Isoimmune Neonatal Neutropenia

Abstract

An unselected population of newborn infants at a tertiary perinatal center was the subject of an investigation of isoimmune neonatal neutropenia (INN) to determine the incidence of the disorder and further characterize its clinical and immunologic aspects. We screened 1465 consecutively born infants for neutropenia on the first day of life, and evaluated those with neutropenia for the presence of antineutrophil antibodies utilizing EDTA-microagglutination and indirect immunofluorescence. Of the 16 infants with persistent neutropenia, 3 were confirmed to have INN, representing 2/1000 live births and 1.5% of special care nursery admissions during the period. INN is not a rare disorder and should be considered in the evaluation of all infants with neutropenia, with or without infection. Our rapidly expanding knowledge of the neutrophil-specific antigen system is refining our ability to diagnose and treat immune neutropenias.

Resistance to Recombinant Human Granulocyte Colony-Stimulating Factor in Neonatal Alloimmune Neutropenia Associated With Anti-Human Neutrophil Antigen-2a (NB1) Antibodies

“…[1][2][3][4][5][6][7][8][9][10][11] During the period of neutropenia, antibiotic treatment is somewhat controversial. Prophylactic antibiotics may be used until the results of 12 rhG-CSF administration is generally very effective in NAN, rapidly increasing the ANC to levels considered safe.…”

Platelets and Neutrophils from Healthy Term Neonates Exhibit Increased Levels of Immunoglobulins

“…Neonatal immune-mediated neutropenia is associated with maternal alloimmunization against neutrophil specific antigens, especially NA1, NA2, NB1, and NB2, and has been reported to be as common as 11500 live births (2). In published studies, the presence of neutrophil-associated Ig was not necessarily associated with decreased neutrophil counts, for only 6 of 29 infants born to mothers alloimmunized to granulocytespecific antigens demonstrated abnormal absolute neutrophil counts (6).…”

“…Serum samples from these healthy newborns manifested a significantly decreased level of IgM binding to target platelets compared with serum from healthy adult controls. There Thrombocytopenia and neutropenia are not uncommon findings in neonates (1,2). Immune-mediated thrombocytopenia and neutropenia represent a significant etiology for these cytopenias (3,4).…”

“…The laboratory evaluation of immune-mediated cytopenias depends upon the detection and quantitation of Ig against platelets and neutrophils compared with healthy controls (2,(4)(5)(6). However, the paucity of normal values for healthy, term infants hampers the interpretation and limits the diagnostic was not a significant difference in direct platelet-associated IgM, or indirect Ig to neutrophils or platelets.…”

Transient Effect of Granulocyte Colony-Stimulating Factor in Allo-Immune Neonatal Neutropenia

“…It is a result of neutrophil destruction due to the transplacental passage of specific antibodies against neutrophil antigens, of which NA1, NA2, NB1, NC1, SH [1,2] and RED have been identified. The incidence of this pathology is estimated to be within a range of 0.5-2 per 1,000 live births [3][4][5][6]. In very preterm neonates, it can be associated with life-threatening infections [7].…”