AC-10 - Punctate Nucleolar

Densely distributed but distinct grains seen in the nucleoli of interphase cells. In metaphase cells, up to 5 bright pairs of the nucleolar organizer regions (NOR) can be seen within the chromatin body. The cytoplasm of mitotic cells may be slightly positive. e.g. anti-NOR-90, anti-RNA polymerase I.
Associação Antigênica
RNA polymerase I, hUBF/NOR-90
Doença Associada
SSc, SjS
Relevância Clínica (Primeiro Nível)
If the AC-10 pattern is observed in the serum of patients with conditions mentioned above, follow-up testing for anti-NOR90 (hUBF) antibodies is to be considered; the antigen is included in disease specific immunoassays (i.e. SSc profile).
While AC-10 is associated with anti-RNApol I antibodies, these antibodies almost always coexist with anti-RNApol III antibodies which reveal the AC-5 pattern; therefore, if SSc is clinically suspected, it is recommended to perform a follow-up test for anti-RNApol III antibodies (See also AC-5); specific immunoassays for anti-RNA pol I antibodies are currently not commercially available.
Fritzler MJ, von Muhlen CA, Toffoli SM, et al. Autoantibodies to the nucleolar organizer antigen NOR-90 in children with systemic rheumatic diseases. J Rheumatol 1995;22:521–4.

Fujii T, Mimori T, Akizuki M. Detection of autoantibodies to nucleolar transcription factor nor 90/hUBF in sera of patients with rheumatic diseases, by recombinant autoantigen-based assays. Arthritis Rheum 1996;39:1313–8.

Imai H, Ochs RL, Kiyosawa K, et al. Nucleolar antigens and autoantibodies in hepatocellular carcinoma and other malignancies. Am J Pathol 1992;140:859–70.

Kuwana M, Kaburaki J, Mimori T, et al. Autoantibody reactive with three classes of RNA polymerases in sera from patients with systemic sclerosis. J Clin Invest 1993;91:1399–404.

Reimer G, Rose KM, Scheer U, et al. Autoantibody to RNA polymerase I in scleroderma sera. J Clin Invest 1987;79:65–72.

Yamasaki Y, Honkanen-Scott M, Hernandez L, et al. Nucleolar staining cannot be used as a screening test for the scleroderma marker anti-RNA polymerase I/III
antibodies. Arthritis Rheum 2006;54:3051–6.