The term extractable nuclear antigens (ENAs) is a historical denomination, though
still in use, derived from the observation that several antigens from the cell nuclei
are soluble and can be isolated or “extracted” in isotonic buffers, which facilitated
the characterisation of several autoantibodies. Nowadays, the term has broadened and
it also includes other antibodies directed against antigens from the cytoplasm and
other cell compartments, such as ribonucleoproteins, histones or antigens only expressed
when the cell is found in its mitotic state. Amidst this variety of autoantibodies,
the anti-Ro antibodies are directed against a small intracellular RNA-protein complex,
whose protein component has been described as polypeptides with molecular weights
ranging from 50 to 150 kD [
[1]
]. The major antigenic protein is a 60 kD polypeptide (also known as Sjögren's syndrome
[SS] antigen A or SSA), but other chains of different molecular weights can be also
found within this complex, such as a 48 kD polypeptide (also known as SS antigen B
or SSB), or a 52 kD polypeptide (also known as Ro52 or TRIM21) [
[2]
]. The first two antigenic proteins, Ro/SSA and La/SSB, have traditionally been more
studied than the last one, Ro52/TRIM21, possibly because historically autoantibodies
to Ro52/Ro60 antigens could not be identified separately [
[1]
,
[3]
].To read this article in full you will need to make a payment
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References
- A 52-kD protein is a novel component of the SS-A/Ro antigenic particle.J Exp Med. 1988; 167: 1560-1571https://doi.org/10.1084/jem.167.5.1560
- The Ro small cytoplasmic ribonucleoproteins: identification of the antigenic protein and its binding site on the Ro RNAs.Proc Natl Acad Sci U S A. 1984; 81: 1996-2000https://doi.org/10.1073/pnas.81.7.1996
- Molecular definition and sequence motifs of the 52-kD component of human SS-A/Ro autoantigen.J Clin Investig. 1991; 87: 68-76https://doi.org/10.1172/JCI115003
- Clinical associations of the positive anti Ro52 without Ro60 autoantibodies: undifferentiated connective tissue diseases.J Clin Pathol. 2018; 71: 12-19https://doi.org/10.1136/jclinpath-2015-203587
- Latest update on the Ro/SS-A autoantibody system.Autoimmun Rev. 2009; 8: 632-637https://doi.org/10.1016/j.autrev.2009.02.010
- Anti-Ro52 and/or anti-Ro60 immune reactivity: autoantibody and disease associations.Clin Exp Rheumatol. 2021; 38: S134-S141
- 2016 American college of rheumatology/European league against rheumatism classification criteria for primary Sjögren's syndrome.Ann Rheum Dis. 2017; 76: 9-16https://doi.org/10.1136/annrheumdis-2016-210571
- Anti-Ro (SS-A) and anti-La (SS-B) in patients with Sjögren's syndrome.Arthritis Rheumatol. 1986; 29: 196-206https://doi.org/10.1002/art.1780290207
- How immunological profile drives clinical phenotype of primary Sjögren's syndrome at diagnosis: analysis of 10,500 patients (Sjögren big data project).Clin Exp Rheumatol. 2018; 36: S102-S111
- Immunization of mice with human 60-kd Ro peptides results in epitope spreading if the peptides are highly homologous between human and mouse.Arthritis Rheumatol. 1999; 42: 1017-1024https://doi.org/10.1002/1529-0131(199905)42:5<1017::AID-ANR22>3.0.CO;2-7
- Immunization with 60kD Ro peptide produces different stages of preclinical autoimmunity in a Sjögren's syndrome model among multiple strains of inbred mice.Clin Exp Immunol. 2013; 173: 67-75https://doi.org/10.1111/cei.12094
- Pattern of cutaneous immunoglobulin G deposition in subacute cutaneous lupus erythematosus is reproduced by infusing purified anti-Ro (SSA) autoentibodies into human skin-grafted mice.J Clin Investig. 1989; 83: 1556-1562https://doi.org/10.1172/JCI114052
- Concentration of autoantibodies to native 60-kd ro/ss-a and denatured 52-kd ro/ss-a in eluates from the heart of a child who died with congenital complete heart block.Arthritis Rheumatol. 1994; 37: 1698-1703https://doi.org/10.1002/art.1780371120
- Clinical significance of anti-Ro52 (TRIM21) antibodies in adult patients with connective tissue diseases.Eur J Intern Med. 2021; https://doi.org/10.1016/j.ejim.2021.04.020
- Systematic review and meta-analysis of the epidemiology of polyautoimmunity in Sjögren's syndrome (secondary Sjögren's syndrome) focusing on autoimmune rheumatic diseases.Scand J Rheumatol. 2018; 47: 141-154https://doi.org/10.1080/03009742.2017.1324909
- Clinical and serological hallmarks of systemic sclerosis overlap syndromes.J Rheumatol. 2011; 38: 2406-2409https://doi.org/10.3899/jrheum.101248
- Inflammatory myositis in systemic lupus erythematosus.Lupus. 2020; 29: 776-781https://doi.org/10.1177/0961203320918021
- Clinical profiles and prognosis of patients with distinct antisynthetase autoantibodies.J Rheumatol. 2017; 44: 1051-1057https://doi.org/10.3899/jrheum.161480
- Autoantibodies in systemic sclerosis.Autoimmun Rev. 2013; 12: 340-354https://doi.org/10.1016/j.autrev.2012.05.011
- Short-term and long-term outcome of anti-Jo1-positive patients with anti-Ro52 antibody.Semin Arthr Rheum. 2012; 41: 890-899https://doi.org/10.1016/j.semarthrit.2011.09.008
- Usefulness of anti-p155 autoantibody for diagnosing cancer-associated dermatomyositis: a systematic review and meta-analysis.Arthritis Rheumatol. 2012; 64: 523-532https://doi.org/10.1002/art.33379
- Clinical usefulness of anti-RNA polymerase III antibody measurement by enzyme-linked immunosorbent assay.Rheumatology. 2009; 48: 1570-1574https://doi.org/10.1093/rheumatology/kep290
Article info
Publication history
Published online: June 30, 2021
Accepted:
June 11,
2021
Received:
June 11,
2021
Identification
Copyright
© 2021 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
