Gaps in the Traceability Chain of Human Growth Hormone Measurements

Human growth hormone is an important peptide hormone that stimulates growth, cell reproduction, and cell regeneration. Measuring growth hormone in the blood is an important clinical assay, but may be problematic due to heterogeneity of the hormone that may arise from alternative splicing, different post-translational or modifications, oligomerization, formation of complexes, and proteolytic processing. Although standards for growth hormone are available, data from external quality assessment programs show large differences exist between measurement results obtained with different assays.