Aim to evaluate the impact of Gilbert’s Syndrome (GS) on the course of the disease and the development of complications in cystic fibrosis (CF)

Material and Method Polymorphic variants of the UGT1A1 gene were identified in 54 patients (11.3 ±4 years, 28 boys and 26 girls) with CF by PCR method. Hyperbilirubinemia was detected in all 54 patients during receiving targeted drug therapy of CF elexacaftor/tezacaftor/ivacaftor. The analysis of the clinical course and complications was carried out on the basis of data to the national CF registry 2021 (2826 children).

Results CF patients with GS more often had severe genotype (91.8%) against 80.3% CF patients without GS (p=0.044); more often had cystic fibrosis liver disease (CFLD) - 44.2% against 25% CF patients without GS (p=0.022), including cirrhosis with portal hypertension – 5.8% against 3.2% CF patients without GS (p<0.05) and without portal hypertension – 9.6% against 3.7% CF patients without GS (p<0.05); more often had chronic rhinosinusitis – 86.3% against 60.9% CF patients without GS (p=0.001). There were no significant differences in the microbial status of the respiratory tract, as well as in the nutritional status. Lung function (FEV1 pred,%) tended to be higher in CF patients with GS – 98% against 89% CF patients without GS (p=0.06). During targeted therapy with the elexacaftor/tezacaftor/ivacaftor, all these patients had a persistent increase in total and unconjugated bilirubin of 1.5–2.5 normal values.

Conclusions CF patients with GS are a higher risk group for the development of liver diseases and chronic rhinosinusitis. Further monitoring of CF patients with GS is necessary.