Immunology Flashcards
Leukocytes:
Function
- Destroy micro-organisms at site of infection
- Remove foreign substances & body debris
- Independent movement - can pass through blood vessel walls into tissue
- ↑ WBC’s – leukocytosis
- ↑ abnormal WBC’s -leukemia
- ↓ WBC’s – leukopoenia
Hematopoiesis:
- Stem cells:
undifferentiated cells capable of renewal &
differentiation - Progenitor cells:
committed to production of particular cell lines - Precursors:
recognisable as early forms of particular cell lines
(blasts) - Mature cells
Classification of WBCs (Leukocytes):
- Granulocytes
Granulocytes
- Most numerous WBC’s
- Granules in cytoplasm
- Phagocytic
- Lobed nucleus
- Polymorphonuclear cells
Eosinophil:
- Destroy parasites
- Involved in allergy, eczema
- Involved in asthma
- Granules — chemicals
histamine, eosinophil peroxidase
plasminogen, major basic
protein, cathepsin, lipase - Toxic to parasites, host tissues
Eosinophilia:
- High number of
Eosinophils in blood - IgE allergies, asthma, hay fever is one cause
- Parasitic infection (helminth)
- Allergy to drugs, allergic reaction
- Some cancers cause eosinophilia
- Disappears with resolution of the disease
Eosinophilia:
- Some diseases that feature eosinophilia:
- Asthma, hay fever, drug allergies, dermatitis
- Eosinophilic esophagitis
- Parasitic infections
- Addisons disease
- Some blood cancers
- Systemic autoimmune diseases, SLE
- HIV infection
Eosinopenia:
- Decrease of Eosinophils in blood
- Usually, eosinophils move out from
blood to site of inflammation - Can be induced by stress, use of steroids (Cushing Syndrome)
- Tumour in pituatary gland, adrenal glands
- Other causes
- Surgery, shock, trauma, burns, mental distress
Eosinopenia:
Can be induced by Cushing Syndrome
- Cushing Syndrome
- prolonged use of cortisol or tumor
- Symptoms, abdominal obesity with thin arms and legs
- Round red “moon” face
- Headache, tiredness
- Red stretch marks
- Weak bones
- Weight gain
- Depression
Basophil:
- Least common cells
- Large granules, obscures cell nucleus
- Similar in appearance to Mast Cells (not in blood, reside in tissues)
- Both – histamine
- Major cell involved in
Allergic reactions - Involved in inflammation
Basophil:
- Abnormal elevation of Basophils in blood
- Basophilia as an isolated finding is rare
- Usually seen in chronic myeloid leukemia, ulcerative colitis,
juvenile RA, (inflammatory disorders), viral infections,
drugs, diabetes, Fe deficiency, allergies
Basopenia:
- Basophil deficiency
- Agranulocytosis
CAUSE
- Urticaria (hives),
- Anaphylaxis
- Drug induced reactions
- During ovulation
- Hyperthyroidism, acute infection, steroids
Mast Cell:
- Resident cells
- Not usually found in blood
- Granules —- histamine —
allergy, anaphylaxis - IgE receptor
- Granules — heparin
- Function and appearance
similar to basophil
Mastocytosis:
- Abnormal accumulation of
mast cells
-Mainly in skin and other
organs (bones, GIT, liver,
spleen)
- People with mastocytosis susceptible to itching, hives, anaphylactic shock (skin) (excessive histamine release)
- Most common cutaneous
mastocytosis is:
Urticaria pigmentosa
Neutrophil:
Segmented neutrophils
- Multi-lobed nucleus
- 2-5 lobes
- Polymorphonuclear cells
- Destroy harmful micro-organisms
- Destroy foreign particles
- Anti-bacterial
- Phagocytes
- Acute Inflammation
- Predominant in pus
Neutrophilia (Granulocytosis):
- High number of Neutrophils in blood
- Occurs in the first stage of infection
- Stored neutrophils in the venous sinuses are released into the general bloodstream
- If pronounced, may indicate sepsis
- If the demand is too high, many immature cells are
released
Neutrophilia (Granulocytosis)
High neutrophil number may indicate:
- Malignancy
- Hematologic disorder (CML)
- Appendicitis
- Splenectomy
- Burns
- Hemorrhage (internal)
- Chemicals, drugs
- Medications– prednisolone
Neutropenia:
- Too Few Neutrophils in blood, < 2000 / ml
- If < 500 /ml =
agranulocytosis - Susceptible to bacterial infections
- If not treated — life threatening –neutropenic sepsis, pneumonia …..,
Neutropenia:
DIAGNOSIS
- When a patient has developed sever infections or sepsis
- Fevers, frequent infections, mouth ulcers, diarrhea
- Unusual redness, pain, swelling around a wound
Neutropenia - Causes:
- Cancers, chemotherapy
- Toxins
- Radiation
- Vitamin B12 deficiency
- Haemodialysis
- Medications
- Chronic infection
Classification of WBCs (Leukocytes):
- Agranulocytes
Agranulocytes
- No granules
- or have few small granules in cytoplas
Monocyte
- Largest of all WBCs
- Move from blood – tissues
- – macrophages
- 1-10% of WBC’s
Monocytosis:
- Increase number of monocytes
in the blood
CAUSES
- Acute or chronic infection
- Leukemia’s
- Hodgkin’s Disease
- Autoimmune diseases
- Neutropenia
Monocytopenia:
- Low number of monocytes
in the blood - Rare
CAUSES
- Hairy cell leukemia
- Chronic use of prednisolone
- Acute infections
- AML (acute myeloid leukemia)
- Drugs
Lymphocytes
- 20 – 40% of WBC’s
- Involved in immune response
Three types - B cells – produce Abs against antigens, bacteria - T cells – Kill (CD8) or help (CD4) kill foreign Ag, tumours - NK Cells – Kill viruses, tumours
Lymphocytosis:
- Increase number of lymphocytes in the blood
- 20-40% normal, > 40% lymphocytosis
CAUSES
- Acute viral infection, EBV
- Leukemia’s, lymphoma
Lymphocytopenia:
- Low level of lymphocytes in the blood
- 20-40% normal, < 20%
lymphocytopenia - T cell, B cell, NK cell - lymphocytopenia
CAUSES
- Cancer
- Immune deficiency
- AIDS
- High cortisol
Alterations of Leukocyte Function
Quantitative disorders
- Increases or decreases in cell numbers
- Bone marrow disorders or premature destruction of cells
- Response to infectious microorganism invasion
Qualitative disorders
- Disruption of cellular function
Leukocytosis:
- White blood cell count above average
- Involves all leukocytes
- Often normal response to a stressor, e.g. pathogen
- Inflammation
- Also occurs in Leukemia
& Polycythemia Vera
Leukocytosis:
Principals?
5 principle types
Neutrophilia Eosinophilia Basophilia Monocytosis Lymphocytosis
Leukopenia:
- Decreased number of white blood cells
- White blood cell count <1000/mm³
- Becomes life threatening when WBC <500/mm³
- Causes include radiation, chemotherapy, SLE
- Circulating WBC can decrease in response to infection, as
they all move to the infected tissue
Lymphadenopathy
- Enlarged lymph nodes that become palpable and
tender
Local lymphadenopathy: Drainage of an inflammatory lesion located near the enlarged node
- General lymphadenopathy: Occurs in the presence of malignant or nonmalignant
disease (infections, autoimmune diseases)
infectious mononucleosis:
Also known as -- Glandular fever, kissing disease (spread by saliva) - Swollen lymph nodes - Viral disease, EBV - Acute infection of B lymphocytes - Effects 15-35yrs - Long incubation time, 30-50 days - Lasts weeks to months
Infectious mononucleosis:
SYMPTOMS
- Fever, sore throat, enlarged lymph nodes
- Increase lymphocyte count
- Serious complication are rare (<5 %)
- Splenic rupture
- Increase risk of Hodgkin lymphoma
Multiple Myeloma
- Multiple myeloma, plasmacytoma, myeloma, myelomatosis.
- Plasma cell neoplasm. B cells
- Overproduction of plasma cells in Bone Marrow
- Bone pain, Lytic bone lesions, hypercalcemia, bleeding
- Hyperviscosity syndrome –
purpura, visual failure,
neuropathy, heart failure etc.
Multiple Myeloma – XRAY:
- Cancer in the bone marrow
- Pain in spine
- Pain in ribs
- Worsens with activity