SAT and serology in adult coeliacs, seronegative coeliac disease seems a reality.

UNLABELLED

The aim of this study was to assess the correlation of sugar absorption test (SAT) using Lactulose/Mannitol/Sucrose (LMS), with IgA-endomysium (EMA), and IgA-gliadin (AGA) antibodies in relation to the severity of the intestinal mucosal damage in adult coeliacs. We have differentiated the Marsh classification in partial villous atrophy (VA) (III a), subtotal VA (III b), and total VA (III c). Twenty-nine untreated adults coeliacs, with a mean age of 47 years, range 20-76 yrs were studied over 3 years. SAT, IgA-AGA and IgA EMA were performed in 29 consecutive coeliac patients with villous atrophy on a gluten containing diets.

RESULTS

Histopathological evaluation of small intestinal mucosa showed a partial VA in 14/29, subtotal VA in 10/29 and total VA in 5/29. All coeliacs with total VA had positive EMA (5/5 100%). However in coeliacs with partial VA sensitivity of EMA was poor (4/14 29%). Sensitivity of EMA in patients with subtotal VA was 50% (5/10). AGA was raised in 3/14 (21%), 6/10 (60%), and in 4/5 (80%) coeliacs with partial, subtotal and total VA respectively. AGA was raised in 13/29 (sensitivity 45%). SAT was abnormal in 26/29 (sensitivity: 89%). One patient had abnormal SAT, EMA and AGA. Eleven of 29 patients (38%) were negative for AGA and EMA, but SAT was abnormal in 10 of them. One patient was positive for EMA, negative for AGA, normal for SAT. EMA and/or AGA were positive in 18/29 (sensitivity 62%). Our study suggests that negative predictive value of serology should be interpreted cautiously since coeliacs with partial VA are negative in serology. Over the last ten years SAT and EMA have been accepted as screening tools for CD. SAT seems to be more sensitive than serology. However there is no standardized agreement in the literature for serology and SAT. A combination of SAT and serology may provide a good sensitivity in order to detect that subgroup of coeliacs with milder histopathological abnormality.