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| Previous Nomenclature | 1 to 6 nuclear dots, coiled body, Cajal bodies |
| Description | Countable discrete speckles (1 to 6 nuclear dots/cell in most cells). These are known as Cajal bodies or coiled bodies. e.g. anti-p80-coilin |
| Antigen Association | p80-coilin, SMN |
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Clinical Relevance
First level information About Clinical Relevance & List of Abbreviations |
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▶ The AC-7 pattern has low positive predictive value for any disease (40, 41) ▶ Antigens primarily localized in the dots include p80-coilin and SMN complex; specific immunoassays for these autoantibodies are currently not commercially available (42, 43) |
| First level information references |
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40. Onouchi H, Muro Y, Tomita Y. Clinical features and IgG subclass distribution of anti-p80 coilin antibodies. J Autoimmun 1999;13:225-32. 41. Fujimoto M, Kikuchi K, Tamaki T, et al. Distribution of anti-p80-coilin autoantibody in collagen diseases and various skin diseases. Br J Dermatol 1997;137:916-20. 42. Andrade LE, Chan EK, Raska I, et al. Human autoantibody to a novel protein of the nuclear coiled body: immunological characterization and cDNA cloning of p80-coilin. J Exp Med 1991;173:1407-19. 43. Satoh M, Chan JY, Ross SJ, et al. Autoantibodies to survival of motor neuron complex in patients with polymyositis: immunoprecipitation of D, E, F, and G proteins without other components of small nuclear ribonucleoproteins. Arthritis Rheum 2011;63:1972-8. |
| Second level information |
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▶ Anti‐p80‐coilin antibodies may rarely occur in SLE, (localized linear) SSc, and SjS (15‐17) ▶ Isolated (without anti‐snRNPs) anti‐SMN antibodies are reported in patients with AIM or SSc‐AIM overlap syndrome (18) ▶ The specificity of antibodies to p80‐coilin and the SMN complex can be confirmed by Western blot, solid phase immunoassays using recombinant proteins and immunoprecipitation (15, 18, 19) Notes: Most reports describe autoantibodies directly binding to specific antigens (i.e. antigen‐specific immunoassays) and do not actually show clear correlations with the AC‐7 pattern as such; specific immunoassays for these autoantibodies are currently not commercially available. |
| Second level information references |
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15. Andrade LE, Chan EK, Raska I, et al. Human autoantibody to a novel protein of the nuclear coiled body: immunological characterization and cDNA cloning of p80-coilin. J Exp Med 1991;173:1407-19. 16. Fujimoto M, Kikuchi K, Tamaki T, et al. Distribution of anti-p80-coilin autoantibody in collagen diseases and various skin diseases. Br J Dermatol 1997;137:916-20. 17. Onouchi H, Muro Y, Tomita Y. Clinical features and IgG subclass distribution of anti-p80 coilin antibodies. J Autoimmun 1999;13:225-32. 18. Satoh M, Chan JY, Ross SJ, et al. Autoantibodies to survival of motor neuron (SMN) complex in patients with polymyositis - immunoprecipitation of D-EF-G without other components of small nuclear ribonucleoproteins. Arthritis Rheum 2011;63:1972-8. 19. Amlani A, Hazlewood GS, Hamilton L, et al. Autoantibodies to the survival of motor neuron complex in a patient with necrotizing autoimmune myopathy. Rheumatology 2018;57:199-200. |
| FAQ |
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How to deal with just a “nuclear speckled” IFA report? In my practice I have followed patients with ANA findings, with a nuclear speckled pattern (without specifying whether fine/dense/coarse), in patients with very heterogeneous phenotypes, some with a clinical picture that suggests further investigation of systemic autoimmune disease (one patient with proximal muscle weakness and skin thickening) and others who represent only non-specific findings. In such situations, as a precaution, I request more specific autoantibodies. However, this pattern (nuclear speckled pattern) is not described by the "ICAP" and I am in doubt about which antigenic association it represents, even to guide which autoantibody may be present and which ones to look after. How to interpret this pattern? Does the lab describe it when it is not possible to "refine" such a conclusion? Could this be associated with deficiency in the methodology, sample, interpretation? |