Neutrophilia



Neutrophilia


Kathryn Foucar, MD





Key Facts


Terminology



  • Absolute neutrophil count (ANC) that exceeds age-related normal ranges



    • Newborn > 28.0 × 109/L


    • Infant > 10.0 × 109/L


    • Child > 8.0 × 109/L


    • Adult > 7.0 × 109/L


Etiology/Pathogenesis



  • Many causes of secondary neutrophilias



    • Infections most common


    • Other causes: Inflammation, metabolic disorders, medications


    • Rare constitutional neutrophilias


  • Pathogenesis



    • Demargination


    • Release of bone marrow reserve compartment


    • Increased neutrophil production in bone marrow


Microscopic Pathology



  • Absolute neutrophilia


  • Variable degree of left shift of neutrophil lineage


  • Toxic changes usually present



    • Other lineages generally unremarkable


Top Differential Diagnoses



  • Chronic myelogenous leukemia (CML)


  • Chronic neutrophilic leukemia (CNL)


  • Other myeloproliferative neoplasm


Diagnostic Checklist



  • Careful history for possible cytokine therapy


  • Consider myeloproliferative neoplasm



    • If splenomegaly or basophilia present






Blood smear from a patient with rectal prolapse and acute bacterial infection is shown. Note toxic changes in the neutrophils. Anemia is also present, likely from chronic disease.






Blood smear from a patient receiving recombinant G-CSF shows toxic changes and left shift to blasts. Note that mature neutrophils predominate after early recovery occurs.


TERMINOLOGY


Synonyms



  • Granulocytosis


Definitions



  • Absolute neutrophil count (ANC) that exceeds age-related normal ranges



    • Newborn > 28.0 × 109/L


    • Infant > 10.0 × 109/L


    • Child > 8.0 × 109/L


    • Adult > 7.0 × 109/L


ETIOLOGY/PATHOGENESIS


Diverse Etiologies for 2° Neutrophilias



  • Infections (usually bacteria)


  • Occasional viral infections (SARS, Hantavirus)


  • Medications/hormones/endogenous overproduction



    • Colony-stimulating factors


    • Chemokines


    • CSF/chemokine-producing neoplasms


    • Epinephrine


    • Corticosteroids


    • Lithium


  • Inflammatory and metabolic disorders



    • Burns, trauma


    • Infarction, gout


    • Collagen vascular disease


    • Ketoacidosis


    • Eclampsia


  • Other



    • Stress


    • Asphyxia


    • Pregnancy


    • Smoking


    • Toxins


    • Venoms


Constitutional Neutrophilic Disorders



  • Leukocyte adhesion deficiency (LAD)



    • Neutrophil production increased


    • Marked neutrophilia in blood


    • Neutrophils unable to migrate to sites of infection


    • Multiple genetic types


  • Hereditary neutrophilia


  • Familial cold urticaria


Pathophysiology



  • Astronomical daily production rates of neutrophils in bone marrow


  • Large reserve of neutrophils, bands, and neutrophilic myelocytes is present in central medullary regions of bone marrow


  • Reserve pool can be released into blood


  • Neutrophils circulate for only a few hours before migrating to tissue


  • Neutrophils migrate by attaching to endothelium and passing through vessel wall


  • ANC highest normal range at birth



    • Should decline rapidly after birth


    • Lymphocytes outnumber neutrophils by 1 week of age


  • Neutrophil homeostasis maintained largely via steady bone marrow production


Mechanisms of Neutrophilia

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Jun 13, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Neutrophilia

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