Yasuhito Hamaguchi1, Masataka Kuwana2, Kazuhiko Takehara3. 1. Department of Dermatology, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8641, Japan. yasuhito@med.kanazawa-u.ac.jp. 2. Department of Allergy and Rheumatology, Nippon Medical School Graduate School of Medicine, Tokyo, Japan. 3. Department of Dermatology, Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8641, Japan.
Abstract
INTRODUCTION/ OBJECTIVES: A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple anti-nuclear antibody specificities. Here, we evaluated the performance of a commercial LB assay developed for the identification of myositis- or systemic sclerosis (SSc)-related autoantibodies (autoAbs). METHOD: We screened 300 serum samples from patients with various connective tissue diseases using an LB assay and compared the results of myositis- or SSc-related autoAbs with those identified by RNA and protein immunoprecipitation (IP) assays or indirect immunofluorescence (IIF). RESULTS: The IP assays revealed anti-Jo-1 Abs in 14 patients, anti-EJ Abs in 12, anti-PL-7 Abs in 8, anti-PL-12 Abs in 4, anti-Mi-2 Abs in 6, anti-SRP Abs in 8, anti-topoisomerase I Abs in 54, anti-RNA polymerase III Abs in 24, anti-U3 RNP Abs in 9, anti-Th/To Abs in 9, anti-Ku Abs in 14 and anti-hUBF Abs in 4, whereas IIF identified anti-centromere in 35. Good agreement between the IP assays and the LB assay was found only for anti-Jo-1 and anti-centromere antibodies. When a cut-off was adjusted to reconcile with the results of IP assays, the detection performance of LB assay was improved for anti-EJ, anti-PL-7, anti-PL-12, anti-SRP, anti-topoisomerase I and anti-RNA polymerase III Abs. However, the results of anti-Mi-2, anti-U3 RNP, anti-Th/To, anti-hUBF and anti-Ku Abs remained discordant between the LB assay and IP assays at all cut-off levels. CONCLUSIONS: Detection of myositis- or SSc-related autoAbs using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results. Key Points • A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple antibodies with anti-nuclear specificities. • Detection of myositis- or systemic sclerosis-related autoantibodies using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results.
INTRODUCTION/ OBJECTIVES: A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple anti-nuclear antibody specificities. Here, we evaluated the performance of a commercial LB assay developed for the identification of myositis- or systemic sclerosis (SSc)-related autoantibodies (autoAbs). METHOD: We screened 300 serum samples from patients with various connective tissue diseases using an LB assay and compared the results of myositis- or SSc-related autoAbs with those identified by RNA and protein immunoprecipitation (IP) assays or indirect immunofluorescence (IIF). RESULTS: The IP assays revealed anti-Jo-1 Abs in 14 patients, anti-EJ Abs in 12, anti-PL-7 Abs in 8, anti-PL-12 Abs in 4, anti-Mi-2 Abs in 6, anti-SRP Abs in 8, anti-topoisomerase I Abs in 54, anti-RNA polymerase III Abs in 24, anti-U3 RNP Abs in 9, anti-Th/To Abs in 9, anti-Ku Abs in 14 and anti-hUBF Abs in 4, whereas IIF identified anti-centromere in 35. Good agreement between the IP assays and the LB assay was found only for anti-Jo-1 and anti-centromere antibodies. When a cut-off was adjusted to reconcile with the results of IP assays, the detection performance of LB assay was improved for anti-EJ, anti-PL-7, anti-PL-12, anti-SRP, anti-topoisomerase I and anti-RNA polymerase III Abs. However, the results of anti-Mi-2, anti-U3 RNP, anti-Th/To, anti-hUBF and anti-Ku Abs remained discordant between the LB assay and IP assays at all cut-off levels. CONCLUSIONS: Detection of myositis- or SSc-related autoAbs using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results. Key Points • A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple antibodies with anti-nuclear specificities. • Detection of myositis- or systemic sclerosis-related autoantibodies using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results.
Entities:
Keywords:
Autoantibody; Dermatomyositis; Immunoprecipitation assay; Line blot assay; Systemic sclerosis
Authors: Maria Casal-Dominguez; Iago Pinal-Fernandez; Assia Derfoul; Rose Graf; Harlan Michelle; Jemima Albayda; Eleni Tiniakou; Brittany Adler; Sonye K Danoff; Thomas E Lloyd; Lisa Christoper-Stine; Julie J Paik; Andrew L Mammen Journal: Semin Arthritis Rheum Date: 2021-04-28 Impact factor: 5.431