Radin Tsonev's PhD thesis is written in a volume of 105 pages, contains 47 tables and 21
figures. It is structured correctly and includes the following sections: Abbreviations and symbols
used -1 page; Introduction - 4 pages; Literature Review - 38 pages; Purpose and tasks - 1 page;
Materials and Methods - 11 pages; Own results - 33 pages; Discussion and Conclusion - 5 pages
Bibliography - 5 pages; Annexes - 4 pages The bibliographic reference contains 125 literary
sources, 6 of which are in Cyrillic and 119 in Latin. Of these, 18 (14.6%) have been published in
the last 5 years.
The Introduction clearly defines the problem and substantiates the purpose of research in
the dissertation work.
The Literature Review is well structured and in line with the topics being discussed. It is
written competently and demonstrates profound knowledge of the issue in its various aspects.
The social significance of chronic hepatitis C infection, the role of liver biopsy in diagnosis, non-
invasive methods for assessing liver fibrosis, quality of life and health care in HCV patients are
examined.
The Purpose of the dissertation is well formulated in accordance with the topic of the
dissertation and the presented literature review. The assigned tasks, 6 in total, are completely
sufficient and have been fully accomplished in the dissertation.
The Materials and Methods section describes in detail 366 patients with chronic viral
hepatitis and cirrhosis, of which 193 men and 173 women, aged 18 to 75 years, who were
enrolled in the study between 2016 and 2018. Of these, 241 patients had hepatitis C, 37 had
hepatic C cirrhosis, and 88 had hepatitis B. All patients underwent Menghini liver biopsy or
targeted liver biopsy, as well as TE-FibroScan while fasting with fibrotic activity assessment in
kPa and received a fibrosis score from 1 to 4. Comparable liver density testing was performed in
149 patients with hepatitis C using TE before and after a 12-month treatment period with direct-
acting antivirals (DAAs). All patients completed a quality of life questionnaire. It was evaluated
using the SF-8 Health Survey, scientifically validated and reliable for physical and mental health
status. For statistical data processing appropriate methods and an up-to-date statistical program
(IBM Statistics SPSS Statistics Base 23) were used, which guarantee the reliability of the results
obtained.
Results and Discussion: The results presented are convincing and clear. The more
notable ones are the following.
There was no correlation between the degree of fibrosis and cytolytic activity - AST and
ALT.
Comparability of liver biopsy and TE-FibroScan results has been established in patients
with liver fibrosis, especially in F3 and F4. For F1 and F2 this correlation is lower. These
results lead to the conclusion that an additional method, fibrotest or APRI, is needed to
improve the comparability of liver biopsy and TE-FibroScan results.