Tohoku J. Exp. Med., 2006, 208(4)

Case Report

Serum Antibody Against Granulocyte/Macrophage Colony-Stimulating Factor and KL-6 in Idiopathic Pulmonary Alveolar Proteinosis

MASAYUKI NARA, KUNIO SANO, HIROMASA OGAWA, TSUTOMU TAMADA, MIYUKI NAGAOKA, KATSUNORI OKADA,¹ MIKA WATANABE,² TAKUYA MORIYA,² HIROSHI MIKI,³ KOH NAKATA,⁴ MASAKAZU ICHINOSE⁵ and TOSHIO HATTORI

Department of Infectious and Respiratory Diseases, ¹Department of Respiratory Surgery, ²Department of Pathology, Tohoku University School of Medicine, Sendai, Japan, ³Sendai Medical Center, Sendai, Japan, ⁴Bioscience Medical Research Center, Niigata University, Niigata, Japan, ⁵The Third Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan

Here we describe a case of idiopathic pulmonary alveolar proteinosis (I-PAP), in which anti-granulocyte/macrophage colony-stimulating factor (GM-CSF) antibody and high level of KL-6 were found in the serum. Anti-GM-CSF antibody is responsible for I-PAP, and KL-6 is a serum marker for the activity of diffuse interstitial lung disease. A 38-year-old woman, who had no symptoms, was found to have an abnormal shadow on chest radiograph 5 years previously at a health check up. Chest radiograph showed a patchy shadow in the left lower lung field. Thoracoscopic biopsy was performed because the shadow had gradually expanded during the 5 years. Histological examination revealed proteinous material filling the alveoli and positive staining by the PAS method, suggesting PAP. Anti-GM-CSF antibody and a high level of KL-6 were detected in the serum at the time of diagnosis. Three years later, the shadow disappeared spontaneously. During this period, the level of KL-6 dramatically decreased, although that of GM-CSF antibody remained unchanged. The present case suggests that the serum level of the anti-GM-CSF antibody represents a useful marker for the diagnosis but not for follow-up of the clinical course. On the contrary, KL-6 is an excellent marker for the assessment of the clinical course of I-PAP.

keywords —— GM-CSF; proteinous material; autoimmune disease; thoracoscopic biopsy

© 2006 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2006, 208, 349-354

Correspondence: Masayuki Nara, M.D., Ph.D., Division of Infectious and Respiratory Diseases, Department of Internal Medicine, Tohoku University School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai 980-8574, Japan.

e-mail: nara@rid.med.tohoku.ac.jp