Endocrine Abstracts

Background: Current guidance recommends screening for coeliac disease (CD) at diagnosis of type 1 diabetes mellitus (T1DM) using measurement of serum anti tissue transglutaminase immunoglobulin A (tTG-IgA). It is recognized that tTG-IgA levels can fluctuate and there are reports of transient rises in tTG-IgA levels in response to acute stress, such as infection and acute coronary syndrome. The effect of diabetic ketoacidosis (DKA) on tTG-IgA has not been reported. We investigated whether serum tTG-IgA levels were higher in children at T1DM diagnosis, who presented with DKA compared to those not in DKA.

Methods: Electronic patient records for children (<18 years) presenting with a new diagnosis of T1DM to University Hospital Southampton NHS Foundation Trust between 01/01/2017 and 30/05/2020 were reviewed. DKA was defined using the British Society for Paediatric Endocrinology and Diabetes 2020 guideline (blood pH<7.29 or bicarbonate <15 mmol/l). tTG-IgA was considered raised if it was above the upper limit of normal (ULN) for the assay.

Results: 77 children presented with T1DM during the study period (48.1% male, mean age 9.73 years (SD 4.21)). 32.5% presented with DKA. One child had pre-existing CD. tTG -IgA was assessed at acute presentation in 69 (90.8%) children. Raised tTG-IgA was found in 6 of 69 (8.7%) children, but with similar frequency in children with (4.5%) and without DKA (10.6%, P=0.66). Total tTG-IgA did not differ between children presenting with and without DKA (P=0.72). 3 of the 6 children with raised tTG-IgA had CD diagnosed without biopsy (tTG-IgA 87-225 x ULN). 2 children with moderately raised tTG-IgA (3.8-4.7 x ULN) were diagnosed with CD following intestinal biopsy, and one child (not in DKA at diagnosis) had a tTG-IgA 3.0 x ULN, which had normalized 6 months after diagnosis of T1DM.

Conclusions: Diabetic ketoacidosis did not affect serum tTG-IgA levels in our patient group. Given the high frequency of undiagnosed CD at presentation of T1DM, screening should not be delayed until recovery from DKA, but the potential for normalization of a raised tTG-IgA should be considered in the further investigations/referral of child with a moderately raised tTG-IgA.