2 x 1.0mL plain micro tubes.
Normally no Tissue Autoantibodies detected.
Variable, dependent on volume of requesting, typically 1-2 weeks
Autoimmune diseases are classified as either "tissue or organ specific" or as "non organ specific". The first group are diseases such as thyroiditis, myasthenia gravis, diabetes mellitus, Addison disease. Some non-organ specific diseases are systemic lupus erythematosus, rheumatoid arthritis and progressive systemic sclerosis. The latter group is an autoimmune response to antigens common to various organs and tissues in the body whereas the former is an autoimmune response to antigens present in only one particular tissue or organ.
Parietal Cell Antibodies
Seen in 80 - 90% of patients with pernicious anaemia. Seen in 60% of females with atrophic gastritis without anaemia. 20% of patients with gastric carcinoma have positive results. 33% of patients with thyroiditis and Graves disease show positive parietal cell antibodies. 30% of patients with iron deficiency anaemia also have positive parietal cell antibodies. Only 1% of the normal population under 20 years of age have positive results while 12 - 15% of the normal population over 70 years show positive results. 6% of females between the ages of 30 and 70 have positive parietal cells.
Smooth Muscle Antibodies
80 - 90% of patients with chronic active hepatitis develop smooth muscle antibodies along with a positive ANA result and raised IgG level. Titres greater than 1:160 are rarely found in other disorders. 10 - 50% of patients with primary biliary cirrhosis have low titres of smooth muscle antibodies. 60% of patients with viral hepatitis develop these antibodies for a transient period, as do 80% of patients with infectious mononucleosis, RA, alcoholic liver disease and variety of malignancies. 2% of normal population have smooth muscle antibodies related to recent viral infections.
Mitochondrial Antibodies
Seen in 90% of patients with primary biliary cirrhosis with 50% of the titres being greater than 1:160. Seen in low titres in patients with thyrotoxicosis, hashimoto thyroiditis and pernicious anaemia. 2 - 10% of patients with rheumatoid arthritis, SLE, Sjogren syndrome and systemic sclerosis show positive results. Low titre mitochondrial antibodies found also in patients with biological false positive tests for syphilis i.e. VDRL positive, TPHA and FTA negative.
Mitochondrial antibodies are seen, in various degrees, in chronic active hepatitis and cryptogenic cirrhosis. Less than 3% of patients with Addison's disease, myasthenia gravis and autoimmune haemolytic anaemia have positive mitochondrial antibodies.
Titre significance
|
Titre |
Significance |
|
Negative |
Strong evidence against some common tissue?specific Autoimmune and non-organ specific diseases. |
|
1:40 - 1:80 for PCA, AMA, Adrenal, SMA |
A positive result in this titre range is regarded as being of borderline significance. Note: A repeat specimen should be tested in 2 weeks to check if there is an increase in titre. |
|
1:160 or greater |
A positive result in this titre range is of significance. High SMA commonly seen in CAH. High ADR in idiopathic Addisons. High AMA commonly seen in PBC. High PCA commonly in P.A and chronic gastritis. High SAL in Sjogren syndrome with or without sicca complex. |
References
1. Atlas of Autoantibody Patterns - on Tissues Bradwell, Stokes and Johnson.
2. Advanced Atlas of Autoantibody Patterns Bradwell, Stokes and Mead.
For further information contact the laboratory, (09) 307 4949 ext 22103 or:
Associate Professor Rohan Ameratunga
, Immunopathologist: Locator
93-5724,