Prednisolone / Q000627:therapeutic use; D037663:Pulmonary Surfactant-Associated Protein D / Q000378:metabolism*; D012189:Retrospective Studies; D017565:Sarcoidosis, Pulmonary; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1; D037663:Pulmonary Surfactant-Associated Protein D; D011239:Prednisolone
Acute exacerbation; Hypersensitivity pneumonitis; Idiopathic pulmonary fibrosis; Krebs von den Lungen-6; Surfactant protein D