Ultrasound subclinical synovitis in anti-CCP-positive at-risk individuals with musculoskeletal symptoms: an important and predictable stage in the rheumatoid arthritis continuum.

OBJECTIVES: To investigate whether anti-CCP2-positive at-risk individuals with musculoskeletal (MSK) symptoms but without clinical synovitis (CCP2+ at-risk) develop US subclinical synovitis before inflammatory arthritis and if US subclinical synovitis can be predicted. METHODS: First, US scans of CCP2+ at-risk individuals who developed inflammatory arthritis ('progressors') were reviewed for subclinical synovitis prior to inflammatory arthritis development. Patients in whom the pre-progression US scan was negative but the scan was conducted >6 months before progression were excluded. Subsequently, regression analyses were performed to identify predictors of US synovitis in CCP2+ at-risk individuals without baseline US abnormalities who had one or more longitudinal US scan and a complete dataset. RESULTS: US subclinical synovitis was detected in one or more scan in 75 of 97 progressors (77.3%) {median time to inflammatory arthritis development from first evidence of US synovitis 26.5 weeks [interquartile range (IQR) 7-60]}, in whom one or more scan was available, excluding those with a negative scan >6 months from inflammatory arthritis development (n = 38). In 220 CCP2+ at-risk individuals with normal baseline US scans, who had one or more longitudinal US scan and a complete dataset, US synovitis was detected in 69/220 (31.4%) [median time to first developing US synovitis 56.4 weeks (IQR 33.0-112.0)]. In the multivariable analysis, only anti-CCP3 antibodies were predictive for the development of US synovitis [odds ratio 4.75 (95% CI 1.97, 11.46); P < 0.01]. CONCLUSIONS: In anti-CCP2+ at-risk individuals, a stage of subclinical synovitis usually precedes the development of inflammatory arthritis. Anti-CCP2+/CCP3+ individuals without clinical or US subclinical synovitis may represent the optimal window of opportunity for intervention to prevent joint disease.

Eficacia diagnóstica de anticuerpos antipéptidos citrulinados de segunda y tercera generaciones para la artritis reumatoide / Diagnostic effectiveness of anti-citrullinated peptides antibodies of second and third generations for rheumatoid arthritis

Introducción: La artritis reumatoide es una enfermedad autoinmune caracterizada por la presencia de anticuerpos contra péptidos citrulinados, que constituyen indicadores para el diagnóstico de la enfermedad. Es necesario determinar la utilidad de diferentes métodos de determinación de estos anticuerpos para el diagnóstico de pacientes cubanos con artritis reumatoide. Objetivo: Determinar la eficacia de los ensayos de determinación de anticuerpos anti-CCP2 y anti-CCP3 para el diagnóstico de pacientes cubanos con artritis reumatoide. Material y método: Participaron 101 pacientes con artritis reumatoide, 58 pacientes con otras enfermedades reumáticas e inflamatorias y 43 individuos sanos. Se determinó la eficacia diagnóstica de los anticuerpos factor reumatoideo (FR), anti-CCP2 y anti-CCP3 medidos mediante ELISA, con el cálculo de la sensibilidad, especificidad, valores predictivos positivos y negativos. Resultados: El ensayo anti-CCP2 mostró un mejor balance sensibilidad (48,5 por ciento) y especificidad (98,0 por ciento). Cuando se fijó la especificidad a 98 por ciento, se observó la menor sensibilidad para el FR (40,3 por ciento). Utilizar los ensayos anti-CCP2 y FR aumentó la especificidad a 100 por ciento. Todos los autoanticuerpos mostraron asociación con la proteína C reactiva y correlación con la velocidad de sedimentación globular. Solamente los anticuerpos anti-CCP2 no mostraron correlación con el indicador clínico de actividad DAS 28. Conclusiones: Los anticuerpos anti-CCP2 son los de mayor eficacia para el diagnóstico de pacientes cubanos con artritis reumatoide. La determinación de FR permite identificar pacientes con artritis reumatoide seronegativos de anticuerpos anti-CCP2, por lo que la combinación de ambos inmunoensayos produce una mejoría en la eficacia diagnóstica(AU)

Introduction: Rheumatoid arthritis is an autoimmune disease characterized by the presence of antibodies against citrullinated peptides, which are one of the indicators for the diagnosis of a disease. The usefulness of different methods for the determination of these antibodies in the diagnosis of Cuban patients with rheumatoid arthritis is necessary to be established. Objective: To establish the diagnostic effectiveness of the second (anti-CCP2) and third (anti-CCP3) generation assays for the determination these antibodies against citrullinated peptides in Cuban patients with rheumatoid arthritis. Material and method: 101 patients with rheumatoid arthritis, 58 patients with other rheumatic and inflammatory diseases, and 43 healthy persons participated in the study. The diagnostic efficiency of rheumatoid factor (RF), anti-CCP2 and anti-CCP3 antibodies were determined using ELISA test, by calculating sensitivity, specificity, and positive and negative predictive values. Results: The anti-CCP2 assay showed a better balance of sensitivity (48.5 percent) and specificity (98.0 percent). The lower sensibility was observed for RF (40.3 percent) when the specificity was set at 98 percent. Specificity increased to 100 percent when anti-CCP2 and RF assays were used. All autoantibodies showed association with C-reactive protein and correlation with erythrocyte sedimentation rate. Only anti-CCP2 antibodies showed no correlation with the DAS28 clinical indicator. Conclusions: Anti-CCP2 antibodies are the ones of greater effectiveness in the diagnosis of Cuban patients with rheumatoid arthritis. RF identification allows to identify seronegative anti-CCP2 patients; therefore, the combination of both immunoassays leads to an improvement in the diagnostic effectiveness(AU)