Preferred test for initial diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) and quantification of PNH clones.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin).
- Specimen Preparation
- Transport 4 mL whole blood. (Min: 4 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Bone marrow. Clotted or hemolyzed specimens.
- Specimens must be analyzed within stability times provided.
- Ambient: 24 hours; Refrigerated: 72 hours; Frozen: Unacceptable
New York State Clients: Ambient: 24 hours; Refrigerated: 48 hours. Frozen: Unacceptable
WBC analysis is the most accurate measurement of the PNH clone size. FLAER and CD157 are used as GPI-linked markers; CD15 (PMNs) and CD64 (monocytes) are used as lineage-specific markers. RBC analysis quantifies Type II and Type III RBC clones when the percentage of PNH RBCs is greater than 1 percent. Glycophorin A (CD235a) is used to gate the RBC population, and CD59 is the GPI-linked antigen. Recent RBC transfusions may decrease the percentage of PNH cells measured in RBCs (Cytometry 2000; 42:223). The presence of a subclinical PNH population in myelodysplastic bone marrow disorders, such as aplastic anemia or refractory anemia, may correlate with a positive immunotherapeutic response (Blood 2006; 107, 1308-1314).
|Component Test Code*||Component Chart Name||LOINC|
|2004367||% PNH RBC||33662-8|
|2005004||% PNH Monocytes||60554-3|
|2005005||% PNH PMN||53831-4|
- CD15, CD33, CD14, CD24, FLAER, CD59, Glycophorin A
- PI-Linked Antigens, RBCs, Monocytes and Granulocytes