Interferon Gamma Release Assays EQA
| Accreditation Status: | UKAS Schedule of Accreditation | ||||||||||||||||||
| Date Scheme started: | 2009 | ||||||||||||||||||
| Clinical Applicability: | Test for latent tuberculosis infection and a useful aid for diagnosing M. tuberculosis complex infection | ||||||||||||||||||
| Analytes: | IGRA TB (SER/039) | ||||||||||||||||||
| Units for Reporting: | Qualitative responses (Positive, Negative and Indeterminate), Quantitative responses (IU/mL), number of T-spots, Clinical and Technical Interpretations | ||||||||||||||||||
| Samples Distributed: |
Normal and pathological human serum Distributions are linked to cases on the UK NEQAS for Immunology, Immunochemistry & Allergy Interpretative EQA Scheme (iEQA) website |
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| Number of Distributions per year: | 6 | ||||||||||||||||||
| Number of Samples per Distribution: | 2 sets of 4 (Nil, TB1 antigen, TB2 antigen and Mitogen), or one pre-incubated microtiter strip consisting of two samples | ||||||||||||||||||
| Frequency of Distributions: | Every two months as outlined in the Distribution Schedule | ||||||||||||||||||
| Schedule of Analysis: | Data entry is via the web for the submission of results. Data analysis commences 21 days after sample dispatch. Late returns are accepted and will contribute to the laboratory's cumulative performance statistics. | ||||||||||||||||||
| Data Analysis: |
All Laboratory Trimmed Mean (ALTM) with truncation at 2SD, SD and CV%. Reports show method specific statistics. Individual laboratory performance is expressed in terms of MRBIS, SDBIS and MRVIS Chosen Coefficient of Variation for Interferon gamma is 20% Qualitative responses are assessed in relation to the designated response |
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| Performance Scoring: | MRVIS / MI scoring | ||||||||||||||||||
| Criteria of Performance: |
OMIS for qualitative results over a running analytical window of 6 Distributions (12 months)
Individual laboratory performance over a running analytical window of 6 Distributions (12 months) for Interferon Gamma Release Assay quantitation is expressed in terms of MRBIS, SDBIS and MRVIS
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| Persistent Poor Performance: |
Defined as being in the Poor Performance category for two or more successive Distributions |