Plasma is not a suitable specimen type
Minimum volume of separated serum: 500uL
NOTE! : 3 x 1mL plain / red top Micro-collect tubes required
Refer individual test entries for smooth muscle antibodies, mitochondrial antibodies, LKM-1 antibodies and SLAA antibodies
Uncertainty of Measurement
For the following assays UOM titre is defined as one single doubling dilution titre (i.e. a reported titre of 160 has a UOM titre range of 80-320)
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Smooth muscle antibodies
INOVA mouse LKS tissue IIF (manual)
Mitochondrial antibodies
Screen:
INOVA mouse LKS tissue IIF
(manual)
Confirmation:
EUROIMMUN ALD line immunoassay
(EUROBLOT One equipment)
Liver Kidney Microsomal antibodies
Screen:
INOVA mouse LKS tissue IIF
(manual)
Confirmation:
EUROIMMUN ALD line immunoassay
(EUROBLOT One equipment)
Soluble liver antigen antibodies
EUROIMMUN ALD line immunoassay (EUROBLOT One equipment)
Smooth Muscle antibodies
Smooth muscle antibodies at titres >= 160 favours a diagnosis of Type 1 Autoimmune Hepatitis (AIH-1) particularly if there is evidence of F-Actin antibodies which give a characteristic "picket-fence" staining on immunofluorescence and where these antibodies are seen in combination with high titre ANA, elevated IgG and characteristic liver findings. These antibodies are seen in approximately 50-80% of patients with AIH-1 and 20% of primary biliary cirrhosis. Lower titres in adults are relatively non-specific and may be found in viral infections, including viral hepatitis, NAFLD and liver cirrhosis.
Soluble Liver Antigen antibodies
Soluble Liver Antigen antibodies are highly specific for autoimmune hepatitis (AIH) however theses are only seen in 10-30% of patients. These antibodies cannot be detected on tissue immunofluorescence and the method of identification is line immunoassay.
Liver Kidney Microsomal antibodies
There are 3 subtypes of Liver Kidney Microsomal (LKM) antibodies [LKM-1, LKM-2 and LKM-3]. LKM-1 antibodies are strongly associated with Type 2 Autoimmune Hepatitis (AIH-2) and are found in 80-95% of cases . This subgroup of AIH, more common in children and young adults, is associated with a more severe disease course. On immunofluorescence LKM-1 titres >=20 are considered significant. These antibodies give a characteristic smooth staining(liver hepatocytes and proximal renal tubules) on mouse tissue sections, in our laboratory these are confirmed on further testing with line immunoassay.
Mitochondrial antibodies
There are nine subtypes (M1- M9) of mitochondrial antibodies (AMA) described. The M2 subtype (AMA-M2) has a very high association with symptomatic primary biliary cirrhosis and is detected in approximately 95% of cases. For non-symptomatic patients there is a significantly increased risk of developing PBC in the future if AMA-M2 are detected. On immunofluorescence AMA titres >=20 are considered significant. In our laboratory confirmation by line immunoassay against two targets (AMA-M2 and AMA M2-3EBPO) increase overall AMA sensitivity and specificity.
The Immunopathology team can be reached via email: immunology@adhb.govt.nz or via Lablink (09) 307 4949 ext 22000:
- Professor Rohan Ameratunga (Immunopathologist)
- Dr Maia Brewerton (Immunopathologist)
- Dr Miriam Hurst (Immunopathologist)
Links to other Tests:
Transport on chiller pads either centrifuged SST tubes or separated sera