PROBLEM TO BE SOLVED: To provide a novel protease inhibitor and curative remedies and a therapeutic method for chronic obstructive pulmonary disease or immunodeficiency syndrome.SOLUTION: The preventive or therapeutic agent is used for chronic obstructive pulmonary disease or immunodeficiency syndrome, and the preventive or therapeutic agent for chronic obstructive pulmonary disease, alveolar proteinosis or circulatory disease is contains at least one kind selected from IL-18 excluding redox-active protein and a gene encoding the same.【課題】新たなプロテアーゼ阻害剤，慢性閉塞性肺疾患・免疫不全症候群の根治的治療薬及び治療法の提供。【解決手段】レドックス活性蛋白質を除く，及び慢性閉塞性肺疾患又は免疫不全症候群の予防又は治療剤，並びに、ＩＬ－１８またはこれをコードする遺伝子から選択される少なくとも一種以上を含むことを特徴とする、慢性閉塞性肺疾患・肺胞蛋白症・循環器疾患の予防又は治療剤。【選択図】なし
