Identification of unsuspected PNH-type cells in flow cytometric immunophenotypic analysis of peripheral blood and bone marrow.

In this report, the flow cytometric expression patterns for CD14 on monocytic cells and CD16 on granulocytic cells in peripheral blood or bone marrow specimens are illustratedfor 15 patients proven to have a paroxysmal nocturnal hemoglobinuria (PNH) phenotype by flow cytometric analysis for CD55 and CD59. The varied clinical manifestations of PNH and its rarity may make it difficult to recognize clinically. As a result, blood or bone marrow samples may be submitted for flow cytometric analysis to exclude bone marrow neoplasia or dysplasia in patients with cytopenias rather than to exclude PNH.