Provided are a neutrophil activation regulator and a therapeutic agent against diseases caused by neutrophil activation. A thrombin-like enzyme is used as an active ingredient of the neutrophil activation regulator and the therapeutic agent against diseases caused by neutrophil activation.本發明提供一種嗜中性白血球活化調節劑及起因於嗜中性白血球活化之疾病之治療藥。 本發明係使用凝血酶樣酶作為嗜中性白血球活化調節劑及起因於嗜中性白血球活化之疾病之治療藥之有效成分。