Pathologic classification of chronic hcv infection

The old qualitative classification of chronic hepatitis has now been replaced by newer, semiquantitative scoring systems. In general, the 2 histologic features used for semiquantitative classification are the degree of inflammation and hepatocyte necrosis (activity) and the hepatic response (fibrosis). Each classification system has advantages and disadvantages and, at present, none uses all the clinical, etiologic, and histologic information available. The METAVIR scoring system and the Ishak grading system have received the greatest attention. The choice of the scoring system depends on its intended use (ie, clinical work or research purposes). For routine reporting and clinical follow-up, simpler systems, such as the METAVIR scoring system, could be used. More detailed systems, such as the Ishak system, are more suitable for research purposes. The METAVIR and Ishak systems are detailed in the table below.

Comparison of the METAVIR and Ishak systems

Stage	METAVIR System	Ishak System
0	No fibrosis	No fibrosis
1	Periportal fibrosis expansion	Fibrous expansion of some portal areas, with or without short fibrous septae
2	P-P septae >1 septum	Fibrous expansion of most portal areas, with or without short fibrous septae
3	P-C septae	Fibrous expansion of most portal areas with occasional P-P bridging
4	Cirrhosis	Fibrous expansion of portal areas with marked bridging (P-P or P-C)
5		Marked bridging (P-P or P-C) with occasional nodules (incomplete cirrhosis)
6		Cirrhosis

P-P: portal-portal; P-C: portal-central

Treatment of chronic HCV infection

The approval of the pegylated forms of interferon (alfa-2a and alfa-2b) led to an improvement in the treatment of chronic hepatitis C. In combination with ribavirin, both forms of pegylated interferon produce a sustained virologic response 7-12% higher than regular interferon combined with ribavirin. Pegylated forms of interferon combined with ribavirin are the new standard of care for previously untreatable patients with chronic hepatitis C. The duration of therapy and dose of ribavirin are determined by the patient’s HCV genotype, which is the single most important pretreatment predictor of response. Patients with genotype 1 should receive treatment with peginterferon and ribavirin (1000 or 1200 mg/d based on weight) for 48 weeks. Patients with genotype 2 or 3 should receive 24 weeks of therapy of peginterferon and a lower dose of ribavirin (800 mg/d). Until further guidelines are established for the treatment of other HCV genotypes (4, 5, or 6), therapy similar to that of genotype 1 is suggested. Peginterferon monotherapy for 48 weeks may be considered for patients with contraindications to ribavirin therapy, although the response rate to monotherapy is likely to be lower than the response rate to combination therapy.