Cystic fibrosis (CF) is a genetic disease primarily affecting the lungs and digestive system, but its impact extends to other organs, including the liver. Recent advancements in treatment, particularly with the drug combination elexacaftor-tezacaftor-ivacaftor (ETI), have dramatically improved lung function and growth for many individuals with CF. Now, research is focusing on whether these benefits extend to mitigating liver complications associated with the disease. A new retrospective cohort study suggests that earlier employ of ETI may be linked to improved liver enzyme levels in children and young adults with CF.
The study, utilizing data from a large, de-identified database, investigated biochemical markers of cystic fibrosis-associated hepatobiliary involvement (CFHBI). Researchers aimed to determine if ETI, a modulator therapy targeting the underlying cause of CF, could positively influence liver health in patients. Understanding this connection is crucial, as liver disease is a significant cause of morbidity and mortality in individuals with CF. The findings offer a promising signal regarding the broader benefits of this newer treatment approach.
Study Design and Patient Population
Researchers conducted a 1:1 retrospective cohort study using the TriNetX database, a platform containing de-identified patient data from multiple healthcare organizations. The study included individuals aged 6 to 21 years diagnosed with cystic fibrosis, as indicated by ICD-10 diagnostic codes and who were prescribed pancreatic enzyme replacement therapy. Two groups were analyzed: a group receiving ETI (patients seen between January 1, 2020, and January 1, 2024) and a control group not receiving ETI (patients seen between January 1, 2014, and January 1, 2018). To ensure comparability, the groups were matched using propensity scores, a statistical technique used to balance potential confounding factors. Statistical analyses were performed directly within the TriNetX environment, with a significance level set at p = 0.05.
Key Findings: Improved Liver Enzymes with ETI
The study included 533 children with CF aged 6-12 years and 1177 adolescents and young adults aged 13-21 years in each cohort. In the younger children (6-12 years), those treated with ETI demonstrated significantly lower levels of alanine aminotransferase (ALT) – 33 ± 44 U/L compared to 45 ± 57 U/L in the non-ETI group (p = 0.003) – and gamma-glutamyl transferase (GGT) – 18 ± 20 U/L versus 28 ± 51 U/L (p = 0.004). Improvements were also observed in albumin and prothrombin time/international normalized ratio (PT/INR) in the ETI group. Among adolescents and young adults (13-21 years), the ETI group again showed significantly lower GGT levels (21 ± 26 U/L vs. 32 ± 63 U/L, p = 0.002) and improved albumin and PT compared to the non-ETI group. However, a notable difference emerged: indirect bilirubin levels were higher in the ETI group (0.7 ± 0.5 mg/dL vs. 0.3 ± 0.4 mg/dL, p < 0.001).
Implications and Future Research
These findings suggest that initiating ETI treatment earlier in children with CF may be associated with improvements in key liver enzyme markers, offering reassurance regarding the risk of widespread drug-induced liver injury. The researchers emphasize the need for continued, long-term follow-up, including imaging and, when available, liver biopsies, both before and after ETI initiation, to comprehensively assess the drug’s impact on CFHBI and the progression of advanced CF liver disease. Further investigation is needed to understand the clinical significance of the observed increase in indirect bilirubin levels in the older age group.
The study highlights the evolving understanding of CF and the potential for modulator therapies like ETI to address multiple organ system manifestations of the disease. While the initial focus of these therapies was on improving lung function, emerging evidence suggests a broader range of benefits. Continued research will be critical to optimizing treatment strategies and improving the long-term health outcomes for individuals living with cystic fibrosis.
Disclaimer: This article provides informational content and should not be considered medical advice. Always consult with a qualified healthcare professional for diagnosis and treatment of any medical condition.
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