We read with great interest the comments of Chen, Li, Wu about our study entitled “Usefulness of collagen type IV in the detection of significant liver fibrosis in nonalcoholic fatty liver disease” published in Annals of Hepatology [1].
Concerning the researchers’ notes, we would like to clarify the following points:
- 1
It is indeed interesting to know if the collagen type IV level is associated with the diagnosis of NAFLD, but it was not the aim of our present work, and that explains the absence of control group.
- 2
Second, we thank you for the opportunity to clarify the data regarding underlying diseases in the two groups (significant fibrosis and advanced fibrosis) of our study. Of note, they do not explain the differences in type IV collagen levels as hypothesized by Chen et al. The observed frequencies of comorbidities are as it follows: 76.32% of patients with significant fibrosis had diabetes, 76.32% dyslipidemia, 50% hypertension and 76.31% obesity. The group of NAFLD patients with advanced fibrosis had 72.22%, 77.78%, 55.56% and 38.89% of those complications respectively. Therefore, the only statistically different feature was obesity, which was interestingly more frequent in the group with less fibrosis.
- 3
At last, we appreciate the sagacious remark about the size of each group of fibrosis classification. Necessarily, the number of patients with significant fibrosis (F2–F4) has to be greater than the number of patients with advanced fibrosis (F3–F4) because one group encompasses the other. We had 38 patients with significant fibrosis; 20 were classified as F2 and 18 as advanced fibrosis. To eliminate the doubt raised by Chen et al., we calculated the mean type IV collagen level of each group, 26.81 for the F2 and 35.91 for the F3–F4, with a two-tailed T-test of 0.02.
We consider the researchers’ notes are relevant. Still, we believe that they do not detract from the data already revised by the committee of the editorial board of Annals of Hepatology and published in this renowned journal. Thank you for the opportunity to clarify possible doubts about our paper.
