Laboratory texts for the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH).
| Diagnostic tests . | . |
|---|---|
| * The flow cytometric analysis of bone marrow cells or the expression of GPI-linked proteins is of NO diagnostic value. | |
| Traditionally: | |
| The lysis of PNH red blood cells exposed to activated complement tests for the deficiency of CD59 and CD55 on red blood cells. The tests vary in the pathways activating complement. Advantage: Cheap and simple to perform Disadvantage: Labor intensive, decreased sesitivity due to the short half-life of circulating PNH red blood cells. |
| Today: | |
| • Flow cytometric analysis:* | |
| - CD59 and/or CD55 on peripheral blood red cells | Advantage: Useful to determine the degree of GPI anchor deficiency (PNH type I, type II, type III). Disadvantage: Decreased sensitivity due to the short half-life of circulating PNH red blood cells. |
| - CD59, CD24, CD16, or any other GPI-linked proteins expressed on peripheral blood granulocytes | Advantage: The deficiency of at least 2 GPI-linked proteins is sensitive and specific for the diagnosis of PNH. Disadvantage: Might be difficult to perform in severe aplastic anemia when the number of circulating granulocytes is very low. |
| - FLAER (fluorescently labeled inactive toxin aerolysin) binding of peripheral blood granulocytes | FLAER binds the GPI anchor. Advantage: The lack of FLAER binding on granulocytes is sufficient for the diagnosis of PNH. Disadvantage: Cannot be used for the analysis of red blood cells or platelets. Might be difficult to perform in severe aplastic anemia when the number of circulating granulocytes is very low. |
| - PIGA gene mutation analysis | Although very specific is NOT used for diagnosing PNH. |
| Supportive laboratory tests | |
| Are parameters of intravascular hemolysis, they are supportive but not diagnostic. |
| Diagnostic tests . | . |
|---|---|
| * The flow cytometric analysis of bone marrow cells or the expression of GPI-linked proteins is of NO diagnostic value. | |
| Traditionally: | |
| The lysis of PNH red blood cells exposed to activated complement tests for the deficiency of CD59 and CD55 on red blood cells. The tests vary in the pathways activating complement. Advantage: Cheap and simple to perform Disadvantage: Labor intensive, decreased sesitivity due to the short half-life of circulating PNH red blood cells. |
| Today: | |
| • Flow cytometric analysis:* | |
| - CD59 and/or CD55 on peripheral blood red cells | Advantage: Useful to determine the degree of GPI anchor deficiency (PNH type I, type II, type III). Disadvantage: Decreased sensitivity due to the short half-life of circulating PNH red blood cells. |
| - CD59, CD24, CD16, or any other GPI-linked proteins expressed on peripheral blood granulocytes | Advantage: The deficiency of at least 2 GPI-linked proteins is sensitive and specific for the diagnosis of PNH. Disadvantage: Might be difficult to perform in severe aplastic anemia when the number of circulating granulocytes is very low. |
| - FLAER (fluorescently labeled inactive toxin aerolysin) binding of peripheral blood granulocytes | FLAER binds the GPI anchor. Advantage: The lack of FLAER binding on granulocytes is sufficient for the diagnosis of PNH. Disadvantage: Cannot be used for the analysis of red blood cells or platelets. Might be difficult to perform in severe aplastic anemia when the number of circulating granulocytes is very low. |
| - PIGA gene mutation analysis | Although very specific is NOT used for diagnosing PNH. |
| Supportive laboratory tests | |
| Are parameters of intravascular hemolysis, they are supportive but not diagnostic. |