Evaluation of histological activity indexes in cases of chronic viral hepatitis

It is well known that over 240 million people are suffering from chronic hepatitis B and 150 million from chronic hepatitis C all over the world and every year, 600.000 cases worldwide are reported to die of liver diseases due to chronic hepatitis B and over 350.000 cases due to chronic hepatitis C. Turkey is one of the countries with a high hepatitis B prevalence and mid-high anti-HCV prevalence. With the development of new antiviral medications and treatment modalities such as liver transplantation the use of liver biopsies to determine the patients to take advantage of treatment and to evaluate patient response to treatment have increased. The microscopic examination of liver fine needle biopsy samples guides the treatment of all non-neoplastic liver diseases primarily including chronic viral hepatitis not only by providing tissue diagnoses but also by determining liver necroinflammation and fibrosis stage. Knodell histological activity index, very first method recommended for providing a systematic methodology and terminology, has led to clarification of the histopathology of chronic hepatitis; however, its reproducibility has remained controversial. In the following years, Ishak system was modified from Knodell and Batts- Ludwig system was modified from Scheuer. Scoring liver fine needle biopsy samples is a semi-quantative process in chronic viral hepatitis. Although scores given to the lesions are expressed by numbers, they are actually based on subjective evaluation of histopathologic features, not on objective measures. Thus, although lesions observed appear the same, when the subjective evaluations are expressed in numbers the resulting scores may differ between observers and observations at different times according to experience and interpretation of the observers. In the given study we have constructed in order to compare histological activity indexes in chronic viral hepatitis cases; 408 fine needle biopsies obtained from chronic viral hepatitis patients between 2007 and 2011 at Bülent Ecevit University, Department of Medical Pathology were re-scored by three residents in Pathology using Knodell, Ishak, and Metavir systems, and intra-observer and inter-observer reproducibility were both questioned. Intra-observer variation obtained by Knodell, Ishak, and Metavir systems was evaluated with weighted kappa (k) test; on the other hand inter-observer variation was measured with Kendall W test. No significant intra- and inter-observer variation existed in any of the three systems. Although the systems are different, parameters used are similar and scores are based on interpretation of these parameters. The high levels of both intra- and inter-observer agreement obtained in both observations in this study may result from the fact that the residents were trained in the same department, and that before their observations they had discussed the systems and the parameters which are involved in the systems together and had reached a consensus on the scoring criteria.