[Evaluation of an automated system of immunofluorescence analysis in daily practice]

Since a few years indirect immunofluorescence (IIF) enjoys automated screening. These automated systems give an interpretation for the detection of anti-nuclear (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA) and take images in the case of the research of anti-tissue antibodies. We propose an evaluation of the Image Navigator® system for all these kinds of research. 1,435 sera samples are included: 810 for ANA detection, 450 for ANCA detection, 175 for anti-tissue antibodies research. Visual interpretation using microscope is compared to automated interpretation and visual interpretation using the pictures. Sensibility of the automated interpretation to artifacts is assessed too. Accordance between automated interpretation and visual interpretation using microscope is moderate (kappa=0.46) in the case of ANA detection, poor in the case of ANCA detection (kappa=0.30). Accordance between visual interpretation using microscope and visual interpretation using pictures is strong for ANA (kappa=0.79) and for ANCA (kappa=0.63), very strong for anti-tissues antibodies (kappa=0.87). The blur of more than one photography interferes with the interpretation of the system (p<0.01). In any case, a second reading is necessary. The results of our study validate the use of the pictures for the interpretation of AAN but require visual interpretation using microscope for ANCA. The screening of anti-tissue antibodies can be achieved using pictures.