Disorder of WBC Flashcards
what are the 5 types of WBC
- neutrophils (granulocyte)
- basophils (granulocyte)
- eosinophils (granulocyte)
- monocytes
- lymphocytes
what is the primary function of leukocytes (WBC)
- against infection or infestation
what is the role of granulocytes and monocytes
they are phagocytic
what is the difference between infection and infestation
infection: against bacteria etc
infestation: against parasite
what is the role of lymphocytes
- role in the IMMUNE RESPONSE
- cell mediated or abtibody mediated immune response
what % of leukocytes are neutrophils
45-75%
what % of leukocytes are monocytes
2-8%
what % of leukocytes are basophils
0.4-1%
what % of leukocytes are eosinophils
1-4%
what % of leukocytes are lymphocytes
20-40%
how are the granulocytes formed (neuto/baso/eosino)
myeloid stem cells –> colony forming units (granulo-N,Eo,baso, Mono) –> myeloblast –> band cell –> granulocytes
how are monocytes formed
myeloid stem cells –> colony forming units (granulo-N,Eo,baso, Mono) –> monoblast –> monocyte
how are lymphocytes formed
lymphoid stem cell –> pre-T, pre-B cells –> lymphoblast –> lymphocytes (T and B cells)
what are the features of monocytes
- larger cell body
- nuclear dense
what is leukocytosis
INCREASE in total number of leukocytes
what is leukopenia
DECREASE in total number of leukocytes
what is leukaemia
neoplasia of leukopoietic tissue with a MASSIVE INCREASE in total numbers
- MALIGNANT process
what is leukaemoid reaction
massive leukocytosis and immature cells (chronic infections, severe haemolysis)
- BENIGN process
what is the normal range for neutrophils
what is it called when the neutrophil count exceeds this
NORMAL: 2.8-7.5 x10^9/L
Neutrophilia is when this is exceeded (>7.5x10^9/L)
what are the causes of neutrophilia
- bacterial infections
- inflammation/tissue necrosis
- metabolic disorders
- malignant neoplasia
- myeloproliferative disease
- drugs (steroids)
- physiological (pregnancy/exercise)
what is neutropenia
when the numbers of neutrophils are BELOW the normal
- NORMAL: 2.8-7.5 x10^9/L
neutropenia is < 1.5x10^9/L(
what is pancytopenia
deficiency of all three cellular components of the blood (red cells, white cells, and platelets)
what are the causes of neutropenia
both as selctive neutropenia and part of pancytopenia
SELECTIVE:
- drug induced (anti-inflammatory agents)
- autoimmune (eg rheumatoid arthiritis)
- severe bacterial infection eg typhoid
- viral infection
PART OF PANCYTOPENIA:
- bone marrow failure and infiltration
- cytotoxic drug therapy, irradiation, malignant infiltration
- severe megaloblastic anaemia (impaired DNA synthesis)
- hyperslpenism
what are the clinical features of neutropenia
- INFECTIONS : more frequent and serious
- if SEVERE neutropenia((<0.5x10^9/L): can lead to pneumonia, septicaemia
- characteristic signs: glazed mucositis in the mouth and ulceration
what can neutrophils leukocytosis suggest
bacterial infections, tissue damage
what can lymphocytosis suggest
viral infection
what can eosinophilia suggest
parasitic infestation/allergy
what can monocytosis suggest
chronic bacterial infection (eg TB)
malignant neoplasms
what can basophil leukocytosis suggest
it is uncommon
- but can suggest myeloproliferative disorders
what are the causes of lymphocytosis
what is the clinical feature
- acute, viral infections (eg infectious mononucleosis) can be extreme in children
- chronic infections (eg tuberculosis)
- leukaemia (chronic lymphocytic leukaemia CLL) and (acute lymphoblastic leukaemia ALL)
- clinical feature: Lymphadenopathy
what are neoplastic disorders of WBC
give examples
can they co-exist
- malignancies of myeloid and lymphooid systems
- LEUKAEMIA : occurs predominantly in bone marrow and the circulating blood
- LYMPHOMA: in lymphoid tissue, tissue mass is a presenting feature
- Leukaemias and lymphomas may co-exist
how can you differentiate between lymphoma and leukaemia
there is a TISSUE MASS in lymphoma (mainly in lymph node)
- if there is no tissue mass and there are malignant white blood cells then it is leukaemia
what is the pathogenesis of WBC neoplasm
- at least ONE OR MORE MOLECULAR ABNORMALITIES: chromosomal abnormalities detected in leukaemias and lymphomas
- CLONAL PROLIFERATION of cell type
- neoplastic cells TAKING OVER bone marrow or lymphoid tissue (O normal bone marrow function is affected causing symptoms, and shortage of all blood cell types)
how common is leukaemia
- incidence: 10/100,000 (a relatively common cancer)
what is the pathogenesis of leukaemia
what are the pathological features
- NEOPLASTIC MONOCLONAL PROLIFERATION of WBC precursors
PATHOLOGICAL FEATURES:
1) bone marrow REPLACED by leukaemic cells, variable accumulation of abnormal cells in peripheral blood
2) ORGAN INFILTRATION by leukaemic cells (liver, spleenlymph nodes, meninges, gonads)
what is the major consequence of leukaemia
- bone marrow failure (anaemia, neutropenia, thrombocytopenia)
how is leukaemia classified
1) acute/chronic
2) myeloid/lymphoid origin
describe acute leukaemia
- about 50% of all L
- MYELOBLASTIC (AML): affects all age groups, incidence INC with age, FAB (French-American-British) classification: M0-M7
-LYMPHOBLASTIC (ALL):
most commonly in children
FAB: L1-L3
describe chronic leukaemia
about 45% of all L
- MYELOID/granulocytic (CML/CGL)
all age groups
- LYMPHOCYTIC (CLL): .50 years age group
describe the pathogenesis of acute Leukaemia
how do the symptoms arise
- Blast cells divide but fail to differentiate and appear in blood
- > 20% bone marrow taken up by myeloblasts or lymphoblasts
- causes BONE MARROW FAILURE
- SYMPTOMS:
- bone marrow failure: leucopenia –> infections
- bone marrow infiltration: pain
- other organ infiltration: e.g. brain
describe chronic L
in detail
- Usually in adults (but may be seen in children)
- Leukaemic cells retain ability to differentiate
- CLL:
- Commonest leukaemia, esp. in late age
- Lymphocyte count > 100x10^9 /L
- B cell proliferation
- abnormal cells in marrow, blood film, lymph nodes
- CML/CGL
– Leucocyte count > 15x10^9/L
– Mostly neutrophils but also myelocytes
−Chromosome translocation: long arm of 22 fuses with that of 9–> Philadelphia chromosome - MAY TRANSFORM TO AML AND ALL
whata re the clinical features of chronic leukaemia
- very high peripheral WBC counts
- anaemia, thrombocytopenia
- splenomegaly
- hepatomegaly
- lymphadenopathy
- some have NO SYMPTOMS
describe lymphomas
incidence
classification
- the 7th commonest cancer in UK
- Malignant tumours of lymphoid cells - at lymph nodes or extra-nodal
Classification:
- Hodgkin’s Lymphoma:Lymph node origin (mostly);Reed-Sternberg cells
- Non-Hodgkin’s
3/4 in lymph nodes
commonly manifest by lymphadenopathy
describe Hodgkin’s lymphoma
- Peak at 3rd decade of life
- 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(multinucleate B lymphocyte)
- Patient presents with fever, weight loss, sweating(called B symptoms)
describe non Hodgkin’s lymphoma
- Majority of malignant lymphoma are NHL
- Arise in lymph nodes (eg. cervical) & spread,or extra –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:
- B-symptoms (fever, night sweats, weight loss)
- Lymphadenopathy
- extranodal presentation (GI, lung, etc.)
