Immunology

Immunology Tests

Immunology provides testing and advice to support the diagnosis, investigation and monitoring of allergic disease, autoimmune/connective tissue disease, immunodeficiency, monoclonal gammopathies and related disorders.

Autoantibodies

Autoantibodies Associated with Connective Tissue Disorders

  • Requests for Anti Nuclear antibodies (ANA) receive a multiplex automated screen (Bioplex 2200 assay) comprising:
      • Extractable nuclear antigens (ENA) and related antigens – Chromatin, SSA (Ro 52 and 60), SSB (La), RNP (RNP-A and RNP68), Sm, Scl 70, Jo-1, centromere B, ribosomal P, dsDNA antibodies.
      • Requests for patients under 18 years automatically have ANA performed by IIF (indirect immunofluorescence).
  • Rheumatoid factor.
  • CCP.
  • Antiphospholipid antibodies – IgG anti-cardiolipin and IgG anti-beta-2-glycoprotein I antibodies for investigation of possible antiphospholipid syndrome (APS). A test for lupus anticoagulant should also be requested from Haematology when investigating possible APS.

Liver Associated Antibodies – performed by IIF and immunoblot

    • Screen performed by indirect immunofluorescence (liver/kidney/stomach/HEp2 tissue substrates). For investigation of suspected autoimmune liver diseases.
    • Additional tests are added by the laboratory as needed, depending upon the results of the IIF and the provided clinical details.
      • Autoimmune liver disease antigens (M2, LKM1, LC1, SLA/LP).
      • Specific mitochondrial subtypes – M2/M4/M9.

Autoantibodies Associated with Endocrine Disorders

  • Thyroid peroxidase antibodies – autoimmune thyroiditis.
  • Steroid cell antibodies (adrenal and gonadal failure).
  • Pancreatic islet cell antibodies (diabetes mellitus).

Autoantibodies Associated with Gastrointestinal Disease

  • Coeliac screen (IgA anti-TTG). All patients are automatically screened for IgA deficiency. Additional tests are added by the laboratory as needed (IgG anti TTG, and IgA/IgG anti-endomysial antibodies as appropriate). Anti DGP antibodies are tested but only reported if signifantly elevated (>30 u/mL).
  • Gastric parietal cell antibodies.
  • Intrinsic factor antibodies.

Autoantibodies Associated with Vasculitis and Renal Disease

  • Glomerular basement membrane antibodies (GBM)
  • Anti-neutrophil cytoplasmic antibodies (ANCA). Screened using PR3/MPO-ANCA with confirmation by IIF-ANCA.

Other Autoantibodies Performed In-House

  • Skin antibodies for pemphigus and pemphigoid.

Investigation of Allergic Disease

Total and Specific IgE levels

  • Total IgE is required for all patients to aid in the interpretation of the specific IgE results.
  • Specific IgE requests should be selected based on the clinical presentation as outlined below.
  • Providing specific clinical information on the request form will enable us to add extra appropriate tests from the >450 available.
  • Consider environmental exposures such as animals, dusts, pollens, occupation, insects and food.
  • Note the NICE guidance Food allergy in under 19s: assessment and diagnosis which includes guidance for parents and carers.

Seasonal rhinitis

  • Timothy grass (this has a high level of cross reactivity with all grasses).
  • Tree pollen mix (elder, birch, hazel, oak, sycamore).

Perennial rhinitis

  • House dust mite, pets and fungal moulds.

Animal specific rhinitis – either on exposure or perennial in pet owners

  • Consider budgerigar, cat, dog, horse, mouse, rabbit, rat, feather mix (goose, chicken, duck, turkey).

Food allergy

  • Food mix (egg, milk, fish, wheat, peanut, soya).
  • Other specific foods based on careful questioning of the patient.

Nut allergy

  • Peanut, almond, hazel, brazil, walnut, and others.
  • Positive patients should be referred to immunology for assessment.

Insect allergy

  • Bee and wasp (suggest test for both).
  • Positive patients should be referred to immunology for assessment.

Antibiotic allergy

  • Penicillin.
  • Positive patients should be referred to immunology for assessment.

Latex allergy

  • Latex.
  • Positive patients should be referred to immunology for assessment.

Aspergillus fumigatus

  • Associated with Allergic Bronchopulmonary Aspergillosis in asthma and cystic fibrosis.

Tryptase

  • Tryptase is used in the investigation of systemic allergic reactions. Samples are taken at 1 hour, 3 hours and 24 hours following the reaction. The first 2 samples are to demonstrate raised levels the last the patient’s normal baseline level.
  • Tryptase is also used in the investigation of systemic mastocytosis.