In utero development of a warm-reactive autoantibody in a severely jaundiced neonate.
BACKGROUND
The fetus and neonate are widely considered to be immunologically immature. However, there are rare case reports of RBC alloantibody and autoantibody development.


METHODS
This report describes the case of a severely jaundiced full-term boy neonate presenting at birth with an IgG warm-reactive autoantibody.


RESULTS
Mother and neonate were both blood group A, D+. The mother had a negative antibody screen at 18 weeks' gestation and a negative DAT and antibody screen at the time of delivery. The neonate was born with a strongly reactive DAT (IgG) and a panreactive eluate. The serum also contained a panreactive antibody, and all crossmatches were incompatible. The neonate had a bilirubin of 12.5 mg per dL at birth, which peaked at 22.5 mg per dL. However, there was no overt evidence of hemolysis, as evidenced by normal serial Hct levels and reticulocyte counts. The neonate responded well to phototherapy and did not require either simple or exchange transfusion. The neonate's warm-reactive autoantibody maintained its original strength of reactivity on follow-up testing performed at 2 weeks and 2 months of age.


CONCLUSIONS
This report describes a rare case of apparent in utero RBC autoantibody development. The fetal/neonatal immune response to blood group antigens is reviewed.
Blackall
Douglas P
DP
Department of Pathology, University of Tennessee College of Medicine, and the Blood Bank of The Regional Medical Center at Memphis, Memphis, Tennessee, USA. blackall@ucla.edu
Liles
Linda H
LH
Talati
Ajay J
AJ
D001323:Autoantibodies / Q000096:biosynthesis / Q000276:immunology*; D001327:Autoimmune Diseases / Q000151:congenital / Q000196:embryology / Q000276:immunology* / Q000628:therapy; D003298:Coombs Test; D004912:Erythrocytes / Q000276:immunology*; D005333:Fetus / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology*; D007231:Infant, Newborn; D007567:Jaundice, Neonatal / Q000196:embryology / Q000276:immunology* / Q000628:therapy; D008297:Male; D014467:Ultraviolet Therapy
D001323:Autoantibodies; D007074:Immunoglobulin G