Blood Cell Abnormalities Flashcards
What is anaemia?
reduction in amount of haemoglobin in given volume of blood below what would be expected compared to healthy subject of same age and gender
Hb conc is reduced
Reduction in red cell count
Due to reduction in absolute amount of haemoglobin in blood stream
- Sometimes a low Hb from increase in plasma volume (cant happen in healthy person, excess fluid excreted)
List 4 mechanisms of anaemia:
- Reduced production of RBc in bone marrow
- Loss of blood
- Reduced survival of red cells in circulation
- Pooling of red cells in very large spleen
What is the difference between cause and mechanism?
- Cause is underlying thing that puts mechanism into operation eg what causes reduced production of haem or globin
- Mechanism eg reduced synthesis of haemoglobin in bone marrow
List 3 causes of iron deficiency:
1) Insufficient intake – diet, malabsorption (celicac disease, sensitive tgo gluten bowel alters so iron isn’t absorped properly OR H pylori, lack of HCL)
2) Blood loss – menstrual, cancer in gut, hookworm
3) Increased requiremets: pregnancy and infancy
How to determine cause of an anaemia
Classification based on cell size:
- microcyte
- normocyte
- macrocyte
What is megoblast erythropoeiseis?
- Megloblast – abnormal bone marrow erythroblast
- Due to vit B12 deifciency
- Requires bone marrow exxaminations for certainty. Can suspect from blood film.
- Hyper segmented nucleus
CAuses of Megloblast erythropoeiseis:
- Lack of b12
- Drugs interfering with DNA synthesis
- Liver disease and ethanol toxicity
- Blood loss
What is the difference between polychromasia and reticulocytosis?
- Polychromasia: DEAD CELLS RBC w blue tinge to cytoplasm. Young newly released from bone marrow
- Reticulocytosis: ALIVE increase no of young RBC. Recognised by reticulocyte stain. Easier to count how many young cells
What is Polycythaemia?
Too many RBC in circulation
What can cause Polycythaemia?
Pseudo – reduced plasma volume
True – increase in RBC ( due to blood doping, can be due or independent of erythropoietin)
Appropriate vs inappropriate increase in RBC:
Appropriate increase (hypoxia, high altitude) Inappropriate (cancer, drugs)
Effects of Polycythaemia
- Thick blood, (hyperviscosity)
- Mutation, cell independent of ER
- Vascular obstruction
- Blood removed (venesection)
Abdominal mass – carcinoma of kidney
What causes leukaemia?
Results from mutation in single lymphoid or myeloid stem cell
How is leukaemia different from other cancers?
Lymphoid and haemopoitetic stem cells can recirculate bw blood nd tissues. Therefore cant be INVASION or METASTASIS.
What are the 4 types of leukaemia:
Leukamiea can be acute/chronic or lymphoid (B, T, NK) or myeloid (granu, mono, erythro, megakaryocytic)
1) AML - acute myeloid leukaemia
2) CML - chronic myeloid leukaemia
3) ALL - acute lymphoid leukaemia
4) CLL - chronic lymphoid leukaemia
What is difference between chronic and acute?
Benign leukaemia – chronic (cells mature but are abnormal)
Malignant – acute (death in weeks)
What are some causes of leukaemia?
- Oncogenic (irradiation), anti cancer drugs, cigarettes, benzene
- Mutation in proto-oncogene, creation of novel gene, gene involved of translocation under influence of another gene
- Tumor suppressor stopped
- Chromosome breakage
- DNA cant be prepaed normally
- Mutation in somatic cell (aqciored)
What happens in AML?
- Cells proliferate but immature, spill into blood. WBCS not produced. Everything is blast cell
- Mutations affect transcription factors
What happens in CML?
translocation bw chromosomes 9 & 22
Chimaeric gene formed BCR-ABL1
Gives cell growth & survival advantage, rise to clones
Increase in WBCs
Enlarged spleen
BCR ABL1 inhibited by specific tyrosine kinase inhibitors
What happens in ALL?
leucocytosis. Anaemia is normocytic & normochromic. Reduction of platelets.
Normal bone marrow is replaced by lymphoblasts
More common in childhood, enlarged lymph nodes, spleen
How does cytogenetic analysis help leukaemia patients?
gives information about prognosis. How intense treatment needs to be.
What are some treatments of leukaemia?
RBC, plateles, antibiotcs, systemic chemo, intrahecal chemo (spinal fluid)
