Paroxysmal nocturnal hemoglobinuria (PNH) is currently diagnosed by flow cytometry; although highly sensitive, its interpretation and reporting appear as critical as its technique.

Thus, we developed a program of “comparison between laboratories” for the French-speaking region based on the international recommendations for PNH screening. We proposed a two-step survey program to Frenchspeaking clinical laboratory (France, Belgium, Luxembourg and Switzerland).

One survey consisted of sending raw data files to evaluate gating and the interpretation strategy of each center. One survey stipulated sending fresh whole-blood samples to evaluate the whole process and its practice.