Dear Editors,
We read with great interest the article by Angelo et al. in CLINICS (11. Angelo AL, Cavalcante LN, Abe-Sandes K, Machado TB, Lemaire DC, Malta F, et al.
Myxovirus resistance, osteopontin and suppressor of cytokine signaling 3 polymorphisms predict
hepatitis C virus therapy response in an admixed patient population: comparison with IL28B. Clinics.
2013;68(10):1325-32, http://dx.doi.org/10.6061/clinics/2013(10)06.
http://dx.doi.org/10.6061/clinics/2013(1...
). This study revealed interesting points regarding the impact of different
genetic polymorphisms on hepatitis C treatment efficacy in 181 Brazilian patients. The evaluation of
multiple genetic polymorphisms in this study encouraged us to appreciate the authors' attempt
to show the impact of host genetics on the treatment response in hepatitis C virus (HCV)-infected
Brazilian patients of admixed ethnicity. Although the statistical analysis in this study was
comprehensive in its assessment of the association between different genetic polymorphisms and
treatment response, we have several concerns about this statistical analysis. We believe that the
frequencies of the polymorphism genotypes should have been reported for the response groups instead
of the polymorphisms genotypes that were reported throughout the article. As a result, the
presentation of the frequencies of the polymorphism genotypes in Table 2 would be preferable in
vertical order instead of in horizontal order (22. Stern R, Coe R, Allan E, Dale I. Informative presentation of tables, graphs and
statistics. Good statistical practice for natural resources research. 2004 CABI (H ISBN
9780851997223):337-52, http://dx.doi.org/10.1079/9780851997223.0337.
http://dx.doi.org/10.1079/9780851997223....
).
Additionally, the protective genotype frequencies in the sustained virological response group, which
were presented in the abstract, should be considered in the following manner: 44.2% rs4969170 G/G;
17.3% rs2853744 T/T; 69.2% rs11730582 T/T; 76.9% rs2071430 G/T; and 45.5% rs12979860 C/C. On the
other hand, data on the rs12979860 genotype were included for 139 individuals in Table 2, and it
appeared that the data on the rs12979860 genotyping was missing for 42 patients in this study. The
authors reported that the frequency of rs12979860 C/C was 18.8% in the study population, which seems
to be incorrect; considering the missing data in the statistical calculation, we found the
rs12979860 C/C genotype frequency to be 24.5%. Another point that we would like to address in this
letter is that a multivariate analysis should have been considered by the authors to clarify the
adjusted impact of each polymorphism alongside other factors, such as liver fibrosis, on the
response to hepatitis C treatment (33. Tabachnick BG, Fidell LS, Osterlind SJ. Using multivariate statistics.
2001.). Finally, because the
impact of genetic factors on the HCV treatment response in populations with admixed ethnicity has
been not well studied, a study on a large sample of different ethnicities in regions with an admixed
population, such as Brazil, is highly recommended. Each genetic marker could have an
ethnicity-specific influence on the response to hepatitis C treatment, which should be investigated
in a population-based setting.
REFERENCES
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1Angelo AL, Cavalcante LN, Abe-Sandes K, Machado TB, Lemaire DC, Malta F, et al. Myxovirus resistance, osteopontin and suppressor of cytokine signaling 3 polymorphisms predict hepatitis C virus therapy response in an admixed patient population: comparison with IL28B. Clinics. 2013;68(10):1325-32, http://dx.doi.org/10.6061/clinics/2013(10)06.
» http://dx.doi.org/10.6061/clinics/2013(10)06 -
2Stern R, Coe R, Allan E, Dale I. Informative presentation of tables, graphs and statistics. Good statistical practice for natural resources research. 2004 CABI (H ISBN 9780851997223):337-52, http://dx.doi.org/10.1079/9780851997223.0337.
» http://dx.doi.org/10.1079/9780851997223.0337 -
3Tabachnick BG, Fidell LS, Osterlind SJ. Using multivariate statistics. 2001.
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No potential conflict of interest was reported.
Publication Dates
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Publication in this collection
Feb 2014