CYTOGENETICS LABORATORY INTRODUCTION

The Cytogenetics Laboratory of the Haematology Unit of the Coimbra University Hospital (HUC) was created in 1995, and until January, 2004 it occupied a Unit room (floor 7). It is currently located on floor 3 of the S. Jerónimo building (Haematological Techniques Room), and better equipped in terms of facilities.

However, it is now distant from its Unit, which causes some inconvenience. It was created due to the will of the Unitís doctors, who deemed that Cytogenetics was relevant to the diagnosis and treatment of Hemato-Oncologic patients.

Cytogenetics consists in the morphological analysis of chromosomes from neoplastic cells and enables numerical abnormalities (trisomy, monosomy, hyperdiploidy, etc.) and structural abnormalities (deletion, translocation, inversion, etc.), consistently associated with certain diseases and causes of diseases, to be identified.

The importance of Cytogenetics in Haemato-Oncology may be summed up into the following points:

> It provides evidence of clonality and neoplasia

> It indicates probable Oncogenesis mechanisms

> It involves probable etiologic factors

> It supports classifications

> It provides prognostic indications

> It has therapeutic implications

> It provides evidence of disease regression

> It provides evidence of clonal evolution

> In acute leukaemia, it may differentiate relapse of a second disease

> It evaluates Allogenic Transplantation

ACTIVITY

Around 200 karyotypes are analysed every year, almost exclusively of patients treated in the Unit.

Samples of neoplastic cells from bone marrow, peripheral blood and lymph node (in lesser quantity) are processed.

24-hour and 48-hour cultures are made, with and without BrdU synchronisation, as well as colouring and banding using the GTG technique.

Metaphases are examined under Zeiss microscopes (AXIOPLAN 2 and AXIOSCOP 2 plus).

Between January, 1996 and July, 2001, 542 karyotypes were analysed, 71% of which were diagnoses, 18% of which did not result in mitoses, and 11% of which were not conclusive.

Depending on the pathologies, the results were as follows:

LMA diagnosis in 61% LMA second diagnosis in 94%

LLA diagnosis in 54% LMC diagnosis in 91,4%

SMD diagnosis in 64% SMP diagnosis in 77,4%

STAFF

The laboratory currently has two elements:

> Dr. Carlos Moucho, Graduate Assistant in Clinical Haematology. Head of the laboratory.

> Dr. Nélia Jerónimo, with a degree in Biochemistry, in office since 1999. FUTURE

We aim to acquire a System of Image Analysis in the short term, which will improve the capacity of analysis and create a computer image archive.

As soon as authorisation comes through, the ìin situî Hybridisation technique (FISH) will be initiated; this technique complements Conventional Cytogenetics and makes it possible to identify anomalies without morphological representation that may be detected through optical microscopy.

It will also allow the research of anomalies with diagnostic and prognostic relevance without the need for the presence of metaphases, which is extremely important, particularly in (LLC and MM) pathologies where mitoses are rarely obtained.