Haematology Flashcards
(48 cards)
What are the typical features of thrombotic thrombocytopenia purpura?
Pentad:
- Microangiopathic haemolytic anaemia
- Thrombocytopenia
- Fever
- Neurological abnormalities
- Renal impairment
What is the risk of giving children aspirin?
Reye syndrome - rapidly progressing encephalopathy
Name of the condition whereby pancytopenia occurs in rheumatoid arthritis
Felty syndrome (enlarged spleen)
What is the pathomechanism of thrombotic thrombocytopenic purpura, and what is the first line treatment?
- Defect in vWF cleaving protease ADAMTS13
- Autoimmune
- Large multimers of vWF –> thrombi
- Plasma exchange to remove antibodies and replace protease
Risks of hyposplenism
- encapsulated bacteria: meningococcus, pneumococcus, haemophilus influenzae
- malaria
- capnocytophaga canimorsus
How to manage hyposplenism
- Vaccinate against pneumococcus, meningococcus, haemophilia influenzae, and influenza virus
- Lifelong penicillin
- Advise on dog bites/malaria zones/prompt treatment of infection
- Issue splenectomy card and information sheet
Patholophysiology of anaemia of chronic disease
- Reduced RC lifespan
- Reduced proliferation of RC precursors
- Suppressed EPO production
- Impaired iron utilization
- Cytokine release
What are the haematinics in anaemia of chronic disease?
Normochromic, normocytic anaemia
Ferritin high/normal
Fe and transferrin low
Which rhesus blood type is a universal donor?
RhD negative
What type of antibodies are those formed against ABO antigens?
IgM
What type of antibodies are those formed against RhD antigen?
IgG
Which type of antibody is responsible for delayed and immediate transfusion reactions?
Delayed: IgG
Immediate: IgM
Why might blood be irradiated prior to transfusion, and what patient group would be the recipients?
Prevent transfusion associated graft versus host disease in immunocompromised patients
In which 2 conditions is platelet transfusion contraindicated?
heparin-induced thrombocytopenia, and thrombotic thrombocytopenic prupura
What causes febrile non haemolytic transfusion reactions, and how are they managed?
Cytokines released by white blood cells while in storage. Paracetamol.
Which blood transfusion component is most likely to be contaminated by bacteria?
Platelets
What causes immediate collapse during transfusion of bacterial contaminated blood?
Endotoxin
In what condition may allergic reaction to transfusion be life threatening?
IgA deficiency
What is the pathomechanism of transfusion related acute lung injury (TRALI), and how can it be prevented?
Anti WBC antibodies from donor bind to antigens on recipients WBCs. Aggregates collect in pulmonary capillaries.
Prevent by using male donors for plasma and platelets (no HLA antibodies).
Which patients are affected by post-transfusion purpura?
HPA-1a negative patients who have previously been immunised by pregnancy to transfusion to develop HLA-1a antibodies
Which type of antibodies cross the placenta to cause haemolytic disease of the foetus/newborn?
IgG
What are the consequences of haemolytic disease of the newborn to the fetus?
Hydrops fetalis, kernicterus
How to manage a pregnancy where the body has anti-RBC antibodies?
- Monitor fetus for anaemia using MCA doppler USS
- Intrauterine transfusion
- At delivery monitor baby’s Hb and bilirubin
- Exchange transfusion (reduce bilirubin, raise Hb)
- Phototherapy to reduce bilirubin
Which is the most important antibody causing haemolytic disease of the newborn?
Anti-D
