Reviewer's report
Title:Pancreatic-specific autoantibodies to glycoprotein 2 mirror disease location
and behaviour in younger patients with Crohn's disease
Version: 1Date:24 May 2012
Reviewer: Richard RUssell
Reviewer's report:
The authors have examined the role of the GP2 pancreatic antigen in 271
patients with IBD (169 CD, 102 UC). Phenotypic analysis then describes
association with L3 disease, stricturing and paediatric patients. There are
however a number of outstanding issues:
Major Compulsory Revisions
1. The study would be improved by including serological data on healthy controls
rather than using UC patients as proxy controls
2. The authors should justify why IBDU patients were excluded - it would have
been more interesting and useful to have included them in the study
3. The start of the results section on PAB/ASCA/GP2 results could be clearer
and may be more easily understood in a table rather than text
4. The authors should only use fishers exact test when low numbers of patients
are being analysed in one or more groups otherwise it would be better to use a
chi-square test
5. The authors should justify analysing both IGA and IGG in the sub analysis - it
would be simpler just to analyse positive and negative serology whether IGA or
IGG together
6. When generating p - values the authors should not just show the data of
interest eg the proportion of patient in A1 with positive serology they should also
list the numerator and denominator of the comparative data too
7. In making multiple comparisons the authors should use corrected p-values or
justify why they are not used
8. Given that patient were recruited from 3 centres - per centre analysis should
be done to exclude a difference between serology rates in German cf. UK
patients
9. The effect on age may have nothing to do with CD it may just be younger
patients are more likely to have positive serology - again a suitable control cohort
would address this issue
Minor Essential Revisions
1. All data should be listed in the abstract when p-values are being quoted
2. consistent number of decimal places should be used for p-values - suggested
2
3. Age distribution in the study is likely to have a non-uniform distribution thus a
median with IQR rather than mean should be used
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Reviewer's report
Title:Pancreatic-specific autoantibodies to glycoprotein 2 mirror disease location
and behaviour in younger patients with Crohn's disease
Version: 1Date:24 May 2012
Reviewer: Richard RUssell
Reviewer's report:
The authors have examined the role of the GP2 pancreatic antigen in 271
patients with IBD (169 CD, 102 UC). Phenotypic analysis then describes
association with L3 disease, stricturing and paediatric patients. There are
however a number of outstanding issues:
Major Compulsory Revisions
1. The study would be improved by including serological data on healthy controls
rather than using UC patients as proxy controls
2. The authors should justify why IBDU patients were excluded - it would have
been more interesting and useful to have included them in the study
3. The start of the results section on PAB/ASCA/GP2 results could be clearer
and may be more easily understood in a table rather than text
4. The authors should only use fishers exact test when low numbers of patients
are being analysed in one or more groups otherwise it would be better to use a
chi-square test
5. The authors should justify analysing both IGA and IGG in the sub analysis - it
would be simpler just to analyse positive and negative serology whether IGA or
IGG together
6. When generating p - values the authors should not just show the data of
interest eg the proportion of patient in A1 with positive serology they should also
list the numerator and denominator of the comparative data too
7. In making multiple comparisons the authors should use corrected p-values or
justify why they are not used
8. Given that patient were recruited from 3 centres - per centre analysis should
be done to exclude a difference between serology rates in German cf. UK
patients
9. The effect on age may have nothing to do with CD it may just be younger
patients are more likely to have positive serology - again a suitable control cohort
would address this issue
Minor Essential Revisions
1. All data should be listed in the abstract when p-values are being quoted
2. consistent number of decimal places should be used for p-values - suggested
2
3. Age distribution in the study is likely to have a non-uniform distribution thus a
median with IQR rather than mean should be used
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Please review this paper.
user
Reviewer's report
Title:Pancreatic-specific autoantibodies to glycoprotein 2 mirror disease location
and behaviour in younger patients with Crohn's disease
Version: 1Date:24 May 2012
Reviewer: Richard RUssell
Reviewer's report:
The authors have examined the role of the GP2 pancreatic antigen in 271
patients with IBD (169 CD, 102 UC). Phenotypic analysis then describes
association with L3 disease, stricturing and paediatric patients. There are
however a number of outstanding issues:
Major Compulsory Revisions
1. The study would be improved by including serological data on healthy controls
rather than using UC patients as proxy controls
2. The authors should justify why IBDU patients were excluded - it would have
been more interesting and useful to have included them in the study
3. The start of the results section on PAB/ASCA/GP2 results could be clearer
and may be more easily understood in a table rather than text
4. The authors should only use fishers exact test when low numbers of patients
are being analysed in one or more groups otherwise it would be better to use a
chi-square test
5. The authors should justify analysing both IGA and IGG in the sub analysis - it
would be simpler just to analyse positive and negative serology whether IGA or
IGG together
6. When generating p - values the authors should not just show the data of
interest eg the proportion of patient in A1 with positive serology they should also
list the numerator and denominator of the comparative data too
7. In making multiple comparisons the authors should use corrected p-values or
justify why they are not used
8. Given that patient were recruited from 3 centres - per centre analysis should
be done to exclude a difference between serology rates in German cf. UK
patients
9. The effect on age may have nothing to do with CD it may just be younger
patients are more likely to have positive serology - again a suitable control cohort
would address this issue
Minor Essential Revisions
1. All data should be listed in the abstract when p-values are being quoted
2. consistent number of decimal places should be used for p-values - suggested
2
3. Age distribution in the study is likely to have a non-uniform distribution thus a
median with IQR rather than mean should be used
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
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