Analysis of Ana/Dfs70 Pattern in a Large Cohort of Autoimmune/Autoinflammatory Diseases Compared with First Degree Relatives and Healthy Controls Evaluated from Colombia.

BACKGROUND: The presence of Antinuclear antibodies/Dense Fine Speckled 70 (ANA/DFS70) has been proposed as a negative biomarker in the process of exclusion of systemic autoimmune/autoinflammatory rheumatic diseases (SARD). The purpose was to evaluate and characterize ANA/DFS70 patients in a large Colombian population with SARD; rheumatoid arthritis (RA), Psoriasis (PsO), Undifferentiated connective tissue disease (UCTD), first-degree relatives of (FDR), and healthy controls (HC). METHODS: ANA determination was performed using indirect immunofluorescence. Samples with positive dense fine granular staining in the nucleoplasm of the interphase cell (AC2) fluorescence were confirmed with CytoBead/ANA and ANA/modified (Knocked out for the PSPI1 gen). RESULTS: 530 mestizo Colombian participants were included. ANA/DFS70 antibody positivity in the whole group was 2.3%, and 0.8% in SARD; no RA patients were positive. ANA/DFS70 positives in UCTD were three women; the average time of evolution of the disease was 9.4 years. The most frequent clinical findings were arthralgias, non-erosive arthritis, and Raynaud's phenomenon. The PsO positive was a woman with C-reactive protein (CRP) positivity and a negative erythrocyte sedimentation rate (ESR) without any other positive autoantibody or extracutaneous manifestation. FDR and HC positives were 7/8 women. All were negative for other autoantibodies. CONCLUSIONS: ANA/DFS70 autoantibodies were present in Colombian patients with SARD at a shallow frequency, they were more prevalent in healthy individuals.

Frecuencia de ANA/DFS70 en familiares de pacientes con artritis reumatoide comparados con pacientes con artritis reumatoide y población sana y su asociación con el estado de salud / Frequency of ANA/DFS70 in Relatives of Patients with Rheumatoid Arthritis Compared to Patients with Rheumatoid Arthritis and a Healthy Population, and its Association with Health Status

Introducción: Los ANA/DFS70 han atraído el interés por su frecuencia en individuos sin evidencia clínica de enfermedad reumática sistémica autoinmune, no se han evaluado grupos de riesgo genético para artritis reumatoide (AR). Objetivo: Determinar la frecuencia de ANA y ANA/DFS70 en familiares consanguíneos (FC) de AR comparada con pacientes con AR temprana (ARt) e individuos control y su asociación con el estado de salud. Metodología: Estudio de corte transversal con componente analítico. Análisis de 60 pacientes ARt, 60 FC y 120 individuos control pareados por edad y sexo. Se analizaron ANA-HEp2 y ANA/DFS70. Establecieron las frecuencias absolutas y relativas y asociaciones con modelos de regresión logística, con un nivel de significación del 95%. Resultados: ANA de 43% en ARt, 30% en FC y 25,8% en individuos control a título 1:80. El patrón granular fino denso por Hep2 convencional se encontró en el 12,9% de las muestras positivas y el 1,66% del total de muestras. En ANA/DFS70 (+) en 1,66% en FC y 2,5% de individuos control, representando el 75% de la muestras positivas y el 1,25% del total de las muestras. No hubo detección de ANAS-DFS70 en pacientes con ARt. En ARt hubo asociación entre la presencia de ANA y articulaciones inflamadas (p=0,02), PCR (p=0,01), DAS28PCR (p=0,03) y HAQ (p=0,04). Asociación entre ANA y PCR elevada (p=0,05) en FC. En individuos control entre ANA y articulaciones dolorosas (p=0,02). En individuos ANA-DFS70 observamos asociación con VSG normal p=0,032, FR (-), p=0,044 y ausencia de articulaciones dolorosas, p=0,039. Conclusiones: La frecuencia de ANA/DFS70 en los grupos estudiados fue baja, ninguno de los pacientes con ARt fue positivo. Se confirma la presencia de ANA/DFS70 solo en individuos sanos sistémicamente.(AU)

Introduction: DFS70 ANAs have attracted interest due to their frequency in individuals with no clinical evidence of systemic autoimmune rheumatic disease, groups with genetic risk for rheumatoid arthritis (RA) were not assessed. Objective: To determine the frequency of ANA and DFS70 ANA in blood relatives (BR) of people with RA compared to patients with early RA (ERA), and control individuals, and its association with health status. Methodology: A cross-sectional study with an analytical component. Sixty ERA patients, 60 BR and 120 control individuals paired by age and sex were studied. Hep2-ANA and DFS70 ANA were studied. The absolute and relative frequencies and associations were established using logistic regression models, with a significance level of 95%. Results: 43% ANA in ERA, 30% in BR, and 25.8% in control individuals 1:80. The fine dense granular pattern based on conventional Hep2 was found in 12.9% of the positive samples, and 1.66% of the total samples. There was no detection of DFS70 ANAs in patients with ERA. In ERA there was an association between the presence of ANA and inflamed joints (p=.02), CRP (p=.01), DAS28CRP (p=.03) and HAQ (p=.04). There was an association between ANA and elevated CRP (p=.05) in the BR. In the control individuals, there was an association between ANA and painful joints (p=02). In DFS70 ANA individuals we observed an association between a normal ESR p=.032, BR (-), p=.044 and absence of painful joints, p=.039. Conclusions: The frequency of DFS70 ANA in the groups studied was low, none of the patients with ERA was positive. The presence of DFS70 ANA was only confirmed in systemically healthy individuals.(AU)

Frequency of ANA/DFS70 in Relatives of Patients with Rheumatoid Arthritis Compared to Patients with Rheumatoid Arthritis and a Healthy Population, and its Association with Health Status. / Frecuencia de ANA/DFS70 en familiares de pacientes con artritis reumatoide comparados con pacientes con artritis reumatoide y población sana y su asociación con el estado de salud.

INTRODUCTION: DFS70 ANAs have attracted interest due to their frequency in individuals with no clinical evidence of systemic autoimmune rheumatic disease, groups with genetic risk for rheumatoid arthritis (RA) were not assessed. OBJECTIVE: To determine the frequency of ANA and DFS70 ANA in blood relatives (BR) of people with RA compared to patients with early RA (ERA), and control individuals, and its association with health status. METHODOLOGY: A cross-sectional study with an analytical component. Sixty ERA patients, 60 BR and 120 control individuals paired by age and sex were studied. Hep2-ANA and DFS70 ANA were studied. The absolute and relative frequencies and associations were established using logistic regression models, with a significance level of 95%. RESULTS: 43% ANA in ERA, 30% in BR, and 25.8% in control individuals 1:80. The fine dense granular pattern based on conventional Hep2 was found in 12.9% of the positive samples, and 1.66% of the total samples. There was no detection of DFS70 ANAs in patients with ERA. In ERA there was an association between the presence of ANA and inflamed joints (p=.02), CRP (p=.01), DAS28CRP (p=.03) and HAQ (p=.04). There was an association between ANA and elevated CRP (p=.05) in the BR. In the control individuals, there was an association between ANA and painful joints (p=02). In DFS70 ANA individuals we observed an association between a normal ESR p=.032, BR (-), p=.044 and absence of painful joints, p=.039. CONCLUSIONS: The frequency of DFS70 ANA in the groups studied was low, none of the patients with ERA was positive. The presence of DFS70 ANA was only confirmed in systemically healthy individuals.

Frecuencia de ANCA positivos en una población con síntomas clínicos sugestivos de enfermedad autoinmune y la interferencia de ANA en su interpretación / Frequency of positive ANCA test in a population with clinical symptoms suggestive of autoimmune disease and the interference of ANA in its interpretation

ANTECEDENTES: Los anticuerpos anticitoplasma del neutrófilo (ANCA) se asocian con vasculitis. Existen diferentes métodos para determinar su presencia. Se ha descrito la interferencia de anticuerpos antinucleares (ANA) en la diferenciación de los patrones P-ANCA y C-ANCA. OBJETIVO: Determinar la frecuencia de ANCA en una población con manifestaciones de enfermedad autoinmune; y evaluar la interferencia de los ANA en su interpretación. MATERIALES Y MÉTODOS: Estudio de corte transversal retrospectivo, descriptivo no experimental incluyendo 3.330 datos con diagnóstico presuntivo de enfermedad autoinmune y solicitud de ANCA. Las determinaciones de ANCA y de ANA se realizaron mediante inmunofluorescencia indirecta, L-ANCA® y CytoBead® ANCA. Antiproteinasa 3 y antimieloperoxidasa fueron determinados mediante ELISA y CytoBead® ANCA. RESULTADOS: Se encontraron ANCA positivos en el 10,21% y el 12,64% con ANCA positivos presentaban ANA positivos. La concordancia kappa para antiproteinasa 3 entre CytoBead® ANCA y ELISA fue del 100% (K=1; p < 0,05), La concordancia entre antimieloperoxidasa por ELISA y CytoBead®ANCA fue alta (K=0,94; p < 0,05). El 30% de aquellos con ANCA positivos tenía diagnóstico de algún tipo de vasculitis, el 20% cursaba con alguna enfermedad autoinmune. CONCLUSIONES: Los resultados indican una solicitud sobreestimada de este marcador como ayuda diagnóstica en consulta de atención primaria no direccionada. Para una adecuada evaluación de ANCA se debe implementar la técnica de inmunofluorescencia indirecta para tamizaje y confirmar con la determinación de antígenos específicos para antiproteinasa 3 y antimieloperoxidasa por cualquiera de los ensayos confirmatorios. La alta concordancia mostrada por CytoBeads® ANCA hace que planteemos el empleo de dicha alternativa para la determinación de ANCA y su confirmación. Dada la interferencia de los ANA, se recomienda solicitar la prueba ANA por inmunofluorescencia indirecta ante la presencia de resultados P-ANCA positivos, con el fin de minimizar «falsos positivos»

BACKGROUND: Antibodies against neutrophil cytoplasm (ANCA) are associated with vasculitis. There are different methods to determine their presence. The interference of antinuclear antibodies (ANA) in the differentiation between P-ANCA and C-ANCA patterns has been described. OBJECTIVE: To determine the frequency of ANCA in a population with manifestations of autoimmune disease, and evaluate the interference of ANA in its interpretation. MATERIALS AND METHODS: Retrospective, descriptive nonexperimental cross-sectional study, including 3,330 data. The presumptive diagnosis was autoimmune disease and a test for ANCA was requested. The ANCA and ANA determinations were made by indirect immunofluorescence, L-ANCA® and CytoBead® ANCA. Anti-proteinase 3 and anti-myeloperoxidase were detected by ELISA and CytoBead® ANCA. RESULTS: ANCAs were positive in 10.21% and 12.64% of those positive for ANCA were positive for ANA. The inter-rater agreement statistic (Kappa) for anti-PR3 between CytoBead ANCA and ELISA was 100% (K=1.00; P<.05) and the agreement between anti- myeloperoxidase by ELISA and CytoBead® ANCA was high (K=0.94; P<.05). 30% of those with ANCAs had a diagnosis of a type of vasculitis; 20% of them had an autoimmune disease. CONCLUSIONS: The results suggest an overestimated request for ANCAs as a diagnostic aid in primary care which was not addressed. For an adequate evaluation of ANCAs, the indirect immunofluorescence technique should be implemented for the control and confirmation with the determination of specific antigens for anti- proteinase 3 and anti- myeloperoxidase in any of the confirmatory assays. The high concordance shown by ANCA CytoBeads makes us consider the use of this alternative for the determination of ANCAs and the confirmation. Given the interference of ANAs, the ANA test by IFI in the presence of positive P-ANCA results is recommended in order to minimize "false positives"

Frequency of Positive ANCA Test in a Population With Clinical Symptoms Suggestive of Autoimmune Disease and the Interference of ANA in its Interpretation. / Frecuencia de ANCA positivos en una población con síntomas clínicos sugestivos de enfermedad autoinmune y la interferencia de ANA en su interpretación.

BACKGROUND: Antibodies against neutrophil cytoplasm (ANCA) are associated with vasculitis. There are different methods to determine their presence. The interference of antinuclear antibodies (ANA) in the differentiation between P-ANCA and C-ANCA patterns has been described. OBJECTIVE: To determine the frequency of ANCA in a population with manifestations of autoimmune disease, and evaluate the interference of ANA in its interpretation. MATERIALS AND METHODS: Retrospective, descriptive nonexperimental cross-sectional study, including 3,330 data. The presumptive diagnosis was autoimmune disease and a test for ANCA was requested. The ANCA and ANA determinations were made by indirect immunofluorescence, L-ANCA® and CytoBead® ANCA. Anti-proteinase 3 and anti-myeloperoxidase were detected by ELISA and CytoBead® ANCA. RESULTS: ANCAs were positive in 10.21% and 12.64% of those positive for ANCA were positive for ANA. The inter-rater agreement statistic (Kappa) for anti-PR3 between CytoBead ANCA and ELISA was 100% (K=1.00; P<.05) and the agreement between anti- myeloperoxidase by ELISA and CytoBead® ANCA was high (K=0.94; P<.05). 30% of those with ANCAs had a diagnosis of a type of vasculitis; 20% of them had an autoimmune disease. CONCLUSIONS: The results suggest an overestimated request for ANCAs as a diagnostic aid in primary care which was not addressed. For an adequate evaluation of ANCAs, the indirect immunofluorescence technique should be implemented for the control and confirmation with the determination of specific antigens for anti- proteinase 3 and anti- myeloperoxidase in any of the confirmatory assays. The high concordance shown by ANCA CytoBeads makes us consider the use of this alternative for the determination of ANCAs and the confirmation. Given the interference of ANAs, the ANA test by IFI in the presence of positive P-ANCA results is recommended in order to minimize "false positives".