Causes of hemolysis in neonates with extreme hyperbilirubinemia

OBJECTIVE: We instituted a quality improvement process to enhance our capacity to diagnose genetic hemolytic conditions in neonates with extreme hyperbilirubinemia. STUDY DESIGN: During a 1-year period, whenever the total serum bilirubin (TSB) was >25mg dl(-1) a special evaluation was perfomed. If we deemed an erythrocyte membrane defect likely, based on red blood cell morphology, EMA-flow cytometry was performed. Otherwise 'next-generation' sequencing was performed using a panel of genes involved in neonatal hyperbilirubinemia. RESULT: Ten neonates had a TSB >= 25 mg dl(-1). Two others were evaluated as part of this process at the request of their attending neonatologists, because each had a TSB >14mg dl(-1) in the first hours after birth and required phototherapy for > 1 week. Explanations for the jaundice were found in all 12 neonates. Five had hereditary spherocytosis, three of which also had ABO hemolytic disease. Two had pyruvate kinase deficiency. One had severe G6PD deficiency. The other four had ABO hemolytic disease. CONCLUSION: On the basis of the present small case series, we suggest that among neonates with extreme hyperbilirubinemia, it can be productive to pursue a genetic basis for hemolytic disease.