Paroxysmal Nocturnal Hemoglobinuria, High Sensitivity, RBC

This assay tests for CD59 on erythrocytes using flow cytometry. The percentage of red blood cells (RBCs) with normal expression of CD59 is decreased in paroxysmal nocturnal hemoglobinuria (PNH). The presence of a subclinical PNH population (0.005-1.000 percent) in myelodysplastic bone marrow disorders, such as aplastic anemia or refractory anemia, may correlate with a positive immunotherapeutic response (Blood 2006; 107, 1308-1314).

The lower limit of detection of this test is 0.005 percent PNH cells. This test will distinguish between Type II and Type III cells when the PNH cell percentage is 1 percent or greater. Glycophorin A (CD235a) is used to gate the RBC population. CD59 is the GPI-linked antigen. Recent RBC transfusions may decrease the percentage of PNH cells measured in RBCs (Cytometry 2000; 42:223-33).

For the most accurate measurement of the PNH clone size, order Paroxysmal Nocturnal Hemoglobinuria, High Sensitivity, WBC (ARUP test code 2005003) to assist with therapeutic decisions in conventional PNH.

For initial diagnosis of PNH and analysis of both RBCs and WBCs, order Paroxysmal Nocturnal Hemoglobinuria (PNH), High Sensitivity, RBC and WBC (ARUP test code 2005006).