02187nas a2200181   4500008003900000245013500039210006900174260000800243490000700251520160500258100001501863700001401878700001701892700001401909700001501923700001801938856004901956       2016                          d00aTwo cases of maternal alloimmunization against human neutrophil alloantigen-4b, one causing severe alloimmune neonatal neutropenia0 aTwo cases of maternal alloimmunization against human neutrophil   cJan0 v563 aBACKGROUND:

Human neutrophil antigen (HNA)-4a/4bw is encoded by 230G>A in ITGAM, which results in an Arg61His substitution of the αM chain (CD11b) of complement receptor 3 (CR3; CD11b/18 or Mac-1). HNA-4a antibodies have been detected in the sera of female blood donors and in maternal sera that caused alloimmune neonatal neutropenia (ANN), in which maternal immunoglobulin (Ig)G antibodies against a paternally inherited HNA cross the placenta and destroy fetal and neonatal neutrophils. However, to date, antibodies specific for HNA-4b have not been reported. Here, we report the first two examples of HNA-4b antibodies.
STUDY DESIGN AND METHODS:

The two sera studied were both from previously pregnant females, one a multiparous female blood donor implicated in two separate transfusion reactions and the second a mother whose first pregnancy resulted in the birth of a severely neutropenic (0 × 10(6) neutrophils/L) infant affected with ANN. Serum neutrophil antibody testing was by flow cytometry and CD11b/18 monoclonal antibody immobilization of granulocyte antigens assay, and HNA genotyping was performed by polymerase chain reaction with sequence-specific priming and allele-specific 5' exonuclease assays.
RESULTS:

Sera from both women contained IgG antibodies reactive only with HNA-4b+ neutrophils and both typed HNA-4a/a. Both were immunized through pregnancy since their husbands and children all typed HNA-4a/b.
CONCLUSIONS:

The serologic results, together with the genotype results, confirm that these are the first reported cases of neutrophil antibodies specific for HNA-4b.1 aCurtis, BR1 aRoman, AS1 aSullivan, MJ1 aRaven, CS1 aLarison, J1 aWeitekamp, LA  uhttps://www.notifylibrary.org/reference/4739