Reference Interval:
| Test Number
| Components
| Reference Interval
| | | % Normal RBCs
| Normal: 99.995-100.000%
| | | % PNH Cells
| Negative: 0.000-0.005%
|
|
| Interpretive Data: |
The High Resolution PNH-RBC panel detects the absence of phosphatidylinositol-linked membrane proteins CD55 (DAF-decay accelerating factor) and CD59 (MIRL-membrane inhibitor of reactive lysis) on erythrocytes. The erythrocytes are identified with glycophorin staining. All normal RBCs (99.995-100.000%) express CD55 and CD59 and are reported as % Normal RBCs. The expression of CD55 and CD59 is decreased or absent in a subpopulation of RBCs in patients with paroxysmal nocturnal hemoglobinuria. The estimated percentage of RBCs with decreased expression is reported as % PNH cells. Since 'diagnosis of PNH disease requires a deficiency of at least two GPI-linked antigens in two different cell lineages'*, this test may be complemented with a PNH-WBC test (test code 096666) if clinically indicated. Please note that recent RBC transfusions may artifactually decrease the percentage of PNH cells. *Cytometry 42:223-33 (2000)
The detection of a very low percentage of PNH cells (0.006-1.000%) may be found in patients with aplastic anemia, myelodysplasia, refractory anemia, refractory anemia with excess blasts, and myelofibrosis. The presence of PNH cells in these patients may correlate with a better prognosis. Blood 102:1211-1218 (2003)
Please refer to Statement A in the Compliance Statements section in the front of the Laboratory Test Directory.
|
| Note: |
This panel tests for the phosphatidylinositol-linked membrane proteins CD55 (DAF-decay accelerating factor) and CD59 (MIRL-membrane inhibitor of reactive lysis) on erythrocytes. The percentage of RBCs with normal expression of CD55 and CD59 is decreased in paroxysmal nocturnal hemoglobinuria (PNH).
|
| CPT Code(s): |
88184 First marker; 88185 x2 Each additional marker
|