Monteseirín, JVega, A2012-03-202012-03-202008-02Monteseirín J, Vega A. Eosinophil cationic protein is not only a distinctive eosinophil protein. Thorax. 2008 Feb;63(2):185; authors' reply 185.0040-6376http://hdl.handle.net/10668/368We read with interest the article by Qiu et al (Thorax 2007;62:475–82). In this paper, neutrophils and eosinophils were identified using mouse anti-human neutrophil elastase and anti-eosinophil cationic protein (ECP), both monoclonal antibodies (mAbs). mAbs against ECP have been used to detect total eosinophils, but immunostaining techniques evidenced that the number of ECP+ cells was higher than the number of eosinophils.1 Recent studies show that ECP is not only a distinctive eosinophil protein, but has been found in neutrophils.1–3eneosinophilsneutrófiloseusinófilosMedical Subject Headings::Diseases::Respiratory Tract Diseases::Lung Diseases::Lung Diseases, Obstructive::AsthmaMedical Subject Headings::Chemicals and Drugs::Enzymes and Coenzymes::Enzymes::Hydrolases::Esterases::Ribonucleases::Endoribonucleases::Eosinophil Cationic ProteinMedical Subject Headings::Anatomy::Hemic and Immune Systems::Immune System::Leukocytes::Granulocytes::NeutrophilsMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Clinical Laboratory Techniques::Immunologic Tests::Immunoassay::Immunoenzyme Techniques::Enzyme-Linked Immunosorbent Assayletteropen access10.1136/thx.2007.0888071468-3296