Disorders of White Blood Cells Flashcards
what are the 5 varieties of nucleated cells in the peripheral blood?
→ neutrophils (granulocytes)
→ eosinophils (granulocytes)
→ basophils (granulocytes)
→ lymphocytes
→ monocytes
What is the primary function of nucleated cells in the peripheral blood?
- Primary function: Against infection or infestation
- difference between infection and infestation → infection = bacteria, infestation
What is a characteristic of granulocytes and monocytes
they are phagocytic
What are lymphocytes useful for?
immune response - eg cell mediated, Ab
Examples of disorders of white blood cell which contribute to the changes in leukocyte counts
Leucocytosis
Leucopenia
Leukaemia
Leukaemoid reaction
What does Leucocytosis do?
increase total number of white blood cell
What does leucopenia do?
decrease the total number of white blood cells
What does leukaemia do to white blood cell count?
increases
What is leukaemia also known as?
blood cancer
What does leukaemia do to tissues?
neoplasia of leucopoietic tissue
What is the leukaemia reaction?
massive leucocytosis and immature cells - chronic infection and servere haemolysis
What does leukaemoid reaction resemble?
→ look like leukaemia due to number increase → but are not malignant
Neutrophil leucocytosis
bacterial infections, tissue damage
Lymphocytosis
viral infection
Eosinophilia
parasitic infestation / allergy - such as asthma
Monocytosis
chronic bacterial infection (TB), malignant neoplasms
Basophil leucocytosis
(uncommon) myeloproliferative disorders
How much more neutrophils do neutrophilia show?
- normal = 1/1000
- neutrophilic shows more than that
What can changes of WBC count can be used to diagnose?
Neutrophil leucocytosis
Lymphocytosis
Eosinophilia
Monocytosis
Basophil leucocytosis
Causes of Neutrophilia
- Bacterial infections
- Inflammation/tissue necrosis
- Metabolic disorders
- Malignant neoplasia → some involve neutrophils being malignant
- Myeloproliferative disease → bone marrow cancer leading to neutrophil increase
- Drugs (steroids)
- Physiological (pregnancy, exercise)
What is Neutropenia?
→ lack of neutrophils
→ massively decreases
→ two types - selective neutropenia and pancytopenia
What are the two types of neutropenia?
selective neutropenia and pancytopenia
What is reduced in selective neutropenia?
only a reduction in white blood cells
What is reduced in pancytopenia?
all blood cell production
Selective neutropenia
- Viral infection
- Severe bacterial infection, e.g. typhoid
- Drug induced: e.g. anti-inflammatory agents
- Autoimmune: e.g. rheumatoid arthritis
Pancytopenia
- Bone marrow failure & infiltration
→ cytotoxic drug therapy; irradiation; malignant infiltration - Severe megaloblastic anaemia (impaired DNA synthesis due to inhibition which affects RBC and other cell types
→ leads to reduction in neutrophils) - Hypersplenism
What is hypersplenism?
→ when over active can destroy too many healthy cells- its supposed to clear up dead cells
What are the clinical features of neutropenia?
- infections, more frequent and serious
- Severe neutropenia (<0.5x109/L): pneumonia (needs to be treated immediately, septicaemia (blood cell bacteria- serious and causes shock)
What are the characteristic signs of neutropenia?
glazed mucositis in the mouth and ulceration
What are the causes of lymphocytosis?
- Acute, viralinfections:e.g. infectious mononucleosis;can be extreme in children
- Chronic infections: e.g.tuberculosis
- Leukaemia: chronic lymphocytic leukaemia (CLL); acute lymphoblastic leukaemia (ALL)
- Non Hodgkin’s lymphoma
Clinical feature of lymphocytosis
Lymphadenopathy
What are the neoplastic disorders of WBC?
- Malignancies of myeloid and lymphoid systems: leukaemias & lymphomas.
- Leukaemia (cancer cells): occurringpredominantly in bone marrow & circulating blood, no tissue mass
- Lymphoma: inlymphoid tissue; tissue mass is a presenting feature
- Leukaemias and lymphomas may co-exist.
The pathogenesis of WBC neoplasm
- At least one or more molecular abnormalities: chromosomal abnormalities detectedin leukaemias and lymphomas
- Clonal proliferation of one cell type → later becomes a visual tumour
- Neoplastic cells taking over normal bone marrow or normal lymphoid tissue → causes the compromisation of their functions
Leukaemias incidences
10/100,000 per year
What is leukaemias?
Neoplastic monoclonal proliferation of WBC precursors
Common features of laekaemias
- Replacement of normal bone marrow by leukaemic cells; variable accumulation of abnormal cells in peripheral blood
- Circulate and Infiltration of organs by leukaemic cells(liver, spleen, lymph nodes, meninges, gonads)
What is the most important consequence of laekaemias?
- Bone marrow failure
(anaemia, neutropenia, thrombocytopenia (reduction in thrombocytes or platelets)
Classification of leukaemia
Classified as beingacute / chronic, and ofmyeloid / lymphoidorigin
What percentage of leukaemia are acute?
50%
What are the two types of acute leukaemia?
Myeloblastic (AML):
- All age groups; incidence ↑ with age;
FAB (French-American British)classification:M0-M7
Lymphoblastic (ALL):
- Mostly in children; FAB: L1-L3
What leads to the manifestation of acute leukaemia?
- Blast cells divide but fail to differentiateand appear in blood.
- > 20% bone marrow taken upby myeloblasts or lymphoblasts
- Bone marrow failure
What do symptoms from acute leukaemia arise from?
- bone marrow failure: leucopenia →infections
- bone marrow infiltration: pain
- other organ infiltration: e.g. brain
Percentage of leukaemia being chronic
45%
Two types of chronic leukaemia
- Myeloid/Granulocytic (CML/CGL):All age groups
- Lymphocytic (CLL):>50 years age group
CLL
→ Commonest leukaemia, esp. in late age
→ Lymphocyte count > 100x109
→ B cell proliferation
→ Abnormal cells in marrow, blood film, lymph nodes
CML/CGL
→ Leucocyte count > 15x109
→ Mostly neutrophils but also myelocytes
→ Chromosome translocation: long arm of 22 fuses with that of 9→generates Philadelphia chromosome → used to diagnose
→ May transform to AML and ALL
Clinical features of chronic leukaemia
- Some with no symptoms
- Very high peripheral WBC counts
- Anaemia, thrombocytopenia
- Splenomegaly
- Hepatomegaly
- Lymphadenopathy
Features of chronic leukaemia
- Usually in adults(but may be seen in children)
- Leukaemic cellsretain ability to differentiate
Lymphomas
Malignant tumours of lymphoid cells; at lymph nodes or extra-nodal
What are the two types of lymphomas?
Hodgkin’s Lymphoma
Non-Hodgkin’s
Hodgkin’s Lymphoma
→ occurs mainly in lymph node origin (mostly) → Reed-Sternberg cells
Non-Hodgkin’s
→ occurs in 3⁄4 in lymph nodes
- Commonly manifest by lymphadenopathy
Lymphadenopathy
→ rubbery/swollen lymph node (cervical, etc.) spreads (spleen, liver, marrow, gut)
Lymph node histology of Hodgkin lymphoma
Reed-Sternberg cells (very large and multinucleate B lymphocyte)
Hodgkin’s Lymphoma (HL) symptoms
Patient presents with fever, weight loss, sweating (called B symptoms)
What was Hodgkin’s Lymphoma (HL) linked to?
Linked to previous infection with Epstein Barr virus, with a genetic predisposition
Hodgkin’s Lymphoma (HL)
- Peak at 3rd decade
- Lymphadenopathy:
→ rubbery/swollen lymph node (cervical, etc.) spreads (spleen, liver, marrow, gut) - Linked to previous infection with Epstein Barr virus, with a genetic predisposition
- Lymph node histology:Reed-Sternberg cells (very large and multinucleate B lymphocyte)
- Patient presents with fever, weight loss, sweating (called B symptoms)
Non Hodgkin’s lymphoma (NHL)
- Majority of malignant lymphoma are NHL
- Arise inlymph nodes(eg. cervical) & spread, orextra –nodal(eg.gut)& generalised spread (eg. lungs)
- A wide spectrum of disease; highly proliferative or slow & indolent
- Most (85-90%) are B cell origin(Follicular, Burkitts); 10-15% T cell;
Clinical Features of Non Hodgkin’s lymphoma (NHL)
- B-symptoms (fever, night sweats, weight loss)
- Lymphadenopathy
- extranodal presentation (GI, lung, etc.)
Lymphocytosis occurs in which of the following conditions?
a) Tissue necrosis
b) Acute viral infection
c) Parasitic infestation
d) Irradiation
e) Haemorrhage
b
One feature of acute leukaemia is
a) It only affects children
b) Blast cells rarely appear in peripheral blood films
c) There is no spleen enlargement
d) Reed Sternberg cells are present in the lymph node
e) Blast cells are accumulated in the bone marrow
e
