We read with considerable interest a diagnostic 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]. In this study, the authors explored the value of five serological markers in the diagnosis of liver fibrosis in nonalcoholic fatty liver disease (NAFLD) patients. This study utilized serological markers to determine the severity of liver fibrosis in NAFLD patients, which has important clinical guiding value. However, we would like to highlight the following issues.
First, only 126 patients with NAFLD confirmed by biopsy were included in this study, which does not include healthy participants (i.e. the control group). In the absence of a control group, difficulties exist in distinguishing whether the collagen type IV (cIV) level tends to increase or decrease in NAFLD patients. For the purposes of providing further evidence for clinical practice, a preferable option would be to provide the information of a control group and then compare the cIV level differences between the control group and NAFLD patients.
Second, this study stated that “the prevalence of diabetes, dyslipidemia, arterial hypertension, and metabolic syndrome was 68.75%, 82.29%, 63.54% and 81.05%, respectively”, and that most of the patients included in this study had underlying diseases. Yet, pursuant to the information provided in Table 1, it cannot be determined whether there is any difference in baseline characteristics between the two groups (patients with significant fibrosis and patients with advanced fibrosis). A reasonable hypothesis is that patients with advanced fibrosis suffer more underlying diseases than patients with significant fibrosis, resulting in a higher level of cIV in patients with advanced fibrosis. Hence, providing the baseline characteristics of the two groups is essential.
Third, although 126 NAFLD patients were included in this study, this study did not describe the specific number of cases in the two groups (patients with significant fibrosis and patients with advanced fibrosis), which could be a significant error. Another reasonable assumption is that the number of patients with advanced fibrosis was notably less than that of patients with significant fibrosis. The huge difference in sample size leads to significant differences in cIV levels between the two groups. Thus, we strongly recommend that the authors provide the specific number of patients in the two groups.
Declaration of funding interestsNone.
Conflict of interestThe authors have no conflict of interest to declare.
