ABSTRACT
INTRODUCTION@#The antinuclear antibody (ANA) test is a screening test for systemic autoimmune rheumatic disease (SARD). We hypothesised that the presence of anti-DFS70 in ANA-positive samples was associated with a false-positive ANA test and negatively associated with SARD.@*METHODS@#A retrospective analysis of patient samples received for ANA testing from 1 January 2016 to 30 June 2016 was performed. Patient samples underwent ANA testing via indirect immunofluorescence method and anti-DFS70 testing using enzyme-linked immunosorbent assay.@*RESULTS@#Among a total of 645 ANA-positive samples, the majority (41.7%) were positive at a titre of 1:80. The commonest nuclear staining pattern (65.5%) was speckled. Only 9.5% of ANA-positive patients were diagnosed with SARD. Anti-DFS70 was found to be present in 10.0% of ANA-positive patients. The majority (51/59, 86.4%) of patients did not have SARD. Seven patients had positive ANA titre > 1:640, the presence of anti-double stranded DNA and/or anti-Ro60. The presence of anti-DFS70 in ANA-positive patients was not associated with the absence of SARD (Fisher's exact test, p = 0.245).@*CONCLUSION@#The presence of anti-DFS70 was associated with a false-positive ANA test in 8.6% of our patients. Anti-DFS70 was not associated with the absence of SARD.
Subject(s)
Humans , Adaptor Proteins, Signal Transducing , Antibodies, Antinuclear , Autoimmune Diseases/diagnosis , Retrospective Studies , Rheumatic Diseases/diagnosis , Transcription FactorsABSTRACT
RESUMEN Los anticuerpos anti-DFS70 (Dense Fine Speckle, peso molecular de 70 kd) son un subgrupo de anticuerpos antinucleares (ANA) de tipo natural, los cuales se manifiestan por un patrón moteado denso fino (DFS) por inmunofluorescencia indirecta. Este se caracteriza por la fluorescencia granular distribuida irregularmente en la interface de los núcleos y de la cromatina. Inicialmente, este anticuerpo fue descrito en pacientes con cistitis intersticial, dermatitis atópica y algunas neoplasias como el cáncer de próstata. Se ha encontrado que sus antígenos actúan directamente contra co-activadores de la transcripción nuclear (LEDGF/p75), codificada por el gen PSP1 y localizado en la región C terminal entre los a.a. 349 y 435. Adicionalmente, se documenta asociación con algunas funciones fisiológicas como la protección contra la apoptosis inducida por estrés, promover la supervivencia de las células epiteliales del cristalino y actuar como cofactor de replicación del virus VIH a través de su interacción con la integrasa viral. En el campo de la autoinmunidad se ha evidenciado recientemente la importancia de este anticuerpo como marcador biológico útil en la discriminación de personas con ANA positivos que no evolucionan a enfermedad autoinmune sistémica (EAI). Lo anterior se ha basado en la observación de que estos anticuerpos son más frecuentes en individuos sanos que en los pacientes con EAI y que los individuos sanos con anti-DFS70 positivo no desarrollaron EAI después de un seguimiento clínico por 4 arios o más. Este artículo revisa la descripción de los anti-DFS70 y su utilidad en la práctica clínica.
ABSTRACT Anti-DFS70 antibodies (Dense Fine Speckled, 70 kd molecular weight) are a sub-group of anti-nuclear antibodies (ANA) that show a fine dense speckled pattern (DFS) by indirect immunofluorescence. This pattern is also recognized by irregularly distributed granular fluorescence at the interface of nuclei and chromatin. This antibody was initially described in patients with interstitial cystitis, atopic dermatitis, and malignancy, such as prostate cancer. These antigens have been found to act directly against co-activators of nuclear transcription (LEDGF/p75) encoded by the PSP1 gene and located in the C-terminal region between the a.a. 349 and 435. Additionally, associations with some physiological functions have been described, such as protection against stress-induced apoptosis, the survival of lens epithelial cells, and acting as a cofactor of HIV replication through its interaction with viral integrase. As regards autoimmunity, recent evidence has also shown the importance of this antibody as a useful biological marker in the discrimination of individuals with positive ANA that do not progress to systemic autoimmune disease (SID). This is based on the observation that these antibodies are more common in healthy individuals than in patients with SID, and that healthy individuals with positive anti-DFS70 did not develop SIDs after a clinical follow-up of four years or more. This article reviews the description of anti-DFS70 and its usefulness in clinical practice.
Subject(s)
Antibodies , Activator Appliances , Autoimmunity , Fluorescent Antibody Technique, Indirect , AntigensABSTRACT
Se analiza el posible rol de los anti-DFS70 como marcadores biológicos útiles, para excluir enfermedad reumática autoinmune.
The possible role of anti-DFS70 helpful biomarkers analyzed, to exclude autoimmune rheumatic disease.