| Assay | Sample Type (Bottle) | Reference range | Clinical indications | Limitations/interferences |
Technical information |
Clinical sensitivity & specificity and/or Interpretation |
|---|---|---|---|---|---|---|
|
Assay
dsDNA antibodies |
Sample Type (Bottle) Serum. | Reference range 0-10.0 iu/ml |
Clinical indications
Follow-up test only to positive ANA FEIA (ELISA). Antibodies to native dsDNA are characteristic of the autoimmune disease, systemic lupus erythematosus (SLE). There is a body of evidence which suggests that circulating DNA/anti-DNA immune complexes play a role in the pathogenesis of SLE (particularly renal disease). In general, native DNA antibodies are not found in other rheumatic diseases, but if present, their titre is usually lower than those in SLE patients. They may be seen in autoimmune chronic active hepatitis (AICAH) and in rheumatoid arthritis (RA) treated with sulphasalazine. [2] In some cases, an increase in dsDNA antibody levels will precede SLE reactivation. The presence of dsDNA antibodies may precede the onset of SLE clinical symptoms by several weeks and may also indicate remission or control of SLE. First positive result for dsDNA antibody will be confirmed by Crithidia Luciliae IIF which is more specific but less sensitive assay. |
Limitations/interferences
ANA Screen positives are followed up with dsDNA antibodies and ENA screening |
Technical information Turnaround time: 5days/7 days Type of investigations: FEIA/IFA |
Clinical sensitivity & specificity and/or Interpretation The presence of autoantibodies to double stranded DNA is strongly suggestive of SLE, although they are detected in only 40-60% of patients with this disease. dsDNA ab by ELISA sensitivity = 60% specificity = 93% dsDNA ab by Crithidia sensitivity = 30% specificity = 99% |
| Assay ENA Screen | Sample Type (Bottle) Serum. | Reference range 0-0.9 ratio units | Clinical indications Follow-up test only to positive ANA FEIA (ELISA). |
Limitations/interferences
ANA Screen positives are followed up with dsDNA antibodies ENA screening |
Technical information Turnaround time: 5 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation |
| Assay ENA Profile | Sample Type (Bottle) Serum. |
Reference range
0 – 7 u/ml (all except UiRNP) U1TNP 0 – 5 u/ml |
Clinical indications
Sm: Specific for SLE but found in only 20-30% of SLE patients with a higher incidence in non-Caucasians, especially those of Afro-Caribbean descent. There is no correlation with disease activity. U1RNP: A high titre positive result of U1RNP in the absence of other autoantibodies is diagnostic for mixed connective tissue disease (MCTD) but these antibodies are also found in low titres in about 25% of SLE patients. RNP70: is a protein within the U1RNP complex. There are also two other proteins in U1RNP. These are, RNP A and RNP C. Antibodies to RNP70 are more specific for mixed connective tissue disease (MCTD) being found in only about 12% of patients with SLE. Ro or SS-A: The Ro (SS-A) antigen also occurs in the cell cytoplasm and very rarely a serum may be positive for Ro antibodies even in the absence of an ANA. These antibodies can cause congenital heart block and is recommended that all female patients suspected of SLE or Sjögren’s syndrome are screened for anti-SS-A (Ro) antibodies especially if they are considering pregnancy. These antibodies are associated with Sjögren’s syndrome (up to 75% in primary Sjögren’s), SICCA syndrome, and in many cases of Sjögren’s syndrome secondary to a variety of other autoimmune diseases. They are also found in variants of SLE including sub-acute cutaneous lupus and neonatal lupus with congenital heart block and also in SLE resulting from homozygous C2 or C4 deficiency. La or SS-B: Usually found with anti Ro in both primary and secondary Sjögren’s syndrome and SLE. Sjögren’s patients with anti-La are likely to have more extra-glandular disease. Ro and La antibodies are often found together. La is a phosphoprotein and Ro a ribonucleoprotein and both can bind to the same molecule of a transfer RNA. SLE patients positive for Ro & La are likely to have lower DNA antibody titres and less renal disease. Jo- 1: (antibodies to aminoacyl-tRNA histidyl synthetase) Associated with inflammatory muscle disease, especially polymyositis (also called anti-synthetase syndrome). Patients with anti-synthetase syndrome have a characteristic clinical picture comprised of myositis and/or interstitial lung disease and/or chronic arthritis. Raynaud’s phenomenon is frequently observed in this condition. Scl-70: (antibodies to Topoisomerase-I an enzyme catalysing the breaking and re-joining of ssDNA) Found in 20-40% of patients with systemic sclerosis, it is associated with facial skin, kidney and heart involvement, ischaemic fingertip ulcers and pulmonary fibrosis. Centromere: antibodies are associated with limited cutaneous systemic sclerosis (CREST syndrome: Calcinosis, Raynaud’s phenomenon, Oesphageal immobility, Sclerodactyly and Telangectasia). They can also be found in ~10% of patients with primary biliary cirrhosis who may or may not have features of scleroderma, and primary Raynaud’s. |
Limitations/interferences
ENA screen positives are followed up and typed for these individual ENA(Extractable nuclear antigens),and other ANA/cytoplasmic specificities |
Technical information Turnaround time: 5 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Refer to ANA for individual sensitivities |
| Assay | Sample Type (Bottle) | Reference range | Clinical indications | Limitations/interferences |
Technical information |
Clinical sensitivity & specificity and/or Interpretation |
| Assay ENA – others | Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
PM-Scl: (antibodies to Pm/Scl proteins which function as exoriboncucleases during RNA Processing) Found almost exclusively in patients with idiopathic myositis (including overlap syndromes) or more rarely systemic sclerosis. Cardiac and renal involvement in these patients is very rare, so the prognosis is therefore relatively good. Fibrillarin: (fibrillarin is a 34 Kda protein and is the major component of the nucleolar U3-RNP complex, which is involved in pre-r RNA processing) The antibody is found in about 8% of systemic sclerosis patients overall, in 5% of those with diffuse disease and in 10% of those with limited forms. It is a prognostic marker for small intestine and skeletal muscle involvement, as well as pulmonary hypertension. RNA Polymerase III: (antibodies to RNA polymerase III are directed against 2 proteins (111A of 150Kda and 111B of 138 kDa) located in the nucleoplasm. RNAPs are responsible for the transcription of genes that code for precursor molecules of r RNA. The antibody is found in about 12-20 % of patients with systemic sclerosis, and is thought to be highly specific. They are associated with diffuse or extensive skin manifestations. Mi-2 (antibodies are thought to be directed against a 235-240 Kda antigen within a macromolecular nuclear complex) The antibody is found in 15-30% of patients with adult dermatomyositis, and in 10-15 % of juvenile dermatomyositis. They are rarely found in patients with polymyositis and are therefore highly specific for dermatomyositis.(~ 95%) In comparison to patients with aminoacyl-t RNA Synthetase antibodies (i.e. Jo-1), those with Mi-2 antibodies generally have a milder clinical course, rarely exhibit synovitis, lung manifestations or Raynauds phenomenon. Ribosomal P (antibodies are mainly directed against the c- terminal region of the phosphoproteins P0 (38kda), P1 (19Kda) and P2 (17 Kda) of the 60s subunit of the ribosomal complex) Ribosomal P antibodies are detected in between 10 – 20% of patients with SLE, and rarely in other autoimmune diseases. Although not confirmed by all studies Ribosomal P antibodies seem to be associated with severe depression and other neuropsychiatric manifestations of SLE. The antibody can also be seen in patients with Scleroderma and may be a sign of scleroderma/SLE overlap PCNA (antibodies against Proliferating Cell Nuclear Antigen are directed against a 34kda auxiliary protein of DNA polymerase ) PCNA antibodies are found in about 3-7% of SLE patients but are not specific. In SLE, they are associated with renal involvement, CNS manifestations and thrombocytopenia |
Limitations/interferences
These ENA specificities may be detected by the ANA ELISA test but will be negative on the standard ENA screen and profile follow up testing. In the appropriate clinical and technical situations these autoantibodies will be confirmed or otherwise by a combination of ANA Hep2 and immunoblotting. |
Technical information Turnaround time: 14 days Type of investigations: IIF/Blot |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Endomysial antibodies IgA and IgG |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
This test is used only as a confirmatory test for positive Tissue Transglutaminase antibodies |
Limitations/interferences |
Technical information Turnaround time: 7 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation Specificity = 99% Sensitivity = 95% |
|
Assay
Glutamic Acid Decarboxylase antibodies |
Sample Type (Bottle) Serum. | Reference range 0-9 iu/ml |
Clinical indications
Found in 60% of patients with Stiff man syndrome, usually associated with high titer antibodies. These antibodies are also found in up to 80% of patients with recent onset Type 1 Diabetes Mellitus. However these antibodies reduce with disease duration. In the assessment of first degree relatives for autoimmune diabetes, positive results in more than one of the marker antibodies (GAD, Islet cell, IA-2 or insulin) can be associated with the onset of autoimmune diabetes. |
Limitations/interferences
The combination of two or more autoantibodies gives a higher positive predictive value for Type 1 Diabetes Mellitus than any single autoantibody. |
Technical information Turnaround time: 14 days Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation |
|
Assay
Ganglioside IgG and IgM GM1/GD1B/GQ1B antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
The test detects autoantibodies against gangliosides which are found in patients with peripheral neuropathies including Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), sensory neuropathy and Miller-Fisher syndrome MFS; a subtype of GBS) using both Immunoglobulin class IgG and IgM as separate test strips containing GM1,GD1b and GQ1b. |
Limitations/interferences |
Technical information Turnaround time: 21 days Type of investigations: Immunoblot |
Clinical sensitivity & specificity and/or Interpretation Antibodies against the monosialoganglioside GM1 are associated with multifocal motor neuropathy (MMN) with a prevalence of 40 to 70 %. These antibodies are in most cases of class IgM. Furthermore elevated antibody titres of GM1 occur in patients with Guillain-Barré syndrome (GBS) in 22-30% of cases. Antibodies against the disialoganglioside GD1b have been described in rare cases of patients with sensory neuropathy. Antibodies against tetrasialoganglioside GQ1b can be detected in more than 90 % of patients with Fisher syndrome. |
|
Assay
Gastric parietal cell **test also performed as part of liver Ab screen |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
These antibodies have a strong association with pernicious anaemia and autoimmune gastritis. Low titres are commonly found in normal elderly females. Positive results will automatically be referred for Intrinsic factor antibodies which are more specific but less sensitive for pernicious anaemia. Antibodies can also be found in patients with autoimmune thyroid disease and Sjogren's syndrome. |
Limitations/interferences
Sensitivity = up to 90% for pernicious anaemia |
Technical information Turnaround time: 5 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation |
|
Assay
Glomerular basement membrane antibodies (GBM) |
Sample Type (Bottle) Serum. | Reference range 0-7 iu/ml |
Clinical indications
These antibodies are positive in Goodpasture's syndrome, which is a rapidly progressive glomerulonephritis and can be associated with pulmonary haemorrhage. The antibody levels can also be of value in monitoring response to therapy of this disease. If the laboratory is contacted arrangements can be made to carry out a test with results ready in 3 hours during the working day. Screening for patients with rapidly progressive glomerulonephritis and/or pulmonary haemorrhage (pulmonary-renal syndrome) should include anti-GBM and ANCA testing |
Limitations/interferences
Patients can have co-occurring PANCA with anti MPO antibodies, which is of uncertain clinical significance. |
Technical information Turnaround time: 2 days (urgent 3 hours) Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = 94% Specificity = 100% |
|
Assay
Haemophilus Antibodies type B (HIB) |
Sample Type (Bottle) Serum. |
Reference range
0.15µg/ml Minimal protective and 1.0µg/ml optimal protective level. |
Clinical indications
This test measures antibodies to the HIB. It is used to assess the T cell dependent antibody production pathway. This test is recommended for use in the following clinical conditions: 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) Immunological reconstitution following Bone Marrow Transplant. f) Patients having haemoglobinopathies or who are due to undergo or who have had a splenectomy should have their levels of antibodies to encapsulated bacteria (i.e. pneumoccocal & 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 |
Technical information Turnaround time: 21 days Type of investigations: Luminex |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Histone and associated Antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
This test is used for detection of antibodies against histones and nucleosomes. Histones are basic proteins which bind to DNA within the nuclei of cells. Anti-histone antibodies drug induced Lupus (DIL). Drugs implicated in DIL include hydralazine, procainamide and isoniazid. Antibodies can be found in patients with SLE, lupus nephritis and Rheumatoid arthritis. Anti-nucleosome are more sensitive than anti-dsDNA antibodies to active SLE and active nephritis. Anti-nucleosome antibody reactivity may be a useful marker in the diagnosis and assessment of active SLE. |
Limitations/interferences
Anti-nucleosome are more sensitive than anti-dsDNA antibodies to active SLE and active nephritis. Anti-nucleosome antibody reactivity may be a useful marker in the diagnosis and assessment of active SLE. |
Technical information Turnaround time: 10 days Type of investigations: Immunoblot |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
High sensitivity CRP (hsCRP) |
Sample Type (Bottle) Serum. | Reference range 0-3 mg/L |
Clinical indications
CRP measurement by high sensitivity methods can indicate the risk for future cardiovascular and peripheral vascular disease. Elevated values may be indicative of the prognosis of individuals with acute coronary syndromes or stable coronary disease. High sensitivity CRP (hsCRP) measurement should not be used as a substitute for assessment of traditional cardiovascular risk factors [1]. Individuals with evidence of active infection, inflammation or trauma should not be tested for cardiovascular disease risk assessment by hsCRP measurement until these conditions have abated. |
Limitations/interferences
CRP measurement by high sensitivity methods can indicate the risk for future cardiovascular and peripheral vascular disease. Elevated values may be indicative of the prognosis of individuals with acute coronary syndromes or stable coronary disease. High sensitivity CRP (hsCRP) measurement should not be used as a substitute for assessment of traditional cardiovascular risk factors [1]. Individuals with evidence of active infection, inflammation or trauma should not be tested for cardiovascular disease risk assessment by hsCRP measurement until these conditions have abated. |
Technical information Turnaround time: 5 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Islet tyrosine phosphatase 2 (IA2) antibodies |
Sample Type (Bottle) Serum. | Reference range 0 – 10 iu/ml |
Clinical indications
Autoantibodies to IA2 (IA2A), a member of the protein tyrosine phosphatase family, are found in 50-75% of type 1 diabetic patients at and prior to disease onset. They are generally more prevalent in younger onset patients and are associated with rapid progression to disease onset. |
Limitations/interferences |
Technical information Turnaround time: 14 days Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation The combination of two or more autoantibodies gives a higher positive predictive value for Type 1 Diabetes Mellitus than any single autoantibody. |
|
Assay
Immunoglobulins (IgG, IgA, IgM) |
Sample Type (Bottle) Serum. |
Reference range
Age and sex related, refer to reports or table 1 |
Clinical indications
The main indications for IgG, IgA and IgM quantification are in the diagnosis, exclusion or monitoring of patients with immunodeficiency or B cell gammopathies. Low levels are found in many primary immune deficiencies but more commonly found in adults as a result of secondary immune deficiencies (e.g. lymphoproliferative disorders, nephrotic syndrome or protein losing enteropathy). Isolated IgA deficiency can be found in up to 1/800 of the normal population, but may be clinically significant. Polyclonally raised IgG can be a feature of chronic infections (notably HIV, TB and trypanosomiasis), connective tissue disease or liver disease. Polyclonally raised IgA is also found in late stage HIV infection but more commonly associated with liver disease, especially alcoholic in origin. IgM is raised in Primary biliary cirrhosis. Where appropriate samples will automatically be referred for Serum electrophoresis for investigation of monoclonal immunoglobulin presence. |
Limitations/interferences |
Technical information Turnaround time: 1 day Type of investigations: Turbidimetry *Note – assay performed in Clinical Biochemistry |
Clinical sensitivity & specificity and/or Interpretation N/A |
| Assay IgG Subclasses | Sample Type (Bottle) Serum. | Reference range |
Clinical indications
Adult Normal Range: IgG1: 3.20- 10.20g/l IgG2: 1.20 - 6.60 g/l IgG3:0.20-1.90g/l IgG4: 0.00-1.30 g/l Age-matched reference ranges see table 2. |
Limitations/interferences |
Technical information Turnaround time: 5 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation This test may be of limited clinical value in investigating possible immune deficiency. This test should be combined with measurement of functional antibodies, to fully evaluate clinical significance of IgG subclass deficiency. Detection of elevated serum IgG4 is useful for the diagnosis of the IgG4 related disease spectrum, including autoimmune pancreatitis. IgG2 deficiency with elevated or normal IgM and with poor functional antibody deficiency is a key feature of the dominantly inherited combined immunodeficiency caused by an activating mutation of gene encoding PI3 kinase delta subunit. |
| Assay IgE (total) | Sample Type (Bottle) Serum. |
Reference range
Age reference range ku/l 6 weeks <2.3 3 months < 4.1 6 months < 7.3 9 months < 10 12 month < 13 2 years < 23 3 years < 32 4 years < 40 5 years <48 6 years < 56 7 years < 63 8 years <71 9 years <78 10 years <85 >10 <114 |
Clinical indications
The indication for measuring total IgE antibodies is limited. Elevated specific IgE levels can occur in the presence of normal total IgE levels. The test is useful in evaluating the presence of multiple highly positive specific IgE antibodies and is essential for the diagnosis of Hyper IgE syndrome (>1000Ku/L). Very high IgE levels can be seen in patients with severe atopic dermatitis and in those with parasitic infection. Elevated levels are included among diagnostic criteria for Allergic Broncho Pulmonary Aspergillosis |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Insulin IgG antibodies |
Sample Type (Bottle) Serum. | Reference range 0 – 5 mg/l |
Clinical indications
This test is used to discriminate between type I and type II Diabetes Mellitus. The test should not be considered to be of diagnostic value in itself. Results should not be used in isolation but used in conjunction with the patient's symptoms, the patient's history and any other available data to produce an overall diagnosis 5-10 mg/l equivocal and > 10 mg/l positive |
Limitations/interferences
This assay is not able to distinguish between disease predictive autoantibodies and antibodies to exogenous Insulin. Therefore patient history, symptoms, and current prescriptions should be taken into account when interpreting results. |
Technical information Turnaround time: 7 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Intrinsic factor antibodies |
Sample Type (Bottle) Serum. | Reference range 0-24 u/ml |
Clinical indications
The combination of intrinsic factor antibody positivity and low vitamin B12 is diagnostic of Pernicious Anaemia (PA). However, a negative test for serum antibodies against intrinsic factor does not exclude pernicious anaemia. This test is reflexed from a positive anti-GPC. This assay is more specific but less sensitive for PA than anti-GPC. |
Limitations/interferences |
Technical information Turnaround time: 10 days Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity for pernicious anaemia = 60% |
|
Assay
Liver Autoantibody screen |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
A variety of positive antibodies can be identified by this test. Smooth Muscle antibodies (SMA) are present in up to 75% of patients with Autoimmune Hepatitis type 1; however they can be found in other autoimmune diseases and can be present at low titres with no clinical significance. Anti-Mitochondrial Antibodies (AMA) of the M2 (pyruvate dehydrogenase) type are strongly associated with Primary Biliary Cirrhosis (PBC). Positive AMA will be confirmed by testing for antibodies to pyruvate dehydrogenase (BPO/MIT3 and M2-3E on liver autoantibody line blot). Liver Kidney Microsomal (LKM) antibodies are an uncommon but specific marker for a severe subset of patients with autoimmune hepatitis (formerly known as autoimmune chronic active hepatitis) and some drug induced hepatitis. Also see Liver Autoantibody Blot. |
Limitations/interferences
ANA by indirect Immunofluorescence HEp-2 cells is undertaken as part of this screen for the purposes of testing for AMA negative PBC in which case few nuclear dot and nuclear membrane pores patterns are detected. This will be follow up by liver autoantibody line blot. Other positive ANAs will generally not be followed up in this situation. For the investigation of suspected connective tissue disease we recommend the use of the ANA ELISA test (see above) |
Technical information Turnaround time: 5 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation A variety of positive antibodies can be identified by this test. Smooth Muscle antibodies (SMA) are present in up to 75% of patients with Autoimmune Hepatitis type 1; however they can be found in other autoimmune diseases and can be present at low titres with no clinical significance. Anti-Mitochondrial Antibodies (AMA) of the M2 (pyruvate dehydrogenase) type are strongly associated with Primary Biliary Cirrhosis (PBC). Positive AMA will be confirmed by testing for antibodies to pyruvate dehydrogenase (BPO/MIT3 and M2-3E on liver autoantibody line blot) . Liver Kidney Microsomal(LKM) antibodies are an uncommon but specific marker for a severe subset of patients with autoimmune hepatitis |
|
Assay
Liver Autoantibody blot |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
This assay detects antibodies to AMA-M2 (M2-3E and BPO/MIT3 fusion antigen), Sp100, PML, gp210, LKM-1, LC-1, SLA/LP, and Ro-52. M2, M2-3E (BPO/MIT3), Sp100, PML and gp210 antibodies are all associated with primary biliary cirrhosis and have high specificity for the disease. Anti LKM antibodies are found in type 2 autoimmune hepatitis. This is a more aggressive disease than type1. Liver Cytosolic type 1(LC-1) autoantibodies are associated with autoimmune hepatitis, as are antibodies to Soluble liver antigen/Liver pancreas(SLA/LP) |
Limitations/interferences
Only performed as follow up to liver autoantibody screen or when there is a very high clinical suspicion of autoimmune liver disease |
Technical information Turnaround time: 10 days Type of investigations: Immunoblot |
Clinical sensitivity & specificity and/or Interpretation Sp100, PML and gp210 are highly specific autoantibodies for PBC. They are usually found in AMA negative patients. LKM-1 antibodies associated with autoimmune chronic active hepatitis recognize P450 2D6, a cytochrome P450 mono-oxygenase. The frequent association of anti-LKM-1 antibodies and hepatitis C virus (HCV) infections and the probable existence of an infectious and autoimmune form of anti-LKM-1-associated hepatitis, requiring different therapeutical strategies. |
| Assay Lymphocyte Phenotyping | Sample Type (Bottle) EDTA. |
Reference range
Age related, refer to reports table 3 |
Clinical indications
This test is indicated in known HIV patients for CD4 T cell monitoring, investigation of patients with suspected immune deficiency, post biological therapy (i.e. rituximab and campath) and some haematological malignancies (but please note for haematological malignancy phenotype please refer to Haematology). |
Limitations/interferences
Fresh EDTA sample must be analysed. Extended lymphocyte phenotype (TCR alpha/beta,gamma/delta and HLA Class 1 and 2) and Freiburg B cell panel will be performed only with compatible clinical information and/or discussion with Consultant Immunologist |
Technical information Turnaround time: 5 days Type of investigations: Flow cytometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Mast cell tryptase |
Sample Type (Bottle) Serum. | Reference range 2-14 ng/l |
Clinical indications
Mast cells release α and β tryptase upon activation. Both types are detected in this assay. This test is used for the investigation on anaphylaxis and mastocytosis. Specific sample requirements must be adhered to as it is impossible to distinguish between the two conditions on a single positive sample |
Limitations/interferences
For Anaphylaxis investigations: samples required at immediate, 1-2hrs (or upto 4 hours) post reaction and after 24hrs (baseline levels). Time should be stated on request. This is in line with NICE guidelines for the investigation of suspected anaphylaxis during general anaesthesia. For mastocytosis one sample is required, if positive a second should be provided for confirmation. |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = 60% Specificity = 90% Negative tryptase result does not exclude anaphylaxis. Serial tryptase measurement increases sensitivity and specificity. |
|
Assay
MPO ANCA antibodies |
Sample Type (Bottle) Serum. | Reference range 0-3.4 iu/ml |
Clinical indications
Confirmatory test for the presence of anti-MPO antibodies in ANCA positive samples. High titre MPO with P ANCA occurs in active microscopic polyangiitis (and its renal-limited variant), Churg-Strauss syndrome, and sometimes Granulomatosis with polyangiitis (GPA) (formally Wegener granulomatosis). P-ANCA positive/MPO-ANCA negative (or weak positive): This result may occur in treated, inactive, or relapsing microscopic polyangiitis (and its renal-limited variant), GPA, and Churg-Strauss syndrome. This result also is common in inflammatory bowel disease and other autoimmune diseases where its clinical significance is unclear. It can also be found in cocaine-induced midline destructive lesions, which presents similar to GPA. Patients with systemic vasculitis in whom ANCA recur are more likely to relapse. |
Limitations/interferences |
Technical information Turnaround time: 1 day urgent 4 hrs) 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 = 58% MPA; 24% GPA |
| Assay Myositis Antibodies | Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
Mi-2,Ku,PM-Scl100,PM-Scl75,Jo-1,SRP,PL-7,PL-12,EJ,OJ,SS-A/Ro52kD are myositis specific and/or associated antibodies which can be tested for by immunoblotting if specifically requested on clinical grounds, or as a follow-up investigation. Mi2 antibodies: more frequently found in patients with dermatomyositis than in patients with polymyositis. They are associated with better prognosis. Pm-Scl antibodies 100 and 75: found in patients with polymyositis/scleroderma overlap syndrome and less frequently in the individual diseases. Jo-1 antibodies: anti-synthetase antibody present in 30% of adults with polymyositis/dermatomyositis with risk of pulmonary involvement Other anti synthetase antibodies (PL-7; Pl-12; EJ, OJ: Found in patients with anti-synthetase syndrome (myositis, arthritis) and have high risk of developing interstitial lung disease Signal recognition particle (SRP) antibodies: are found in patients with polymyositis and they do not occur with overlap syndromes. They are usually associated with chronic progressive disease. Ku antibodies: are found in polymyositis/scleroderma and in patients with pulmonary hypertension, SLE and Sjogrens syndrome. Ro52 antibodies: are the most common ENA specificity amongst autoimmune diseases. They can be seen in Sjögren's syndrome, SLE, cutaneous lupus erythematosus, neonatal lupus, primary biliary cirrhosis and some patients with myositis. |
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
N-Methyl-D-Aspartate Receptor Antibody (NMDA) Serum |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
In women younger than 45 years, a form of encephalitis associated with ovarian teratoma and presenting with seizures and schizophrenia-like psychiatric symptoms has been described. The condition has uncommonly been described with other neoplasms. A few patients may not have detectable tumors. Since the initial description this condition has been rarely identified in males and children. Most patients have antibodies to NR1/NR2 heteromers of the N-methyl-D-aspartate receptor (NMDAR). This test is useful in the differential diagnosis of encephalitis of unknown origin with memory deficit, behavioral changes, movement disorders and seizures. The test may be useful in diagnosis and monitoring treatment responses. |
Limitations/interferences
This test may only be requested on Serum for CSF please see refered tests below. Test can be requested as urgent but MUST be pre-arranged via the Immunology Consultant or the Immunology Duty Doctor. Urgent service not offered on weekends. |
Technical information Turnaround time: 14 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Oxidase function Phagocyte |
Sample Type (Bottle) EDTA | Reference range N/A |
Clinical indications
Investigation of patients suspected to have Chronic Granulomatous disease. Presentation usually in childhood with: 1) Deep seated infection (liver, perirectal or lung abscess, adenitis, or osteomyelitis) due to Staphylococcus, Serratia marcescens, candida or Aspergillus 2) Diffuse granulomata in respiratory, gastrointestinal or urogenital-tracts 3) Failure to thrive and hepatosplenomegaly or lymphadenopathy. 4) Invasive infection by Burkholderia cepacea. |
Limitations/interferences
These tests can only be performed after prior discussion with the Consultant Immunologist or Immunology Clinical Scientist. |
Technical information Turnaround time: 5 days Type of investigations: Flow cytometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Ovarian Antibodies |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
These antibodies are found in 15-50% of patients with premature ovarian failure under the age of 40 years. These antibodies react with steroid producing cells and thus also stain the steroid producing Leydig cells of the testis, the placenta and often also in the adrenal cortex. They are often seen in Autoimmune Polyglandular Syndrome-1 (APS-1) where adrenal and ovarian failure may co-exist. Up to 70% of women may have transient anti-ovarian antibodies during IVF therapy. Patients with APS-1.have mutations in the Autoimmune Regulator (AIRE) gene. |
Limitations/interferences |
Technical information Turnaround time: 14 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation N/A |
