Haem

Question 1

Acute intermittent porphyria

Answer 1

autosomal dominant

defect in porphobilinogen deaminase

raised urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks)

raised serum levels of delta aminolaevulinic acid and porphobilinogen

Question 2

Porphyria cutanea tarda

Answer 2

presents with photosensitive skin bullae.

Question 3

ALL (6) Good prognostic factors

Answer 3

1) French-American-British (FAB) L1 type
2) common ALL
3) pre-B phenotype
4) low initial WBC
5) del(9p)
6) hyper diploidy

Question 4

ALL (9) Poor prognostic factors

Answer 4

1) FAB L3 type
2) T or B cell surface markers
3) Philadelphia translocation, t(9;22)
4) age < 2 years or > 10 years
5) male sex
6) CNS involvement
7) high initial WBC (e.g. > 100 * 109/l)
8) non-Caucasian
9) Hypodiploidy

Question 5

AML prognostic factors

common form of acute leukaemia in adults.

may occur as a primary disease or following a secondary transformation of a myeloproliferative disorder.

Answer 5

Poor prognostic features
> 60 years
> 20% blasts after first course of chemo
cytogenetics: deletions of chromosome 5 or 7

Question 6

Acute myeloid leukaemia. What is the single most important test in determining his prognosis?

Answer 6

chromosomal abnormalities detected by cytogenetics

Question 7

Acute promyelocytic leukaemia (APML, the M3 subtype of AML

Answer 7

associated with the t(15;17) translocation which causes fusion of the PML and RAR-alpha genes

good prognosis

Question 8

Radioallergosorbent test (RAST)

Answer 8

Determines the amount of IgE that reacts specifically with suspected or known allergens, for example IgE to egg protein. Results are given in grades from 0 (negative) to 6 (strongly positive)

Useful for food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom

Question 9

Skin prick test

Answer 9

Most commonly used test as easy to perform and inexpensive.

Drops of diluted allergen are placed on the skin after which the skin is pierced using a needle.

A large number of allergens can be tested in one session.

Normally includes a histamine (positive) and sterile water (negative) control.

A wheal will typically develop if a patient has an allergy. Can be interpreted after 15 minutes

Useful for food allergies and also pollen

Question 10

Skin patch testing

Answer 10

Useful for contact dermatitis.
Around 30-40 allergens are placed on the back.

Irritants may also be tested for.

The patches are removed 48 hours later with the results being read by a dermatologist after a further 48 hours