Laboratory Tests

The current range of available laboratory tests that can be undertaken are given below:

Serological Crossmatching and Antibody Screening Tests

• Flow cytometry crossmatch (FCXM)

  This is a more sensitive crossmatch than CDC and uses donor or recipient lymphocytes and recipient sera using a fluorochrome labelled secondary antibody in order to detect IgG donor-specific antibodies against T and/or B cells. Donor specific antibodies detected using these techniques are considered an intermediate/high risk to transplant.
• HLA Class I & Class II antibody detection by Luminex based methods

  This is specific for IgG HLA class I and/or II antibodies, including both complement and non-complement fixing sub classes, utilising Luminex technologies. This technique is more sensitive that CDC, is highly specific and can resolve complex antibody profiles in highly sensitised patients using beads coated with a single HLA antigen. This technique is used to detect and specify antibodies in solid organ recipients, potential HLA mismatched HSCT recipients, platelet refractoriness and for monitoring HLA antibodies in HLA antibody incompatible transplants.
• HNA antibody screening by Luminex based methods

  This is specific for IgG HLA class I and/or II antibodies, including both complement and non-complement fixing sub classes, utilising Luminex technologies. This technique is used to detect HNA antibodies in solid organ recipients and as part of TRALI risk reduction measures.
• MAIPA (Monoclonal Antibody Immobilisation of Platelet Antigen)

  This sensitive technique detects antibodies directed to different platelet glycoproteins. This allows the identification of mixtures of platelet specific antibodies in the presence of HLA antibodies. The patient's serum is incubated with a panel of HPA typed platelets and defined antibodies reported.

DNA-based HLA and HPA typing

• HLA Class I & II DNA typing: low resolution

  Determination of HLA-A, -B, -C,-DR, -DQ and DP alleles or groups of alleles by DNA analysis giving definition comparable to serological typing, for the purpose of HLA typing in solid organ transplantation, as an aid to disease diagnosis and for selection of HLA compatible platelet transfusions.
• HLA Class I & II DNA typing: high resolution (2nd field)

  Determination of HLA-A, -B, -C,-DR, -DQ and -DP alleles by DNA analysis giving high resolution definition. This is used for matching in haemopoietic stem cell transplantation in the related and unrelated setting and assists in HLA antibody specification.
• Human Platelet Antigen (HPA) Typing

  Determination of HPA 'antigens' by typing for HPA alleles by DNA analysis.
• HLA B*S7:01 typing by molecular techniques

  Determination of HLA-8*57:01 (positive or negative) and differentiation of the 'common' HLA B57 subtypes (subtypes determined by NGS). This is used to determine patients at risk of hypersensitivity type reactions to Abacavir.

Additional tests

• HLA-B27 typing by flow cytometry

  Determination of HLA-B27 (positive or negative) and differentiation of the common HLA-B27 subtypes '8*27:02', '8*27:05' and 8*27:08 (subtypes '8*27:02' and 8*27:08 confirmed by PCR based methodology).

  Associations of HLA antigens with rheumatic diseases have been well established over the last two decades. Notably HLA-B27 typing has been particularly useful in the diagnosis of the atypical spondyloarthropathies. (Determination of patient HLA-B27 status by flow cytometry, Coates & Darke, European Journal of Immunogenetics 1998, 25, 29).

• HLA and disease association testing

  WTAIL performs routine HLA typing in relation to disease association investigations for specific patients, e.g. patients being investigated for suspected coeliac disease. In consultation with our customers we can undertake any specific HLA typing request, or family studies.

  We also undertake disease susceptibility/association projects via prior agreement with the Head of WTAIL.

  Determination of HLA-A, B, C, DRB1/3/4/5, DQA1/DQB1, DPB1 HLA types in combinations and resolution appropriate to user requirements.

• ABO titres

  This is performed using donor cells and recipient plasma for assessing and monitoring ABO antibody removal for ABO incompatible kidney transplants. A diamed gel card method is used to determine titres by saline and AHG.

In addition to these tests, expert H&I advice is available from our staff.