Haematology and Oncology Flashcards
(60 cards)
What is the single most important test in determining the prognosis in acute myeloid leukemia?
Cytogenetic analysis is the most important prognostic factor in acute myeloid leukaemia (AML).
Specific chromosomal abnormalities are strongly associated with treatment outcomes and survival rates. For example, t(8;21), inv(16), and t(15;17) are associated with favourable prognosis, while complex karyotype, monosomy 5 or 7, and 11q23 abnormalities indicate poor prognosis. This information directly influences treatment decisions and helps predict response to therapy.
What are some features of lead poisoning?
Features
abdominal pain
peripheral neuropathy (mainly motor)
neuropsychiatric features
fatigue
constipation
blue lines on gum margin (only 20% of adult patients, very rare in children)
What are the investigations for lead poisoning?
1) Lead levels in bloods greater than 10 mcg/dl are considered significant
2) FBC: microcytic anaemia. Blood film shows red cell abnormalities including basophilic stippling and clover-leaf morphology
3) Raised serum and urine levels of delta aminolaevulinic acid may be seen (making it sometimes difficult to differentiate from acute intermittent porphyria)
4) Urine coproporphyrin is also increased (urinary porphobilinogen and uroporphyrin levels are normal to slightly increased). In children, lead can accumulate in the metaphysis of the bones although x-rays are not part of the standard work-up
How is lead poisoning managed?
Management
various chelating agents are currently used:
dimercaptosuccinic acid (DMSA)
D-penicillamine
EDTA
dimercaprol
How does acute intermittent porphyria typically present?
The classical presentation is a combination of abdominal, neurological and psychiatric symptoms:
abdominal: abdominal pain, vomiting
neurological: motor neuropathy
psychiatric: e.g. depression
hypertension and tachycardia common
What can you measure in someone who is having an acute intermittent porphyria attack?
Urinary porphobilinogen
What is the pathophysiology of acute intermittent porphyria?
Acute intermittent porphyria (AIP) is a rare autosomal dominant condition caused by a defect in porphobilinogen deaminase, an enzyme involved in the biosynthesis of haem. The results in the toxic accumulation of delta aminolaevulinic acid and porphobilinogen. It characteristically presents with abdominal and neuropsychiatric symptoms in 20-40-year-olds. AIP is more common in females (5:1)
How can you diagnose acute intermittent pophyria?
classically urine turns deep red on standing
raised urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks)
assay of red cells for porphobilinogen deaminase
raised serum levels of delta aminolaevulinic acid and porphobilinogen
How is immune thrombocytopenia managed?
First line treatment for ITP is oral prednisolone
pooled normal human immunoglobulin (IVIG) may also be used
it raises the platelet count quicker than steroids, therefore may be used if active bleeding or an urgent invasive procedure is required
splenectomy is now less commonly use
How do you manage acute intermittent pophyria?
1) avoiding triggers
2) acute attacks:
IV haematin/haem arginate
IV glucose should be used if haematin/haem arginate is not immediately available
Name the medications which may cause drug-induce pancytopenia
Drug causes of pancytopaenia:
- cytotoxics
- antibiotics: trimethoprim, chloramphenicol
- anti-rheumatoid: gold, penicillamine
carbimazole*
- anti-epileptics: carbamazepine
- sulphonylureas: tolbutamide
Which antibodies are typically seen in immune thrombocytopenia?
Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex.
What is Evan’s syndrome?
ITP in association with autoimmune haemolytic anaemia (AIHA)
How does cyclophosphamide work?
Cyclophosphamide is an alkylating agent which causes cross-linking in DNA
What are some adverse effects of cyclophosphamide?
Adverse effects include: haemorrhagic cystitis, myelosuppression, transitional cell carcinoma
How do these cytotoxic antibiotics work?
1) Bleomycin
2) Anthracyclins
Bleomycin: degrades preformed DNA
Anthracyclins e.g. doxorubicin: stabilises DNA-topoisomerase II complex inhibits DNA & RNA synthesis
What is meant by the ‘leukaemoid reaction’?
The leukaemoid reaction describes the presence of immature cells such as myeloblasts, promyelocytes and nucleated red cells in the peripheral blood. This may be due to infiltration of the bone marrow causing the immature cells to be ‘pushed out’ or sudden demand for new cells
Causes
severe infection
severe haemolysis
massive haemorrhage
metastatic cancer with bone marrow infiltration
How can you distinguish between a leukaemoid reaction and chronic myeloid leukaemia?
Leukaemoid reaction
high leucocyte alkaline phosphatase score
toxic granulation (Dohle bodies) in the white cells
‘left shift’ of neutrophils i.e. three or fewer segments of the nucleus
Chronic myeloid leukaemia
low leucocyte alkaline phosphatase score
What is the universal donor of fresh frozen plasma?
AB RhD negative blood
What are the adverse effects of cytotoxic agents?
1) Bleomycin
2) Anthracyclines
1) Bleomycin - haemorrhagic cystitis
2) Anthracyclines - cardiomyopathy
What is the pathophysiology of G6PD deficiency?
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the commonest red blood cell enzyme defect. It is more common in people from the Mediterranean and Africa and is inherited in an X-linked recessive fashion. Many drugs can precipitate a crisis as well as infections and broad (fava) beans
What are some features of G6PD?
1) neonatal jaundice is often seen
2) intravascular haemolysis
3) gallstones are common
4) splenomegaly may be present
5) Heinz bodies on blood films. Bite and blister cells may also be seen
What are some medications which may cause haemolysis in G6PD?
Some drugs causing haemolysis
anti-malarials: primaquine
ciprofloxacin
sulph- group drugs: sulphonamides, sulphasalazine, sulfonylureas
What is the inheritance pattern of hereditary spherocytosis?
Autosomal dominant