| Assay | Sample Type (Bottle) | Reference range | Clinical indications | Limitations/interferences |
Technical information |
Clinical sensitivity & specificity and/or Interpretation |
|---|---|---|---|---|---|---|
|
Assay
Paraneoplastic Antibodies (Including: Anti-Yo, Anti-Hu, Anti-Ri, Anti-amphiphysin) |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
Paraneoplastic neurological syndromes (PNS) are remote effects of cancer on the nervous system. Examples include paraneoplastic limbic encephalitis (PLE), subacute sensory neuronopathy (SSN), paraneoplastic cerebellar degradation (SSN), paraneoplastic cerebellar degradation (PCD) and paraneoplastic opsoclonus-myoclonus (POM). Virtually any neoplasm can result in PNS but some cancers are more frequently encountered such as small cell lung carcinoma, breast and ovarian and plasma cell tumours. Patients with PNS often present with neurological symptoms before the underlying cancer is detected so it is therefore important to test for these antibodies in suspected PNS. Results may aid direction to the source of the tumour. |
Limitations/interferences |
Technical information Turnaround time: 10 days Type of investigations: IIF and Immunoblot |
Clinical sensitivity & specificity and/or Interpretation Anti-Hu (ANNA-1) antibodies: associated mainly with small cell lung carcinomas, neurologic syndromes, include sub-acute sensory neuropathy and paraneoplastic encephalomyelitis. Anti-Ri (ANNA2) antibodies: associated with opsoclonus/myclonus, paraneoplastic cerebellar degeneration and brainstem encephalomyelitis. The underlying neoplasm may be neuroblastoma (children), SCLC (adults) or breast tumours (adults). Anti-Yo antibodies: associated with Paraneoplastic Cerebellar Degeneration. The most frequent underlying tumours are ovary and breast. Anti Amphiphysin antibodies: are found in Stiff Person Syndrome and paraneoplastic encephalmomyelitis and are associated with breast cancer and small cell lung carcinoma. When found in breast cancer they are associated with the stiff person syndrome and when found in lung cancer with sensory neuropathy and paraneoplastic encephalitis. Anti CV2/CRMP5 antibodies: are found in peripheral neuropathy, cerebellar ataxia and limbic encephalitis. They are associated with small cell lung carcinoma and thymoma Anti Ma1 antibodies: are found in paraneoplastic neurological disorder and brainstem encephalomyelitis, and are associated with various tumours, including lung cancer but not testicular cancer. Ma 2/Ta antibodies: are found in brainstem and limbic encephalomyelitis, and are associated with testicular cancer. Anti Tr antibodies: found in paraneoplastic cerebellar degeneration, and are associated with Hodgkin’s lymphoma. |
|
Assay
Pemphigus/ Pemphigoid Antibodies |
Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
Useful in investigations of blistering autoimmune disease that affects skin and mucosa membranes. - Pemphigus vulagaris - Bullous pemphigoid - Epidermolysis bullosa acquisita - Dermatitis herpetiformis - Linear IgA disease |
Limitations/interferences
Antinuclear (ANA), Anti-Mitochondrial (AMA), Anti Smooth muscle (ASMA) and skeletal muscle antibodies may react with the oesophagus substrate and should be referred to the duty doctor. Blood group Anti-A and Anti-B antibodies give a staining pattern that mimics the Pemphigus pattern |
Technical information Turnaround time: 14 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation Intra-epidermal IgG antibodies present in the desmosomes joining the cells which characterise various clinical forms of Pemphigus, including idiopathic and penicillamine-induced, react with antigens present on the cell surface of epidermal keratinocytes. A positive result gives a characteristic “chicken wire” pattern. A positive result on IIF gives a distinct IgG basement membrane zone pattern. The Pemphigoid hemidesmosomal antigens have been identified as BP230 and BP180. |
|
Assay
PR3 ANCA Antibodies |
Sample Type (Bottle) Serum. | Reference range 0-1.9 iu/ml |
Clinical indications
Confirmatory test for the presence of anti-PR3 antibodies in ANCA positive samples, identified by indirect immunofluorescence. C-ANCA positive— PR3-ANCA: This result occurs in active Polyangitis with granulomatosis (Wegener's granulomatosis), microscopic polyangiitis (and its renal-limited variant), and Churg-Strauss syndrome. Patients with systemic vasculitis in whom ANCA recur are more likely to relapse C-ANCA positive—PR3-ANCA negative and MPO-ANCA negative: This result may occur in treated, inactive, or relapsing Polyangitis with granulomatosis (Wegener's granulomatosis), microscopic polyangiitis (and its renal-limited variant), and Churg-Strauss syndrome. This combination can also be seen in patients with chronic infections. |
Limitations/interferences |
Technical information Turnaround time: 1 day (urgent 4hrs) Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation International multi-centre studies indicate that the presence of ANCA detected by both IIF and ELISA (CANCA / PR3-ANCA & P-ANCA / MPOANCA) is very strongly linked to the presence of small vessel vasculitis. Specificity = 66% for GPA; 26% MPA |
|
Assay
Pancreatic islet cell Antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
Presence of islet cell antibodies can aid in the diagnosis of type 1 Diabetes Mellitus (IDDM). Antibodies are present in up to 70% of new- onset diabetes but their presence is transient, often disappearing once the islets have been destroyed. Various antibody targets (glutamic acid decarboxylase 65 antibodies (GAD65) and protein tyrosine phosphatase-like protein (IA2) antibodies) will result in the same staining pattern. This test can also be useful in testing first degree relatives of patients with IDDM as the presence of high titre islet cell antibodies (ICA) confers a risk for development of IDDM. This is most useful if GAD65 and IA2 antibodies are measured Islet cell antibodies along with GAD65, insulin antibodies and IA2 antibodies may be of use when investigating latent autoimmune diabetes of adulthood (LADA). Approximately 10% of patients diagnosed with type 2 diabetes have LADA which requires insulin therapy. LADA may be distinguished from type 2 diabetes by the presence of the autoantibodies |
Limitations/interferences
The presence of ICA does not always correspond to GAD65 and/or IA2 antibodies due to different sensitivities of the assays. |
Technical information Turnaround time: 10 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation IDDM = 70% sensitive |
|
Assay
Phospholipid antibodies (Anti-Cardiolipin and Anti-B2GP1 Abs) |
Sample Type (Bottle) Serum. |
Reference range
0-9 gplu/ml 0-6u/ml b2gp |
Clinical indications
Anti-cardiolipin antibodies (ACA) are associated with anti-phospholipid syndrome, idiopathic spontaneous abortion and systemic lupus erythematosus (SLE). The international consensus statement clarifies that anti-phospholipid syndrome can be diagnosed with: Vascular thrombosis in any organ or tissue or pregnancy event (one or more miscarriages after 10th week of gestation, three or more miscarriages before 10th week of gestation, or one or more premature births before 34th week of gestation due to eclampsia and persistently positive IgG or IgM anti-phospholipid antibodies (at moderate-high titre : >40 GPL or MPL U/mL), or moderate-to-high titre beta-2 glycoprotein antibodies. Anti-cardiolipin antibodies should be positive on at two occasions at least 12 weeks apart to fulfil the criterion of positive ACA antibodies. IgG anti-cardiolipin antibodies are the most prevalent and demonstrate the greatest clinical correlation. The significance of IgM anti-cardiolipin antibodies is uncertain. All samples positive for anti-cardiolipin automatically receive anti-B2GP1 tests. |
Limitations/interferences
ACA are frequently detected in syphilis, HIV infected patients and other viral, bacterial and parasitic infections but are not correlated with the thrombosis risk or haematological manifestations of anti-phospholipid syndrome |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Anti-Cardiolipin (ACA) are not diagnostic in themselves and can be found without a clinical antiphospholipid syndrome. Lupus anticoagulant (DRVVT) must also be checked and APS can be present with an isolated positive LA and undetectable ACA. Cardiolipin antibodies should be repeated at least 12 weeks apart to provide evidence of a persistent autoantibody |
| Assay Quantiferon TB |
Sample Type (Bottle)
Plasma ** specific Quantiferon Tubes required Adults and children: 1ml of blood must be drawn directly into each of the four QuantiFERON-GOLD Plus tubes in order, which must be all labelled with appropriate patient identifying information |
Reference range N/A |
Clinical indications
QuantiFERON®-TB Gold (QFT-G) is an indirect test for latent M. tuberculosis infection (LTBI). QFT-G have been developed using the tuberculosis antigens ‘early secretion antigen target 6’ (ESAT6 ) and ‘culture filtrate protein 10’ (CFP-10), which are not present in BCG, and are found in only a few species of environmental mycobacteria Tuberculosis is a communicable disease caused by infection with M. tuberculosis complex organisms (M. tuberculosis, M. bovis, M. africanum), which typically spreads to new hosts via airborne droplets from patients with respiratory tuberculosis disease. A newly infected individual can become ill from tuberculosis within weeks to months, but most infected individuals remain well. Latent tuberculosis infection (LTBI), a non-communicable asymptomatic condition, persists in some, who might develop tuberculosis disease months or years later. The main purpose of diagnosing LTBI is to consider medical treatment for preventing the development of tuberculosis disease. Until recently the tuberculin skin test (TST) was the only available method for diagnosing LTBI. Cutaneous sensitivity to tuberculin develops from 2-10 weeks after infection. However, some infected individuals, including those with a wide range of conditions hindering immune functions, but also others without these conditions, do not respond to tuberculin. Conversely, some individuals who are unlikely to have M. tuberculosis infection exhibit sensitivity to tuberculin and have positive TST results after vaccination with bacille Calmette-Guerin (BCG), infection with mycobacteria other than M. tuberculosis complex, or undetermined other factors. QFT-G is not licensed for diagnosis of active tuberculosis and it cannot distinguish active disease and LTBI. Who is eligible for testing? QFTG can be used in patients who have been evaluated for possible M. tuberculosis – complex infection or LTBI. In other words it can be used in all circumstances where the tuberculosis skin test is considered. |
Limitations/interferences
Specific Sample requirements: Adults and children: 1ml of blood must be drawn directly into each of the four QuantiFERON-GOLD Plus tubes in correct order: (1) GREY TOP (2) Green TOP (3)Yellow TOP (4)PURPLE TOP Each individual tube must be all labelled with appropriate patient identifying information. (Collection tubes available from outpatients Phlebotomy and Clinical Immunology, CUH). Samples must be delivered directly to the laboratory and must arrive between 08.00 and 18.00 Monday-Friday. Samples must be incubated at 37ºC within 16 hrs of collection, and must be kept at room temperature prior to this. Please contact the laboratory for further information if requesting test from non-Addenbrookes locations. What are the current limitations of QFTG test? Specimens for testing must be transferred to the laboratory for processing within 12 hours of venesection. The test has not been extensively studied in many groups, such as those with immunodeficiency, those on immunosuppressive drugs and clinical conditions which may reduce immunocompetence including diabetes, silicosis, chronic renal failure, and haematological disorders, or malignancy. The test has not been extensively evaluated in children or in pregnant women. It has not been extensively tested in those who have been treated for latent TB infection or tuberculosis disease. The ability of QFTG test to predict the risk of LTBI progression to tuberculosis disease has not been determined. The risk may be different in those positive for the QFTG test than in those with a positive tuberculosis skin test. QFT-G is highly specific and a positive test is strongly predictive of true infection with M. tuberculosis complex (MTB). However it cannot distinguish between latent and active disease. |
Technical information Turnaround time: 5 days Type of investigations: ELISA Must arrive between 08.00 and 18.00 Monday-Friday. |
Clinical sensitivity & specificity and/or Interpretation The diagnosis or exclusion of tuberculosis disease, and assessing the probability of LTBI, requires a combination of epidemiological, historical, medical, radiological and microbiological findings that should be taken into account when interpreting test results. See general guidance on the diagnosis and treatment of tuberculosis disease and LTBI (http://www.cdc.gov/nchstp/tb/) or the NICE guidance on tuberculosis: http://www.nice.org.uk/guidance/index. QUANTIFERON-TB Gold results are reported as positive, negative or indeterminate. 1. Positive (ESAT-6 and/or CFP-10 and/or TB7.7 responsiveness detected): M. tuberculosis infection likely. See text above 2. Negative (No ESAT-6 or CFP-10 and/or TB7.7 responsiveness detected): M.tuberculosis infection unlikely, but cannot be excluded especially when: a. any illness is consistent with tuberculosis disease b. likelihood of progression to disease(e.g. because of immunosuppression) is increased. See text above 3.Indeterminate Test not interpretable. Unable to determine a result due to lack of |
|
Assay
RAST test (Specific IgE) |
Sample Type (Bottle) Serum. |
Reference range
Kua/l Grade 0: <0.35 Grade 1: 0.35-0.70 Grade 2: 0.70 - 3.5 Grade 3: 3.5 - 17.5 Grade 4: 17.50 - 50.0 Grade 5: 50.0 - 100.0 Grade 6: >100.0 Please refer to table 4 for list of useful components |
Clinical indications |
Limitations/interferences
It is essential that the results are interpreted alongside a full allergic history and any tests that have been performed, such as skin prick tests |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Bee and Wasp Venom Specific IgE tests are available. However it is strongly recommended that these patients who are at risk of anaphylaxis after a sting should have a clinical evaluation by Dr Ewan in the Allergy Clinic as desensitisation is an effective therapy. In cases of drug sensitivity (e.g. antibiotic, anaesthetic agents) it is advisable to discuss the case with Dr P.Ewan or Dr.S.Nasser. RAST testing for specific IgE to penicillin is not completely reliable for diagnosing immediate type hypersensitivity to this drug. Sampson HA, Ho DG. Relationship between food-specific IgE concentrations and the risk of positive food challenges in children and adolescents. J Allergy Clin Immunol 1997;100:444-1 |
|
Assay
Rheumatoid factor (performed in biochemistry) |
Sample Type (Bottle) Serum. | Reference range 0- 14 iu/ml |
Clinical indications
In Rheumatoid Arthritis, the presence of a high titre RF at onset is of some predictive value as these patients have a worse prognosis than seronegative patients and are more likely to suffer from systemic manifestations of the disease than those who are RF negative. This test is of no value in monitoring RA; use CRP instead. A negative test for RF can be helpful in the differential diagnosis of rheumatic diseases as they are not usually detected in rheumatic fever, gout, Reiter's syndrome, ankylosing spondylitis, osteoarthritis, psoriatic arthritis and Juvenile Chronic Arthritis. Rheumatoid Factors are immunoglobulins which react with IgG and are found in a variety of conditions (viral infections, chronic bacterial infections, connective tissue diseases, lymphoproliferative disorders and low titres may be found in normal elderly people) and by themselves are of low diagnostic value. |
Limitations/interferences |
Technical information Turnaround time: 1 day Type of investigations: Turbidimetry |
Clinical sensitivity & specificity and/or Interpretation Positive rheumatoid factor is not specific for rheumatoid arthritis, and can be found in other connective tissue diseases (e.g. Sjogren's, lupus), infections, and in up to 15% of the normal population. Interpretation of Rheumatoid factor in patients suspected with Rheumatoid Arthritis: Result Relative risk of Rheumatoid arthritis 25-50 Iu/ml 3.6 (95% Confidence interval: 1.7-7.3) 50-100 IU/ml 6 (95% Confidence interval: 3.4-10) >100 IU/ml 26 (95% Confidence interval: 15-46) (Reference: BMJ 2012 , vol 345, e5244) |
|
Assay
SARS- CoV-2-IgG |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
This test is not the front line assay for Sars-Cov-2 antibody measurement. For routine antibody levels please see SARS-CoV-2 Total Antibody. Measuring serum antibodies to the SARS-CoV-2 (COVID-19) virus is useful to assess if patient have been infected with this virus. It is of use to confirm infection in suspected PCR/RNA+ individuals, but in particular in symptomatic individuals who have been found to be negative on PCR/RNA testing. It can be used to screen for evidence of exposure in asymptomatic individuals as in most cases the virus will not be detectable anymore. |
Limitations/interferences
Negative results may occur in patients with immunodeficiency Plasma, heat inactivated serum unsuitable. Reject heavily haemolysed or lipaemic samples. Ideally, samples for this assay should be taken 2 weeks post disease onset |
Technical information Turnaround time: 21 days Type of investigations: multiplexed particle-based flow cytometry |
Clinical sensitivity & specificity and/or Interpretation This assay has been validated in patients with clinically confirmed COVID-19 and SARS CoV-2 PCR positivity from upper respiratory tract swabs. The assay in this cohort has a sensitivity of 84% and specificity of 100%. At present there is no data for other clinical groups. A positive result does not confirm protection against SARS CoV-2 infection, or the ability of the antibody to neutralise the SARS CoV-2 virus. The cross reactivity of this assay for antibodies raised against other corona viruses is yet to be established, but a control group of sera obtained pre-2018 were negative for antibodies. Management decisions must continue to be based on clinical presentation and SARS CoV-2 PCR result as per established CUH guidelines. |
|
Assay
Scleroderma antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
Scl-70,CENP A,CENP B RP11,RP155,Fibrillarin,NOR90,Th/To, PM-Scl100, PMScl75, Ku, PDGFR, Ro-52, are scleroderma specific and/or associated antibodies which can be tested for by immunoblotting if specifically requested on clinical grounds, or as a follow-up investigation RNA Polymerase 3 antibodies (RP11 and RP155 subunits) and fibrillarin have a high specificity for Systemic Sclerosis. Th/To-antibodies are found in patients with Systemic sclerosis; predominantly the limited cutaneous form but also with Primary Raynauds phenomenon, SLE, Polymyositis and RA. NOR-Nucleolar Organising Region 90 antibodies are rare and are associated with patients with Scleroderma and Raynaud’s phenomenon. |
Limitations/interferences
This test will be accompanied by a ANA HEp-2 which is essential for the interpretation of the myositis autoantibody line blot assay |
Technical information Turnaround time: 14 days Type of investigations: Immunoblot |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Serum Free light chains |
Sample Type (Bottle) Serum. |
Reference range
3.30 – 19.4 mg/l (Serum kappa free light chain) 5.71 – 26.3 mg/l (serum lambda free light chain) 0.26 – 1.65 kappa:lambda ratio |
Clinical indications
Guidelines for the management and monitoring of myeloma suggest that serum FLCs may be useful in monitoring free light chain only myeloma. Abnormal FLC levels and ratio can be found in multiple myeloma, Bence Jones proteinuria, non-secretory myelomas, free light chain disease and primary amyloidosis. Serum concentrations of FLCs are dependent on the balance between production and renal clearance. Elevated levels of both free kappa and free lambda light chain can be found in renal failure (due to decreased loss in urine) or in inflammation (increased synthesis). In these conditions kappa and lambda are affected equally. |
Limitations/interferences
Haemolysis, grossly lipaemic or icteric samples. |
Technical information Turnaround time: 5 days Type of investigations: Turbidimetry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Serum protein electrophoresis/ myeloma screen |
Sample Type (Bottle) Serum. |
Reference range
Normal electrophoretic pattern |
Clinical indications
Immunochemical measurement of immunoglobulins cannot substitute for electrophoresis in the diagnosis of paraproteins and should be done together. Current guidelines for the investigation of Multiple Myeloma and Monoclonal Gammopathy of Uncertain Significance (MGUS) recommend that serum and urine electrophoresis should be used in the detection of B cell malignancy or plasma cell dyscrasia. This should be followed by immunofixation if there are any monoclonal bands present, or there are no bands present but there is high suspicion of B cell malignancy. The guidelines also suggest that serum free light chains may be useful in monitoring free light chain only myeloma. The concomitant use of serum free light chain measurements in specific circumstances is advocated, but it cannot currently replace current methods. Guidelines for the analysis of Bence Jones Protein suggest that urine electrophoresis is useful when myeloma is diagnosed, during follow-up and in the investigation of patients who have suspected monoclonal gammopathy. Reductions in immunoglobulin levels can indicate primary immunodeficiencies (PID) or other severe secondary immunosuppression depending on the clinical history of the patient. Exclusion of other causes, results of other laboratory tests, and whether they fit the European Society for Immunodeficiencies (ESID) criteria for diagnosis should be considered during diagnosis. |
Limitations/interferences |
Technical information Turnaround time: 4 days Type of investigations: Capillary zone electrophoresis (CZE) and immunofixation |
Clinical sensitivity & specificity and/or Interpretation Each trace is interpreted individually in conjunction with clinical details and associated analysis. |
|
Assay
Serotype Specific Pneumococcal Antibodies |
Sample Type (Bottle) Serum. |
Reference range
Putative protective level 0.35 µg/ml |
Clinical indications
Antibodies to 13 pneumococcal specific serotypes are measured. This test is used in the diagnosis of Primary Immune deficiency. This test should be requested for patients who have clinical history of recurrent infections and/or evidence of bronchiectasis. 11/13 serotypes tested are contained in the childhood conjugated pneumococcal vaccine Prevenar13 (introduced in 2010). Protective levels of these show satisfactory response to the T cell dependent antibody production pathway. All 13 serotypes are contained in the unconjugated vaccine Pneumovax. Protective response to Pneumovax infers normal functioning of the T-independent antibody production pathway. Patients should have this test done in the following clinical circumstances: a) Patients, especially children, with recurrent bacterial sepsis; particularly of the upper and lower respiratory tract. b) Patients with invasive disease caused by encapsulated organisms. c) Patients with selective antibody deficiency states. d) To assess Immunological reconstitution following Bone Marrow Transplant. e) Patients with haemoglobinopathies or who have had a splenectomy should have their levels of antibodies to encapsulated bacteria (i.e. pneumoccocal and Hib) monitored. |
Limitations/interferences
Knowledge of vaccine history is imperative for correct interpretation. Specific clinical symptoms also advantageous. If a poor response if found, patients will be required to be vaccinated and retested 4 week post. Specific interpretation is given for each patient result. Children under the age of 2 years do not normally mount an immune response to either Pneumovax or to natural exposure. In contrast, the conjugate pneumococcal vaccine (Prevenar); is fully immunogenic from birth. |
Technical information Turnaround time: 15 days Type of investigations: Luminex |
Clinical sensitivity & specificity and/or Interpretation Interpretation of pneumococcal serotype specific responses in patients under 15 years of age. For children born since 2006 who have received the UK standard immunisations: 1. Post immunisation serotype specific antibody concentration >0.35ug/ml suggests protection against invasive pneumococcal disease; the concentration of antibody required to protect against mucosal disease is likely to be greater for most serotypes 2. Most infants (>90%) develop antibody responses >0.35ug/ml to most of the vaccine serotypes and this response is generally retained for a least one year post immunisation. 3. Persistence of antibody response >1year post immunisation is unclear however routine re-immunisation is not generally recommended. For children born before 2006 and/or >2 years and immunised as per UK schedule, who are immunised with Pneumovax: Aged 2-7 years: 95% of healthy children show an increased in antibody concentration >0.35ug/ml to at least 6 of the 13 serotypes tested. Aged 8 years and older, 95% of healthy children show an increased in antibody concentration >0.35ug/ml to at least 8 of the 13 serotypes tested. If pneumococcal responses are impaired as defined above, and the patient has increased susceptibility to infection, consider referral to a paediatric immunologist for review. Interpretation of pneumococcal serotype specific responses in patients above 15 years of age. This assay is to be used in the assessment of immunodeficiency and NOT for predicting protection from pneumococcal sepsis. Antibody responses can only be interpreted at least 4 weeks post vaccination with Pneumovax. After immunisation with Pneumovax, antibody responses (>0.35 ug/ml) to less than 7/13 serotypes has a 95% sensitivity and 85% specificity for the diagnosis of antibody deficiency. The results should be interpreted in the context of the clinical picture. If there is a high index of suspicion of immunodefiency; please contact us to discuss further. If the response to immunisation Pneumovax results is less than 7/13 serotypes >0.35ug/ml, consider further immunisation with Prevenar and repeat serology 4 weeks later. If pneumococcal responses are abnormal as defined above, consider referral to an immunologist. Note: Prevenar is a more powerful immunogen than Pneumovax and activates T cell dependent antibody responses. Therefore antibody responses to Prevenar cannot be used to evaluate thymus independent responses to polysaccharides. |
|
Assay
Specific IgG aspergillus |
Sample Type (Bottle) Serum. | Reference range 0 – 40 mg/l |
Clinical indications
Allergic broncho pulmonary Aspergillosis. This is a complex inflammatory response to inhaled spores and is seen in about 1% of asthma sufferers and up to 15% of patients with cystic fibrosis. Patients have a characteristic X ray appearance and elevated total IgE, and both specific IgG and specific IgE to aspergillus fumigatus. Levels of specific IgG have been defined which make the diagnosis likely. This is >90 mg/L in patients with cystic fibrosis and >35 mg/L in other patients. |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Specific IgG pigeon |
Sample Type (Bottle) Serum. | Reference range 0 -10 mg/l |
Clinical indications
For suspected bird fanciers lung, the test for IgG antibodies to pigeon serum is performed. This will detect antibodies to all commonly kept birds including pigeon, budgerigar, finch, cockatiel, parrot and canary. Levels above 10 mg/L indicate significant exposure to the antigen. |
Limitations/interferences |
Technical information Turnaround time: 5 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Specific IgG Micropolyspora Faeni Specific IgG Laceyella sacchari |
Sample Type (Bottle) Serum. | Reference range 0- 22 mg/l 0- 36 mg/l |
Clinical indications
For suspected farmer’s lung, tests are available for IgG antibodies to Saccheropolyspora reactivirgula (formally Micropolyspora faeni) and to Laceyella sacchari |
Limitations/interferences |
Technical information Turnaround time: 5 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Striated muscle antibodies/ skeletal muscle antibodies |
Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
Anti-Striated muscle/skeletal muscle antibodies (ASTM) are circulating serum auto antibodies directed against Striated muscle and are found in Myasthenia Gravis (MG). Their presence is good evidence of Thymoma in MG patients. |
Limitations/interferences |
Technical information Turnaround time: 10 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation Sent to Sheffield Immunology for analysis, This test alone should not be considered diagnostic. All other factors including the clinical history, other serological or biopsy results must be taken into account. |
|
Assay
Tetanus Antibodies |
Sample Type (Bottle) Serum. |
Reference range
Tetanus Minimum 0.1 iu/ml Optimum > 1.0 iu/ml |
Clinical indications
This test is used to assess the T-cell dependent antibody pathway. Patients should have this test done in the following clinical circumstances: a) Patients being investigated to diagnose antibody deficiency. b) To test immunological reconstitution following Bone Marrow Transplant. e) To assess whether an individual with uncertain immunisation history is protected from tetanus. |
Limitations/interferences
Knowledge of vaccine history is imperative for correct interpretation. If a poor response if found, patients will be required to be vaccinated and retested 4 week post. Specific interpretation is given for each patient result |
Technical information Turnaround time: 21 days Type of investigations: Luminex |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Thyroid peroxidase antibodies (performed in biochemistry) |
Sample Type (Bottle) Serum. | Reference range 0- 60 iu/ml |
Clinical indications
Anti-thyroid peroxidase antibodies are present in patients with autoimmune thyroid disease: Grave’s disease (60%), Hashimoto’s (90%) and primary myxoedema (80%). They may be present without overt thyroid dysfunction in cases of autoimmune polyendocrine disease High titre thyroid antibodies are a good predictor for the future development of biochemical thyroid disease |
Limitations/interferences |
Technical information Turnaround time: 1 day Type of investigations: Turbidimetry |
Clinical sensitivity & specificity and/or Interpretation |
|
Assay
Tissue Transglutaminase antibody |
Sample Type (Bottle) Serum. | Reference range IgA 0 – 6 iu/ml IgG 0 – 7 iu/ml |
Clinical indications
IgA Tissue Transglutaminase antibodies are present in at least 80% of patients with active coeliac disease. It will be absent in patients on a gluten free diet. As part of the investigation selective IgA deficiency will be excluded, with samples giving low responses on the IgA ttg assay |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = >95% Specificity = >90% |
|
Assay
Thyroid Stimulating Immunoglobulins (performed in Biochemistry) |
Sample Type (Bottle) Serum. | Reference range < 0.56 iu/l |
Clinical indications
The hyperthyroidism of Grave’s disease is caused by the presence of stimulatory IgG antibodies which bind to thyrotrophin (TSH) receptors on the thyroid follicular cells and cause unregulated stimulation of thyroid hormone production. |
Limitations/interferences
This assay utilizes recombinant human TSH receptors (hTSHR) for the specific detection of thyroid stimulating autoantibodies. (please note –this is not a TSH receptor antibody assay which detects both stimulating and inhibitory binding antibodies) |
Technical information Turnaround time: 5 days Type of investigations: Chemiluminescence |
Clinical sensitivity & specificity and/or Interpretation Clinical sensitivity = 100% Clinical specificity = 98.7% Renato Tozzoli et al Clin Chem Lab Med 2016 |
|
Assay
Urine electrophoresis |
Sample Type (Bottle) Urine. | Reference range N/A |
Clinical indications
Bence-Jones Protein (free light chains κ or λ) BJP is associated with multiple myeloma, Waldenstroms macroglobulinaemia, monoclonal light chain associated amyloidosis and light chain deposition disease. It can also be seen in lymphoma and leukaemia. This assay is part of both the screen and follow-up investigations for myeloma. |
Limitations/interferences |
Technical information Turnaround time: 5 days Type of investigations: Electrophoresis |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Voltage Gated Potassium Channel Associated Protein Profile Antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
CASPR2 auto antibodies are seen in neuromyopathy, Morvan’s syndrome, limbic encephalitis and epilepsy. About a third of cases can be attributed to paraneoplastic syndrome, mostly in connection with thymoma. Autoantibodies against LGI1 can be detected in limbic encephalitis, Morvan’s syndrome, isolated neuromyotonia, isolated epilepsy and other neurological syndromes. of limbic encephalitis. A positive result is an indication for investigation for a possible tumour. |
Limitations/interferences
This test may only be requested on Serum for CSF please see refered tests below |
Technical information Turnaround time: 14 days Type of investigations: Indirect Immunofluorescence test |
Clinical sensitivity & specificity and/or Interpretation This test is indicated in the investigation of Limbic encephalitis (LE) and acquired neuromyotonia (Isaacs’s syndrome). |
