title: Severe neonatal neutropenia due to anti-human leucocyte antigen B49 alloimmunization only: a case report.
abstract: Alloimmune neonatal neutropenia (ANN) is a rare but potentially life-threatening disorder of neonates. Demonstration of alloantibodies against granulocyte-specific antigens shared by neonatal and paternal granulocytes in the maternal serum is essential in the diagnosis of ANN. In contrast to granulocyte-specific alloantibodies, the significance of human leucocyte antigen (HLA) class I antibodies for ANN is still a matter of debate. We report on a case of severe isolated and prolonged neutropenia due to anti-HLA B49 alloimmunization only. Immediately after birth, severe, isolated neutropenia was observed and lasted for up to 2 months. Results of serologic testing showed only anti-HLA B49 antibodies in the maternal and neonate's sera. HLA typing showed HLA class I (B49) incompatibility between the mother and the child. Granulocyte-specific antibodies were not detected. Adsorption of the maternal serum with HLA B49-bearing platelets removed serum reactivity with paternal neutrophils. Our results support the idea that certain HLA class I antibodies can induce ANN.
authors.affiliation: Croatian Institute of Transfusion Medicine, Zagreb, Croatia. maja.tomicic@hztm.tel.hr
authors.forename: M
authors.initials: M
authors.lastname: Tomicić
authors.forename: M
authors.initials: M
authors.lastname: Starcević
authors.forename: J
authors.initials: J
authors.lastname: Bux
authors.forename: V
authors.initials: V
authors.lastname: Zach
authors.forename: Z
authors.initials: Z
authors.lastname: Hundrić-Haspl
authors.forename: V
authors.initials: V
authors.lastname: Drazić
authors.forename: B
authors.initials: B
authors.lastname: Grahovac
mesh_terms: D000328:Adult; D005260:Female; D005838:Genotype; D006098:Granulocytes / Q000276:immunology*; D015235:HLA-B Antigens / Q000235:genetics / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007114:Immunization; D007231:Infant, Newborn; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008297:Male; D008431:Maternal-Fetal Exchange; D009503:Neutropenia / Q000151:congenital* / Q000276:immunology; D011247:Pregnancy
chemical_list: D015235:HLA-B Antigens; C483912:HLA-B*49 antigen; D007518:Isoantibodies