The challenge of measuring IL‐33 in serum using commercial ELISA: lessons from asthma

ME Ketelaar, MC Nawijn, DE Shaw… - Clinical & …, 2016 - Wiley Online Library
ME Ketelaar, MC Nawijn, DE Shaw, GH Koppelman, I Sayers
Clinical & Experimental Allergy, 2016Wiley Online Library
Summary Background Interleukin‐33 (IL‐33) has been subject of extensive study in the
context of inflammatory disorders, particularly in asthma. Many human biological samples,
including serum, have been used to determine the protein levels of IL‐33, aiming to
investigate its involvement in asthma. Reliable methods are required to study the
association of IL‐33 with disease, especially considering the complex nature of serum
samples. Objective We evaluated four IL‐33 ELISA kits, aiming to determine a robust and …
Background
Interleukin‐33 (IL‐33) has been subject of extensive study in the context of inflammatory disorders, particularly in asthma. Many human biological samples, including serum, have been used to determine the protein levels of IL‐33, aiming to investigate its involvement in asthma. Reliable methods are required to study the association of IL‐33 with disease, especially considering the complex nature of serum samples.
Objective
We evaluated four IL‐33 ELISA kits, aiming to determine a robust and reproducible approach to quantifying IL‐33 in human serum from asthma patients.
Methods
IL‐33 levels were investigated in serum of well‐defined asthma patients by the Quantikine, DuoSet (both R&D systems), ADI‐900‐201 (Enzo Life Sciences), and SKR038 (GenWay Biotech Inc San Diego USA) immunoassays, as well as spiking experiments were performed using recombinant IL‐33 and its soluble receptor IL‐1RL1‐a.
Results
We show that 1) IL‐33 is difficult to detect by ELISA in human serum, due to lack of sensitivity and specificity of currently available assays; 2) human serum interferes with IL‐33 quantification, in part through IL‐1RL1‐a; and 3) using non‐serum certified kits may lead to spurious findings.
Conclusion and Clinical Relevance
If IL‐33 is to be studied in the serum of asthma patients and other diseases, a more sensitive and specific assay method is required, which will be vital for further understanding and targeting of the IL‐33/IL‐1RL1 axis in human disease.
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