Evaluation of antibodies to thymine ROS-modified DNA poly(dT), in patients with immunologic disorders: relationships to anti n-DNA and anti ENA autoantibodies.
BACKGROUND
Hydroxyl radical, one of the most potent of all reactive oxygen species, is known to modify adenine and thymine in cellular DNA, producing some modified DNA fragments (ROS-DNA) with different antigenic properties. Despite several in vitro studies about ROS-DNA, data regarding their clinical significance are scanty. The aim of our study was to seek out the presence and clinical significance of the anti poly(dT) auto-antibodies in a group of patients suspected of autoimmune disease.


METHODS
We initially evaluated more than 900 consecutive sera of hospitalized patients (range age from 6 to 70 yrs) referred to our laboratory during 18 months. Anti n-DNA, anti-ENA and poly(dT) autoantibodies were performed on 158 ANA positive sera and 28 ANA negative sera from patients strongly suspected of rheumatic diseases or affected by HCV infection.


RESULTS
Anti poly (dT) were found in 22 out of 186 sera. As regards the clinical evaluation, 8 patients were affected by SLE, 5 by Scleroderma, 3 by HCV-related chronic hepatitis, 4 by recurrent abortions (without presence of the anti-cardiolipin antibodies and other clinical symptoms). In two patients the ACR criteria and the clinical aspects did not allow a definite diagnosis. Anti-Histones were detected in 18 out of 22 poly (dT) positive patients.


CONCLUSIONS
Our data suggest that anti poly(dT) autoantibodies are sensitive markers of various autoimmune diseases, but with a minor specificity as compared to anti n-DNA for the diagnosis of SLE.
Brusca
I
I
Department of Laboratory Medicine, Buccheri La Ferla Fatebenefratelli Hospital, Palermo, Italy. ignbr@tin.it
Li Vigni
P
P
Sucato
R
R
Cilluffo
N
N
La Chiusa
S M
SM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000032:analysis*; D002648:Child; D004247:DNA / Q000276:immunology*; D005260:Female; D006801:Humans; D007154:Immune System Diseases / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011071:Poly T / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013941:Thymine / Q000502:physiology*
D000974:Antibodies, Antinuclear; D017382:Reactive Oxygen Species; C033055:anti-extractable nuclear antigen antibodies; D011071:Poly T; D004247:DNA; D013941:Thymine