Notre expérience de la consommation de l'antiglobuline (test de Dixon) dans la recherche des anticorps fixés sur les plaquettes

Abstract

We measured the quantity of IgG bound to platelets (IgGP) by the antiglobulin consumption test (Dixon technic). In controls, the IgG level did not exceed 10 X 10(-15) g for one platelet. The amount of IgGP was often incraeased (more than 10 X 10(-l5) g) in some autoimmune diseases as lupus erythematosus, chronic lymphocytic leukemia and chronic active hepatitis. Among 26 patients presenting an idiopathic thrombocytopenic purpura (ITP) with a low number of platelets, 21 (77%) had a high titer of IgGP. In 6 ITP in remission, the IgGP titer was normal. After a review of the different technics detecting the IgG bound to platelets, we explain why we choose the antiglobulin consumption. This test is excellent for the research of anti-platelets auto-antibodies in ITP. Yet, the reaction remains negative in a minority of ITP. Several explanations are possible: low quantity of IgGP, presence of other anto-antibodies as IgM or IgA, cellular auto-immunity anti-platelets without antibodies, non immunologic ITP.