Thresholds for conjugated hyperbilirubinaemia and hepatobiliary scintigraphy in biliary atresia: A 12-year national follow-up

Abstract

Aim

To investigate liver biochemistry in infants screened for biliary atresia (BA) at the time of hepatobiliary scintigraphy (HS) and to evaluate the effect of change in threshold for HS.

Methods

Infants born from 2010 to 2021, who underwent HS <6 months postpartum for BA, were included and data sourced from electronic medical records. The change in threshold in 2018 from ≥20 (and/or if conjugated bilirubin exceeds 20% of total bilirubin) to ≥17 μM (regardless of total bilirubin) was evaluated.

Results

In the cohort of 635 infants, 48 had BA, 247 had AATD, and the remaining 343 were categorised as ‘other’. After the threshold adjustment, HS timing was unaffected (p = 0.27), but the annual HS rate rose from 39 to 87, yet evaluations following the new guideline only accounted for 12%. All liver parameters were elevated in the BA group compared with the additional groups (p < 0.001). Amongst the 104 patients with non-excretory HS, gamma-glutamyl transferase (p < 0.001) and alanine aminotransferase (p = 0.002) remained elevated for BA. The lowest conjugated bilirubin measured in BA children was 36 μM.

Conclusion

After threshold change, HS use increased without earlier BA diagnostics, but most were not due to the new guideline. Alanine aminotransferase and gamma-glutamyl transferase should be considered in BA diagnostics.