Cytogenetics
Haematology Overview / Directory
Purpose of the test
Patients with haematological disorders require an accurate diagnosis of their condition, which is assessed by morphology, immunophenotyping and cytogenetics. Different chromosomal abnormalities occur in patients with these diseases, and some abnormalities are very specific to certain disease types, such as the translocation t(15;17) in acute promyelocytic leukaemia, and the translocation t(8;14) in mature B cell acute lymphoblastic leukaemia. Some abnormalities will indicate a good prognosis, whereas others will herald a poor prognosis. These parameters are important when tailoring treatment for the patient. Monitoring the patient following treatment and/or transplant is also essential in order to establish the extent of remission, both haematological and cytogenetic.
Sample Requirements
Bone marrow aspirate in specially provided transport medium (2 ml) or peripheral blood in a lithium heparin tube (5ml), (if blast cells are present in sufficient numbers) are the samples of choice.
For patients with suspected lymphoma, a lymph node biopsy is preferable to be placed in the transport medium as above.
For patients with suspected CLL, testing is usually preferred on a peripheral blood sample.
Storage and Transport
Ideally, the sample should arrive in the laboratory the same day as sampling occurs to prevent loss of viability. However, if a delay is anticipated in transportation, the samples should be stored in the fridge at 4°C. Alternatively, first class post is also accepted for samples which have a long distance to travel.
Turnaround Time
AML, ALL, CML - within 3 working days
MDS, MPD - within 5 working days
CLL and lymphoma – within 8 working days
Myelomas – within 10 to 15 working days
Time Limit for Extra Tests
2 weeks
Factors affecting results or interpretation
The following factors are known to have an adverse effect on results:
i) Delay in transit
ii) Low white cell counts - All low count samples will be grown for two to three days. This will lead to a delay in results availability
iii) High counts which have had a delay in transit
iv) Sample arriving too late to apply synchronisation culture
Percentage plasma cells in suspected myeloma and WCC, if known, will aid us in interpreting test results.
Price
Please contact the laboratory for prices
Tel: 020 3299 5796
Fax: 020 3299 2628
(*Discounts available for significant workload)
Contacts
Barbara Czepulkowski (Laboratory Head)
Tel: 020 3299 7636
Fax: 020 3299 2628
e-mail: bczepulkowski@nhs.net
Cytogenetics Department,
Haematological Medicine,
King's College Hospital,
Denmark Hill,
London SE5 9RS
