WBC abnormalities

% of wbc in peripheral blood

• Neutrophils: 50-70%

  • 3-5% are band forms

• Lymphocytes: 25-35%

• Monocytes: 4-6%

• Eosinophils: 1-3%

• Basophils: 0.4-1%

Absolute count of wbc in peripheral blood

Total leukocytes: 4-11 e9 /L

• Neutrophils: 2.5-7.5 e9/ L

• Lymphocytes: 1.5-3.5 e9/ L

• Monocytes 0.2-0.8 e9/ L

• Eosinophils 0.04-0.4 e9/ L

• Basophils: 0.01-0.1 e9/ L

Suffix for increase in cell line

• -Osis

  • Leukocytosis

• -Philia

  • Eosinophilia

Suffix for decrease in cell line

• -penia

  • neutropenia, leukopenia

Causes of increase in WBC

Causes of decrease in WBC

Stages of WBC phagocytosis

WBC qualitative defects

• May happen in cytoplasm or nucleus

• May be inherited or acquired

  • Acquired more common

• Results as stress during maturation and activity in circulation or tissue

  • toxic changes

1. Toxic granulation

2. Human ehrlichiosis

3. Nuclear abnormalities

Toxic changes in WBC

• Visible changes in the response of WBC to infection and inflammation occurs along the path

• Usually increased number of segmented neutrophils in peripheral smears

  • Neutrophilia: shift to the left. Younger cells appear

Toxic granulation (in neutrophil)

• More granules in segmented and bands

  • vivid blue-black color

• Direct response to enhanced lysosome enzyme production

  • due to severe stress or immune activation

• Need to carefully differentiate between toxic granulation of neutrophils from basophils

Toxic vacuolization (in neutrophils)

• Small and large vacuoles in cytoplasm

  • Large, uneven vacuoles distributed= serious infections, maybe sepsis

• Causes: drugs (sulfonamides, chloroquine), prolonged blood storage from phagocytosis of cytopalsmic granules

• 10% of neutrophils affected

• Indicates prognosis

Döhle Bodies

• Ribosomal RNA

• Cytoplasmic inclusions near membrane

• Pale blue-grey, rod-shaped

• Transient inclusions in neutrophils

  • may also appear in monocytes and bands

• Can be due to non-pathological conditions like pregnancy

Human Ehrlichiosis

Ehlrlichia bacteria is from tics

1. Human Monocytic Ehrlichiosis (HME)

• Ehrlichia chaffeensis

• Southwest and Mid-atlantic US

• Flu-like symptoms

2. Human Granulocytic Anaplasmosisi (HGA)

• Anaplasma Phagocytophilum

• Midwest US

• Acute high fever, chills, headaches

Hypersegmented

Abnormality in neutrophils where it has more than 5 lobes

• usually in megaloblastic anemia

• accompanied by ovalocytes

Hereditary WBC disorders

1. May-Hegglin Anomaly

2. Alder’s Anomaly

3. Pelger-Huët Anomaly

4. Chediak-Higashi Syndrome

May-Hegglin Anomaly

• thrombocytopenia (low number of thrombocytes)

• giant platelets

• Dohle bodies in neutrophils

  • Larger than normal dohle bodies in infections

nmemonic: Hegglin→ thrombocytes hagglin away

Alder’s Anomaly (Alder-Reilly Anomaly)

• Decreased mucopolysaccharide production

  • Causes lipid deposits in cytoplasm

• Alder-Reilly granules: Coarse dark granules in all WBC cell lines

  • Differentiated from toxic granulation by staining with toluidine blue

• Toxic granulation: in clusters

  • only in neutrophils and monocytes

  • Surrounded by vacuoles

  • does not affect cell fxn

• Inclusions seen in BM, not in peripheral

nmemonic: O’Reilly oil change→ oil is fat

Pelger-Huët Anomaly

• hyposegmentation in 70-95% of neutrophils

  • Heterozygous nucleus: peanut, dumbbell, pince-nez- shaped

  • Homozygous nucleus: spherical, no lobes

  • neutrophils have normal fxn

Chédiak-Higashi Syndrome

• Defective fusion protein that affects lysosomal secretion

  • Giant lysosomes in cytoplasm

  • Green-grey peroxidase-positive bodies

  • Fusion of primary, secondary, non-specific, specific granules

• Autosomal disorder of neutrophilic granules

  • Cytoplasmic granules are giant purple-grey

  • Lymphocytes and monocytes may also have a single large granule

• WBCs not fully functional

  • shows reduced chemotaxis→ poor phagocytosis of pathogens

• S/S:

  • Neutropenia

  • Albinism, photophobia due to melanosome abnormality

  • Staph Aureus recurrent infections

    • Usually causes childhood death

Chronic Granulomatous Disease (CGD)

• inherited

  • 65% x linked

  • 35% autosomal recessive

• Defects in respiratory burst oxidase system

  • recurrent infections leading to granulomas

• Affected cells are morphologically normal but cannot generate antimicrobial oxygen metabolites like H2O2

  • Neutrophils can phagocytize but cannot kill them

  • Catalase-positive organisms destroy the H2O2 of their own metabolism→ continues to grow intracellularly where they are protected from antibiotics

  • Catalase-negative organisms kill themselves by generating H2O2 that the phagocyte uses as antimicrobial defense mechanism

• Peripheral neutrophil count is normal but increases with infection

  • IGs increased due to chronic infection

  • Treatment: prophylactic Abs

  • NBT test detects abnormal oxygen metabolism of neutrophils

Myeloperoxidase Deficiency

• Benign autosomal recessive disorder

• Absence of myeloperoxidase in neutrophils and monocytes

  • MPO is used in bactericidal process but there’s no increase in infections in this deficiency

  • Neutrophils use alternative antimicrobial systems (just more slowly)

• May experience disseminated fungal infections: usually with C albicans

Leukocyte Adhesion Deficiency

Two forms: LAD I, LAD II

LAD I:

• Rare autosomal recessive

• Decreased/ absent leukocyte cell-surface adhesion proteins

  • β-integrins, AKA CD11/ CD18 complex

• Neutrophils have functional defects

  • impaired adhesion to endothelial cells, chemotaxis, phagocytosis, respiratory burst activation, degranulation

LAD II:

• Failure of endothelial cells to synthesize ligand for leukocyte L-selectin

• Leukocyte fxn is normal but cannot adhere to vessel wall endothelium and cannot exit the circulation to enter tissues

Features:

• Recurrent soft tissue bacterial and fungal infections

• persistent leukocytosis and granulocytosis from increased stimulation of BM

Reactive lymphocytosis in common disease states

• 1-4 yrs: lymphocytosis is normal

• Normal WBC differential: shows a reversal in numbers of lymphocytes to neutrophils

• Lymphocytes have normal fxn

Lymphocytosis: infectious mononucleosis

• Caused by Epstein-Barr virus

  • Most common disease showing lymphocytosis

• Enters orally→ infects B lymphs

  • normal lymphs transform to reactive lymphs

• Enlarged lymph nodes

• hepatosplenomegaly

Lymphocytosis: infectious mononucleosis smear

• 10-60% are reactive lymphocytes

• Reactive lymphs are enlarged

  • has royal blue cytoplasm that scallops red cells

  • Must be recorded separately from non-reactive normal lymphocytes

• Viral disorders often affect CBCs similarly

HIV/AIDS on hematology parameters

AIDS: Acquired immunodeficiency syndrome

• Mainly targets T-helper lymphocytes (CD4)

• Normal CD4:CD8 ratio is 2:1

  • in HIV infection, CD4 drastically decreased to 1:2→ failure in immune response

    • CD4 lymph count reduced to <200/ uL

• Lymphocytes show extreme basophilic cytoplasm, possible folds, vacuolization

Lipid storage disorders

• Missing or inactive strategic metabolic enzyme in the WBCs from single gene deletion

• Undigested metabolic products accumulate in cells→ affects cell integrity

• RES (reticuloendothelial system) cells most affected: histiocytes, monocytes, macrophages, BM cells, liver, spleen, lymph nodes

• BM contains easily-identifiable cells specific to each disease

  • Not usually seen in laboratory

Most common Lipid Storage Diseases

1. Gaucher’s Disease

2. Niemann-Pick’s Disease

3. Tay-Sachs Disease

• All autosomal recessive from single gene mutation

• Abnormal facial features in Gaucher’s and Niemann-Pick

• CNS involvement in infant forms

• BM transplant and enzymes produced through biotechnology available

Gaucher’s Disease (pronounced Go-shay)

Missing Enzyme: β-Glucocerebrosidase

• crinkled paper appearance of cytoplasm

• Glucocerebrosides build up in liver, spleen, lungs, BM

  • macrophage cannot digest stroma of ingested cells→ lipid glucocerebrosides accumulate

• Abnormal facial features

• Splenohepatomegaly→ may result in anemia

nmemonic: Goshay→ glucocerebrosidase

Niemann-Pick disease

Missing enzyme: Sphingomyelinase (breaks down lipids)

• Excessive sphingomyelin storages

• Niemann-Pick type A and Type B disease

• Macrophages are large and have foamy appearance in lymphoid tissue and BM

  • Off center nucleus, cytoplasmic inclusions

• Splenohepatomegaly from increased sequestration

• Blood lymphocytes have vacuoles that are lipid-filled lysosomes

• Abnormal facial features

• Fatal by 3 years

nmemonic: Niemyelinase

Tay-Sachs disease

Missing enzyme: Hexosaminidase A

• Accumulation of GM2 ganglioside in brain and spinal cord→ breaking them down

• Early childhood fatality

  • or neurological issues in adulthood

Bacteria in Blood stream

Bacteremia→ sepsis

• Intra and extracellular bacteria must be recognized in peripheral blood smear ASAP

Platelet Satellitism

• blood reacts with EDTA (lav tops)

• Platelets form a ring around neutrophils

• Causes low platelet count

  • Can be corrected only with blood collected in sodium citrate instead (light blue tops)

Pyknosis

• Seen in degenerated neutrophils

• Segmented nucleus becomes amorphous, smooth, bloblike structure

  • Chromatin shrinks, gets darker, breaks apart

• No clear segments

• Not counted in WBC peripheral smear