Anti-topoisomerase antibodies (ATA) are autoantibodies directed against topoisomerase and found in several diseases, most importantly scleroderma. Diseases with ATA are autoimmune disease because they react with self-proteins. They are also referred to as anti-DNA topoisomerase I antibody (anti-topo I).
Anti-topoisomerase antibodies can be classified according to their immunoglobulin class (IgM, IgG or IgA). IgG-ATA is found most frequently in scleroderma, with IgA being quite common but IgM very infrequent.[5]
Topoisomerase I is an enzyme that relaxes the strain on DNA by nicking and ligating the DNA. ATA inhibits the activity of this enzyme.[6] Since this activity occurs in the nucleus of the cell ATA is a form of antinuclear antibody. Scleroderma results from the overproduction of collagen in affected tissues, one study claims that there is an increased density of Topoisomerase I sites in the collagen genes, and that the antibodies may be altering transcription at these loci.[7]
ATA correlates with rapid progression of disease.[8]
HLA-DR2 (DR15 and DR16) are associated with scleroderma and systemic sclerosis. It has been found that patients with ATA that recognize the ET4 domain of topoisomerase were frequently HLA-DR2,[12] and in another population study it was found that DR-15 is associated with ATA in systemic sclerosis.[13] In addition to HLA-DR, the protein tyrosine phosphatase, non-receptor type 22 (lymphoid) (1p13.2 - PTPN22), "CT/TT" genotype showed significant association with anti-topo I.[14] The TAP1 gene (6p21.3, HLA complex) has also been found in association with ATA+ sclerosis.[15]
^Guldner HH, Szostecki C, Vosberg HP, Lakomek HJ, Penner E, Bautz FA (1986). "Scl 70 autoantibodies from scleroderma patients recognize a 95 kDa protein identified as DNA topoisomerase I". Chromosoma. 94 (2): 132–8. doi:10.1007/BF00286991. PMID2428564. S2CID24851422.
^Table 5-9 in: Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson (2007). Robbins Basic Pathology. Philadelphia: Saunders. ISBN978-1-4160-2973-1. 8th edition.
^JB Imboden, DB Hellmann, JH Stone. Current Rheumatology Diagnosis & Treatment, Second Edition. McGraw-Hill, 2007.
^de Rooij DJ, Van de Putte LB, Habets WJ, Van Venrooij WJ (1989). "Marker antibodies in scleroderma and polymyositis: clinical associations". Clinical Rheumatology. 8 (2): 231–7. doi:10.1007/BF02030079. PMID2547546. S2CID23132993.
^Hildebrandt S, Weiner E, Senécal JL, et al. (1990). "The IgG, IgM, and IgA isotypes of anti-topoisomerase I and anticentromere autoantibodies". Arthritis & Rheumatism. 33 (5): 724–7. doi:10.1002/art.1780330515. PMID2161233.
^Perera A, Fertig N, Lucas M, et al. (2007). "Clinical subsets, skin thickness progression rate, and serum antibody levels in systemic sclerosis patients with anti-topoisomerase I antibody". Arthritis & Rheumatism. 56 (8): 2740–6. doi:10.1002/art.22747. PMID17665460.
^Hamidou MA, Audrain MA, Masseau A, Agard C, Moreau A (2006). "Anti-topoisomerase I antibodies in systemic lupus erythematosus as a marker of severe nephritis". Clinical Rheumatology. 25 (4): 542–3. doi:10.1007/s10067-005-0061-9. PMID16525896. S2CID289409.
^Takeuchi F, Kawasugi K, Nabeta H, Mori M, Tanimoto K (2002). "Association of CTLA-4 with systemic sclerosis in Japanese patients". Clinical and Experimental Rheumatology. 20 (6): 823–8. PMID12508774.
^Kuwana M, Kaburaki J, Mimori T, Tojo T, Homma M (1993). "Autoantigenic epitopes on DNA topoisomerase I. Clinical and immunogenetic associations in systemic sclerosis". Arthritis and Rheumatism. 36 (10): 1406–13. doi:10.1002/art.1780361013. PMID7692859.
^Joung CI, Jun JB, Chung WT, et al. (2006). "Association between the HLA-DRB1 gene and clinical features of systemic sclerosis in Korea". Scandinavian Journal of Rheumatology. 35 (1): 39–43. doi:10.1080/03009740510026751. PMID16467040. S2CID23157796.
^Gourh P, Tan FK, Assassi S, et al. (2006). "Association of the protein tyrosine phosphatase, non-receptor type 8 R620W polymorphism with anti-topoisomerase I- and anticentromere antibody-positive systemic sclerosis". Arthritis and Rheumatism. 54 (12): 3945–53. doi:10.1002/art.22196. PMID17133608.
^Song YW, Lee EB, Whang DH, Kang SJ, Takeuchi F, Park MH (2005). "Association of TAP1 and TAP2 gene polymorphisms with systemic sclerosis in Korean patients". Human Immunology. 66 (7): 810–7. doi:10.1016/j.humimm.2005.03.006. PMID16112028.