Evaluation of anti-citrullinated filaggrin antibodies as hallmarks for the diagnosis of rheumatic diseases

Abstract

Background: Anti-filaggrin antibodies (AFA) are among the most specific antibodies for rheumatoid arthritis, so procedures for their detection should be included in early biological diagnoses. AFA can be detected by indirect immunofluorescence (anti-keratin antibodies, AKA) or by new enzyme immunoassays (EIA). Their comparative performance needs to be established. Objective: To compare these technical procedures to optimise the serological diagnosis of rheumatoid arthritis. Methods: Results obtained using AKA and EIA were compared in 271 sera from 140 patients with rheumatoid arthritis at various stages, 98 patients with other autoimmune diseases, and 33 healthy subjects. EIA were successively undertaken with citrullinated linear filaggrin peptide (home made EIA) or cyclic citrullinated peptide (CCP2, commercial kits). Rheumatoid factor (RF) was assessed by EIA in all patients. Results: Anti-CCP2 kits showed the best sensitivity and specificity (65% and 96%, respectively). Among the 140 patients with rheumatoid arthritis, those with very recent disease (less than six months' duration, n = 21) were studied as a separate group. In this group, the sensitivity of anti-CCP2 kits decreased to ,50%. Nevertheless this assay remained the most accurate when compared with AKA or home made EIA using linear filaggrin peptides. The combination of anti-CCP2 and RF only slightly increased the sensitivity of the diagnosis of very early rheumatoid arthritis. Conclusions: Kits using citrullinated cyclic peptides (CCP2) were more suitable than either AKA or EIA using linear filaggrin peptides for the diagnosis of early rheumatoid disease.

Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in leprosy patients with articular involvement

“…The anti-CCP positivity found among RA patients in the present study is in agreement with Dubucquoi et al (27), who reported a sensitivity of 85%. The anti-CCP2 test used in our study has higher sensitivity than the anti-CCP1 test (28).…”

Anti Citrullinated Protein / Peptide Antibody Assay, Rheumathoid Factor or Both as Shifted Test in Diagnostic and Prognostic Evaluation in Patients with Rheumathoid Arthritis

“…The report for sensitivity of the second [2] generation anti-CCP 2 antibody is approximately 64-74%, with the specificity of 90-99% [11][12][13][14][15][16]32]. The advantages of the use of anti-CCP 2 test might be seen as a possibility of an early differentiation of arthritis.…”

“…These findings suggest an important role of citrullinated antigens in the diagnosis of RA. Sensitivity of the anti-CCP 2 test varies between 64% and 74% in different populations, but the specificity varies between 90% and 99% [11][12][13][14][15][16].…”

Anticuerpos anti-CCP en artritis reumatoidea: relación con características clínicas, citocinas Th1/Th2 y HLA-DRB1.

“…Dubucquoi et al compararon la positividad de anticuerpos anti-CCP en pacientes con AR en función de la linealidad del péptido citrulinado (34). El uso de péptidos citrulinados cíclicos mostró mejor sensibilidad y especificidad que los AKA y que el péptido citrulinado lineal (34). Igualmente, este estudio mostró una menor sensibilidad de los anticuerpos anti-CCP al inicio de la enfermedad que en pacientes con AR establecida (34).…”

“…Estudios previos señalaron una prevalencia de hasta el 20% en pacientes con LES (54) y del 4% en pacientes con SSp (34). Además del origen racial que pudiera explicar la diferencia entre los resultados, los criterios de selección de los pacientes deben ser también considerados en la interpretación de los mismos.…”