Application and validation of a new histologic staging and grading system for primary biliary cirrhosis.

BACKGROUND

We proposed a new grading and staging system for primary biliary cirrhosis (PBC), which takes into account the degree of both chronic cholangitis activity (CA) and hepatitic activity (HA) for grading disease activity and that of fibrosis, bile duct loss, and chronic cholestasis for staging. In this study, we validated our new system.

METHODS

Using liver biopsy specimens from 166 cases of PBC, chronic cholangitis with mild periductal lymphoplasmacytic infiltration, including chronic nonsuppurative destructive cholangitis, and the combined activity of interface hepatitis and lobular hepatitis were categorized into 4 grades on the basis of their degree and distribution (CA0-3 and HA0-3, respectively). For staging, because orcein staining was not available in this study, 2 criteria (fibrosis and bile duct loss) were independently scored from 0 to 3 on the basis of their degrees, and a final stage score was created from the sum.

RESULTS

Although there was a relatively uniform distribution of CA0/1/2/3 cases, the cases of HA0/1/2/3 were distributed as 21%, 64%, 13%, and 3%, respectively, with a prominent number of cases categorized as having none or mild HA. The distribution of stages 1 to 4 using our system was considerably different from that using the classic system and, importantly, showed a correlation with patient outcome.

CONCLUSIONS

Our system revealed that the activities of chronic cholangitis and hepatitis did not correlate with each other in terms of degree and that our staging system properly reflected the outcome of PBC patients. The present study could validate the effectiveness of this new system for characterizing the pathologic condition of PBC.