Tissue transglutaminase antibody (IgA TTG) - Black Country Pathology Services

Investigation Name:Tissue transglutaminase antibody (IgA TTG)

Alias or Abbreviation:IgA TTG, Coeliac

Intro:

Indication: Coeliac disease, dermatitis herpetiformis NOTE: • Testing should only be carried out when patient is on a gluten-containing diet. • Total IgA will be tested at the same time as TTG-A testing • TTG-IgA is the first line test. If the patient’s IgA <0.20g/L then the TTG-IgG is automatically reflexed by lab • Endomysial IgA antibodies are cascaded onto new positive (first time positive) TTG-A results for confirmation Further information: NICE guidelines NG20 (2015) recommend screening with IgA TTG antibodies and IgA as the first line test followed by endomysial IgA antibodies to confirm positive TTG results. IgA antibodies to TTG may be falsely positive especially in liver disease.

Requestable Seperately?Yes

Minimum Sample Volume:1mL

Test Code:TTGA

Sample Type:

Serum Gel Tube (Gold top)/ EDTA/ Sodium citrate Plasma

Complex Reference Range:<7 U/mL = Negative

Collection Conditions / Other Information:1st class post or Transport

Referred to Another Laboratory?No

Storage Requirements:Ambient temperature

NPEX / PDF Reporting Available:Yes

EQA Scheme:Yes

Further information:First line test Heparin samples are not suitable for analysis.

Lead Contact Details:rwh-tr.bcpsimmunologyclinicalqueries@nhs.net

Email Address For Chasing Results:rwh-tr.ImmunologyLab@nhs.net

Methodology:Fluoroenzymeimmunoassay

UKAS Reference Number:9580 (recommended)

Site Sample Tested:Immunology, New Cross Hospital, Wolverhampton

Minimum Request Interval (MRI):180 days (6 months) over 16y only