Review for 10.1186/1471-230X-10-145 (2010)

Reviewer's report
Title:Association between HLA-DRB1 alleles polymorphism and hepatocellular
carcinoma:A Meta-analysis
Version: 5Date:12 August 2010
Reviewer: Adriana Rojas-Villarraga
Reviewer's report:
Minor Essential Revisions (such as missing labels on figures, or the wrong use of
a term, which the author can be trusted to correct)
- Page 4, Methods section, Search Strategy:
Specify if terms in addition to HLA such as MHC or HLA-DRB1 were used to
search for the studies.
-Page 4, Methods section, inclusive selection criteria:
Specify detailed study characteristics including the criteria that the diagnosis of
patients with HCC was based on and give the age range of patients that were
included. Move the information that is in the results section (Page 7) “The
diagnosis of HCC was based on at least one of the following criteria: classical
histological characteristics or a serum a-fetoprotein (AFP) level higher than
500µg/ml together with radiological findings (ultrasound and/or CT) consistent
with HCC” to the inclusive selection criteria part of the methods section.
In addition, specify if the criteria for HCC diagnosis are author based or if they
are based on specific reported guidelines. If so, include the specific reference.
-Page 6, Statistical analysis, first paragraph:
State if I2 was used as an additional method for heterogeneity because it is
shown in the author’s attached forest plots. Furthermore, it is important to state if
Tau squared was used to evaluate heterogeneity because it is also reported on
the forest plots.
-Page 6, Statistical analysis:
Clarify if the crude number of patients and controls was used to calculate ORs
and if specific allele frequencies were not used. Indicate what the reason was for
not doing it. Specify that heterozygosity and homozygosity (allelic dosage) were
not taken into account for these calculations.
-Page 7, Results section, Association between HLA-DRB1 alleles with HCC:
Clarify if the results by random effect model were the same as the results from
the fixed effect model in the article in the case of HLA-DRB1*07 where I2 shows
some heterogeneity other than the Q statistics results (54%).
-Page 8, results section, last paragraph:
Specify that fixed effect model was used for the results reported for
HLA-DRB1*15 in Asians.
Major Compulsory Revisions (which the author must respond to before a
decision on publication can be reached)
-Page 3 and 4, Methods section, selection criteria:
As stated in the author guidelines, authors are requested to make use of the
PRISMA checklist (http://www.prisma-statement.org/) when reporting systematic
review and meta-analysis. Authors have to refer to this in the methods section
and be sure they fit the minimum set of items for reporting in systematic reviews
and meta-analyses included there.
-Page 8, Discussion section:
It is important that the authors explain why the DRB1*07 and DRB1*12 could be
of interest in HCC. Do these two groups/alleles share some pocket specificities?
Are these groups/alleles described in association with specific viral hepatic
infections? Do these groups/alleles have a similar preference for specific types of
amino acids? Do the authors have a specific hypothesis regarding why these
groups/alleles confer susceptibility to HCC?
All of the information in the discussion section is of essential importance for
understanding functional and biological aspects of HCC and HLA.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
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