Review for 10.1186/1471-230X-14-36 (2014)

Reviewer's report
Title:Screening for celiac disease in 1st degree relatives: a 10-year follow-up
study
Version: 3Date:14 June 2013
Reviewer: Edgardo Smecuol
Reviewer's report:
The study is interesting because it raises significant topics in clinical practice.
Thus, the question raised by authors is well defined. Since CD frequently occurs
in families, first degree relatives (FDR) of affected individuals are tested for the
disease irrespective of the presence of symptoms. Moreover, FDR found to be
negative at a first serological screening can subsequently develop CD with an
unknown frequency. Although prevalence of the disorder among FDR is
well-known, only few studies are available about incidence.
The question regarding the incidence is important since the response would
determine how to perform an appropriate follow-up of these subjects. Thus, until
now, there are no evidence-based guidelines for when or how often test relatives
In my opinion, for publication, the authors should clarify an important
epidemiological issue related with data provided. Although data on the
prevalence (19/450 subjects,4.2%) at baseline is clear in this study, data offered
about incidence of the disease in FDR do not seem to express this concept
exactly. Incidence should not be confused with prevalence. As it is well-known,
the incidence-rate is the number of new cases per population in a given time
period and to measure incidence it must take into account how many years each
person contributed to the study and when the developed the disease. In this
regard, the interval between the first and second test and the average time to
seroconversion is not informed in this paper. It is important to note that
“incidence” is only expressed as percentage by the authors.
Some additional recommendations for improvement are the following:
1- INTRODUCTION:The introduction presents an imbalance between the
extensive explanation on the geographical variability of the disease which is not
the most important issue of this study and a small paragraph about the evolution
of the knowledge of the most important topic (prevalence and incidence of CD in
FDR of celiac patients.
2- DISCUSSION.
a- Page 9, third paragraph. As part of the discussion it mentions a high
prevalence rate reaching 44%. However the bibliographic citation (33) does not
support this assertion. “…The prevalence of CD among first-degree relatives of
celiac patients has been estimated to vary from 2.0% to 44.1% depending on the
method of diagnosis (biopsy vs. serologic testing) and the country of study [33],
b- In the same paragraph, it should expand the explanation of the variability of
the data provided by the different works (from 2.0% to 44.1%) on the prevalence
of CD in FDR. It could be include the consideration about this variability reflecting
different case selection, recruitment, and testing. Moreover, variation in the
number and type of FDR that are studied for each celiac index case, studies with
exclusively pediatric or adult patients, absence of histological confirmation in the
index cases and the use of different screening tools should be consider.
c- The last sentence of the third paragraph (Page 9) also mentions “an annual
incidence ranging from 0.3% to 1.7% [33]…” Once again, the paper by Chang et
al. (33) does not support this concept and the form to express incidence is not
aappropriate
d- Data from the three new patients detected observed at the 1st paragraph
(Page 10) who were not biopsied should be included in or at least detailed in the
Section Results. Moreover, the explanation given in the Section Discussion is
long.
3- CONCLUSION. The conclusion is not clear. It says something right as the
assertion about how hard it is to have an algorithm for the follow-up of FDR of
CD patients. However, it is assumed that this difficulty would be caused by
special circumstances of Brazil (background of the population and the
characteristics of health coverage) instead of reaffirming the lack of a clear
algorithm on this issue. Finally the decision of the authors to perform a genetic
study before the serologic screening could be mentioned but remembering that
the place of this practice and its cost-benefit has not yet been clarified.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'