Prognostic indicators in primary biliary cirrhosis: significance of revised IAHG (International Autoimmune Hepatitis Group) score

Abstract

Background/aims: Primary biliary cirrhosis (PBC) is a slowly progressing autoimmune disease of the liver that is characterized by portal inflammation and immune-mediated destruction of the intrahepatic bile ducts. Serum total bilirubin is one of the various prognostic factors that have been proposed. A recent study found that PBC with accompanying autoimmune hepatitis (AIH) carries a negative prognosis. This study examined the clinical characteristics of PBC and analyzed the factors that affect its prognosis.

Methods: Patients diagnosed with PBC between January 1998 and December 2010 based on clinical and histopathological findings were compiled and analyzed retrospectively.

Results: Among 27 patients, 24 (1 male and 23 females, ages 50.0±9.3 years) were followed up. The follow-up period was 8.6±0.9 years. Of the 24 patients, 9 patients progressed to liver cirrhosis (LC). Comparison between patients who did and did not progress to LC revealed statistically significant differences in the patients' serum total bilirubin (2.7±1.8 vs. 0.8±0.4, P=0.012), the Mayo risk score (5.1±0.7 vs. 3.9±0.6, P=0.001), the revised IAHG (International Autoimmune Hepatitis Group) score (9.2±2.3 vs. 5.4±3.0, P=0.004) and frequency of AIH overlap (5/9 [55.6%] vs. 0/15 [0%], P=0.001) at the time of diagnosis.

Conclusions: We propose that serum total bilirubin, the Mayo risk score, and the revised IAHG score at the time of diagnosis are helpful for predicting PBC prognosis. In particular, since all of the patients with accompanying AIH progressed to LC, the presence of overlap syndrome at the time of diagnosis is helpful for predicting PBC prognosis and providing an adequate treatment.

Keywords: Overlap syndrome; Primary biliary cirrhosis; Prognosis.

Figure 1

Serum bilirubin relative to the progression of PBC. Serum total bilirubin was significantly higher in the progressed group (2.7±1.8) than in the unprogressed group (0.8±0.4; P=0.012, Mann-Whitney U test).

Figure 2

The risk score of the Mayo clinic model relative to the progression of PBC. The Mayo score was significantly lower in the unprogressed group (3.9±0.6) than in the progressed group (5.1±0.7; P=0.001, Mann-Whitney U test).

Figure 3

AIH score relative to the progression of PBC. The revised IAHG score was significantly lower in the unprogressed group (5.4±3.0) than in the progressed group (9.2±2.3; P=0.004, Mann-Whitney U test).

Figure 4

Frequency of overlapping AIH relative to the progression of PBC. Among nine PBC patients whose case progressed to LC, five exhibited overlap with AIH, and the prevalence of AIH was significantly higher among these progressed patients than among the unprogressed group, in which no patients had accompanying AIH (P=0.001, Fisher's exact test).