We thank Dr. Shariff and colleagues for their interest in our study1 and for their helpful comments. We are more than happy to provide further detailed information on our cohorts and results in relation to the risk of hepatocellular carcinoma (HCC) development in patients with autoimmune liver diseases (AiLD) as requested.
As described in our previous epidemiological study,2 36% of our autoimmune hepatitis (AIH) cohort had histological evidence of cirrhosis at diagnosis, a rate comparable to most other population-based epidemiological studies. In addition, 20% of the AIH cohort had Metavir stage 3 fibrosis, and 44% had stage 2 or lower degree of fibrosis at diagnosis. As reported in our current study, 3 out of 130 AIH patients developed HCC during total follow-up of 1,156 years. This is equivalent to a crude annual incidence of 259 per 100,000 years or 0.3% per year. Mean duration to a diagnosis of HCC from AIH diagnosis was 25 years, and 2 out of 3 of them were cirrhotic from diagnosis. Interestingly, our HCC annual incidence is much lower than that reported by Yeoman and colleagues3 (annual incidence of 1.1%). The discrepancy is likely due to the difference in the group of cohorts that were studied, as their cohort may have been affected by the referral pattern to tertiary specialist centers with a higher proportion of their cohort (56%) having cirrhosis.
In our primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) cohorts, 12% and 9%, respectively, had cirrhosis at diagnosis. The prevalence of PBC in Canterbury is low compared to AIH and PSC, and that reported from Europe or North America.4 Our small PBC cohort is certainly a potential explanation for not detecting any HCC during the study period as acknowledged and discussed in our article.
The aim of our study was to examine the survival and risk of malignancy in unselected population-based cohorts compared to that of the general population. Our results demonstrated increased mortality in patients with AiLD and increased risk of malignancy in AIH and PSC patients. Future studies should investigate for factors that could predict cirrhosis, malignancy, poor response to treatment, and death so that tailored management strategies and surveillance plans can be devised.