Haematology Flashcards
What is Haemopoeisis?
The physiological developmental process that gives rise to cellular components of blood. (2 lineages: myeloid & lymphoid)
What are the origins of haemopoeisis?
Day 27: at the Aorto-Gonado-Mesonephros
Day 40: disappears (migration of these haematopoietic stem cells to the foetal liver)
Examples of Myeloid cells?
Granulocytes (wbc)
Erythrocytes (rbc)
Platelets
Examples of Lymphoid cells?
B-Lymphocytes (wbc)
T-Lymphocytes (wbc)
What does the term ‘Reference Range’ mean in clinical practice?
The set of values for a given test that incorporates 95% of the normal population.
What does Sensitivity mean in clinical practice?
The proportion of abnormal results correctly classified by the test. The ability to DETECT a TRUE ABNORMALITY. =TP/(TP+FN)
What does Specificity mean in clinical practice?
The proportion of normal results correctly classified by the test. The ability to EXCLUDE an ABNORMAL RESULT in a HEALTHY PERSON. =TN/(TN+FP)
(WBC)…
1) Eosinophilia? (^ numbers)
2) Basophilia? (^ numbers)
3) Monocytosis? (^ numbers)
1) Eosinophilia… due to= parasitic infection, allergies
2) Basophilia (part of primitive immune system)… due to= CML
3) Monocytosis (phagocytic & antigen presenting)… due to= TB
(WBC)…
4) Lymphocytosis? (^ numbers)
5) Lymphopenia? (decreased numbers)
6) Plasmacytosis?
4) Lymphocytosis… due to= glandular fever, CLL
5) Lymphopenia… due to= post-bone marrow transplant
6) Plasmacytosis… due to= infection & myeloma
What is myelodysplastic syndrome?
Mutated stem cells produce a clone of abnormal cells that replace normal haemopoiesis= abnormal cells, bone marrow is CELLULAR.
Manifestations vary–> chronic anaemia, ends in acute myeloid leukaemia.
Treatment of myelodysplastic syndrome?
Transfusions
Lenalidomide
Azacytidine
What parts of the coagulation cascade can be assayed?
Prothrombin Time
Activated Partial Thromboplastin Time
Thrombin Time
What is Microcytic Hypochromic anaemia caused by?
(anaemia of chronic disease)
- Iron Deficiency
- Thalassaemia
- Lead Poisoning
What is Normocytic Normochromic anaemia caused by?
(many haemolytic anaemias, anaemia of chronic disease)
- After acute blood loss
- Renal disease
- Bone Marrow failure
What is Macrocytic Megaloblastic anaemia caused by?
Vit B12 or folate deficiency
What is Macrocytic Non-megaloblastic anaemia caused by?
Alcohol, liver disease, hypothyroidism
The tissue oxygenation depends on what?
Hb concentration
The oxygen saturation of Hb
The affinity of Hb to oxygen
The oxygen requirements of tissues
Why would you transfuse with Fresh Frozen Plasma?
Coagulopathy with bleeding/surgery, massive haemorrhage
CONTRAINDICATIONS= Warfarin reversal or replacement of a single factor dificiency
Why would you transfuse with Platelets?
Treatment of bleeding due to severe thrombocytopenia (low platelets). Prevent bleeding.
CONTRAINDICATIONS= Heparin-induced thrombocytopenia & thrombosis.
What classifies as a delayed transfusion complication? What are the clinical manifestations?
Onset 3-14 days after RBC transfusion
Due to immune IgG antibodies against RBC antigens
Clinical= Fatigue, fever, jaundice.
What is an Immunological Delayed Transfusion reaction?
- Transfusion-associated graft-versus-host disease
- Post transfusion purpura
What is a Non-immunological Delayed Transfusion reaction?
Transfusion Transfusion Infection (TTI)
What is an Immunological Acute Transfusion reaction?
Acute haemolytic transfusion reaction
ABO incompatability
Allergic/ anaphylactic reaction
TRALI (transfusion-related acute lung injury)
What is a Non-immunological Acute Transfusion reaction?
Bacterial contamination
TACO (transfusion associated circulatory overload)
Febrile non-haemolytic transfusion reaction
What is crossmatching?
It is for compatibility. Patients plasma is mixed with donor RBC to see if a reaction occurs.
What is a transfusion threshold (trigger)?
How we determine the ideal Hb concentration for different patients. It is the lowest concentration of Hb that is not associated with symptoms of anaemia.
What are some mechanisms of adaption to anaemia?
- Increased cardiac output
- Increased cardiac artery blood flow
- Increased oxygen extraction
- Increase erythropoeisis
- Increase RBC 2,3 DPG
Why is there increased oxygen extraction in chronic anaemia?
Due to the rise in levels of 2,3 DPG becuase the kidneys respond to hypoxia by increasing the production of erythropoeitin.
In what type of anaemia is the respiration rate more markedly increased?
Acute anaemia
What is TRALI?
Transfusion Related Acute Lung Injury.
Activated WBC lodge in pulmonary capillaries. Release substances that cause endothelial damage and capillary leak.
CRITERIA: sudden onset of ‘Acute Lung Injury’ occurring within 6 hours of transfusion.
What is TACO?
Transfusion-Associated Circulatory Overload.
Signs/symptoms= sudden dyspnea, orthopnoea, tachycardia, hypertension.
What are some allergic reactions associated with blood transfusion?
- Urticarial Rash (often not severe)
- Anaphylaxis (severe, life threatening acute reaction)
Difference between TRALI and TACO?
- Type of component
- BP
- Temp
- Diuretics
- Fluid loading
TRALI: Usually platelets/plasma. TACO: Any
TRALI: BP reduced TACO: Often raused
TRALI: Temp raised TACO: Temp normal
TRALI: Diuretics worsen TACO: Diuretics improve
TRALI: Fluid improves TACO: Fluid worsens
What are Febrile non-haemolytic transfusion reactions (FNHTR) due to?
FNHTR are due to cytokines or other biologically active molecules that accumulate during storage of blood components.
What is von Willebrand Disease?
- Autosomal dominant inheritance (most common heritable bleeding disorder
- Variable reduction in Factor VIII levels
- Treatments: Antifibrinolytics (tranexamic acid), DDAVP (type 1 vWD), Factor concentrates with vWF
What are the Haemophilias?
Haemophilia A= Factor VIII deficiency
Haemophilia B= Factor IX deficiency (both intrinsic factors)
X-linked recessive disorders. ~30% cases are new mutations. Expressed in males, carried by females.