OBJECTIVE: To evaluate the clinical usefulness of measuring anti-RNA polymerase (RNAP) III antibody with a commercially available ELISA in Japanese patients with SSc. METHODS: This multicentre study involved 354 patients with SSc, 245 with non-SSc CTDs and 102 healthy controls. ELISAs were used to detect anti-RNAP III antibody, anti-topo I antibody and ACA. The presence of anti-RNAP III antibody in selected serum samples was confirmed by immunoprecipitation (IP) assay. RESULTS: By ELISA, anti-RNAP III antibody was detected in 38 (10.7%) patients with SSc, 3 (1.2%) with non-SSc CTD and no healthy controls. The clinical specificity for SSc was excellent (98.8%), although a small number of false positives occurred. The sensitivity of the anti-topo I and ACA ELISAs for SSc was 59.9%, which increased to 68.2% without a reduction in specificity when the anti-RNAP III measurement was added. Clinical features associated with positivity for the anti-RNAP III antibody include dcSSc, a high total skin score and a trend towards high prevalence of renal crisis, consistent with previous studies that used an IP assay. Furthermore, on clinical severity scales, SSc patients with anti-RNAP III antibody scored highest for skin and renal involvement among patients subgrouped by the presence of individual SSc-related antibodies. CONCLUSIONS: The measurement of anti-RNAP III antibody by ELISA is useful in routine clinical practice, because it helps diagnose SSc and identify a disease subset with severe skin and renal involvement.
OBJECTIVE: To evaluate the clinical usefulness of measuring anti-RNA polymerase (RNAP) III antibody with a commercially available ELISA in Japanese patients with SSc. METHODS: This multicentre study involved 354 patients with SSc, 245 with non-SSc CTDs and 102 healthy controls. ELISAs were used to detect anti-RNAP III antibody, anti-topo I antibody and ACA. The presence of anti-RNAP III antibody in selected serum samples was confirmed by immunoprecipitation (IP) assay. RESULTS: By ELISA, anti-RNAP III antibody was detected in 38 (10.7%) patients with SSc, 3 (1.2%) with non-SSc CTD and no healthy controls. The clinical specificity for SSc was excellent (98.8%), although a small number of false positives occurred. The sensitivity of the anti-topo I and ACA ELISAs for SSc was 59.9%, which increased to 68.2% without a reduction in specificity when the anti-RNAP III measurement was added. Clinical features associated with positivity for the anti-RNAP III antibody include dcSSc, a high total skin score and a trend towards high prevalence of renal crisis, consistent with previous studies that used an IP assay. Furthermore, on clinical severity scales, SSc patients with anti-RNAP III antibody scored highest for skin and renal involvement among patients subgrouped by the presence of individual SSc-related antibodies. CONCLUSIONS: The measurement of anti-RNAP III antibody by ELISA is useful in routine clinical practice, because it helps diagnose SSc and identify a disease subset with severe skin and renal involvement.
Authors: M Satoh; M Vazquez-Del Mercado; M E Krzyszczak; Y Li; A Ceribelli; R W Burlingame; T T Webb; E S Sobel; W H Reeves; E K L Chan Journal: Lupus Date: 2011-10-24 Impact factor: 2.911
Authors: Angela Ceribelli; Malgorzata E Krzyszczak; Yi Li; Steven J Ross; Jason Y F Chan; Edward K L Chan; Rufus W Burlingame; Tyler T Webb; Michael R Bubb; Eric S Sobel; Westley H Reeves; Minoru Satoh Journal: Arthritis Res Ther Date: 2011-07-22 Impact factor: 5.156