Fluorescence cytoplasmique dense sur cellule Hep-2 : ne pas passer à côté des anti-PL

Abstract

Any dense cytoplasmic fluorescence on Hep-2000 cells seen in the immunology laboratory of the Clermont-Ferrand teaching hospital was closely studied to determine the presence or not of anti-PL antibodies. From January 2006 to January 2007, twelve patients presented a dense cytoplasmic fluorescence on Hep-2000 cells. So we activated a Hep-2 cells'slide, a triple substrate's slide and a dot in order to exclude antiribosomes and anti-JO1 antibodies. After having excluded these antibodies, we sent the sera to the immunology laboratory of the South Lyon hospital to confirm the dense cytoplasmic fluorescence and to detect anti-PL antibodies. Four patients presented anti-PL7 and three anti-PL12. For four other patients, the dense cytoplasmic fluorescence was only due to anti-SSA antibodies. Last for one patient, no antibody was found despite an evocative clinic of myositis. The systematically extensive exploration during the discovery of a dense cytoplasmic fluorescence proved very efficient, permitting to diagnose five new cases of antisynthetases syndrome including three not evoked by the clinician and to confirm two cases clinically known. This study permitted us to better recognize anti-PL from others dense cytoplasmic fluorescences and not to mix them up with particular anti-SSA.