Implementation: getting started

This section highlights 2 areas of the coeliac disease guideline that could have a big impact on practice and be challenging to implement, along with the reasons why change is happening in these areas (given in the box at the start of each area). We identified these with the help of stakeholders and Guideline Committee members.

The challenge: making sure laboratories offer testing for tissue transglutaminase and endomysial antibodies

See recommendations 1.2.2, 1.2.3 and 1.2.7

The benefit of implementing IgA tissue transglutaminase (IgA tTG) as the first‑choice test will result in optimal sensitivity and specificity in serological testing. However, there is no clear guidance on how to interpret weakly positive IgA tTG results. Conducting an endomysial antibody test to follow up people with weakly positive IgA tTG test results will provide the opportunity for a secondary serological screen to inform the decision to biopsy in people with suspected coeliac disease.

Offering both tTG and endomysial antibodies tests

Many laboratories currently offer only one of these tests, usually only tTG. This may be because of a lack of demand, lack of equipment, or a lack of expertise to conduct the endomysial antibodies (EMA) test. Some laboratory staff may not be trained or may not have experience in carrying out EMA tests.

What can laboratories do to help?
  • Work with commissioners and local pathology networks to make a business case. If demand is sufficient they may wish to include offering EMA tests in‑house (this may include purchasing new equipment such as immunofluorescence microscopes and slide staining equipment, and training staff to carry out EMA testing). Or if demand is low, look at alternative options to providing EMA testing in‑house, such as sending samples for testing to other laboratories in their network.

Ensuring that anti‑tTG assays have been appropriately validated in each laboratory before use

There are several different testing kits and methods available to laboratories to detect tTG. However, in the absence of international standards for IgA (and IgG) anti‑tTG, there is wide variability in sensitivity and specificity between these assays and currently no method to ensure comparability between tests.

What can laboratories do to help?
  • Internally validate their serological testing assays and develop an appropriate threshold for their local screening population to ensure optimal diagnosis, and re‑audit this threshold at regular time intervals.

Interpreting the results of the tTG and EMA tests

Often laboratories report the results of the assays to the requesting GP as numbers, with no other indication about whether coeliac disease is serologically suspected or not. Without help or explanation of the appropriate threshold, it is possible that the requesting GP could wrongly interpret the result.

What can laboratories do to help?
  • Change the way the results of serological assays are reported to clearly state if coeliac disease is suspected so that the results are not open to incorrect interpretation by the requesting GP.

The challenge: making sure people have access to a healthcare professional trained to give specialist dietetic advice in relation to coeliac disease

See recommendation 1.4.3 and recommendation 1.5.1

The only treatment for coeliac disease is for the person to follow a gluten‑free diet. The advice and support of a healthcare professional with specialist knowledge of the dietary requirements of coeliac disease is one approach to help ensure lifelong adherence to a gluten‑free diet.

Providing access to a healthcare professional trained to give specialist dietetic advice in both primary and secondary care settings

There is a lack of dietitians in the NHS nationally, and specifically a lack of dietitians who have a specialist interest in coeliac disease or gastroenterology. This leads to variation in the provision of specialist dietetic advice.

What can commissioners and providers of services for people with coeliac disease do to help?