Scheme Information Sheets

Peptide Hormones II

Scheme Particulars Indicative Details
Accreditation body UKAS
ISO/IEC Accreditation status ISO/IEC 17043:2023
UKAS Accredited Proficiency Testing Provider No 7860
Objective of Scheme Provides EQA coverage for Peptide Hormone Assays.

Parathyroid Hormone (PTH) is measured to investigate the cause of hypo- or hypercalcaemia, and may be measured intra-operatively during parathyroid excision to help confirm removal of parathyroid glands. Adrenocorticotrophic Hormone (ACTH) may be measured in the investigation of adrenal and pituitary conditions affecting the hypothalamic-pituitary-adrenal axis. Calcitonin is produced by the thyroid gland and is mainly used in the diagnosis and monitoring of medullary thyroid cancer.

All analytes are labile, therefore a separate lyophilised K3-EDTA plasma specimen is provided for each analyte.

The scheme provides both endogenous and manipulated lyophilised specimens to cover both normal and pathological concentration ranges
Pre-, Analytical, Post- status Analytical
Number of distributions per year (nominal) 11
Specimens per distribution 3
Number of Specimens per annum 33
Frequency of distribution Monthly
Scoring system ABC
Material distributed Pooled or single donations of lyophlised human EDTA plasma with or without exogenous added analyte
Programme Director(s) / Organiser(s) Rachel Marrington
Criteria for participation All, but overseas by courier
Nominal sample volume (mL) 0.5
Sample presentation TACs Individual tubes for all analytes
Data in Chemistry on-line Dashboard Yes
Analyte Approx Range Default Units Target Value B Score Limit (%) * C Score Limit (%) *
ACTH 0 – 500 ng/L [pg/mL] MLTM 25.0 25.0
Calcitonin 0 – 500 ng/L [pg/mL] MLTM 20.0 25.0
PTH 0 – 500 pmol/L MLTM 25.0 25.0

* Under review and likely to be reduced from April 2027

Abbreviation Expansion
ALTM All Laboratory Trimmed Mean
GLTM Group Laboratory Trimmed Mean – which is the Method Principle Mean
MLTM Method Laboratory Trimmed Mean – usually a manufacturer system / analyser mean
XALTM An external value that may be from a Reference Method System
OGLTM A Method Principle Mean used as the target for all laboratories
OMLTM A specific Method Mean used as a target for all laboratories
OMMED A Method Median used as the target for all laboratories
MED Median

This will also allow us to cover a wide concentration range without impacting other analytes.

We will be using a Method Laboratory Trimmed Mean (MLTM) Target Value for all analytes. The reason for this is because different manufacturers give different results and we do not know what the 'correct' result is therefore the ALTM is not really suitable especially when working up a new Scheme and in the first few months there may be changes in the proportion of participants contributing to each manufacturer, therefore impacting the Target Value, if the ALTM. There are no Reference Measurement Procedure services available and the existing legacy IRPs have not undergone commutability studies with the current methodologies. We will be monitoring longitudinal method performance to identify insidious method drift.

We plan to link this Scheme with other Schemes offered by Birmingham Quality for specific scientific studies to look at pre- and post-analytical elements.

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