ICAP
AC-7 - Few nuclear dots
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
Clinical Relevance
First level information
About Clinical Relevance

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
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

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
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.
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Online since 19 May 2015