PBL 2 Flashcards

Question

How do you treat sickle cell anaemia

Answer 1

Bone marrow transplant can potentially cure children Hydroxyurea → drug which increases HbF production → this helps to reduce the symptoms and complication of SCD Antibiotics → reduce risk of infection Pain relief → reduce pain levels Blood transfusion → transfuse non-sickled blood into a patient Oxygen → increase O2 concentration in the blood In the future? Possibly mutant ß-globin chain switching → epigenetics

Answer 2

Being a sickle cell carrier gives an individual a protective advantage over non-carriers in malaria This might be why sickle cell is still present in malaria endemic regions RBCs infected with malaria have lower O2 levels This makes them sickle, and allows the RBCs to degrade As a result, the parasite dies

Answer 3

P. Falciform infects an HbAS RBC This requires higher oxygen consumption, and decreases partial pressure of oxygen This leads to sickling of RBCs and then subsequent removal of the cells Thus, the parasite is killed

Answer 4

- haemoglobin S - sickle cell anaemia CFTR - resistance to tuberculosis - cystic fibrosis HEXA - tay sachs HBA1/HBA2 thalassemia

Answer 5

Glutamic acid - charged - polar - tucks into haemoglobin valine - hydrophobic - non polar - sticks out of haemoglobin

Answer 6

Describes several independent acute conditions that occur in patients with SCD Most of these crises last between 5-7 days Infection, dehydration, and acidosis are all triggers as they favour sickling However, most of the time, there is no definitive predisposing cause

Answer 7

Infection, dehydration, and acidosis are all triggers | as they favour sickling

Answer 8

Treated with hydration, analgesics, and blood | transfusion

Answer 9

Caused by sickled RBCs obstructing capillaries and restricting blood flow to an organ - Dactylitis → due to recurrent ischaemic necrosis of the small bones in the hands and feet - Swelling persists for 1-2 weeks even after pain is resolved - Infarction of abdominal and retroperitoneal organs - Initially spleen enlarges - Then undergoes auto-splenectomy - Can lead to hepatic (liver) infarct

Answer 10

- this is an acute, painful enlargement of the spleen

Answer 11

Results in Hb levels falling, and a potential for hypovolaemic shock Because the spleen has narrow vessels, and is responsible for clearing defective RBCs, the spleen is commonly affected in SCD

Answer 12

- caused by intrasplenic trapping of red blood cells

Answer 13

- Damage in spleen leads to an increased risk of infection from encapsulated organisms (i.e. bacteria with a protein coat) - Emergency → patient will die within 1-2 days without treatment

Answer 14

``` Classified by two of the following symptoms: - Chest pain - Fever - Pulmonary infiltrate/focal abnormality - Respiratory symptoms - Hypoxaemia - 80% of patients have a vaso-occlusive crisis during acute chest syndrome ```

Answer 15

afro caribbean parents

Answer 16

Hepatosplenomegaly → splenic sequestration syndrome Lung field rales, sonorous wheeze → lung infection Low haemoglobin → due to haemolytic anaemia associated with SCD White cell count increased → due to infection Platelet count low → vaso-occlusive crisis → spleen is blocked and so platelets can’t exit into the circulation High ESR → because RBCs are being destroyed quicker and, therefore, need to be replaced quicker Chest radiograph with bilateral haziness → lung infection Dactylitis → vaso-occlusive crisis in the vessels leading to and from the peripheral digits Peripheral blood smear → low oxygen levels lead to sickling of sickle cell RBCs

Answer 17

The genetic inheritance of SCD Disease-related health problems e.g. splenic sequestration syndrome Future family planning

Answer 18

1. learn about the illness 2. join a support group 3. face the possibility of early death 4. maintain open and honest communication 5. share leadership 6. include all family members in decision making

Answer 19

this is the action of listening to a person’s lungs, heart and intestines during a physical examination in order to find a diagnosis

Answer 20

``` Foetal Haemoglobin - has a higher affinity for oxygen than adults, can carry 30% more oxygen, this is because the maternal blood has to dissociate from oxygen in an area that has a low partial pressure for oxygen this means that the fatal haemoglobin needs to have an higher affinity in this area in order to bind to it - 2 alpha, 2 gamma chains (dominates up to 6 weeks of age) ``` Adult haemoglobin - has 2 alpha chain and 2 beta subunits - dominates after 6 weeks of age - lower affinity for oxygen

Answer 21

parasitisation of AS red blood cells this increases the oxygen consumption and deceases the partial pressure of oxygen therefore the red blood cells sickle - these red blood cells are removed as fewer surface proteins which adhere to the endothelium

Answer 22

this is a form of treatment for sickle cell anaemia that promotes production of foetal haemoglobin so they can pick up more oxygen - given to patients once a day - drug is withdrawn and causes increase in haemoglobin

Answer 23

- solubility test - electrophoresis - blood smear

Answer 24

- parents of new borns with a sickle cell disorder or trait | - pregnant women/prenatal counselling

Answer 25

``` Able to differentiate between heterozygous (HbAS) and homozygous (HbSS) states ``` The charged glutamic acid AA changes the speed which the sample moves Therefore, in HbAS one strand moves much faster than the other On the other hand, in HbSS both strands move quickly