• autoimmune disease
• coeliac disease

We recently suggested in a study on 909 adolescent and young adults aged 15+ years (mean 16.1) that the prevalence of autoimmune diseases in coeliac adults is related to the length of gluten exposure, independently of the expected age effect.¹ Recently, Sategna Guidetti et al (

) presented a paper which, in the title itself, negates this hypothesis.

However, we feel quite happy with the contribution of Sategna Guidetti et al as we found strong confirmation of our findings in their paper. As mentioned by the authors, their paper stimulates some interesting observations.

1. The population they studied was affected by a very strong “age” selection as the vast majority were aged over 40 years and hence all had maximum exposure to the risk factors (100% had been exposed to gluten for >20 years, including “actual gluten exposure”) and there was no modulation of effect, just the end point, which surprisingly was identical to our own results. We have not studied a paediatric population, but young adults with a mean age of 16.7 years and the risk factor was evaluated over the whole range of ages before the outcome (autoimmune disease) was expected.

2. “Age at diagnosis” is a robust variable and is unlikely to be biased. Sategna Guidetti et al showed, very consistently, that age at diagnosis was related to outcome. The actual prevalence of autoimmune diseases was even higher than that observed by us (possibly due to age range?).

3. The variable “actual gluten exposure”, artificially built by the authors, was largely based on age at diagnosis (hard data) together with minor components related to self reported compliance and follow up.

4. In summary, if they included in a multivariate model the strong variable “age at diagnosis” which explains a significant part of the variance in the outcome variable, it is very unlikely …