Medical Student University of Virginia School of Medicine charlottesville, Virginia, United States
Background: Parenteral Nutrition-Associated Cholestasis (PNAC), diagnosed by elevated serum conjugated bilirubin secondary to liver damage, correlates with very low birthweight (VLBW, < 1500g) and prolonged parenteral nutrition. Previous untargeted fecal metabolomics from our group identified 12 sphingomyelins as potential PNAC biomarkers. Successful identification of a stool biomarker for PNAC risk could reduce reliance on blood tests and promote preventative interventions to mitigate liver damage. Objective: To validate and quantify fecal sphingomyelins as PNAC biomarkers through targeted metabolomics. Design/Methods: We are currently enrolling VLBW infants admitted to a level IV NICU with IRB approval and guardian consent. We aim to enroll 100 participants, with 36 recruited to date, of whom 4 (12%) have developed PNAC. We are performing biweekly collection of stool samples and recording comprehensive clinical data in a REDCap database. We will use mass spectrometry for stool sphingomyelin quantification. Preliminary analysis of nine stool samples (seven non-PNAC and two PNAC) confirmed the presence of 10 sphingomyelins previously associated with PNAC. Statistical analyses will include summary statistics of cohort characteristics and comparing infants with and without PNAC. We will use univariate and multivariable regression models to evaluate associations between sphingomyelin measurements, clinical variables, and PNAC risk.