[Role of DNA-associated autoantibodies to cell membrane in the diagnosis of juvenile systemic lupus erythematosus].
OBJECTIVE
To establish a method of indirect immunofluorescence (IIF) to measure DNA (mDNA)-associated autoantibodies to cell membrane, and to evaluate diagnostic value of the anti-mDNA antibodies in patients with juvenile systemic lupus erythematosus (SLE) in comparison with anti-dsDNA antibody.


METHODS
Forty-four children with SLE were enrolled in this study. As a control group, 30 children with other rheumatic diseases were also enrolled. Anti-mDNA and anti-dsDNA antibodies were measured by IIF. Anti-smooth muscle (Sm) antibodies were measured by immuno-double diffusion (ID) and IIF.


RESULTS
Out of 44 juvenile SLE patients, 34 (77.27%) were seropositive for anti-mDNA, which was significantly higher than that of patients with other rheumatic diseases (20.00%, P<0.05). The sensitivity and specificity of anti-mDNA for juvenile SLE diagnosis were 77.27% and 80.00%, respectively. The positive predictive value and negative predictive value were 85.00% and 70.59%, respectively. The positive rate of anti-mDNA in SLE lacking of anti-dsDNA and anti-Sm antibodies were 68.00% (17/25) and 79.49% (31/39), respectively.


CONCLUSIONS
The detection of anti-mDNA antibodies is useful for diagnosis of juvenile SLE, especially in patients who are negative for anti-dsDNA antibodies and anti-Sm antibodies.
Ru
Jin-li
JL
Department of Rheumatology, the Second Hospital, Shanxi Medical University, Taiyuan 030001, China.
Wei
Hua
H
Lü
Zhi-qin
ZQ
Zhao
Chun-yang
CY
Li
Xiao-feng
XF
D000293:Adolescent; D000974:Antibodies, Antinuclear / Q000032:analysis*; D016022:Case-Control Studies; D002462:Cell Membrane / Q000276:immunology*; D002648:Child; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D000974:Antibodies, Antinuclear