High Sensitivity Paroxysmal Nocturnal Hemoglobinuria Assay by Flow Cytometry

Abbrev Code:FLOWB   
Order Code:LAB4625Order Name:PNH by Flow
Synonyms:CD59 (MIRL); PNH, Flaer
Methodology:Multi-color immunofluorescence and flow cytometry
CPT Codes: 88184 x1, 88185 x7, 88187 x1
Test Includes:CD59, Flaer, CD14, CD15, CD24, CD64 and CD235a
Turnaround Time:Performed Mon-Fri 08:00-17:00 and on Saturday before noon. Results are reported within 1-3 business days.
Special Instructions:Provide diagnosis, age, collection date, and time. Samples will be tested Mon-Fri 08:00-17:00 and on Saturday before noon. Samples are received in the Core lab when the Flow Cytometry lab is not staffed. Contact the IFC laboratory at 612-273-5248 for further information. If testing is needed outside of scheduled hours, contact the hematopathology fellow.

This test was developed and its performance characteristics determined by University of Minnesota Medical Center, Fairview Clinical Laboratories. It has not been cleared or approved by the US Food and Drug Administration. FDA does not require this test to go through premarket FDA review. This test is used for clinical purposes and should not be regarded as investigational or for research. This laboratory is certified under the Clinical Laboratory Improvement Amendments (CLIA) as qualified to perform high complexity clinical testing.

Collection Instructions

Optimal Volume:4 mL
Minimum\Peds Volume:2 mL
Container:Purple (EDTA)
Collection Instructions:Mix specimen well after collection.
Causes for Rejection:Improper specimen collection or handling, blood with low WBC and/or percentage of granulocytes, clotted specimen, specimen received >48 hours after collection.

Processing and Shipping

Specimen Processing:Do not centrifuge. Store in refrigerator.
Shipping Instructions:Ship at room temperature. Must arrive within 24 hours.
Test Performed at or Referral Lab UM Flow Cytometry (W)  (UMMC East Bank)


Reference Range:Expression of CD59 on patient's cells is compared with expression on normal control red blood cells. Expression of Flaer and CD24 on granulocytes and Flaer and CD14 on monocytes is compared with expression on normal granulocytes and monocytes.

For diagnosis of PNH. Includes evaluation of CD59 (MIRL) antigens on the surface of red cells, Flaer and CD24 on granulocytes and Flaer and CD14 on monocytes in the peripheral blood of patients with PNH or suspected of having PNH. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematologic disorder characterized by abnormal erythrocytes, granulocytes and platelets that have an increased sensitivity to complement. These cells show deficiency, absolute or partial, of cell-membrane-associated complement regulatory proteins anchored to the membrane by the glycosylphosphatidynositol (GPI) anchor.


Flow cytometry immunophenotyping of peripheral blood is performed to evaluate the presence or absence of GPI-linked proteins using monoclonal antibodies. One of the best reagents available to study GPI-linked antigens on leukocytes is in the reagent FLAER. This is a fluorochrome-conjugated inactive variant of the bacterially derived channel-forming protein aerolysin which binds specifically to GPI anchors. Flaer can be used in multicolor combination with monoclonal antibodies to GPI-linked and non-GPI antigens for the detection of PNH clones. Individuals without PNH have normal expression of all GPI-linked antigens on peripheral blood leukocytes. A normal value study confirmed the presence of these antigens on peripheral blood leukocytes and red blood cells.


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