TPMT User Leaflet city hospital birmingham

BBC Midlands Today

TPMT Test....


Azathioprine on BBC News

Following on from this story follow this link to see the work of our specialist TPMT Laboratory in monitoring patients starting on azathioprine......


Thiopurine S-methyl transferase (TPMT) Service

We offer a TPMT activity assay service to UK laboratories and also take referrals from outside the UK. Our TPMT assay carries the CE mark and has been registered with the MHRA.  Deficient results are confirmed in our DNA laboratory.

Our offer is very much a service rather than an assay. We have clear policies for analysing samples for genotype - for example any patient details where an indication that blood products have already been given is analysed for TPMT activity and also genotype studies.

We continue to invest in this service to enable us to meet demand and keep to our 1 day turn round, electronic reporting is available.

We jointly organise an international external quality assurance programme for TPMT activity analysis in conjunction with UK NEQAS. If you would like to consider participating in the pilot scheme then contact:


Paper link: Barlow NL, Graham V, Berg JD. Expressing thiopurine S-methyltransferase activity as units per litre of whole-blood overcomes misleading high results in patients with anaemia, Ann Clin Biochem, ePub 1 July 2010


Download user information leaflet for "TPMT Activity" assay here...




Thiopurine S-methyl transferase (TPMT)



Clinical Biochemistry,

City Hospital Birmingham

Specimen Type:

4ml EDTA preferred


4oC prior to posting

Posting Details:

First class post - Our laboratory opens post on a Saturday so samples sent on Friday should be handled appropriately.

Posting Address:

Department of Clinical Biochemistry, City Hospital, Dudley Road, Birmingham

B18 7QH

Clinical Use:

Assessment of TPMT is useful in the treatment of patients with thiopurine drugs such as azathioprine, mercaptopurine and 6-thioguanine. 0.3 % of the population do not have this enzyme and can build up toxic levels of the active metabolites. Another 10% have a medium activity and may also need a lower dose than other patients. Information for patients can be found at

Special Details:

Patients who have had a blood transfusion may give misleading results. This is important as patients who may have had adverse affects due to azathioprine may well have had blood transfusions.

DNA confirmatory analysis is carried out on deficient results – there is no additional charge for this service.




1 working day with electronic reporting available

External QA Scheme:

Currently there is no EQA Scheme available

CPA Accredited Lab/Test:

Full Accreditation

CE Marking:

This internal assay at City Hospital carries a CE mark.

Key Contact Points:


BMS Supervisor

Tel: 0121 507 5345


Additional background information here ...