JPAC Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee

9.1: General requirements

Update notice:  Table 9.1 - Technical information has been updated following the the issue of Change Notification 12 - 2016.

All screening must be performed within Blood Safety and Quality Regulations (BSQR)1 compliant laboratories and meet any other appropriate regulatory requirements.

Secure and effective procedures must be in place to ensure that:

  • all donations, any subsequent components/products and their laboratory samples are correctly identified by barcoded and eye-readable numbers
     
  • donations can be linked to their donor
     
  • information about previous test results which would preclude issue of a subsequent donation cannot be automatically overridden by a subsequent negative test result
     
  • donor samples are suitably stored under appropriate conditions of temperature and time to preserve the targets for which they will be screened
     
  • the screening assays used are properly evaluated and validated
     
  • tests are appropriately performed and controlled, and the results properly and accurately recorded, using validated procedures
     
  • test results and other relevant test information are retained for the appropriate period, as set out in the BSQR1 or equivalent
     
  • appropriate confirmatory testing is available to investigate screen reactivity
     
  • relevant data relating to screening and confirmatory test results are reported to a centralised surveillance system, allowing the monitoring of trends in screening test reactivity and confirmed positive results.

9.1.1: Test reagents, kits and equipment

All assays used must be CE marked and must have been assessed (in respect of sensitivity and specificity) and deemed suitable by the UK Blood Transfusion Services kit evaluation groups (NHSBT KEG or SNBTS/NIBTS MTEG) for the detection of the required markers in the donation types being screened. Unless specifically validated for alternative use/performance, test kits and reagents must be stored and used according to the manufacturer’s instructions.

Each new manufacturer’s lot of each assay should be assessed prior to being accepted and put into use.

Additionally, all testing laboratories must ensure that the expected standard of performance of the assays used is being achieved, by using appropriate assay batch pre-acceptance testing, delivery acceptance testing and statistical monitoring of test results on defined quality control samples.

All test procedures must be documented and an inventory maintained of kits and reagents in stock, including supplier, batch number, expiry date, date of receipt, version number of product insert and record of pre-acceptance testing.

Procedures must ensure the traceability of the batch number and manufacturer of kits and reagents and the serial number of equipment used to test every donation.

Equipment must be validated, calibrated and maintained. Appropriate records for these activities must be made and retained as defined in extant regulations (currently 30 years).

Appropriate reactivity with manufacturers’ and any external control samples must be demonstrated with every series of tests.

A series/batch of tests is defined as the number of tests set up at the same time, under the same conditions and processed in a similar manner:

  • Where the microplate format is used each plate constitutes a series of tests even if only a few wells are used.
     
  • Where a closed system is used the size of a series/batch of tests must be determined by each individual Service through an appropriate risk assessment.

9.1.2: Recording and reporting of results

The laboratory final output should indicate the result of every test performed, using a system that provides positive sample identification. Each test result should be recorded by a system that does not require transcription. If manual completion of screening is performed it must be thoroughly documented and controlled and the results handled electronically following the same basic principles applied to fully automated testing.

9.1.3: Release of tested components/products

Standard procedures must ensure that no donations, or components/products prepared from them, can be released for issue until all the required laboratory tests (mandatory and additional) have been completed, documented and approved within a validated system of work. Compliance with this requirement can only be achieved by the use of a validated computerised system that requires the input of valid and acceptable test results for all the mandatory and required laboratory tests to permit the release of each individual donation.

Table 9.1 Screening required for blood donations

Infectious agent Minimum requirement Comments

HIV 1+2

anti-HIV 1+2 or HIV 1+2 Ag/Ab (M)

HIV RNA*

RNA screening in pools of a maximum of 48 donations**

HCV

anti-HCV (M)

HCV RNA (M)

RNA screening in pools of a maximum of 48 donations**

HBV

HBsAg (M)

HBV DNA*

anti-HBc [+ anti-HBs] (A)

DNA screening in pools of a maximum of 48 donations**

Donations that are anti-HBc reactive and have anti-HBs >100 mIU/mL are considered suitable for release

Syphilis

anti-treponemal Ab (M)

 

HTLV I/II

anti-HTLV I/II (A)***

ID or screening in pools of a maximum of
48 donations**

HEV HEV RNA (A) Screening in pools of a maximum of 24 donations**

HCMV

anti-HCMV (A)

Ideally both IgG and IgM, but IgG alone is considered sufficient

Plasmodium sp.

anti-P. falciparum/vivax (A)

 

Trypanosoma cruzi

anti-T. cruzi (A)

 

West Nile Virus (WNV)

WNV RNA (A)

RNA screening in pools of a maximum of 16 donations****

(M) – mandatory (release criteria) for the purpose of these guidelines

(A) – additional due to specifically identifiable risk

* Although neither are mandatory for blood donations in most of the UK, HIV RNA and HBV DNA are included in the nucleic acid amplification techniques (NAT) screen as the commercial systems available are now triplex assays. HIV RNA is mandated within Scotland.

** The minimum sensitivity of the molecular screening is dependent upon pool size.
The maximum validated pool size for use for blood screening within the UK Blood Transfusion Services is 48 donations.

*** anti-HTLV screening is only required for blood donations from previously untested donors and for blood donations destined for use to prepare non-leucodepleted products

**** The maximum validated pool size for WNV NAT screening is 16 donations.