15. Leukocyte Disorders Flashcards Preview

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Flashcards in 15. Leukocyte Disorders Deck (28)
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1
Q

Quantitative vs. Qualitative WBC Examination

A

Quantitative: Leukocytosis, leukopenia; Absolute vs. relative
Qualitative changes: Nuclear, Cytoplasmic

2
Q

Neutrophil Number is affected by:

A
  1. Influx - production and release from bone marrow
  2. Circulating vs. marginal
  3. Exit from blood - as circulating become marginal, there is a drop in Neutrophil count
3
Q

Leukocytosis

  • physiologic
  • pathologic
  • responses (lab findings)
  • factors determining host response
A

Physiologic:

  • Causes a distribution change (increase in circulating, decrease in marginal)
  • due to Severe exercise, Stress, fear, anger, or Hypoxia

Pathologic:

  • Infection -Toxins, (uremia, spider bite, Pb poisoning)
  • Tissue necrosis (MI, burns)
  • Malignant neoplasm
  • Hemorrhage, especially in gut
  • Acute hemolysis
Response to infection
- Increased WBC - higher WBC indicates good response
- Left Shift
- Decreases eosinophils
Recovery from infection
- Decrease neutrophils
- Increase monos
- Increase lymphs, eos

Factors determining host response: Age, Nutritional status, Kind of invading organism

4
Q

Morphologic of Neutrophils in infection

A
  • Toxic granulation - immature azurophilic granules due to rapid WBC production
  • Dohle bodies - Cytoplasmic, residual RNA
  • Cytoplasmic vacuoles - phagocytosis
  • Nuclear spicules - found in some infections
5
Q

Neutropenia

A
  • Decrease entry into blood (production)
  • can be caused by:
    • Viral infection, Inherited - infants, Drugs, Ineffective granulopoieses
    • Increase removal from blood (destruction): Severe uncompensated infection, Hypersplenism, Antibodies (leukoagglutinins)
    • Circulating and marginal pool alterations
6
Q

Chronic Granulomatous Disease

A
  • Sex-linked or autosomal recessive
  • 1/500,000
  • Recurrent bacterial or fungal infections
  • Most often seen in the pediatric population
  • Treatment is prophylactic antibiotics, early treatment of infections
  • Neutrophils appear normal, but have abnormal function
  • Organisms are phagocytized, but not killed
  • Defects in the respiratory burst system
  • Reduced superoxide production
7
Q

Nitroblue Tetrazolium Test

A
  • Neutrophils are mixed with a yellow dye (NBT] and microorganisms
  • Normal: dye is reduced by the generation of oxygen metabolites to blue
  • CGD: dye is not reduced because of inability to generate a respiratory burst (can engulf but can’t break things down)
8
Q

Chediak-Higashi Syndrome

A
  • Rare autosomal recessive disorder
  • Death usually occurs in infancy or childhood
  • Giant granules formed by aggregation and fusion of primary and specific granules (seen in most granule-containing cells)
  • Prevents delivery of granules to phagosomes
  • Lab Values: neutropenia, thrombocytopenia
  • Patient Presentation: Skin hypopigmentation, Silvery hair, Photophobia (abnormal melanosomes), Lymphadenopathy and hepatosplenomegaly
9
Q

May-Hegglin Anomaly

A
  • Rare, autosomal dominant trait
  • Dohle-like inclusions in granulocytes: consist mainly on RNA from rough endoplasmic reticulum
  • Giant platelets
  • Variable thrombocytopenia
  • Only clinical problem is bleeding due to thrombocytopenia, if present
10
Q

Alder-Reilly Anomaly

A
  • Characterized by the presence of large purplish granules in all leukocytes
  • Cells function normally
  • Associated with mucopolysaccharidosis such as Hurler’s syndrome and Hunter’s syndrome
11
Q

Pelger-Huet Anomaly

A
  • Benign, autosomal dominant
  • 1/5000
  • Neutrophil hyposegmentation
  • Neutrophil nucleus does not segment beyond two lobes
  • Nuclear clumping intense
  • Dumbbell, pince-nez
  • Yet, neutrophils still function normally
12
Q

Acquired or pseudo Pelger-Huet

A
  • seen in myeloproliferative disorders or myelodysplastic states
  • frequently accompanied by hypogranulation
13
Q

Morphology of Monocytes

A
  • Spectrum of mononuclear phagocytic cells
  • Small (14 - 20u) to large (20 - 30u)
  • Nucleus: Reniform, fine chromatin, no nucleolus
  • Cytoplasm: Gray-blue, contains fine lysosomal granules; Vacuoles, particularly when sample sits
  • Numerous small mitochondria in gray cytoplasm
  • Complex golgi zone - produces granules
  • Lysosomal granules
  • Move by undulating pseudopods
14
Q

Monocyte - Macrophage Transformation

A

Bone Marrow = Monoblast, Promonoblast
Blood = Monocyte
Tissue = Macrophage

  • Enlargement (25 - 50u)
  • Increased energy production and consumption
  • Azurophilic granules disappear, new enzymes synthesized
  • Active phagocytosis, pinocytosis
  • Respond to chemotaxis
15
Q

Macrophage Function

A
  • Interferon production: prevent viral spread
  • Antibody response: Trap antigen, “process antigen”, cell-mediated immunity
  • Wound healing: stimulate fibroblast formation
  • Granulocyte and monocyte regulation: Colony stimulating factor
16
Q

Macrophage Types

A
  • Fixed (sessile)
  • Wandering (motile)
    • Peritoneal
    • Liver (Kupffer cells)
    • Alveolar (lung)
    • Splenic
    • Osteoclasts (bone resorption)
17
Q

Monocytosis

A
  • Absolute: >1000/uL
  • Relative: >10%
  • Causes:
    • recovery from acute bacterial infection
    • Other infections (TB*, SBE, syphilis, some viral)
    • Protozoal and rickettsial infection - malaria, typhus, Rocky Mountain spotted fever
    • Malignancy
    • Hematologic disease (over 1/2): Leukemia, lymphoma, myeloproliferative disorders, multiple myeloma, lipid storage disease
    • Collagen, vascular disease: SLE, rheumatoid arthritis
    • “Preleukemia” - precedes leukemia
    • Poisoning - rare (ex. tetrachloroethane)
18
Q

Lipid Storage Diseases

A
  • Gaucher’s Disease
  • Niemann-Pick Disease
  • Tay-Sachs Disease
19
Q

Gaucher’s Disease

A
  • lipid storage disease
  • Autosomal recessive, lipid storage disease
  • Type I more common in Ashkenazi Jews
  • *** Lack of Beta-glucocerebrosidase
  • Unable to digest the stroma of ingested cells
  • Lipid accumulates in macrophages (Gaucher cells)
20
Q

Gaucher cells

A
  • Large cells with small, eccentric nuclei
  • Fibrillar (onion skin-like) cytoplasm
  • Cells often filled with debris
  • Cells found in lymphoid tissue, spleen, liver, and bone marrow (not blood)
21
Q

Niemann-Pick Disease

A
  • Autosomal Recessive, most commonly seen in Ashkenazi Jews
  • Shingomyelinase Deficiency
  • Sphingomyelin and cholesterol accumulate in macrophages
  • Foamy macrophages found in lymphoid tissue and bone marrow
  • Most common (85%) have onset in infancy
  • Failure to thrive
  • Retarded mental and physical development
  • Hepatosplenomegaly
  • Half with cherry-red spot in macula of eye
  • Prognosis is poor; few survive beyond third birthday
22
Q

Normal Lymphocyte

A
  • Infants - 90% of cells are lymphs (because they still have to build their immunity)
  • Adults - about 1/3 are lymphs
  • T-cell count is highest at birth
23
Q

Lymphocytosis in the Blood

A
  • Increased lymphocyte count
  • Absolute Lymphocytosis ( >9 x 10^9/L (child), >4 x 10^9/L (adult))
  • Relative Lymphocytosis (>70% (child), >45% (adult))
24
Q

Lymphocytopenia in the Blood

A
  • Decreased lymphocyte count

- Absolute Lymphocytopenia (<20% (adult))

25
Q

DiGeorge Syndrome

A
  • T-cell abnormality
  • Underdeveloped thymus
  • Markedly decreased T lymphocytes
  • May have neurologic, cardiac, parathyroid complications
  • Treatment with thymus transplant
26
Q

Combined T and B Lymphocyte Abnormalities

A
  • Severe Combined Immunodeficiency (SCID): Results in severely decreased T, B, and natural killer lymphocytes
  • Wiskott-Aldrich syndrome:
    • Deficiency of protein required for migration, adhesion and activation of WBC
    • Causes immunodeficiency, eczema, and thrombocytopenia
27
Q

Infectious Mononucleosis:

  • who it commonly effects
  • caused by:
  • transmitted by:
A
  • Dr. M.A. Epstein, 1964
  • Young adults, rarely over 24 years old
  • Caused by the Epstein-Barr Virus
  • EBV is a herpes virus
  • Transmitted by: Oral contact (“kissing disease”), Fomites (toothbrush, drinking glass), Transfusions
  • Over 200,000 cases per year
  • Peak incidence ages 17 - 25
  • 95% of adults between 35 & 45 have been infected
  • Incubation 2- 4 weeks
28
Q

Infectious Mononucleosis:

  • symptoms
  • laboratory findings
A
  • Triad of Symptoms: Fever, Lymphadenopathy, Sore Throat
  • Leukocytosis due to lymphocytosis
  • Atypical/reactive lymphocytes >10%
  • Serologic testing

*Note: MONOnucleosis does not involve monocytes. It involves reactive lymphocytes