Richard S. Mangus, Michael O' Connor, A. Joseph Tector, Chekar Kubal, Jonathan Fridell, Rodrigo Vianna

Surgery, Indiana University School of Medicine, Indianapolis, IN, United States

Background: Infants receiving standard parenteral nutrition (PN) are at high-risk of liver dysfunction and fibrosis. Liver function enzymes are frequently utilized to monitor liver dysfunction in PN-dependent infants, though these laboratory values may have poor sensitivity to predict early fibrosis. The aspartate aminotransferase to platelet ratio index (APRI) has good correlation with liver fibrosis progression in adult patients with hepatitis C. This study evaluates standard liver function tests and calculated APRI in assessing liver dysfunction and fibrosis in infants who are PN-dependent after intestinal resection.

Methods: Study inclusion criteria included infants less than 1-year of age at initial intestinal resection with subsequent continuous PN-dependence of 3 months or greater. Laboratory values (total bilirubin, AST, ALT, calculated APRI) and biopsies were collected from the time of initial intestinal resection, and thereafter for a period of 26 weeks (6 months).

Results: Thirty-one children, all less than two months of age at the time of initial intestinal resection (range 0-58 days, mean 12.6 days), were included in the study. APRI was the only tested liver function value statistically associated with METAVIR fibrosis score, with median APRI by fibrosis grade of: F≤ 2: 1.87, F3: 5.71, and F4: 14.74 (p=0.02). Two distinct periods were identified: from 0-8 weeks post-resection, there is little change in liver function tests. At 8 weeks and 16 weeks post-resection, there are incremental increases in all laboratory values. These variances were maintained in subgroup analysis based upon estimated gestational age (EGA), age at resection and residual intestinal length.

Conclusion: There is minimal liver dysfunction in the first 8 weeks post-resection in short-gut infants on PN. Thereafter, there are significant elevations in liver enzymes which occur at 8 and 16 weeks. APRI is statistically associated with liver fibrosis progression, and close monitoring is warranted in at-risk infants to determine the need for liver biopsy and referral for intestinal transplant evaluation.