Clinical Relevance
First level information About Clinical Relevance & List of Abbreviations |
▶ Autoantibodies revealing the AC-18 pattern have been reported in distinct SARD and in a variety of other diseases; their prevalence in unselected or specified disease cohorts has not been thoroughly studied (84) ▶ Antigens recognized include GW-body (Processing or P body) antigens (Ge-1/Hedls, GW182, and Su/Ago2) and endosomal antigens (EEA1, CLIP-170, GRASP-1, and LBPA); specific immunoassays for these autoantibodies are currently not commercially available Notes: Autoantibodies to GW-bodies and endosomes may yield slightly different HEp-2 IIFA patterns (84, 85). |
First level information references |
84. Bhanji RA, Eystathioy T, Chan EK, et al. Clinical and serological features of patients with autoantibodies to GW/P bodies. Clin Immunol 2007;125:247-56. 85. Stinton LM, Eystathioy T, Selak S, et al. Autoantibodies to protein transport and messenger RNA processing pathways: endosomes, lysosomes, Golgi complex, proteasomes, assemblyosomes, exosomes, and GW bodies. Clin Immunol 2004;110:30-44. |
Second level information |
Autoantibodies to GW bodies: ▶ The most common clinical presentations in a single study with 55 positive sera were neurological symptoms (i.e. ataxia, motor and sensory neuropathy; 33%), SjS (31%), and the remainder had a variety of other diagnoses including SLE, RA, and PBC (28) ▶ Analysis by ALBIA and immunoprecipitation of recombinant proteins indicated that autoantibodies were directed against Ge-1/Hedls (58%), GW182 (40%), and Su/Ago2 (16%) (28) Autoantibodies to endosomal components: ▶ Autoantibodies to EEA1 were seen in a variety of conditions, but ~40% of the patients had a neurological disease (29) ▶ Autoantibodies to CLIP-170 were reported in 4 patients with different diseases including the prototype patient with SLE and AIM; the remaining 3 patients had limited cutaneous SSc, glioblastoma, and idiopathic pleural effusion (30) ▶ Autoantibodies to both LBPA and GRASP-1 have not been studied thoroughly in unselected or specified disease cohorts; anti-GRASP-1 autoantibodies were detected in 17% of PBC sera (31, 32) Notes: Most reports describing autoantibodies directly binding to specific endosomal antigens do not show correlations with the AC-18 pattern as such; specific immunoassays for the autoantibodies reacting with antigens of GW bodies or endosomes are currently not commercially available. |
Second level information references |
28. Bhanji RA, Eystathioy T, Chan EKL, et al. Clinical and serological features of patients with autoantibodies to GW/P bodies. Clin Immunol 2007;125:247-56. 29. Stinton LM, Eystathioy T, Selak S, et al. Autoantibodies to protein transport and messenger RNA processing pathways: endosomes, lysosomes, Golgi complex, proteasomes, assemblyosomes, exosomes, and GW bodies. Clin Immunol 2004;110:30-44. 30. Griffith KJ, Ryan JP, Senecal JL, et al. The cytoplasmic linker protein CLIP-170 is a human autoantigen. Clin Exp Immunol 2002;127:533-8. 31. Stinton LM, Selak S, Fritzler MJ. Identification of GRASP-1 as a novel 97 kDa autoantigen localized to endosomes. Clin Immunol 2005;116:108-17. 32. Stinton LM, Swain M, Myers RP, et al. Autoantibodies to GW bodies and other autoantigens in primary biliary cirrhosis. Clin Exp Immunol 2011;163:147-56. |
FAQ |
Reporting AC-18 - does it change with the 2021 classification chart revision? Question: I have one question for the new classification tree. As AC-18 was removed from the category of cytoplasmic speckled and assigned still at the expert level. If the lab only reports competent-level patterns, how should AC-18 be reported? Should they just report the first branch of the classification tree as "cytoplasmic"? |