Five year time course of celiac disease serology during gluten free diet: results of a community based "CD-Watch" program.

Background: Little information is available on the effect of a follow-up strategy in celiac disease patients during gluten-free diet.

Aims: To assess 5 year time course of t-transglutaminase antibodies (t-TG) in celiac disease patients enrolled in a community based follow-up program.

Methods: Annual t-TG testing and periodical clinic visit in 2245 patients.

Results: Proportion of patients with negative t-TG progressively increased from 83% to 93% during the 5-year follow-up: poor adherence to gluten-free diet (HR 4.764), long duration of gluten-free diet (HR 0.929) and female gender (HR 1.472) were independently associated with serological outcome. In individual patients, 69% tested t-TG "persistently negative", 1% "persistently positive" and 30% "intermittently negative or positive". By applying mathematical modelling to t-TG conversion rates observed in this latter group at beginning and end of the follow-up program, the predicted proportion of t-TG negative population increased from 90% to 95% over 5 years.

Conclusions: Time-course of t-TG serology in the community fluctuates in 1/3 of celiac disease patients suggesting inconstant adherence to gluten-free diet and need of follow-up strategy. Periodical serological and clinical follow-up is a viable and efficacious strategy to promote adherence to gluten-free diet as inferred from time-course of t-TG serology.