Project

When eculizumab (Soliris) was available, the various clinicians involved wanted PNH flow cytometry diagnostic tests to be relatively standardised nationally.

• Leukocytes must be analysed at diagnosis and RBCs must be analysed to confirm a suspected diagnosis.
• Gating with one or more non-GP anchored antibodies is necessary to create an immunological gating of the various subpopulations.
• Concomitant marking with one or more GP-anchored antibodies is performed to determine the size of the pathological clone.
• A 5% sensitivity was proposed. The assessment of small clones (around 1%) is possible depending on the centre’s experience.
• The results must specify the size of each PNH clone then the suggested diagnosis within that context.

The arrival of publications using the FLAER reagent, and especially the publication in early 2010 of international guidelines (Borowitz MJ et al. 2010), led to a second workshop. A meeting was held in Paris under the aegis of the AFC to review the proposed rules in the presence of one of the authors of the guidelines (F. RICHARDS). The participants took stock of the practices in place (see AFC presentation 2010) and the bases for a workshop were laid out.

During the summer of 2010, it was proposed that 5 “normal bloods” and 9 “pathological bloods” be analysed, with three different monoclonal antibody combinations, provided by Beckmann Coulteur and BD Biosciences to their different respective customers. The FLAER, delivered by the AFC, was obviously tested. During 2010, the files obtained in a mode list were reanalysed by 5 laboratory organizers. Preanalytical and analytical strategies and especially reprocessing strategies are proposed.