TY - JOUR
T1 - Evaluation of two antibodies against double-stranded DNA assays in discriminating between active and non-active systemic lupus erythematosus
T2 - Correlation between the cut-off and the specificity
AU - Martin, J.
AU - Durant, C.
AU - Rimbert, M.
AU - Hemont, C.
AU - Hamidou, M.
AU - Audrain, M.
PY - 2012/12
Y1 - 2012/12
N2 - This study aimed to evaluate, improve and compare the performances of two anti-double-stranded DNA (dsDNA) detection kits, differing by their affinity, in discriminating between active and non-active systemic lupus erythematosus (SLE). Eighty-two anti-nuclear antibody positive sera (45 patients) were tested by two anti-dsDNA commercial quantitative assays (Fidis™, Farrzyme™). All the patients fulfilled at least four of the revised American College of Rheumatology criteria. SLE disease activity was assessed using a modified SLEDAI to remove anti-dsDNA descriptors. When using the manufacturers' cut-offs, no difference in the frequency of positive results was found with respect to disease activity, with Fidis™. On the contrary, with Farrzyme™, a significantly higher frequency of positive sera was found in active SLE patients. Nonetheless, poor performances were observed for both tests. With thresholds defined by ROC methodology, 212. IU/mL for Fidis™ (Se: 83.9%, Sp: 86.3%), and 68.8. IU/mL for Farrzyme (Se: 71.0%, Sp: 96.1%), a great improvement of the accuracy of the two methods was observed. Moreover, the better specificity and pLR, obtained after optimization of the Farrzyme™ test, could also be obtained with the Fidis™ assay by using a higher threshold than that obtained after optimization of the test. We concluded that when using manufacturers' cut-offs, the two assays appeared to be of poor clinical usefulness in the determination of disease activity. A great improvement was observed using higher thresholds. Moreover, a good concordance could be observed between the two assays (κ = 0.764).
AB - This study aimed to evaluate, improve and compare the performances of two anti-double-stranded DNA (dsDNA) detection kits, differing by their affinity, in discriminating between active and non-active systemic lupus erythematosus (SLE). Eighty-two anti-nuclear antibody positive sera (45 patients) were tested by two anti-dsDNA commercial quantitative assays (Fidis™, Farrzyme™). All the patients fulfilled at least four of the revised American College of Rheumatology criteria. SLE disease activity was assessed using a modified SLEDAI to remove anti-dsDNA descriptors. When using the manufacturers' cut-offs, no difference in the frequency of positive results was found with respect to disease activity, with Fidis™. On the contrary, with Farrzyme™, a significantly higher frequency of positive sera was found in active SLE patients. Nonetheless, poor performances were observed for both tests. With thresholds defined by ROC methodology, 212. IU/mL for Fidis™ (Se: 83.9%, Sp: 86.3%), and 68.8. IU/mL for Farrzyme (Se: 71.0%, Sp: 96.1%), a great improvement of the accuracy of the two methods was observed. Moreover, the better specificity and pLR, obtained after optimization of the Farrzyme™ test, could also be obtained with the Fidis™ assay by using a higher threshold than that obtained after optimization of the test. We concluded that when using manufacturers' cut-offs, the two assays appeared to be of poor clinical usefulness in the determination of disease activity. A great improvement was observed using higher thresholds. Moreover, a good concordance could be observed between the two assays (κ = 0.764).
KW - Antibodies against double-stranded DNA
KW - Laboratory tests
KW - Systemic lupus erythematosus
UR - https://www.scopus.com/pages/publications/84870392433
U2 - 10.1016/j.patbio.2011.12.003
DO - 10.1016/j.patbio.2011.12.003
M3 - Article
C2 - 22265124
AN - SCOPUS:84870392433
SN - 0369-8114
VL - 60
SP - 387
EP - 391
JO - Pathologie Biologie
JF - Pathologie Biologie
IS - 6
ER -