Frequency of positive ANCA test in a population with clinical symptoms suggestive of autoimmune disease and the interference of ANA in its interpretation

ConclusionsThe 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 minimise “false positives”.ResumenAntecedentesLos 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.ObjetivoDeterminar la frecuencia de ANCA en una población con manifestaciones de enfermedad autoinmune; y evaluar la interferencia de los ANA en su interpretación.Materiales y métodosEstudio 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 medi...
Source: Reumatologia Clinica - Category: Rheumatology Source Type: research