Introduction: Non-alcoholic Fatty Liver Disease (NAFLD) constitutes a spectrum of liver disorders including the simple steatosis at one end and steatohepatitis at the other. In contrast to the previous believes, Non-alcoholoc Steatohepatitis (NASH) can lead to advanced fibrosis and cirrhosis. Implementation of a valid and reliable scoring system is necessary for better determination of prognosis and monitoring the effectiveness of different treatment modalities in this disease. We faced some practical difficulties using the system proposed by Brunt and coworkers from Saint Louis University in 1999 and proposed some revisions in the original scoring system. This study was performed to evaluate the validity, reliability and practicability of the revised scoring system by correlating the scores with the serum levels of the aminotransferases in the patients with NASH.

Methods: Microscopic slide sets of 60 patients with NASH were reviewed by two independent pathologists expert in histological diagnosis of liver diseases. The four histological criteria of steatosis, ballooning degeneration, lobular and portal inflammation were scored zero to 3 according to the existence and severity of each criterion. Spearman's rho test was used for determination of correlation of the level of serum transaminases with the necro-inflammatory scores. Degree of inter-observer variation of the proposed scoring system was evaluated by the Cohen Kappa Coefficient.

Results: Except for portal inflammation, significant statistical correlation existsted between the scores for the histological criteria and level of serum aminotransferases (p<0.01). The interobserver agreement for the histological diagnosis was good (p<0.01).

Conclusion: The proposed revised scoring system is easy to use, reliable and reproducible and shall be considered in clinical practice for grading of the necro-inflammatory process in non-alcoholic fatty liver disease.

 Hakim Research Journal 2006 8(4) 1-7.