Fractionated Bilirubin Among 252 892 Utah Newborns with and Without Biliary Atresia: A 15-year Historical Birth Cohort Study.

OBJECTIVES: To determine whether neonatal conjugated or direct bilirubin levels were elevated in infants with biliary atresia (BA) and to estimate the number of newborns who would have positive screens in the nursery necessitating repeat testing after discharge. STUDY DESIGN: We used administrative data from a large integrated healthcare network in Utah to identify newborns who had a fractionated bilirubin recorded during birth admission from 2005 through 2019. Elevated conjugated bilirubin was defined as greater than 0.2 mg/dL and direct bilirubin was defined as greater than 0.5 mg/dL (>97.5th percentile for the assays). We performed simulations to estimate the anticipated number of false-positive screens. RESULTS: There were 32 cases of BA and 468 161 live births during the study period (1/14 700). There were 252 892 newborns with fractionated bilirubin assessed, including 26 of those subsequently confirmed to have BA. Conjugated or direct bilirubin was elevated in all 26 infants with BA and an additional 3246 newborns (1.3%) without BA. Simulated data suggest 9-21 per 1000 screened newborns will have an elevated conjugated or direct bilirubin using laboratory-based thresholds for a positive screen. Screening characteristics improved with higher thresholds without increasing false-negative tests. CONCLUSIONS: This study validates the previous findings that conjugated or direct bilirubin are elevated in the newborn period in patients with BA. A higher threshold for conjugated bilirubin improved screening performance. Future studies are warranted to determine the optimal screening test for BA and to assess the effectiveness and cost-effectiveness of implementing such a program.

Outcome after discontinuation of immunosuppression in children with autoimmune hepatitis: a population-based study.

OBJECTIVE: To assess sustained immunosuppression-free remission (SIFR) in children with autoimmune hepatitis (AIH). STUDY DESIGN: We retrospectively reviewed all children with AIH in the region between 1986 and 2011 using a population-based methodology. RESULTS: We identified 56 children with AIH (62.5% females; median age, 11.1 years [IQR, 5.7-14.4 years], followed for a median of 5.6 years [IQR, 2.8-8.6 years]). Liver disease was characterized by type II AIH in 8.9%, cirrhosis in 14.0%, and primary sclerosing cholangitis in 21.4%. Coexisting nonhepatic immune-mediated diseases occurred in 37.5%. Biochemical remission on immunosuppressive therapy was achieved in 76.4% of all patients with AIH at a median of 1.2 years (IQR, 0.4-3.6 years); 23.1% of these patients experienced a subsequent relapse. Discontinuation of all immunosuppressive medications was attempted in 16 patients and was successful in 14 patients (87.5%) with type 1 AIH (median age at discontinuation, 8.9 years [IQR, 3.5-17.9 years], treated for a median of 2.0 years [IQR, 1.3-3.5 years] after diagnosis), with SIFR occurring at a median of 3.4 years (IQR, 2.6-5.8 years) of follow-up. Excluding patients with inflammatory bowel disease who received immunosuppressive therapy independent of their liver disease, the probability of achieving SIFR within 5 years of diagnosis of AIH was 41.6% (95% CI, 25.3%-62.9%). Baseline patient characteristics associated with an inability to achieve biochemical remission on immunosuppression or SIFR were elevated international normalized ratio, positive antineutrophil cytoplasmic antibody titer, cirrhosis, and a nonhepatic autoimmune disorder. CONCLUSION: We found a high rate of successful discontinuation of all immunosuppressive medications in carefully selected patients with AIH in a population-based cohort. SIFR is an achievable goal for children with AIH, particularly those with type I disease in stable biochemical remission on immunosuppressive therapy.