Passive Transfer of Hepatitis B Antibodies through Intravenous Immunoglobulin in a Neonate.

Passive transfer of antibodies secondary to intravenous immunoglobulin infusion is a rare but important side effect that can lead to the wrong diagnosis and therapeutic decisions. It has never been reported in a newborn. A male newborn, vaccinated against hepatitis B and diagnosed with dilated cardiomyopathy, presented positive hepatitis B core antibodies at 12 days of life. Exclusion of hepatitis B infection was mandatory as it would be a contraindication to heart transplant. Passive transfer of antibodies was confirmed at 44 days of age, after seroreversion of hepatitis B core antibodies. Passive transfer of antibodies after intravenous immunoglobulin infusion can lead to a misleading diagnosis if not recognized. In our patient it could have been especially harmful had it prevented heart transplant. Screening for hepatitis B should be performed at least 1 month after intravenous immunoglobulin infusion.