RESUMO
BACKGROUND: Biotinidase activity is closely related to liver function. AIM: To evaluate whether maternal chronic hepatitis B virus (HBV) infection affects neonatal biotinidase activity. PATIENTS AND METHODS: Twenty-three asymptomatic pregnant women with HBV (group A) and 28 healthy pregnant women (controls) in the delivery room and their newborns (cord blood) underwent laboratory examinations. Serological HBV and liver function tests were performed with standard techniques, while biotinidase activity was measured with an HPLC method. RESULTS: Serological HBV tests and HBV DNA showed chronic HBV (precore mutant G1896A) in group A, whereas anti-HBc and anti-HBe were detected in their neonates. Liver function chemistry was found normal in controls and both groups of newborns. Moderately increased transaminases were found in the infected mothers. Interestingly, albumin levels did not differ among the studied groups. Biotinidase activity in HBV mothers (5.76+/-0.6 nmol/min/mL) was significantly decreased (p<0.001) as compared to controls (8.43+/-0.65 nmol/min/mL). The enzyme activity did not differ among the neonates. Biotinidase activity inversely correlated with transaminases but not with albumin or with HBV-DNA levels. CONCLUSIONS: Decreased biotinidase activities were evaluated in mothers with HBV and normal in their neonates. Biotin supplementation in the diseased mothers may prevent possible symptoms due to biotin recycling impairment.