ImmunoCAP ECP measures the level of Eosinophil Cationic Protein (ECP) in serum. Eosinophils are the cells chiefly responsible for producing the inflammation associated with asthma. When eosinophils in the airway are activated, they undergo degranulation causing airway epithelial damage. This can lead to chronic inflammatory disease of the airway.
Asthmatic patients with eosinophilic inflammation have elevated levels of ECP in serum and other body fluids such as bronchial alveolar fluid and (induced) sputum. A high level of serum ECP indicates inflammation, which is a risk factor for asthmatic patients.
Asthma therapy consists of suppressing chronic and persistent airway inflammation. Measuring ECP in a serum sample is an objective and direct way to estimate the severity of the airway inflammation and to following the course of the disease.
ECP serum measurements can be used to investigate :
- Inflammation in asthma
- Corticosteroid treatment in asthma
- Non-compliant patients
Specimen collection and preparation
Parameters such as the type of blood collection tube, coagulation time and incubation temperature must be kept within specified limits since each factor affects the concentration of released ECP in serum samples. The ECP measured by this assay is released from eosinophils during the first incubation of the assay.
Collect blood by venopuncture using Terumo Venosafe Serum-Gel tubes. It is important that the tube is completely filled. Contact Phadia AB if a serum collection tube other than Venosafe is to be used.
- After collection, gently invert the tube several times. Do not shake or vortex the tube.
- Release ECP by clotting for 60 to 120 minutes at room temperature 20-24 °C. The temperature must not vary more than ±1 °C between samplings to give comparable results.
- Centrifuge at 1000–1300xg for 10 minutes at room temperature.
- Decant serum into a new tube.
- Serum samples may be kept at room temperature for shipping purposes. Otherwise store at 2-8 °C if assayed within five days after collection or at –20 °C if assayed later.
Note! Plasma and hemolysed serum can not be used.