Immunoglobulin G Levels in Neonates After Receiving Phototherapy

Background: Most cases of newborn hyperbilirubinemia are physiologic; however, excessive unconjugated bilirubin is a potential neurotoxin. Phototherapy treats moderate to severe hyperbilirubinemia. If phototherapy increases immunoglobulin G (IgG) clearance, there is a chance of humoral immune disorders. Objectives: The purpose of the study was to investigate the effect of phototherapy on the level of IgG in neonates. Methods: This study investigated 40 full-term newborns with hyperbilirubinemia. Blood samples were taken before and 72 hours after phototherapy. The IgG level was measured by calorimetry tests. Results: Phototherapy resulted in a decrease in IgG levels. The IgG level significantly decreased from 833.135 to 720.185 mg/dL. Before phototherapy, 12.5% of the population had low IgG levels; however, 32.5% had low IgG levels after the treatment. Conclusions: According to the results of the study, intensive phototherapy caused a reduction in IgG levels. Since there was no significant decrease in IgG levels in neonates who received conventional phototherapy, it can be concluded that this treatment is safe in terms of IgG levels.