Diagnostic value of combined evaluation of neopterin and anti-DNA antibody levels for assessment of disease activity in systemic lupus erythematosus.
OBJECTIVE
The present study was designed to investigate whether the combined evaluation of laboratory tests could improve their diagnostic value. Laboratory parameters of systemic lupus erythematosus (SLE), such as anti-dsDNA, neopterin, soluble IL-2 receptor (sIL-2R), C3, C4, and complement haemolytic activity (CH50), and a logistic model that provides the probable clinical activity (PCA) of a given patient, calculated by stepwise multiple logistic regression analysis from the parameters mentioned above--were evaluated as SLE activation markers.


METHODS
Serum samples from 101 patients were assayed by ELISA (neopterin, sIL-2R, anti-dsDNA), radial immunodiffusion (C3, C4) and haemolytic complement assay (CH50).


RESULTS
Among the parameters investigated, PCA showed the greatest difference between the values representing active and inactive stages of the disease (p < 0.001), the highest correlation with SLEDAI (p < 0.001) and the highest sensitivity and specificity values (0.91, 0.88, respectively). Moreover, this value of PCA was the most useful in discriminating between active and inactive sample pairs.


CONCLUSIONS
We conclude that PCA is more useful in evaluating SLE activity than the single parameters studied.
Nagy
G
G
3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary. ngyorgy@kut.sote.hu
Brózik
M
M
Tornóci
L
L
Gergely
P
P
D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D004247:DNA / Q000276:immunology*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D019798:Neopterin / Q000097:blood*; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D000974:Antibodies, Antinuclear; D019798:Neopterin; D004247:DNA