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.
actin, non-muscle myosin.
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.
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