Serum Level of Alanine- and Aspartate-Aminotransferase Levels in Newborns in India

Abstract

Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤40 IU/L is normal. This cutoff, although determined in adults, is widely used for newborns. We studied the reference ranges for ALT and AST in newborns in India. We prospectively included babies with gestational age (GA) between 34 and 41weeks and birth weight (BW)≥1500g. We excluded the babies who either themselves or their mother had risk factors, which could cause elevation of serum levels of liver enzymes. Serum ALT and AST were measured in venous cord blood. The estimated percentile curves for ALT and AST, for BW and GA covariates, were drawn with General Additive Model for Location Scale and Shape (GAMLSS) with Box-Cox Power Exponential (BCPE). Five-hundred thirty-seven babies (Boys 53.3%; GA 34-36wks 19.7%; appropriate for GA 74.9%; BW<2500g 20.5%) were included. Overall, mean [SD] serum ALT and AST were 4412 IU/L and 5218 IU/L, respectively. The serum AST was significantly higher than the ALT level, regardless of gender, BW, GA, or fetal growth categories. The percentile curve against GA remained flat for ALT, although it showed a slight rise for AST. Serum levels of ALT and AST plotted against BW were also similar and showed an increase up to 2000g and then remained stationary after that. The serum levels of ALT and AST up to 44 IU/L and 52 IU/L, respectively, can be taken as normal in newborns with BW≥2000g or GA ≥34 weeks.