AC-15 - Fibrillar Linear

This pattern is characterized by decorated cytoskeletal fibers, sometimes with small, discontinuous granular deposits. Typical staining show striated actin cables spanning the long axis of the cells. e.g. anti-actin, anti-non-muscle myosin.
Associação Antigênica
actin, non-muscle myosin.
Doença Associada
MCTD, chronic active hepatitis, liver cirrhosis, myasthenia gravis, Crohn`s disease, PBC, long term hemodialysis, rare in SARD.
Relevância Clínica (Primeiro Nível)
Found in patients with AIH type 1, chronic HCV infection, and celiac disease (IgA isotype); rare in SARD.
If AIH type 1 is clinically suspected, it is recommended to confirm reactivity with smooth muscle antibodies (IgG isotype), typically detected by IIFA on rodent tissue (liver, stomach, kidney); anti-smooth muscle antibodies are included in the international criteria for AIH type 1.
F-actin is the main target antigen of anti-smooth muscle antibodies in AIH type 1; autoantibodies to F-actin are of more clinical importance than antibodies to G-actin.
Although anti-F-actin immunoassays are commercially available, technical issues relating to the sensitivity of these immunoassays should be taken into consideration.
Relevância Clínica (Segundo Nível)
High prevalence of IgA and/or IgG type anti-actin antibody has been reported in celiac disease.
Autoantibodies to non-muscle myosin have been described in 3 patients with HCV-positive chronic hepatitis/liver cirrhosis.
Monoclonal antibodies to non-muscle myosin have been reported in chronic lymphocytic leukemia.
Specific immunoassays for non-muscle myosin are currently not commercially available.
Chretien-Leprince P, Ballot E, Andre C, et al. Diagnostic value of anti-F-actin antibodies in a French multicenter study. Ann N Y Acad Sci 2005;1050:266–73.

Chu CC, Catera R, Hatzi K, et al. Chronic lymphocytic leukemia antibodies with a common stereotypic rearrangement recognize nonmuscle myosin heavy chain IIA. Blood 2008;112:5122-9.

Clemente MG, Musu MP, Frau F, et al. Immune reaction against the cytoskeleton in coeliac disease. Gut 2000;47:520-6.

Conrad K, Scho?ssler W, Hiepe F. Autoantibodies in organ specific autoimmune diseases. a diagnostic reference. 8. 2th edn. Autoantigens autoantibodies autoimmunity, 2017.

Fusconi M, Cassani F, Zauli D, et al. Anti-actin antibodies: a new test for an old problem. J Immunol Methods 1990;130:1–8.

Liberal R, Grant CR, Longhi MS, et al. Diagnostic criteria of autoimmune hepatitis. Autoimmun Rev 2014;13:435–40.

Lidman K, Biberfeld G, Fagraeus A, et al. Anti-actin specificity of human smooth muscle antibodies in chronic active hepatitis. Clin Exp Immunol 1976;24:266–72.

Pedreira S, Sugai E, Moreno ML, et al. Significance of smooth muscle/anti-actin autoantibodies in celiac disease. Acta Gastroenterol Latinoam 2005;35:83-93.

von Muhlen CA, Chan EKL, Peebles CL, et al. Non-muscle myosin as target antigen for human autoantibodies in patients with hepatitis C virus-associated chronic liver diseases. Clin Exp Immunol 1995;100:67-74.