Liver antigen abs

Detection and confirmation of antigen specific antibodies associated with primary biliary cirrhosis and autoimmune hepatitis. These include M2, LKM-1, LC-1 and SLA/LP

LKM abs

Autoimmune chronic active hepatitis type 2

Lymphocyte cell markers

Assessment of immunodeficiency and lymphoproliferative diseases

Lymphocyte function tests

Please discuss with Consultant Immunologist.

Mitochondrial (IIF) and Mitochondrial (M2) (ELISA) abs

Primary biliary cirrhosis usually in high titre (>95%)

Muscle specific tyrosine kinase (MuSK) antibodies

Seronegative myasthenia gravis

Myeloperoxidase (MPO) abs

Organ-limited vasculitis including necrotising and crescentic glomerulo- nephritis

Neutrophil cytoplasmic abs (ANCA)

• c-ANCA  associated with Wegener’s granulo-matosis and for microscopic polyarteritis (also proteinase 3)
• pANCA may occur in other vasculitic disorders as well as some forms of glomerulonephritis (also myeloperoxidase)

Neutrophil function test 

Chronic granulomatous disease

Neuromyelitis optica (NMO) antibodies  (aquaporin 4)

Neuromyelitis optica or Devic’s disease and optic-spinal multiple sclerosis.

Test used to distinguish NMO from multiple sclerosis

Tests	Significance
Pancreatic islet cell ab’s Serum: Negative	At the time of diagnosis 75% of type I diabetics have detectable levels of circulating islet cell ab’s. Such ab’s decrease and eventually disappear with duration of disease. Some studies have indicated persistent levels of ab’s in association with polyendocrine disease (type Ib). There have been no reports of ab’s to ICA in type II diabetics.
Paraproteins Reported in g/l.	Levels of monoclonal IgG, IgA, IgM, IgD and in some instances IgE are measured immunochemically and in all cases of follow up the previous specimen is run in parallel to confirm the change in paraprotein level. Immunofixation of presentation sample defines both the isotype and light chain type. Follow up specimens will be subjected only to electrophoresis unless immunofixation is required to confirm complete response. (See ‘guide to appropriate use of tests at the back of this booklet). The presence of a paraprotein should prompt investigation of B cell malignancy, particularly myeloma, (IgG, IgA) and lymphoplasmacytoid lymphoma (IgM). Monoclonal gammopathy of uncertain significance (MGUS) is found in one or more percent of the general population over the age of 50 years.
Paraprotein neuropathies MAG; POEMS Serum: Negative	Myelin associated glycoprotein (MAG) is a glycoprotein component of the myelin of central and peripheral nervous systems present in the priaxonal region, Schmidt-Lantermans incisures, lateral loops and outer mesaxon of the myelin sheath. A member of the immunoglobulin super- family MAG probably functions as an adhesion molecule and mediates cell-cell interactions. Monoclonal reactivities against MAG are detected in about 50-75% of patients with IgM paraproteinaemia and peripheral neuropathy. Sera from patients with neuropathy that are negative for MAG antibodies often exhibit reactivity against various gangliosides.
Proteinase 3 (PR-3) ab’s. Serum: 0-10 EU/ml	PR-3 antibody is a marker for Wegeners granulomatosis and is occasionally detected in microscopic polyarteritis. The quantity of PR-3 antibody generally parallels disease activity with higher levels in the active state of the disease. EIA affords a quantitative assay which is useful when monitoring the disease. Ab’s to PR-3, an elastinolytic neural serine protease, is responsible for the characteristic granular cytoplasmic pattern of the neutrophils when stained by IIF.

Pancreatic islet cell abs

Type 1 (insulin-dependent) diabetes (75%)

Paraprotein (M-protein) quantitation 

• Levels of monoclonal IgG, IgA, IgM, IgD or IgE determined together with light chain type

B cell malignancy (myeloma: IgG, IgA) and lymphoplasmacytoid lymphoma (IgM)Monoclonal gammopathy of uncertain significance (MGUS)

Paraprotein neuropathies: Myelin Associated Glycoprotein (MAG) abs 
 
IgM monoclonal gammopathy associated peripheral neuropathy (50-75%)
Waldenstrom macroglobulinaemia

Proteinase 3 (PR3-ANCA) abs 

Wegener’s granulomatosis

Paraneoplastic pemphigus abs

Malignancies such as haematologic (lymphoma and leukaemia), sarcomas, thymomas and Castleman syndrome

Paraneoplastic neurological antibodies:

Paraneoplastic neurological antibodies are associated with paraneoplastic neurological syndrome and systemic malignancies.

Antibody	Neurological disorder(s)	Most frequent tumour(s)
Yo (PCA-1)	paraneoplastic cerebellar degeneration	Ovary, breast
Ma (Ma1)	paraneoplastic neurological disorder, brainstem encephalomyelitis	Various, lung cancer
Ta (Ma2)	brainstem encephalomyelitis, limbic encephalomyelitis	Testicular cancer
Hu (ANNA1)	paraneoplastic cerebellar degeneration, paraneoplastic encephalomyelitis, sensory neuropathy	small cell lung carcinoma
Ri (ANNA2)	opsoclonus/myclonus, paraneoplastic cerebellar degeneration, brainstem encephalomyelitis	Breast, small cell lung carcinoma, gynaecological
GAD	Stiff person syndrome	Breast, colon, small cell lung carcinoma
CV2/CRMP5	paraneoplastic encephalomyelitis / sensory neuropathy	small cell lung carcinoma, thymoma
Amphiphysin	Stiff person syndrome, paraneoplastic encephalomyelitis	Breast cancer, small cell lung carcinoma
Tr	paraneoplastic cerebellar degeneration	Hodgkin’s lymphoma

The presence of Yo, Hu (ANNA1) and Ri (ANNA2), Ma/Ta, CV2/CRMP5 and amphiphysin antibodies must be confirmed by recombinant line blot.

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RAST (allergen specific IgE)

Common allergies (animal fur or dander, house dust mite, tree and grass pollens, moulds, feathers, range of foods (a variety of nuts)

Rheumatoid factor 

Rheumatoid arthritis (70%)
Other conditions (infections, myeloma, lymphomas, cryoglobulinaemia and connective tissue diseases)

See Cyclic citrullinated peptide (CCP) antibodies

Salivary Duct abs

Suggest testing for ENA antibodies. 

Salivary IgA and secretory piece

Immunodeficiency

Serum electrophoresis - Qualitative immunoglobulins abnormalities

Monoclonal isotype and the light chain
Acute phase responses, immunodeficiency

Serum immunoglobulin free light chains

• Kappa 3.30 – 19.40 mg/l
  Lambda 5.71 – 26.30 mg/l
  Kappa / Lambda ratio 0.26 – 1.65)

Diagnosis and management of light chain amyloid, plasmacytoma, non-secretory myeloma and light chain only myeloma.

Skin abs

• (i) Antibodies to intercellular substance of the epidermis (desmosome) - pemphigus
• (ii) Dermal-epidermal basement membrane - bullous pemphigoid (80%)

Smooth muscle abs

Autoimmune hepatitis (70%)

Striated muscle abs

Myasthenia Gravis with thymoma

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