The autoantibody detection using immunoblot is regarded as one of the most sensitive and comprehensive test for detecting antinuclear antibody. However, the test results are quite dependent upon types of antigens used in this because reactivity
and
readability of the test results will be variable according to the antigens used.
In this study, we have chosen antigens, i.e., rabbit thymus extracts(RTE), bovine spleen extracts(BSE), extracts obtained from human peripheral blood mononuclear cells(MNC or lymphocytes), and HeLa cell extracts to compare the reactivity of human
autoantibodies circulating in the blood of autoimmune disease patients. We have compared the reactivity of four kinds of antigens to autoantibodies from 29 SLE patients, 4 rheumatoid arthritis patients, 4 mixed connective tissue disease patients
using
immunoblot technigue.
The numbers of immunoreactive band resulting from the reaction to the antigens were HeLa cell extracts, rabbit thymus extracts, human lymphocytes and bovine spleen extracts in descending order. The densities of protein bands were also decreased
with the
same order. Especially this tend is more evident in SLE patients when compare to rheumatoid arthritis and mixed connective tissue disease.
The human lymphocyte extracts and HeLa cell extracts contain immunoreactive antigens of higher molecular weight, such as 146, 110, 95, and 64 kDa. We observed the protein bands reacting to antibodies were different from antigens used in terms of
the
number of protein bands and their molecular weight. Therefore, we propose the combined use of two or more antigens to detect the autoantibodies in patients accurately.
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