Review for 10.1186/1471-230X-10-53 (2010)

Reviewer's report
Title:Non-Invasive Index of Liver Fibrosis Generated by Alcohol, Thioacetamide
and Schistosomal Infection in Mice
Version: 2Date:15 November 2009
Reviewer: Emanuel Manesis
Reviewer's report:
The article by Hessien MMH, et al entitled “Non-Invasive Index of Liver Fibrosis
Generated by Alcohol, Thioacetamide and Schistosomal Infection in Mice” is an
experimental work in mice aiming the estimation of liver fibrosis by non-invasive
means by development and validation of a mathematical formula involving simple
serum markers associated with liver function. The concept is original, but the
presentation of data and its statistical analysis is rather cloudy, needing further
clarification and verification. The authors do not present convincing evidence on
the way they derived to their proposed formula or of the discriminating
significance of the cut-off values between the stages of liver fibrosis determined
thereof.
Major Comments:
1. (Abstract): Authors should shorten “Methods” and expand “Results”
respectively.
2. (Page 4, lines 3, from bottom): Reference 16 is inappropriate. Consider
change.
3. (Page 4, last line): Why 600 mg/kg praziquantel and not a different dose were
elected?
4. (Page 5, 1st line from top): Authors should explain how liver fibrosis was
induced in the animals of the validation group. By Thioacetamide, S. mansoni, or
by ethanol? In what numbers per group? Results on the validation group should
appear in a separate section of “Results”.
5. (Page 6, line 6, from top): Hematoxylin-eosin is an excellent staining method
for liver necroinflammation, but appropriate for the fibrous tissue. Was Masson or
a similar staining method used for this purpose?
6. (Statistical Analysis): ANOVA and Pearson’s correlation require a normal
distribution of data. However, most biochemical measurements have a
non-parametric distribution. Authors should verify normality of distribution of their
data by Kolmogorov-Smirnov or a similar test and if normality is not met to use
Kruskal-Wallis and Spearman’s correlation, in place of ANOVA and Pearson’s
test, respectively.
7. (Statistical Analysis): K-mean cluster analysis has been also applied (see page
8 “Biochemical scoring of fibrosis”). Please give details on variables used in
cluster analysis.
8. (Statistical Analysis): Histological stage and grade are ordinal data. A
correlation test, although suggestive, is not the appropriate test to verify relations
with continuous variables. Please consider ANOVA (or Kruskal-Wallis) test
instead.
9. (“Results”-Biochemical panel): “Hepatic panel” data appear in Table 2 only but
their interrelation with the serum parameters and their overall usefulness
justifying their use should also be commented in this section.
10. (“Modeling of hepatic fibrosis”): Authors should explain how they decided that
bilirubin, total protein, #GT and GSH are the most useful tests reflecting liver
fibrosis. Because of their statistical significance in control vs. experimental
animals (was there any? None is mentioned throughout the text). Because of
their relation to fibrosis? But, at least the first three tests represent cholestatic or
synthetic liver function parameters and their association with fibrosis is, at the
best, indirect.
11. (“Modeling of hepatic fibrosis”): No explanation is given by the authors on
how the logarithmic formula was derived. By intuition, empirically or by some
statistical or mathematical process involving their measurements?
12. (Page 8, line 2 from top): Total histological activity in groups II, V and X must
be compared against groups (III, IV) (VI, VII, VIII, IX) and (XI, XII), respectively
and tests of significance mentioned.
13. (Page 8, line 3 from top): Authors should explain what “less nodularity in
hepatocytes surface” means?
14. (“Biochemical scoring of fibrosis”): Significance values between the K-mean
distances should be given.
15. (“Biochemical scoring of fibrosis”): The area under the curve for each cut-off
value and its statistical significance should be given.
16. (Page 9, first line from top): Compare the index score values vs. histological
stage by ANOVA, if normally distributed, or by Kruskal-Wallis test, if not-normally
distributed and give P-test values.
17.
Minor Comments:
1. The article must be extensively reviewed for English language and typing
problems.
2. (Page 4, lines 9-11, from top): The sentence must be further clarified. In its
present form is dubious.
3. (Page 5, lines 14, from bottom): “TBA” is not used elsewhere in the text. The
abbreviation is unnecessary.
4. (Page 5, lines 3, from bottom): “..is a chromophore absorbs light at..”: consider
revision.
5. (Page 6, line 3, from top): Omit “non-invasive”.
6. (Statistical Analysis): What exactly version of the SPSS package was used.
7. (Page 7, line 12, from top): Overproduction.
8. (Page 7, line 11 from bottom): Total serum bilirubin or #GT.
9. (Page 7, line 11 from bottom): “serum Where;” should be omitted.
10. (Page 7, line 7 from bottom): “0.015 mg/dl”, instead of “mg/dl”.
11. (Page 9, “Discussion”): The abbreviations “ECM”, “HSC”, “TIMP-1”, “PT”
need explanation when used for 1st time.
12. (Page 9, last line from bottom): “provides a slow-montion picture”: consider
revision.
13. (Page 10, line 12 from bottom): transglutaminase.
14. (Page 11, line 9 from bottom): reproducible.
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests' below