A new immunoprecipitation-real time quantitative PCR assay for anti-Th/To and anti-U3RNP antibody detection in systemic sclerosis

Table 1 Sensitivity and specificity of our new IP-qPCR method.

Autoantibody specificity ^a	n	Anti-Th/To by IP-qPCR	Anti-U3RNP by IP-qPCR
*Scleroderma*
Th/To	22	100%	4.5% (1/22)
U3RNP	12	0%	100%
Topo I	20	0%	0%
RNAPIII	18	0%	0%
ACA	15	0%	0%
PM-Scl	5	0%	0%
*Others*
TMG	3	0%	100%
La	12	0%	42% (5/12)
NHS	15	0%	0%

Results show the high sensitivity and specificity of the new assay, for the detection of anti-Th/To and -U3RNP antibodies, compared with silver staining as gold standard. ^aAntibody specificity validated by IP, urea-PAGE, and silver staining. ACA, anti-centromere antibodies; IP, immunoprecipitation; NHS, normal human serum; RNAPIII, RNA polymerase III; TMG, trimethylguanosine; topo I, topoisomerase I.

ISSN: 1478-6362