Neonatal hyperbilirubinemia caused by anti-Jra antibodies – The first case report in Serbia

Abstract

Introduction Jra is a high-frequency antigen belonging to the JR blood group system. Population studies have established that the Jr (a-) phenotype is rare. The clinical significance of anti-Jra antibodies is controversial. This case report describes a newborn with prolonged jaundice due to alloimmunization against Jra antigen.

Case Outline A female Roma infant, 27 days of age, was admitted to hospital due to prolonged jaundice and failure to thrive. Immunohematological testing determined a blood group type A, D+ C+ E+ c+ e+, K-, and the presence of an antibody direct against a high-prevalence red blood cell antigens. On admission, total bilirubin was 199.6 μmol/l, direct bilirubin 10.3 μmol/l, hemoglobin concentration 132 g/l, hematocrit 41.1%, reticulocytes 1.08%. The newborn was the third child from a third routinely monitored pregnancy. Maternal sensitization to Jra antigen was detected during the second pregnancy. The titer of anti-Jra reached the highest value of 1,024 at the 28th week of gestation.

Conclusion This is the first description of neonatal hyperbilirubinemia caused by anti-Jra antibody in the Republic of Serbia. This case report provides new data about the clinical significance of anti-Jra in pregnancy and the newborn.

Keywords: Jra alloimmunization; neonatal jaundice; rare blood