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Paroxysmal Nocturnal Hemoglobinuria

FLOW PNH

Test Synonym:

PNH Screen

Test Synonym:

88184 – Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only, first marker
88185 x4 – Each additional marker (multiple)
88187 – Flow cytometry, interpretation; 2 to 8 markers

Turnaround Time:

<24 hours

Methodology:

Flow cytometry, multiparameter analysis

Specimen Requirements:

  • 5.0ml (min. 2.0ml) heparin blood preferred, EDTA whole blood accepted
  • 3.0ml (min. 1.0ml) heparin bone marrow preferred, EDTA bone marrow accepted

    • Causes for Rejection:

    Specimens stored at incorrect temperature; Non-viable specimens; Specimens in inappropriate anticoagulant; Too few cells; Hemolysis; Specimen clotted

    Specimen Stability:

    Whole blood or bone marrow stable for 48 hours at room temperature

    Storage and Handling:

    • Whole blood or bone marrow ship ambient
    • Bone marrow aspirate ship in a styrofoam container with an ice pack (do not allow the ice pack to directly contact the sample)

    Reference Range:

    CD59 and CD55 detected (normal)

    Indication:

    Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the deficiency, absolute or partial, of proteins anchored to the cell membrane by the glycosylphosphatidylinositol (GPI) anchor. At least 15 of these proteins have been shown to be lacking on the abnormal blood cells of patients with this disease.

    The absence of two of these proteins, CD59, also known as membrane inhibitor of reactive lysis (MIRL) or protectin, and CD55, also known as decay-accelerating factor (DAF), are used as markers of PNH. CD59 and CD55 deficiencies are evaluated on either erythrocytes or granulocytes specifically gated in a multi-color flow cytometry procedure, using fluorochrome-labeled anti-human CD59 and CD55. Affected patients demonstrate either completely (PNH III) or partially (PNH I, PNH II) CD 59 and CD 55 deficient red cells and granulocytes.

    References:

    1. Hall et al. (1996). The use of monoclonal antibodies and flow cytometry in the diagnosis of paroxysmal nocturnal hemoglobinuria. Blood 87:5332-5340
    2. Thomason et al. (2004). Identification of unsuspected PNH-type cells in flow cytometric immunophenotypic analysis of peripheral blood and bone marrow. Am J Clin Pathol 122(1):128-34