# Reference spectrophotometric values for glucose-6-phosphate dehydrogenase activity in two-to six-month-old infants on the Thailand-Myanmar border

## TL;DR

This study establishes reference values for G6PD activity in infants aged 2 to 6 months to improve safe drug treatment for malaria and antibiotics.

## Contribution

Provides the first spectrophotometric reference values for G6PD activity in breast-fed infants on the Thailand-Myanmar border.

## Key findings

- G6PD activity in infants decreases with increasing age.
- The reference normal value for infants aged 2–6 months is 10.18IU/gHb.
- Infant G6PD activity is about 140% of adult normal levels in the same population.

## Abstract

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency represents a barrier to the full deployment of anti-malarial drugs for vivax malaria elimination and of first-line antibiotics. Lack of established reference ranges for G6PD activity in breast-fed infants puts them at risk of drug-induced haemolysis and restricts access to safe treatment of their mothers.

Methods: The present work was undertaken to establish age-specific G6PD normal values using the gold standard spectrophotometric assay to support the future clinical use of tafenoquine in lactating women and safer antibiotic treatment in infants.

Results: Spectrophotometric results from 78 healthy infants between the ages of 2 and 6 months showed a trend of decreased enzymatic activity with increasing age and provided a reference normal value of 100% activity for infants 2–6 months old of 10.18IU/gHb.

Conclusions: Normal reference G6PD activity in 2–6-month-old infants was approximately 140% of that observed in G6PD normal adults from the same population. Age specific G6PD activity thresholds should be used in paediatric populations to avoid drug-induced haemolysis.