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Eosinophil Cationic Protein (ECP)

Test Code: 42
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Clinical Utility

Serum ECP levels correlate with the severity of the patient's asthma. Increased ECP levels are predictive of exercise induced asthma and the propensity to develop a late asthmatic reaction (LAR). ECP levels increase after allergen exposure and these increases are reduced after immunotherapy. Serum ECP measurements may be used to monitor anti-asthma treatment and help optimize drug dosing.


ImmunoCAP®-FEIA. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.

5-7 business days from receipt of specimen

Specimen Type Order Code CPT Code NY Approved Volume Assay Range Special Instructions
serum 42 83520 Yes

1 mL (min. 500 uL)

ECP results are reported in nanograms per mL (ng/mL). The reference interval is less than 32.5 ng/mL. This represents the lower 95th percentile of a healthy adult population.

  • Collect the blood in 4 mL vacutainer hemogard SST tube. The tube should be completely filled and then gently inverted 5 times.
  • Allow the blood to clot at room temperature (20-24° C) for 60 minutes (+/- 5 min).
  • Centrifuge the serum at 1000-1300 x g for 10 minutes at room temperature.
  • Stability 48 hours ambient, 7 days at 2-8°, >2 weeks frozen at -20°
  • Stable for 3 freeze/thaw cycles.

Specimens are approved for testing in New York only when indicated in the Specimen Information field above.

The CPT codes provided are based on Viracor Eurofins' interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for general informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Viracor Eurofins assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.


Weller PF. Eosinophils in Clinical Immunology Principles and Practice, 2nd Edition, Rich RR et al (Editors), 2002, Mosby.

Venge P. Serum measurements of ECP in bronchial asthma. Clin Exp Allergy 1993; 23 (2):3 – 7.

Zimmerman B. Clinical experience with the measurement of ECP: usefulness in the management of children with asthma. Clin Exp Allergy 1993; 23 (2): 8 – 12.

D’Amota G et al. Measurements of serum levels of ECP to monitor patients with seasonal respiratory allergy induced by Parietaria pollen. Allergy 1996; 51: 245-250.

Czech W et al. Serum ECP is a sensitive measure for disease activity in atopic dermatitis. Br J Dermatol 1992; 126: 351-355.

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