haem + infection

Question 1

discuss autoimmune haemolytic anaemia

Answer 1

warm and cold subtypes. warm occurs at body temperature

warm is IgG mediated–> reactign with Rh antigen on RBC–> antibody dependent cell mediated cytotoxicity.

Question 2

S+S of Autoimmune haemolytic anaemia + investigations

Answer 2

slow progression over weeks to months.

anaemia
low B12 + folate.
pigmented gallstones (extra bili from all the haemolysis)

Ix: bloods with smear– normocytic anaemia with inc reticulocites.

Coombes test +ve.

spherocites on film.

to differentiate warm and cold- test for IgG’s – if not there but C3D (compliment) is –> its cold.

Question 3

causes of autoimmune haemolytic anaemia

Answer 3

viral, idiopathic, sle, lymphomas, CLL, penicilin, RA.

Rx: Cold- keep warm
Hb<7 - transfuse.
steds
rituximab
splenectomy.

Question 4

discuss sickle cell pathology and how it causes issues

Answer 4

an autosomal recessive disorder
most commonly seen in those of african origin.

homozytes - SS have sickle cell anaemia
heterozytes (HbAS)- have trait.- no disabililty unless under mega stress.

Glu–> Val at position 6.

defective beta chains.
when deoxygenated it changes shape–> aggregating with others–> forlimg long polymers–> crescent chape (sickling)

conditions that lead to sickling: acidosis + low flow vessels (lots of deox)

repetative sickling leads to membran rupture + leakage–> haemochomatosis.

REB clog up vessels –> v painful. AVN. splenic infarct.

only occurs a couple of months into life as HbF is still good for a bit after birth.

Question 5

Ix, Rx sickle cell

Answer 5

Ix: bloods- Hb 60-80, high retics, high bili, normal MCV

smear: sickling + target cells.

protein electrophoresis– confirmatory test.

Rx: hydroxycarbamide if frequent crisis (no role in acute crisis)

opioids, abs + immunisation
blood transfusions

Question 6

discuss healthcare associated infections

Answer 6

a problem which develops as a result of healthcare interventions.
most common MRSA, MSSA, C dif, E coli.

300 000 a year in the uk

1. resp infections
2. UTI
3. Surgical site infections.

gen after 48 hours is considered hospital.

Question 7

what immune defect predisposes to what type of infection

Answer 7

Cell mediated- PCP, pneumonia, disseminated fungal, viral, severe mycobacteria.

compliment: pyogenic encapsulated bacteria

Phagocytic defects: bacterial + fungal of skin + retuculoendothelial system.

recurrent infections at the same anatomical site should prompt concenr i.e cilliary disfunction, CF

generally they present later and need more urgent treatment.

Question 8

lyme disease

Answer 8

borrelia burgdorferi bacteria carried by tics

2-3k new cases a year

RF: occupational field exposure
increaced duration of tick exposure.

S+S:
3 stages have 3 diff symptoms-
1- early localised- erythema migrans + low grade fever, flu like symptoms,

stage 2- 3-12/52 post bite- malaise, fever, neuro (diz, ache) muscle pain + cardiac symptoms, joint pains. CN7 weakness. can get encephalopathy.

stage 3- neuro + rheum involvement- aseptic meningitis, bells palsy, arthritis, cognitive defecits are common. – key feature- arthritis affecting the knee.

Ix: if barn door clinical- ELISA if unclear

Rx: doxy- 100mg DB 21/7.
amox 1000mg TDS 21/7 - 2nd line.