Scheme Information Sheets
AFP and hCG
| 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 a selection of analytes used as Tumour Markers for diagnosis and/or monitoring of cancer treatment and also in pregnancy - Alpha Fetoprotein (AFP) and Human Chorionic Gonadotrophin (hCG). Tumour Markers are used to help diagnosis, monitor and guide treatment of certain cancers, and assess for disease recurrence. AFP and hCG can be used to help diagnose and monitor hepatocellular carcinoma and reproductive cancers. hCG is the earliest routinely measurable marker of pregnancy and is regularly used at all stages of pregnancy The Scheme distributes a number of endogenous and manipulated specimens to cover a range of concentrations. |
| 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 liquid human serum 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 (%) * |
|---|---|---|---|---|---|
| AFP | 0 – 1500 | kU/L | MLTM | 10.0 | 10.0 |
| Total/Intact hCG | 0 – 1500 | U/L | MLTM | 20.0 | 20.0 |
* 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 allows us to predominantly use endogenous material with minimal manipulation therefore allowing specimens to be as commutable (similar) as possible to patient samples. 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.
We also plan to offer a Fluid CEA pilot.
- AFP and hCG 2027 schedule 42 KB
- Roche Analyser Guidance 125 KB
