Leukocytes

White cell indices reported on a full blood exam may include:

Abnormalities

  • Immature Granulocytes (3-5%)
    An ↑ in immature granulocytes granulocytes released from the bone marrow, which:
    • Commonly includes “band” cells, which have not yet developed the segmented nucleus of an adult neutrophil
    • Is described as a left shift, which reflects an ↑ in the ratio of immature:mature neutrophils
    • Occurs in response to either:
      • Inflammation
        • Necrosis
      • Infection
        • Sepsis
      • Anaemia
        • Haemorrhage
      • Bone marrow infiltration

Left-shift of neutrophils is an ↑ in immature (“band”) neutrophils in blood, as an active response of bone marrow to infection or inflammation.

Band and Segmented Neutrophils

  • Toxic Changes
    Toxic changes requires two of the following:
    • Toxic granulation
      Dark, coarse, peroxidase-containing granules that have not been lost with neutrophil maturation. Indicate ↑ release, due to:
      • Infection
      • Inflammation
        • Burns
        • Trauma
      • G-CSF
    • Toxic vacuolation
      Presence of (abnormal) neutrophil vacuoles, indicating active phagocytosis. Occur with:
      • Bacteraemia
      • Fungaemia
      • Liver failure
      • G-CSF
      • Artifact
    • Döhle bodies
      Blue cytoplasmic inclusions, which are the remnant of the rough endoplasmic reticulum. Occur with:
      • Leukemoid reactions
      • Exotic infections
        • Syphilis
        • Typhoid
        • Tuberculosis
Toxic Granulation

Toxic Vacuolation

Döhle Bodies

  • Leukemoid Reaction
    Extreme leukocytosis (>50×103/mL) occurring for a reason other than leukaemia. Features:
    • Predominantly neutrophils
    • Marked left shift
    • Usually due to:
      • Infection
      • Inflammatory
      • Drugs and toxins
      • Malignancy
      • Haemorrhage
      • Haemolysis
Causes of Leukemoid Reactions
Category Examples
Infective
  • C. diff colitis
  • Disseminated TB
  • Shigellosis
Inflammatory
  • Ischaemic hepatitis
  • DKA
  • HHS
Drugs and Toxins
  • Ethylene glycol
  • Corticosteroids
  • Minocycline
  • Recombinant haematopoietic growth factors
Malignancy
  • Carcinoma
  • Hodgkin’s Lymphoma
  • Melanoma
  • Sarcoma
Haemorrhage and Haemolysis
  • Retroperitoneal haemorrhage
Other
  • Alcoholic steatohepatitis
  • Smudge Cells
    Destruction of fragile lymphocytes during blood smear preparation, indicative of CLL.
Smudge Cells

References

  1. Sakka V, Tsiodras S, Giamarellos-Bourboulis EJ, Giamarellou H. An update on the etiology and diagnostic evaluation of a leukemoid reaction. European Journal of Internal Medicine. 2006;17(6):394-398. doi:10.1016/j.ejim.2006.04.004