2011 exam

Question 1

haemolytic disease for newborn - does anti D - extra or intra vascular

Answer 1

extravascular

Question 2

Additional tests you ask the blood bank to complete on baby and mother

Answer 2

?

Question 3

Clinical symptoms of leukaemia

how to confirm?

Answer 3

• tiredness
• severe brusing
• unusual bleeding from gums
• low haemoblobin
• lowplatelets
• low nuetrophils

Anaemia - fatigue, dyspnoea , chest pain
Neutropenia - infection, wounds slow to heal as less good white blood cells
Thrombocytopenia - bruising and bleeding
Bone marrow pain
Enlarger liver, spleen, lymph nodes
Gums

• take a bone marrow examination and could do bone marrow morphology – see if more than 20% are myeloid or lymphoid
• aspirate
• trephine

Question 4

Would it benefit to give G-CSF colony stimulating factor? side effects?

Answer 4

G-CSF - is a haemoatopoitic growth factor, that redcues the impact of neutropenia bu stimulating bone marrow to make more neutrophils

-have seen that this can benefit patients by increasing number of neutrophils, so that the patient can fight of infections better and not get as sick

risk factors - ??

Question 5

Risk factors for leuakaemia

Answer 5

congenital / inherited risk factors - e.g down sydrome have an increased incidence
viral infections
radiation
chemical/dna damaging drugs

Question 6

Transfusion support is critical in management of patients with acute leukaemia. Outline blood products that could be used by this patient and when they may be prescribed?

Answer 6

• platelets

- red cells

Question 7

general / supportive care for leukaemia

Answer 7

General/ supportive care
-intensive transfusion support - red cells, platelets

management of infection
-ID and lab support, antibiotic therapy

Chemotherapy

Stem cell transplantation

Question 8

what is another cause of macrosytic anaemia

Answer 8

liver disease

Question 9

Risk factors for DVT

Answer 9

Stasis of blood
immobility - post op, plane
Pressure - (blockages) catheter, tumour obstruction
Increased viscosity - polycthaemia, dehydration, EPO

Blood hyper coagulability
increased procoagulants
decrease in inhibitors
impaired fibrinolysis (rare)

Question 10

Hereditary abnormalities which may increase the risk of DVT, how common are these?

Answer 10

Inherited thrombophilia - increased tendency to develop VT

1. Factor V leiden
   - most common hereditary cause (4% northern europeans)
   - Where protein C is unable to cleave factor 5a
   - this slows down production of activated 10a
2. APCR gene - heterozygotes carry a 3-7 fold increased risk of thrombosis
   - homozygotes carry a 50-100 fold increase risk of thrombosis
3. deficiencey of inhibitors - e.g antithrombin, protein C, protein S
4. increased factor levels - e.g prothrombin gene mutation 20210a
   - elevated factor 8

if you have both factor 5 leiden and are homozygotes for apcr - have an 80 relative risk comapared to a normal person

Question 11

what are the causes of a prolonged APPT with a normal PT?

Answer 11

1. lupus anticagulant
2. (rare) Autoimmune disease, making an inhibitor bind onto a clotting factor (usually 8) - causes “aquired haemophilia”
3. Heparin (drugs), these are inhibitors of coagulation system
   - can cause bleeding
   - upregulates the affect of anti-thrombin
   - so it blocks activated thrombin
   - because it is blocking the activated protein, it doesnt overcome the effect of the inhibitor and this is why 1 + 1 is prolonged

Also - Dibigatran

Question 12

How can you distinguish between dibigatran and heparin

Answer 12

-both have prolonged APPT, and 1 + 1, however if you add protamine this will correct heparin but not dibigatran

Question 13

How can you have deficiencies with common pathway factors, with a normal APPT ? (but have an abnormal PT)

Answer 13

• because APPT is less sensitive that prothrombin time
• prothrombin will be prolonged if factors are reduced to 40-50%
• but APPT is less sensitive then that, so if have mild common factor deficiencies, the APPT can be normal with a mild prolongation of PT time

Question 14

What further micro test to obtain more info>

Answer 14

Disc suceptibility testing

• on an agar dish, place bacteria all over
• then place an antibiotic disc that you want to test suceptibility onto the agar
• this will difuse into agar in a conc gradient
• then can measure the distance around the disc to see the suceptibility of antibiotic to that certain bacterium grown

Question 15

What further micro test to obtain more info>

Answer 15

Disc suceptibility testing

• on an agar dish, place bacteria all over
• then place an antibiotic disc that you want to test suceptibility onto the agar
• this will difuse into agar in a conc gradient
• then can measure the distance around the disc to see the susceptibility of antibiotic to that certain bacterium grown
• then can use thsi info to presribe antibiotics

Question 16

Most likely cauase of meningitis
-gram stain and virulence factors

-how to identify in lab

Answer 16

Streptococcus pneumonia - older

• gram positive
• polysacharide external capsule - can escape phagocytosis , many different capsule serotypes - prevents opsonisation
• has pneumolysin - can destory human cells

-gram positive, cataluse negative, alpa haemoliticm optochin sensitivity

niseria meningitides - young children

• gram negative cocci
• thcik polysacharide capsule, prevents opsonisation
• Factor H - can bind to this on human cells, and down regulates complement forming

epidemiology of organism - majority infectes young maori and pacfic children

Question 17

How should patient be treated?

Answer 17

dexmotrexane (antiinflammatory) then anitbiotics (penicilin)

Question 18

Innate and adaptive system responses to bacterial infections

Answer 18

Innate - physical barrier, microbial factors - lysozyme, complement,

Adaptive
-inflammation

Question 19

Principles of immunisation with inactivated bacterial vaccines

Answer 19

Inactivated vaccines consist of -polysacharide capsule

• combinant
• protein based
• whole bacteria or parts of it
• toxin
• modify in lab
• get immune response
• but not as strong
• not lifelong
• need to repeat immunisation
• antibody response increases over no. times give vaccine

Question 20

candida albicans

• how to look this up in lab
• what do we use for treatment>

Answer 20

-black yeasts w psuedohyphae on gram stain

=grows well on blood agar