New Review Highlights Variability in Clinical Features, Comorbidities of Biliary Atresia

A recent systemic literature review showed the variability of clinical features and comorbidities of biliary atresia in the US. The findings also demonstrated an increase in biliary atresia incidence in the US, improved diagnosis, and high overall survival rates post-treatment. The findings were presented at the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) 2024 annual meeting in Hollywood, Florida.

“The [systemic literature review] highlights heterogeneity in current [biliary atresia] research, with many variations in studied populations and outcome measures,” wrote investigators, led by Sonia Lee, from Ipsen in Cambridge.

Biliary atresia, a rare, potentially fatal cholangiopathy affecting infants, is primarily treated with surgical intervention, such as Kasai portoenterostomy, which strives to reconstruct bile flow and prevent liver failure. However, this surgical intervention may not be enough, and patients may need liver transplantation. An October 2023 study reported 2754 biliary atresia waitlist additions and 2206 biliary atresia liver transplants were recruited within the UNOS database from January 2010 through December 2021.2

Investigators sought to describe the epidemiology, natural history, and native liver survival among patients with biliary atresia in the United States by 38 examining studies published from 2014 – 2014 (via Embase or Medline) with patients who had biliary atresia and received any type of intervention or no intervention. Interventions include receiving only Kasai portoenterostomy, primary liver transplantation, Kasai portoenterostomy followed by a liver transplant, and combinations of Kasai portoenterostomy or liver transplantation with other interventions, such as steroids. The study included 27 observational, retrospective cohort analyses and 1 clinical trial, with sample sizes ranging from 10 – 4306 patients.

Key outcomes of the study included the incidence, prevalence, and mortality or survival of biliary atresia (epidemiological data), the natural history of the disease such as clinical characteristics, features, hepatic abnormalities, and secondary comorbidities, and lastly the native liver survival including rates at timepoints and waitlist time to liver transplantation.

The study revealed a rising incidence of biliary atresia in children < 1 year old, increasing from 2.85 per 100,000 live births in 1997 to 5.55 per 100,000 in 2012. Two state-based analyses reported similar birth prevalence rates in recent periods: 6.5 per 100,000 live births in 1999 – 2014 and 6.8 per 100,000 live births in 2005 – 2019. The mortality for liver transplant candidates on a waitlist was relatively low (4.2 – 6.1%).

“…the observed increase in diagnosed BA cases likely reflects improved recognition and earlier diagnosis,” investigators wrote.

Following treatment, the survival rates for 1, 5, and 20 years ranged from 93% - 97.9%, 86 – 97.5%, and 80 – 91%, respectively. The reported rates of native liver survival at 2 and 5 years ranged from 50 – 68.8% and 39.1 – 48.5%, respectively. Investigators noted the data on native liver survival was limited as it was only reported in 8 studies (7 observational and 1 clinical trial), and these studies had relatively small sample sizes.

Studies on biliary atresia lacked standardized reporting, with patient clinical features and secondary comorbidities often varied. Common clinical features included portal vein thrombosis, portal hypertension, and septicemia/bacteremia, whereas common comorbidities included ascites, cholangitis, esophageal varices, and cirrhosis.

“…significant clinical burden remains due to [biliary atresia]-associated hepatic dysfunction and clinical features,” investigators wrote. “Future research utilizing real-world data is needed to identify actionable gaps in the care of BA and help inform how to optimize care management strategies.”

References

^{Lee, S, Los, A, Navickas, C, et al. Systematic Literature Review On The Epidemiology, Natural History, And Disease Burden Of Biliary Atresia And Its Impact On Native Liver Survival In The United States. Presented at NASPHGAN 2024 in Hollywood, Florida, from November 7 – November 9, 2024.}

^{Campbell, P. Total Bilirubin, MMP-7, and TBA Show Promise for Predicting Liver Survival in Biliary Atresia. HCPLive. November 9, 2024. https://www.hcplive.com/view/total-bilirubin-mmp-7-and-tba-show-promise-for-predicting-liver-survival-in-biliary-atresia. Accessed November 14, 2024.}