Regarding Chronic Viral Hepatitis -
Classification of hepatitis

In the new classification system of Hepatitis, Grading refers to the assessment of necroinflammatory activity.
Chronic hepatitis represents a series of liver disorders of varying causes and severity in which hepatic inflammation and necrosis continue for at least 6 months.
Earlier chronic hepatitis was categorized into three types depending upon histopathological features. These are


Chronic persistent hepatitis
Chronic lobular hepatitis
Chronic active hepatitis


Now, this categorization has been replaced by more informative classification based upon a combination of clinical serological and histological variables.
Now the classification is based upon —


It's cause
Its histologic activity or grade
It's a degree of progression or stage

(a) Classification by cause —

In this, the hepatitis is classified according to the cause - such as viral hepatitis, autoimmune hepatitis, drug-associated hepatitis.

(b) Classification by Grade —

This classification is based upon an assessment of necroinflammatory activity.
An assessment of following histological features is made on liver biopsy -
Periportal necrosis
Piecemeal necrosis
Bridging necrosis
Portal inflammation

(c) Classification by stage —

This classification is based upon the degree of fibrosis.
It reflects the levels of progression of the disease.
Staging is based upon the degree of fibrosis as follows

0 = No fibrosis
1= Mild fibrosis (limited to portal tract)
2 = Moderate fibrosis (Portal and periportal fibrosis)
3 = Severe fibrosis including bridging fibrosis
4 = Cirrhosis
Hepatitis A virus infection is a common cause in children
Morphological classification into Chronic Active Hepatitis and Chronic Persistent Hepatitis are important
Fatty change is pathognomic of Hepatitis C virus infection
Grading refers to the extent of necrosis and inflammations