AC-1 - Homogeneous
Descrição
Homogeneous and regular fluorescence across all nucleoplasm. The nucleoli maybe stained or not stained depending on cell substrate. Mitotic cells (metaphase, anaphase, and telophase) have the chromatin mass intensely stained in a homogeneous hyaline fashion.
Associação Antigênica
dsDNA, nucleosomes, histones.
Doenças Associadas
SLE, drug-induced lupus, juvenile idiopathic arthritis.
Relevâncias Clínicas - Primeiro nível
Found in patients with SLE, chronic autoimmune hepatitis or juvenile idiopathic arthritis.
If SLE is clinically suspected, it is recommended to perform a follow-up test for anti-dsDNA antibodies, alone or in combination with dsDNA/histone complexes (nucleosomes/chromatin); anti-dsDNA antibodies are included in the classification criteria for SLE.
If chronic autoimmune hepatitis or juvenile idiopathic arthritis is suspected, follow-up testing is not recommended because the respective autoantigens revealing the AC-1 pattern are not completely defined.
Although autoantibodies to Topoisomerase I (formerly Scl-70) may be reported as nuclear homogeneous, they typically reveal a composite AC-29 HEp-2 IIFA pattern; as such, clinical suspicion of SSc may warrant follow-up testing for reactivity to this antigen.
Although AC-1 is the most prevalent pattern in chronic autoimmune hepatitis, other HEp-2 IIFA patterns may occur, but also for these patterns the autoantigens are not completely defined.
Referências
Andrade LEC, Klotz W, Herold M , et al. International consensus on antinuclear antibody patterns: definition of the ac-29 pattern associated with antibodies to DNA topoisomerase I. Clin Chem Lab Med 2018;56:1783–8.doi:10.1515/cclm-2018-0188
Dellavance A, Gallindo C, Soares MG , et al. Redefining the Scl-70 indirect immunofluorescence pattern: autoantibodies to DNA topoisomerase I yield a specific compound immunofluorescence pattern. Rheumatology 2009;48:632–7.
European Association for the Study of the Liver. EASL clinical practice guidelines: autoimmune hepatitis. J Hepatol 2015;63:971–1004.
Conrad K, Schössler W, Hiepe F. Autoantibodies in systemic autoimmune diseases: a diagnostic reference. 2. 3th edn. Autoantigens autoantibodies autoimmunity, 2015.
Petri M, Orbai AM, Alarcón GS, et al. Derivation and validation of the systemic lupus international collaborating clinics classification criteria for systemic lupus erythematosus. Arthritis Rheum 2012;64:2677–86.doi:10.1002/art.34473
Conrad K, Schössler W, Hiepe F. Autoantibodies in organ specific autoimmune diseases. a diagnostic reference. 8. 2th edn. Autoantigens autoantibodies autoimmunity, 2017.