Ordering Recommendation

Use to monitor subclinical paroxysmal nocturnal hemoglobinuria and eculizumab treatment. Preferred initial diagnostic test is Paroxysmal Nocturnal Hemoglobinuria (PNH), High Sensitivity, RBC and WBC (2005006).




Quantitative Flow Cytometry




1-3 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation

New York State Clients: Testing is only approved for the Paroxysmal Nocturnal Hemoglobinuria (PNH), High Sensitivity, RBC and WBC (ARUP test code 2005006) on whole blood specimens.


Lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin).

Specimen Preparation

Transport 4 mL whole blood. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Bone marrow. Clotted or hemolyzed specimens.


Specimens must be analyzed within stability times provided.


Ambient: 4 days; Refrigerated: 4 days; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

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).

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes

86356 x2


Component Test Code* Component Chart Name LOINC
2004367 % PNH RBC 33662-8
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • 59 and Glycophorin A
  • PI-Linked Antigens on RBCs
Paroxysmal Nocturnal Hemoglobinuria, High Sensitivity, RBC