[Comparative study of serological markers for intolerance to gluten]. / Etude comparative des marqueurs sérologiques de l'intolérance au gluten.

In France as well as in most of the other European countries, the prevalence of coeliac disease is underestimated. In order to point out a good screening test, we have determined the most sensitive combination (technique-marker) for the diagnosis of the disease among 81 individuals (50 with coeliac disease and 31 controls). Serum anti-gliadin antibodies were measured using three methods: the qualitative dot-blot (Gliastick-Eurospital) and two quantitative methods Elisa (homemade-Saint-Antoine Hospital and alpha-Gliatest-Eurospital); serum anti-endomysium antibodies (EmA) and anti-reticulin antibodies (ARA) were detected using an indirect immunofluorescence assay. We have shown that the simple and fast Gliastick test can fulfil the selected criterion with a sensitivity of 0.90. Nevertheless, uncertain and positives results have to be confirmed by one of the two more specific quantitative tests. The two other markers (ARA and EmA) have shown a better specificity (1) but they were less sensitive (0.54 and 0.56 for ARA and EmA respectively). Thus, they have both to be used as confirmation tests and for follow-up with supervision of the compliance to recommended diet. In conclusion, the Gliastick can be considered as a good screening test for the detection of anti-gliadin antibodies and it would represent the expected help to determine the prevalence of coeliac disease on a large-scale map.

[Comparison of indirect immunofluorescence on Crithidia luciliae of Farr test, and immunoenzymatic methods for the screening of anti-native DNA autoantibodies]. / Comparaison de l'immunofluorescence indirecte sur Crithidia luciliae du test de Farr, et des méthodes immunoenzymatiques pour le dépistage des autoanticorps anti-ADN natif.

Anti-native DNA (ds DNA) antibodies were measured by the Farr assay, an indirect immunofluorescence on Crithidia luciliae (IIFCL) and a newly commercialised enzyme-linked immunosorbent assay (Elisa) in the sera of 270 patients: 73 negative controls, 67 patients with systemic lupus erythematosus (SLE), 73 with clinical symptoms of another connective tissue disease and 61 patients with liver diseases. The Farr assay remains a reliable method, IIFCL seems to be as specific but less sensitive and Elisa has a higher sensitivity but a lower specificity. Finally, 35 sera from the 270 patients were tested for anti-ds DNA antibodies using two other commercialised Elisa-related techniques. The results suggest little correlation between the three Elisa methods.

[Evaluation of a radioimmunologic technique for the detection of anti-native DNA antibodies]. / Evaluation d'une technique radio-immunologique pour la détection des anticorps anti-ADN natif.

The anti-native DNA antibodies were measured by a radioimmunoassay (RIA) type Farr assay in the sera from 648 patients: 108 with active or inactive systemic lupus erythematosus (SLE), 181 with clinical symptoms of another connective tissue disease, 171 with liver diseases, 29 with different pathology and 159 normal sera were obtained from a blood bank. The anti-DNA kit has been calibrated against the first international units/ml. This assay has proved to be sensitive and specific, and appears to be reliable for the diagnosis and follow-up of SLE patients. The authors propose a new reference cut-off level higher than producer's one.