Table 1.
Causes of Neutropenia in Neonates
| Decreased neutrophil production |
| Infants of hypertensive mothers (unknown; possible causes include presence of a placenta-derived inhibitor of neutrophil production) |
| Donors of twin-twin transfusions |
| Neonates with Rh hemolytic disease (precursors diverted towards erythroid differentiation to increase RBC production) |
| Congenital Neutropenias |
| Bone Marrow Failure Syndromes |
| Kostmann syndrome (maturation arrest and increased apoptosis of precursors; neutrophil elastase mutations) |
| Reticular dysgenesis (severe combined immunodeficiency with impairment of both myeloid and lymphoid production) |
| Barth syndrome (organic aciduria, dilated cardiomyopathy, and neutropenia) |
| Shwachman-Diamond syndrome (exocrine pancreatic insufficiency, failure to thrive, skeletal abnormalities, and neutropenia; defect in SBDS protein, which may be involved in ribosomal biogenesis) |
| Cartilage-hair hypoplasia (short-limbed dwarfism; impairment of proliferation in neutrophil precursors) |
| Cyclic Neutropenia (cyclic hematopoiesis with nadirs at 3-week intervals; associated with neutrophil elastase mutations that prevent membrane localization of the enzyme) |
| Inborn Errors of Metabolism |
| Organic acidemias (loss of neutrophil precursors) |
| Glycogen storage disease type 1b (increased neutrophil apoptosis) |
| Viral infections (infection of neutrophil progenitors, hypersplenism) |
| Cytomegalovirus |
| Rubella |
| Copper deficiency |
| Alloimmune neutropenia associated with anti-HNA-1b antibodies (antigen present on neutrophil precursors) |
| Increased neutrophil destruction |
| Bacterial or fungal sepsis (increased tissue migration; marrow suppression in severe cases) |
| Necrotizing enterocolitis (egress into intestines and peritoneum) |
| Anti-neutrophil antibody-mediated disorders (alloimmune neonatal neutropenia, neonatal autoimmune neutropenia, and autoimmune neutropenia of infancy |
| Idiopathic neutropenia of prematurity (precursors diverted towards erythroid differentiation to compensate for anemia of prematurity) |
| Drug-induced neutropenia (β-lactam antibiotics, thiazides, ranitidine, acyclovir) |
| Pseudoneutropenia (benign condition; circulating neutrophil pool is smaller than the vascular marginated pool) |
| Artifactual Neutropenia (benign condition; neutrophils agglutinate upon exposure to ethylenediaminetetraacetic acid, an anticoagulant used in blood collection tubes) |