Patients of celiac disease with mild villous atrophy are clinically similar to those with moderate to severe atrophy

Titers of anti-tissue transglutaminase antibody correlate well with severity of villous abnormalities in celiac disease

GOALS

We reviewed our celiac disease (CeD) database to study if anti-tissue transglutaminase (tTG) antibody (ab) titers correlate with severity of villous abnormalities in Indian patients and to find out a cutoff value of anti-tTG ab fold-rise, which could best predict CeD.

BACKGROUND

Guidelines for diagnosing CeD suggest that biopsy could be avoided in some patients with high anti-tTG ab titer.

STUDY

We reviewed a cohort of 366 anti-tTG ab-positive individuals in whom duodenal biopsies were performed. Anti-tTG ab was obtained before initiation of gluten-free diet. Anti-tTG ab results were expressed in terms of fold-rise by calculating ratio of observed values with cutoff value. CeD was diagnosed if in addition to positive serology, patients had villous atrophy (>Marsh grade 2) and unequivocal response to gluten-free diet.

RESULTS

The mean anti-tTG fold-rise in groups with Marsh grade ≤2 was 2.6 (±2.5), grade 3a was 4.0 (±3.9), 3b was 5.7 (±5.1), and 3c was 11.8 (±8.0). The positive likelihood ratio for diagnosing CeD was 15.4 and 27.4 at 12- and 14-fold-rise of anti-tTG ab titer, respectively. The positive predictive value of diagnosis of CeD was 100% when anti-tTG ab titer was 14-fold higher over the cutoff value. Fifty-seven (43.9%) individuals with anti-tTG titer rise <2-fold high also had CeD.

CONCLUSIONS

As severity of villous abnormality increases, titer of anti-tTG also rises. Presence of villous atrophy can be predicted at very high anti-tTG ab titer. In contrast to emerging belief, mucosal biopsies should be performed even if anti-tTG ab titer is <2 times, because many patients with CeD have low titers.

Validation of point-of-care testing for coeliac disease in children in a tertiary hospital in north India

OBJECTIVE

Some of the conventional serological tests for coeliac disease (CD) are expensive, time-consuming and not readily available in developing countries, leading to a delay in diagnosis. Recently, point-of-care tests (POCT) have been manufactured and tested in Europe but have not been validated in our setting. We therefore aimed to study the diagnostic accuracy of the POCT 'Biocard' test in diagnosing CD in Indian children.

DESIGN

Cross-sectional study.

SETTING

Tertiary care centre in north India.

PATIENTS

Children, aged 2-18 years, with chronic diarrhoea, short stature or refractory anaemia underwent serological testing for CD with antiendomysial antibodies (AEA), antitissue transglutaminase (tTG) antibodies and Biocard test followed by duodenal biopsy irrespective of serological results. CD was diagnosed with positive AEA and duodenal biopsy showing >grade 2 changes using modified Marsh criteria. Those who were both AEA negative and had normal histology were considered CD negative.

RESULTS

Of 319 children who underwent the serological testing, 170 agreed for biopsy. Of these, 110 were diagnosed with CD and 30 were found to be CD negative. Remaining 30 had discordant AEA and histology results and were not included in analysis. Biocard test agreed with 92/110 positive and 27/30 negative diagnoses based on reference tests (83.6% sensitivity and 90% specificity). tTG was found to be 93.8% sensitive and 96.4% specific.

CONCLUSIONS

We successfully validated the POCT for CD in our setting. It could be used to increase case detection rates in developing countries with a large undiagnosed CD burden.