Review for 10.1186/1471-230X-13-168 (2013)

Reviewer's report
Title:Autoimmune Pancreatitis - A Comparative Description Highlighting North
American Experiences In Diagnosis And Management
Version: 1Date:28 December 2012
Reviewer: Siddharth Singh
Reviewer's report:
In this descriptive study, Patel and colleagues report their experience with
autoimmune pancreatitis (AIP). They performed a retrospective chart review (with
its inherent biases) of 55 cases of AIP diagnosed from 1998-2010, seen at two
referral centers in Toronto, Canada, with emphasis on imaging characteristics
and also report response to therapy. They subsequently report the clinical utility
of 3 well-accepted diagnostic scoring systems, HISORt, Japan Pancreas Society
and Korean guidelines in diagnosing AIP.
Overall, it is useful article on a rare condition, which mimics pancreatic cancer
but is associated with a much better prognosis. However, the article has several
major limitations which warrant attention. Most importantly, given significant
missing data, it is invalid to report the clinical utility of diagnostic criteria which
rely on these. I agree that histological diagnosis may be too invasive, but in the
real-world, imaging, serum IgG4 and response to corticosteroids are routinely
used.
Major Compulsory Revisions
1. The article may be better re-framed as a descriptive study of AIP because that
is the core of the article. In its current form, the title and abstract are confusing,
and the discussion is superficial with little comparison of the study’s results with
known findings from other studies
2. The selection of patients as having a ‘clinical label of AIP’ (‘Methods’, page 3,
para 1) is inherently prone to bias. Since patients were selected dating back to
1998 when this entity was poorly known and understood, it is likely that several
patients were misdiagnosed. It would be useful to discuss this, and also to report
how many patients were diagnosed each year.
3. It is unclear from the writing what the apparent ‘gold standard’ was against
which the 3 established criteria were measured. Was it a physician label of AIP?
What is meant by ‘clinical and/or radiologic evidence of AIP’ (‘Results’, page 7,
para 1) – while radiologic features are well-defined, what was considered ‘clinical’
evidence of AIP since manifestations were protean?
4. Even for patients in whom AIP diagnostic criteria were fulfilled, response to
corticosteroids was sub-optimal (45-57%), much lower than usual response
>80%. What may be the reason for this, and this should be discussed.
Additionally, reporting response to therapy in an easier to read would be helpful,
perhaps through a flowchart.
5. Please report how ‘renal’ involvement (Page 8, para 2) was diagnosed? The
current figure of 14/55 patients seems high.
Minor Essential Revisions
1. It is unclear how many patients had histological confirmation of AIP (Page 9,
para 2 reports 7; page 10, para 2 reports 8).
2. The total for pancreatic imaging findings (page 8, para 1) does not add to
100% [44% with diffuse enlargement, 9% with multifocal, 33% with focal, 9% with
atrophic pancreatic changes and 13% with no changes] – did patients have
multiple findings and if so, which?
3. If 36 patients had pre-treatment IgG4 serology, how was post-treatment
serology reported for 38 patients (page 8, para 3)?
4. For patients with liver biochemical abnormalities, how were other causes
excluded?
5. Please describe statistical methods used in the study.
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.