9 April update - ABOi titre investigations are NOT changing from 4 May 2020

For reasons relating to COVID-19, standardising ABOi titre methodology has been put on hold. RCI will advise you when it is going ahead.

We have reviewed the way we test and report ABOi titre investigations. The aim of the review was to standardise the ABOi titre methodology used within the 8 RCI laboratories and to take into consideration the recommendations made by the National External Quality Assurance Scheme (NEQAS). The panel performing the review included RCI laboratory staff and managers, NHSBT Consultant haematologists and a Hospital Transplant Consultant Lead.

Following the outcome of the review we will be changing the way ABOi titre investigations are tested and reported from 4 May.

 There are multiple advantages to moving to a single standardised method. This includes the following:

  • Improved ability for testing laboratories to compare the titre results obtained in order to maintain accuracy and quality of the process (improved inter-laboratory reproducibility)    
  • Improves ability for transplant centres to compare transplant protocols used at different Hospitals when RCI is used to provide the ABOi titre results (important when assessing the immunological risk associated with ABOi transplantation and the requirement for pre-transplant antibody removal).
  • Greater resiliency and contingency within NHSBT to be able to ensure continuity of service.
  • Simplification of the results and reports provided by RCI.

The impact of the change will depend on which RCI laboratory currently performs the testing for your hospital. Your blood bank will be able to provide you with the name of your RCI referral laboratory.

In order to allow you to prepare for the change RCI has performed some comparison studies to allow you to assess the impact that the change will have on the titre endpoint that we will report following the change. The expected effect that this will have on the titre result compared to our current method is provided in the tables below.

Table 1 Example for IgM ABOi titre

Testing Lab

Example for IgM ABOi titre*

Current result

Future result**

Birmingham, Colindale, Newcastle,
Leeds, Sheffield, (Barnsley), Tooting

 

1/4

1/8

1/8

1/16

1/16

1/32

1/32

1/64

1/64

1/128

1/128

1/256

1/256

1/512

Filton (Bristol)

No change

* ABOi titres are tested using doubling dilutions therefore the results reported will be one dilution higher

** Based on comparison testing using NEQAS (National External Quality Assurance Scheme) results over the last 4 exercises

 

Table 2 Example for IgG ABOi titre

Testing Lab

Example for IgG ABOi titre*

Current result

Future result**

Birmingham, Newcastle

 

1/4

1/8

1/8

1/16

1/16

1/32

1/32

1/64

1/64

1/128

1/128

1/256

1/256

1/512

Colindale, Filton (Bristol), Leeds, Sheffield, (Barnsley), Tooting

 

No change

* ABOi titres are tested using doubling dilutions therefore the results reported will be one dilution higher for Birmingham and Newcastle

** Based on comparison testing using NEQAS (National External Quality Assurance Scheme) results over the last 4 exercises

The format of the report will also change for samples processed at Leeds or Sheffield RCI Laboratories. In the new style report the titre results will be laid out in a table as shown in figure 1.

For clinical questions regarding this change, please email Fiona Regan fiona.regan@nhsbt.nhs.uk, and for laboratory questions please email Tracey Tomlinson tracey.tomlinson@nhsbt.nhs.uk, Head of Lab RCI Colindale.

Tracey Tomlinson, Head of Laboratory - RCI Colindale