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Updated: May 13, 2026
Comparative Analysis of Human Growth Hormone in Serum Using SPRi, Nano-SPRi and ELISA Assays
Published on: January 7, 2016
Gaps in the traceability chain of human growth hormone measurements
Sébastien Boulo1, Katja Hanisch, Martin Bidlingmaier
1Institute for Reference Materials and Measurements (IRMM), Joint Research Centre, European Commission, Geel, Belgium.
Insights
Reconstitution and spiking protocols for human growth hormone (hGH) reference materials significantly impact immunoassay quantification, causing discrepancies between commercial methods despite traceability claims.
Area of Science:
- Clinical Chemistry
- Endocrinology
- Biotechnology
Background:
- Human growth hormone (hGH) measurements are crucial for diagnosing secretion disorders.
- In vitro diagnostic medical devices require traceability to higher-order reference materials per EU Directive 98/79/EC.
- External quality assessment reveals significant discrepancies in hGH measurements across different methods.
Purpose of the Study:
- To investigate the causes of discrepancies in hGH measurements between different methods.
- To evaluate the commutability and recovery of hGH in the International Standard (IS) 98/574.
- To understand the impact of reconstitution and spiking protocols on hGH quantification.
Main Methods:
- Investigated commutability and recovery of hGH in reconstituted IS 98/574.
- Tested various reconstitution protocols and four different serum matrices for spiking.
- Quantified hGH using five different methods across four laboratories, comparing IS preparations with serum samples.
Main Results:
- Method comparisons showed good correlation for serum samples, with mean discrepancies ≤20%.
- No IS preparation demonstrated commutability across all method comparisons.
- hGH recovery in IS 98/574 preparations varied significantly (>10-fold) based on reconstitution protocol and was affected by the background matrix (≤17% differences).
Conclusions:
- Different protocols for reconstituting and spiking hGH reference preparations influence immunoassay quantification.
- This variability can introduce bias between commercial hGH measurement methods.
- Traceability claims to a common reference material may not guarantee consistent results across different assays.
Background:
Human growth hormone (hGH) is measured for the diagnosis of secretion disorders. These measurements fall under the EU Directive 98/79/EC on in vitro diagnostic medical devices requiring traceability of commercial calibrator values to higher-order reference materials or procedures (Off J Eur Communities 1998 Dec 7;L 331:1-37). External quality assessment schemes show large discrepancies between results from different methods, even though most methods provide results traceable to the recommended International Standard (IS 98/574). The aim of this study was to investigate possible causes for these discrepancies.
Methods:
We investigated the commutability and recovery of hGH in reconstituted IS 98/574. We tested different reconstitution protocols and used 4 different serum matrices for spiking. These IS preparations were measured together with serum samples. We quantified hGH by 5 different methods in 4 different laboratories.
Results:
Results from the different methods correlated well for the serum samples. Mean discrepancies between results from different methods were ≤20%. None of the IS preparations was commutable for all the method comparisons. The recovery of hGH in preparations of IS 98/574 depended on the reconstitution protocol (>10-fold differences) and background matrix (relative differences ≤17% for different serum matrices).
Conclusions:
The use of different protocols for reconstitution and spiking of hGH reference preparations affects quantification by immunoassays, potentially leading to a bias between commercial methods, despite the use of calibrators with values claimed to be traceable to the same higher-order reference material.
