Carboxyhemoglobin levels in neonatal immune hemolytic jaundice treated with intravenous gammaglobulin.

In order to examine the effect of intravenous immunoglobulin (IVIG) on the rate of hemolysis in immune hemolytic hyperbilirubinemia, we measured the carboxyhemoglobin levels of 5 newborn infants who were subjected to IVIG treatment. The pretreatment rate of hemolysis, in the 5 patients with isoimmune hemolytic jaundice (3 patients with Rh hemolytic disease of the newborn and 2 patients with ABO hemolytic disease of the newborn), as reflected by carboxyhemoglobin levels was higher than the rate of hemolysis in normal newborn infants. In 4 out of the 5 patients treated with IVIG, there was a rapid decline ( > 30%) of carboxyhemoglobin levels, a pattern which was different from that observed in normal newborn infants with no hemolytic jaundice and in 3 untreated patients with ABO hemolytic disease of the newborn. None of the treated patients required an exchange transfusion. Our preliminary results support the theory that the attenuation of jaundice observed following IVIG treatment in patients with immune hemolytic hyperbilirubinemia is caused, at least in part, by the reduction in hemolysis.