All of the tests available in NEHODS can be found in the Test Directory by filtering for NEHODS – see Test directory – Newcastle Hospitals Laboratories
Genetics
Detection of acquired genetic abnormalities in haematological malignancies is essential in the diagnosis, prognosis, and monitoring of patients with blood cancer. The genetics team employs numerous techniques to identify clinically significant chromosome and other genetic changes by means of karyotype analysis, FISH, and molecular techniques. Some of the tests we use are below:
Karyotyping
G-banded metaphase chromosome analysis (karyotyping) can identify genome-wide structural chromosome abnormalities including balanced translocations and inversions and can identify genomic complexity in living cells actively undergoing mitotic division. Karyotyping is vital in many haematological malignancies especially in myeloid malignancies where karyotype analysis is vital for prognosis and treatment decisions.
FISH
Fluorescence in situ hybridisation (FISH) is generally carried out using commercial probesets on interphase cells from short term cell cultures (e.g. bone marrow or blood) or on FFPE (formalin fixed paraffin embedded) sections or cells released from FFPE blocks or curls. FISH can identify specific gene fusion events such as the Philadelphia chromosome in CML (BCR::ABL1) or deletion of tumour suppressor gene e.g. TP53 in CLL.
SNP array
Single Nucleotide Polymorphism array testing can identify genome wide copy number changes (gains/losses/gene amplifications) and loss of heterozygosity (LOH).
RNA fusion panel
This panel can detect gene fusions from a wide-variety of cancer-associated genes. It us useful in detecting cryptic fusions where karyotyping and FISH results in a normal result. It is used particularly in acute lymphoblastic leukaemia and eosinophilic malignancies.
Molecular testing
We employ a number of methods such as Sanger sequencing, MassARRAY using mass spectrometry technology (MALDI-TOF – Matrix-assisted laser desorption/ionisation – time of flight), targeted PCR, fragment analysis, reverse transcriptase PCR, targeted next generation sequencing panels and whole genome sequencing.
Cellular pathology
The lab processes tissue biopsies and specimens from around the region. We specialise in a variety of different pathological techniques. The main tissues we review are bone marrow and lymph node, but as haematological malignancy can appear in any organ, we frequently review specimens from all over the body. The lab processes the tissues to preserve the cellular architecture and stains the sample with a variety of special stains to look at a slide under the microscope. The most common stain we use is haematoxylin and eosin as this allows the easy identification of haematopoietic cells within tissue biopsies. Other stains we use include reticulin to look for marrow fibrosis, Masson trichrome to look for collagen deposition and Congo red to look for amyloid deposition.
Immunocytochemistry (ICC) is a specialised section of histopathology, and the technique involves the identification of specific targets (antigens) within cells and tissues. This involves the use of antibodies that are directed towards the specific targets of interest. The resulting antigen/antibody reaction is then visualised by tagging with a permanent label (chromogen). The presence of the antigen of interest can then be seen by microscopy. This allows haematopathologists to examine the types of antigens expressed by malignant cells to make a diagnosis.
Tissue samples can also be cut for genetic analysis.
Flow Cytometry
Flow cytometry is a powerful technique which allows us to look at the properties of individual cells and is most commonly used for evaluating peripheral blood, bone marrow, and other body fluids; often detecting tens of thousands of cells per minute. There are three major components to a flow cytometer; the fluidics which transports the sample to the flow cell, the optics which provides the excitation source and collect light signals and the electronics which converts optical signals into electrical signals then into digitised data.
Our test repertoire includes over 80 antibodies, covering over 50 CD markers. We have a range of panels designed to assist in the diagnosis of B-cell and T-cell lymphoproliferative neoplasms, acute leukaemias, plasma cell neoplasms, chronic myelomonocytic leukaemia and a screening tube mainly used in myelodysplastic neoplasm investigation. These panels are designed and validated in house by our team of scientists, in accordance with national and international guidance.
Morphology
At NEHODS we review any liquid or tissue sample that may contain a haematological malignancy. Cytological assessment involves reviewing liquid samples such as blood, bone marrow aspirate material, cerebrospinal fluid, ascitic fluid and pleural fluid. After processing and staining, reviewing the liquid using a microscope allows the team to look at the cells that are present and note any morphological abnormalities or abnormal infiltration.
Histological assessment involves reviewing solid tissue samples – mainly lymph node and bone marrow trephine but can include review of a sample from any part of the body that may be infiltrated by haematological malignancy such as skin, bowel, spleen and lung. After processing and staining, reviewing the thin sections using a microscope allows the team to look at the structure of the material as well as the cellular content. Morphological examination of liquid and solid material is supplemented special stains and by techniques such as flow cytometry and immunohistochemistry which allows us to determine if an abnormal population of cells is present and the pattern of antigen expression. Bone marrow trephines are reviewed and reported by haematologists and lymph node and other tissue biopsies are reported by histopathologists.
The team have regular consensus meetings where cases are discussed.