(234) Population-Based Point Prevalence of Cystic Fibrosis Liver Disease Amongst Utah Children

Background: Cystic Fibrosis-associated liver disease (CFLD) has become a major clinical focus, as life expectancy in CF has increased. CFLD pathophysiology and epidemiology are not well characterized, and treatments are limited. Among children, few population-based studies of CFLD exist and definitions of CFLD are variable. Herein, we present the development of a population-based registry of active pediatric CFLD in Utah, including rates of cirrhosis.

Methods: This is an observational study of Utah children with CF. Utah presents a unique opportunity for population-based CF study, as all children with CF in Utah are cared for at the Primary Children’s Cystic Fibrosis Center (PCCFC). This preliminary study includes only patients currently enrolled in care at the center in 2022. Non-cirrhotic CFLD was defined by: elevated Alanine Aminotransferase (ALT) or Gamma-Glutamyl Transferase (GGT) ( >1.5 times normal at 2 or more draws over >6-month period), or either radiologic or biopsy abnormalities consistent with CFLD. Cirrhotic CFLD was noted on imaging, biopsy, direct visualization/laparoscopy, or elastography and further subclassified by portal hypertension or liver failure.

Results: Of 968,012 children in Utah, 319 are diagnosed with CF and receive care at PCCFC. Thus far, we have identified 49 children with CFLD, 13.5% of the pediatric CF population in Utah (see Table 1 for further demographics). This includes 6 patients (1.8% of the total pediatric CF population, 14% of the pediatric CFLD population) that met criteria for cirrhosis, one of whom received a liver transplant for liver failure. Thirty-four patients are currently on treatment with ursodiol and 26 are on a CF transmembrane conductance regulator.

Conclusions: In this study, we applied a consistent CFLD definition and classified rates of pediatric CFLD and cirrhosis at the population-level in the state of Utah. The point prevalence of 13.5% exceeds prior CF Foundation estimates for CFLD in children, as does the 14% of our pediatric CFLD population with cirrhosis. Future directions for this work include analysis to better understand risk factors for CFLD, particularly cirrhotic CFLD, and development of screening and prevention strategies. Further, this population-based pediatric CFLD registry serves as a starting point for longitudinal follow-up and tracking of CFLD clinical outcomes from childhood through transition to adult care. Lastly, this work provides a rubric by which others may work to rigorously report and track CFLD epidemiology at a population-based level, towards true understanding of CFLD epidemiology and mortality impact.

Acknowledgements: This work was supported by the Cystic Fibrosis Foundation Clinical Fellowship Award [SEGURA21B0].

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