| Assay | Sample Type (Bottle) | Reference range | Clinical indications | Limitations/interferences |
Technical information |
Clinical sensitivity & specificity and/or Interpretation |
|---|---|---|---|---|---|---|
|
Assay
Acetylcholine receptor antibodies |
Sample Type (Bottle) Serum. | Reference range 0.2-0.5 nmol/L |
Clinical indications
Results are positive in as many as 90% of patients who have generalized Myasthenia Gravis (MG) but in only 50-70% of those who have only ocular MG; thus false negatives are common in cases of purely ocular MGs. These antibodies have high specificity (>95%) for the diagnosis of MG. Level of antibodies do not correlate with disease activity, so repeated testing is not indicated. In patients with suspected MG who are negative for ACRA, anto-MuSK (muscle-specific receptor tyrosine kinase) antibodies may be indicated. |
Limitations/interferences
Occasional false positives can be seen in patients with low titre antibodies and/or positive rheumatoid factor. |
Technical information Turnaround time: 14 days Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = 80% Specificity > 95% Weak Positive = 0.2 - 0.5 nmol/L Positive = 0.5 - 5.0 nmol/L Strong Positive = > 5.0 nmol/L |
|
Assay
Adrenal cortical antibodies |
Sample Type (Bottle) Serum. |
Reference range
Negative or Positive |
Clinical indications
Antibodies are directed to 21-hydroxylase in patients with idiopathic hypoadrenalism (Addison’s disease) and 17-αhydroxylase enzyme in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (also known as Autoimmune polyendocrine syndrome 1). |
Limitations/interferences
Antibodies cause gradual steroid cell destruction leading to adrenocortical insufficiency therefore repeated testing is not indicated. |
Technical information Turnaround time: 10 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation 99% specific 90% sensitive for APECED, 60% for Addison’s Disease |
|
Assay
Alpha-1 anti-trypsin concentration (Assay performed in Biochemistry Laboratory) |
Sample Type (Bottle) Serum. |
Reference range
0.78- 2.0 g/l |
Clinical indications
Measurement of AAT is indicated in the investigation of chronic obstructive airway disease, emphysema and in neonatal and adult liver disease where low concentrations have diagnostic importance. AAT deficiency has autosomal dominant inheritance occurring in 1/2000 - 5000. If deficiency is found phenotyping of the alleles will be performed (see AAT-PI) |
Limitations/interferences
Grossly lipaemic, icteric or haemolysed samples |
Technical information Turnaround time: 1 days Type of investigations: turbidimetric |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Alpha-1 anti-trypsin phenotyping |
Sample Type (Bottle) Serum. | Reference range N/A |
Clinical indications
Any alpha-1 anti-trypsin concentration ≤1.2 g/l is referred for phenotyping. A1AT is known to have over 75 phenotypes. Most are clinically insignificant but some are associated with complete or partial deficiency of the protein in serum which includes alleles which are homozygous or heterozygous for S or Z. When phenotyping is not conclusive A1AT genotyping can be performed after discussion with Duty Doctor. |
Limitations/interferences
Grossly lipaemic, icteric or haemolysed samples |
Technical information Turnaround time: 15 days Type of investigations: Isoelectric focusing |
Clinical sensitivity & specificity and/or Interpretation A ZZ homozygous individual is predisposed to lung and liver disease. A heterozygous (MZ) individual is at a small risk of developing liver disease but has little increased risk of developing lung disease. The SZ variant results in significantly reduced serum concentrations of alpha-1-antitrypsin and a predisposition to lung disease, especially in smokers, and liver disease. |
|
Assay
Alkaline phosphatase isoemzymes |
Sample Type (Bottle) Serum. |
Reference range
Liver, Bone, Intestinal, Placental, or any combination |
Clinical indications
Causes of a raised ALP can be physiological (e.g. growth/development, pregnancy, gender, transient hyperphosphatasaemia of infancy, macro-ALP complexes) or pathological (e.g. Paget's disease, extra-hepatic biliary tree obstruction, malignancy). Isoenzyme studies are performed to determine which of the predominant isoenzyme, either bone, liver, intestine or if pregnant, the placenta, is causing the total increase. |
Limitations/interferences
Grossly lipaemic, icteric or haemolysed samples |
Technical information Turnaround time: 21 days Type of investigations: Gel electrophoresis |
Clinical sensitivity & specificity and/or Interpretation Interpretative comments used depending on result. |
|
Assay
ALPS immuno-phenotyping |
Sample Type (Bottle) EDTA |
Reference range
0-2.5% TCRαβ double negative CD3+ T cells |
Clinical indications
One of the criteria for diagnosing Autoimmune lymphoproliferative Syndrome (ALPS) is elevated TCRαβ double negative CD3+ T cells (>1.5% of total lymphocytes for >2.5% CD3+ lymphocytes) in the setting of normal or elevated lymphocyte count. The main clinical presentation for this condition is lymphadenopathy in children for which no infectious or malignant cause was found. These patients also can develop autoimmune disease eg. Autoimmune Thrombocytopenia or autoimmune haemolytic anaemia. If you suspect this condition please speak to Clinical Immunologist. |
Limitations/interferences
Refrigerated specimen Clotted Grossly hemolysed |
Technical information Turnaround time: 5 days Type of investigations: Flow cytometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Anti-Nuclear Antibodies (ANA) |
Sample Type (Bottle) Serum. | Reference range 0-0.9 units |
Clinical indications
Our routine assay is a florescent immunoassay which detects antibodies to: U1RNP/RNP70/Sm/Ro/La/Scl-70/Jo-1, centromere, dsDNA, fibrillarin, Pm-Scl, RNA Polymerase III, Mi-2, Ribosomal P, and PCNA(Proliferating Nuclear Antigen). Positive ANA will automatically be followed up by dsDNA testing and specific ENA characterisation. In cases of high ANA ELISA results with negative dsDNA and ENA characterisation confirmation by HEp2 cell IIF will automatically be performed with further cascade testing occurring as required. Also see Myositis/Scleroderma Line Blot. |
Limitations/interferences
Assay only detects antibodies to the most clinically significant connective tissue disease antigens. A negative result does not preclude the presence of other ANA disease associated antibodies. If there is a high clinical suspicion of connective tissue disease, then HEp2 cell IIF should be performed in addition. Occasional false positive results caused by antibodies to carrier proteins have been seen, but will be identified by follow-up investigations. |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity: U1RNP – 30-70% SLE 100% MCTD; Sm - 10-30% SLE; Ssa/Ro - 25 - 50 % SLE; 60 - 90 % SS Neonatal Lupus > 95 %; ; SSb/La - SLE 5 - 15 % 40 - 95 % SS Scl-70 - 20 - 70 % Scleroderma Centromere: 40-90% limited cutaneous scleroderma Jo-1: 60-80% anti-synthetase syndrome (Myositis) |
|
Assay
Anti-neutrophil cytoplasmic antibodies (ANCA) (IIF screen) |
Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
There are two major subclasses of ANCA, characterised by staining patterns found when using fixed human neutrophils as substrate under Indirect Immunofluorescence (IIF): 1. C-ANCA (Cytoplasmic or Classical Staining ANCA), denotes a granular cytoplasmic staining pattern on ethanol fixed neutrophils, with some interlobular accentuation. C-ANCA are principally directed against a proteinase 3 (PR3) present in the azurophil granules in the cytoplasm of human neutrophils. Positive C-ANCA is suggestive but not diagnostic of Granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) (and its renal limited variant) and Churg-Strauss. C-ANCA positive results must be followed up by ELISA tests for anti-MPO and anti-PR3. 2. P-ANCA (Perinuclear Staining ANCA); denotes a staining pattern present in the perinuclear space of the cytoplasm of ethanol fixed neutrophils. P-ANCA antibodies are principally directed against myeloperoxidase (MPO), which is also found in azurophil granules in the cytoplasm of human neutrophils. ANCA measurements are not closely associated with disease activity and should therefore not determine treatment increases or decreases. However treatment withdrawal in patients with a persistently positive ANCA is associated with relapse. Other P-ANCA antigen specificities are for elastase and lactoferrin. P-ANCA is associated in MPA and in some cases of GPA and Churg-Strauss syndrome although can also be seen in inflammatory bowel disease and other autoimmune diseases. P -ANCA positive results must be followed up by ELISA tests for anti-MPO and anti-PR3. |
Limitations/interferences |
Technical information Turnaround time: 3 working days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation Results are reported as WEAK POSITIVE, POSITIVE, ATYPICAL or NEGATIVE. POSITIVE samples are assayed by ELiA immunoassay method for PR3 and MPO reactivity. Atypical P-ANCA patterns are reported as ATYPICAL PATTERN and these may be seen in primary sclerosing cholangitis and Crohn's disease. Samples which may have an ANA present will have MPO and PR3 analysed have a comment stating that ANA is present on the report. This test should only be requested if there is a high suspicion of vasculitis due to the poor negative predictive value and potential for false positives. |
|
Assay
β2 Microglobulin (performed in biochemistry) |
Sample Type (Bottle) Serum. | Reference range 1.00 - 2.40 mg/l |
Clinical indications
In Multiple Myeloma B2M is found to be the single most effective prognostic marker. Repeat testing is not indicated. |
Limitations/interferences
High concentrations can also be found in patients with renal dysfunction and other connective tissue diseases where this test is rarely of clinical utility. |
Technical information Turnaround time: 1 day Type of investigations: Turbidimetry |
Clinical sensitivity & specificity and/or Interpretation N/A |
| Assay Beta Trace |
Sample Type (Bottle)
Nasal or Ear fluid. |
Reference range
>2.0mg/L suggests presence of csf >6.0mg/l strongly suggests CSF presence. |
Clinical indications
Beta trace (also known as prostaglandin D synthetase) is a protein found at high concentration in csf (20mg/L) and low concentration in normal serum (0.5 mg/L). Its measurement is useful in patients with otorrhoea or rhinorrhoea to identify the presence of CSF. |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
| Assay Caeruloplasmin | Sample Type (Bottle) Serum. |
Reference range
0.2 - 0.5 g/L(adults) ranges for other ages quoted on report |
Clinical indications
Low serum concentrations are seen in the majority of patients with Wilson's disease, an inherited defect of copper metabolism |
Limitations/interferences
Concentrations are increased by oestrogens and may be decreased in severe liver disease |
Technical information Turnaround time: 5 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Cardiac muscle antibodies |
Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
Cardiac muscle antibodies (ACMA) are positive in a proportion of patients with Dressler’s Syndrome following myocardial infarction, after cardiac surgery, acute rheumatic fever and in some cardiomyopathies. However diagnostic value is low. |
Limitations/interferences |
Technical information Turnaround time: 10 days Type of investigations: IIF |
Clinical sensitivity & specificity and/or Interpretation Assay referred to Sheffield Immunology ACMA have a sensitivity of 90 % and a specificity of 80 % for idiopathic dilated cardiomyopathy (IDCM). There is a 95 % negative predictive value in the distinction between IDCM and coronary disease but ACMA are not usually required to make diagnosis. |
|
Assay
Cyclic Citrullinated Peptide(CCP) antibodies |
Sample Type (Bottle) Serum. | Reference range 0-7 iu/ml |
Clinical indications
Anti-CCP has a similar sensitivity for Rheumatoid arthritis as Rheumatoid factor but has higher specificity. Presence of these antibodies has been found prior to disease onset and has been associated with erosive disease. These antibodies indicate diagnosis of RA when seen in early arthritis. However it is not indicated as a screening test (as per NICE guidance) but should be used in cases of negative Rf where clinical suspicion is high and to help decision making on whom to treat with DMARDS. |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = 89% Specificity = 98% |
|
Assay
Centromere antibodies |
Sample Type (Bottle) Serum. | Reference range 0- 7u/ml |
Clinical indications
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 in patients with Primary Raynaud’s. |
Limitations/interferences |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation Sensitivity = 70% |
|
Assay
Complement C3 C4 |
Sample Type (Bottle) Serum. |
Reference range
C3 0.75 – 1.65 g/l C4 0.14 - 0.54g/l |
Clinical indications
Measurement of serum complement components C3 and C4 is useful in the diagnosis and monitoring of immune complex disease e.g. SLE and some forms of vasculitis; angioedema, cryoglobulinaemia, some infections and inherited or acquired deficiency of complement components. Complement concentrations are acute phase proteins and may be normal, despite complement consumption, in some inflammatory and infective disorders. Low levels of C3 and/or C4 can indicate that there is an increase in consumption or decrease in synthesis. C3 alone is often decreased in infectious disease (Post- Streptococcal glomerulonephritis, gram - negative sepsis, endocarditis), patients with C3 nephritic factor, and inherited or acquired deficiency of C3 and components of alternative complement pathway (very rare). C3 and C4 are often both decreased in immune complex disease. C4 alone is characteristically decreased in hereditary or acquired angioedema (check C1 inhibitor quantitation and function), immune complex diseases particularly SLE and in cryoglobulinaemia. Complete C4 deficiencies are very rare; partial C4 deficiencies are more common and may be associated with SLE or asymptomatic. |
Limitations/interferences |
Technical information Turnaround time: 4 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
C1 esterase inhibitor (antigenic) |
Sample Type (Bottle) Serum. | Reference range 0.19-0.39g/l |
Clinical indications
Low levels are found in 85% of cases of Hereditary Angioedema Hereditary (Type I HAE), the remaining 15% (Type II) of cases are associated with a non-functioning protein which gives normal results in immunochemical assays and for which a functional assay is available. Most commonly associated with decreased levels of C4. As HAE is an autosomal dominant condition family history should be sought. Low levels also seen in acquired C1 inhibitor deficiency. C1 inhibitor deficiency causes angioedema affecting peripheries and/or head and neck, or severe abdominal pain due to intestinal oedema, both lasting more than 24 hours. |
Limitations/interferences |
Technical information Turnaround time: 5 days Type of investigations: Nephelometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
C1 esterase inhibitor (Functional) |
Sample Type (Bottle) Serum. | Reference range 46-130 % |
Clinical indications
Used for the confirmation of the diagnosis of C1 inhibitor deficiency in patients with angioedema (especially where the C4 level is reduced and the immunochemical levels of C1esterase inhibitor are equivocal.) This test should always be performed once in all new patients with C1 inhibitor deficiency. Where acquired C1 inhibitor deficiency is suspected request paraprotein studies and C1q level as well. These patients also need screening for Lymphoma. |
Limitations/interferences
Sample MUST be separated and frozen within 60 mins to prevent falsely low function results |
Technical information Turnaround time: 21 days Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation Clinical sensitivity = 99% Clinical specificity = 91% |
| Assay CD62L shedding | Sample Type (Bottle) EDTA. | Reference range N/A |
Clinical indications
This test is used to diagnose innate immune defects increasing susceptibility to pyogenic infection caused by S.pneumoniae, S.aureus or gram negative bacteria. (IRAK4 or MyD88 deficiency.) |
Limitations/interferences
These tests can only be performed after prior discussion with the Consultant Immunologist Immunology Clinical Scientist. |
Technical information Turnaround time: 14 days Type of investigations: Flow cytometry |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Component Resolved Allergy testing |
Sample Type (Bottle) Serum. |
Reference range
<0.35 kUA/l |
Clinical indications
Component-resolved diagnostics (CRD) utilize purified native or recombinant allergens to detect IgE sensitivity to individual allergen molecules. These can be helpful in identifying atopic patients with high likelihood of severe/anaphylactic reactions (such cases include peanut and venom allergy) CRD can help to confirm patients who have cross reactive sensitisation that may not lead to severe clinical allergy (e.g. to betv1 homologues reactions in oral allergy syndrome). The use of specific CRD must be discussed with the laboratory prior to testing as a limited number of components are currently available. See associated Table.. |
Limitations/interferences
Results must be interpreted alongside the clinical context. Correlation with history, SIGE testing and SPT is required |
Technical information Turnaround time: 3 days Type of investigations: FEIA |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Complement assays (Functional) |
Sample Type (Bottle) Fresh Serum. |
Reference range
New ELISA assay Classical Pathway Functional ELISA (LAB8884) Alternative Pathway Functional ELISA (LAB8883) Classical Pathway: 69 - 129% Alternative Pathway: 30 - 113% |
Clinical indications
Two tests are performed in conjunction to assess the function of both the classical and alternate complement pathways (CH100 and AP100). Indicated for investigation of Complement deficiency in the setting recurrent infections (Neisseria or encapsulated bacterial infections), some forms of renal diseases and as a part of follow up of patients on Eculizumab . |
Limitations/interferences
Serum sample transported at room temperature to arrive in the laboratory within 2h of venepuncture for freezing. It is recommended that all abnormal results be confirmed by repeat testing to exclude pre-analytical causes of falsely low functional complement activity. Please be aware that due to the change of technology, numerical results will not be directly comparable between methods. The name, units and reference interval will change as listed in the reference range section. EDTA plasma samples should NOT be used as the chelation of calcium ions renders some of the Complement components to be inactive. The Classical functional complement assay is not suitable for the routine monitoring of patients with SLE |
Technical information Turnaround time: 6 weeks Type of investigations: ELISA |
Clinical sensitivity & specificity and/or Interpretation All abnormal results are reviewed by a Consultant in the context of the clinical picture. Low results should be confirmed on repeat to exclude falsely low results which can occur due to in-vitro degradation of complement proteins. |
| Assay Cryoglobulins | Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
Cryoproteins are serum proteins which reversibly precipitate at temperatures below 37°C. There are two types of cryoproteins; cryoglobulins and cryofibrinogens. Cryoglobulins are immunoglobulins which precipitate in both serum and plasma whereas cryofibrinogens, which contain fibrinogen-fibrin complexes, only precipitate in plasma. Cryoglobulins can be further subclassified, according to their immunochemical composition, as Type I, Type II and Type III. Cryoglobulins are found in a wide spectrum of disorders but are often transient during viral or bacterial infection. Type I monoclonal cryoglobulins are invariably associated with haematological disorders such as multiple myeloma or Waldenstrom’s macroglobulinaemia. Mixed cryoglobulins, either with (Type II) or without (Type III) a monoclonal component, are associated infections, autoimmune diseases, immune-complex vasculitis and liver disease. There is a strong association between hepatitis C virus infection and mixed cryoglobulinaemia |
Limitations/interferences
Sample MUST be collected at 370C. Correct sample handling is imperative for accurate result generation. Samples must be delivered directly to the Immunology laboratory by 16:00 Monday to Saturday Not available outside CUH |
Technical information Turnaround time: 7 days Type of investigations: Precipitation |
Clinical sensitivity & specificity and/or Interpretation Reported as negative or Positive (% of cryocrit - percentage of packed cryoglobulins referred to total serum after centrifugation at 4°C). If the Type of cryoglobulin is required please discuss with Clinical Immunologist. |
|
Assay
CSF oligoclonal bands |
Sample Type (Bottle) Serum and CSF. | Reference range Negative |
Clinical indications
The detection of IgG oligoclonal bands (OCB) in the CSF is a valuable aid in the diagnosis of demyelinating disease. OCB can be found in over 90% of patients with clinically defined MS. NICE guidelines suggest that CSF analysis for the diagnosis of MS should be made when the diagnosis is clinically uncertain. They recommend that clinical presentation, exclusion of other causes and magnetic resonance imaging should be the initial diagnostic tests performed. |
Limitations/interferences
Both serum and CSF samples are required for analysis |
Technical information Turnaround time: 15 days Type of investigations: Isoelectric focusing |
Clinical sensitivity & specificity and/or Interpretation Interpret in overall clinical context. Pattern 1: No oligoclonal bands seen. Pattern 2: Oligoclonal bands in CSF only. Pattern 3: More oligoclonal bands in CSF than in serum. Pattern 4: Same oligoclonal pattern in CSF and serum. Pattern 5: Monoclonal gammopathy pattern. Patterns 2 & 3 would signify intrathecal synthesis of Immunoglobulin. |
| Assay Cytokines | Sample Type (Bottle) Li-heparin blood. | Reference range N/A |
Clinical indications
TH1 assays > Cytokine induction algorithm to investigate IFNg and IL12 pathway defects (e.g. patients with primary or secondary defects predisposing to mycobacterial , salmonella infections and other relevant pathogens) T Cell-assays > Cytokine production after various polyclonal T-cell stimulation (e.g. anti CD3, PHA, PMA/Ionomycine) Innate assays > Cytokine induction algorithms to investigate potential innate defects such as Tlr pathway, IRAK4, NEMO and others Fungal assays > Cytokine induction assays looking at Th1 but also Th17 immunity and including response to fungal components in patients with primary or secondary recurrent/persistent fungal infections, including suspected lectin pathway defects Inflammation > Investigation of patients with suspected auto-inflammatory conditions and related syndromes (e.g. IRIS, or post Transplantation) including suspected IL10 pathway defects such as IBD. |
Limitations/interferences
Please send from Patient and from a healthy control: 5-10 ml Li-heparin blood (3 ml from very small children) 2.7 ml Edta-blood 1-2 ml Serum/clotted (not for very small children ) Samples must be sent by courier at ambient temperature (please do not cool and avoid overheating) for same or next day delivery to arrive ideally not later than on a Thursday (exceptions after discussion possible) |
Technical information Turnaround time: 28-35 days Type of investigations: Cell culture, Luminex |
Clinical sensitivity & specificity and/or Interpretation N/A |
|
Assay
Cytokine antibodies |
Sample Type (Bottle) Serum. | Reference range Negative |
Clinical indications
Anti-cytokine serology panel > in patients with suspected secondary immunodeficiency due to anti-cytokine antibodies (e.g. anti IFN gamma, anti IL6) or conditions known to be associated/aggravated with/by anti-cytokine auto-antibodies such as Polyglandular syndrome (APS1, APECED), Thymoma, Pulmonar alveolar Proteinosis (anti GM-CSF) and others. |
Limitations/interferences |
Technical information Turnaround time: 28 days Type of investigations: Luminex |
Clinical sensitivity & specificity and/or Interpretation N/A |
