DIAGNOSTIC RELEVANCE OF AUTOANTIBODIES AGAINST
NUCLEOSOMES
W. Schlumberger, C. Daehnrich, S. Frahm, M. Siegemund, W. Meyer,
W. Suer, W. Stoecker
EUROIMMUN GmbH, Luebeck, Germany
Introduction: Besides specific antibodies against dsDNA, Sm and
ribosomal P-proteins, antibodies against nucleosomes (ANuA) can be
found in SLE patients. However, their clinical significance is questioned
because of their low specificity, with respect to scleroderma. This study
shows the evaluation of newly developed anti-nucleosome test systems
(ELISA, EUROLINE) based on mononucleosomes free of H1 and
nonhistone proteins and their clinical relevance in the differentiation of
rheumatic diseases. Methods: Purified mononucleosomes were coated on
microtiter ELISA plates and were printed as lines onto a membrane
(EUROLINE). Sera of 102 patients with SLE, 117 patients with sclero-
derma, 124 patients with other rheumatic diseases (MCTD, Sjoegrens
syndrome, polymyositis, PM/Scl overlap) and 204 healthy blood donors
were tested for ANuA with both test systems and for antibodies against
dsDNA with ELISA. Results: ANuA were found in 46% (ELISA) and in
27% (EUROLINE) of SLE patients as well as in 26% and 9% resp. of
MCTD patients. ANuA were found in none (ELISA) and 2 (EUROLINE)
of 117 scleroderma patients. The overall specificity of the test systems was
99.3% and 98.5% resp. Antibodies against dsDNA were found in 47% of
SLE patients although they did not always occur in parallel with ANuA.
11% of ANuA reacted exclusively with nucleosomes and not with dsDNA.
Conclusions: ANuA are sensitive and specific markers for SLE and
MCTD. They can be reliably determined using ELISA and EUROLINE.
For the diagnosis of SLE, the serological hit rate provided by an anti-
dsDNA ELISA is increased by determination of ANuA from 47% to 58%.
Abstract Number: 200
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