Diagnosis
Because PNH is so rare, overall awareness of the disease and its natural history
has been very limited. PNH can be difficult to detect and sometimes takes years
to diagnose. The disease affects different people in different ways, and symptoms
can vary widely from patient to patient.
Clinical trials of Soliris® (eculizumab) for the treatment
of PNH have helped provide the medical community with new information about the
severe and progressive nature of PNH.18-20 A growing number of physicians
recognize the importance of accurate diagnosis and early intervention. They are
implementing standardized diagnostic pathways to identify people with a greater
likelihood of having PNH, including patients with bone marrow disorders such as
Aplastic Anemia and Myelodysplastic Syndromes, and people with unexplained blood
clots, hemoglobinuria (dark urine), hemolytic anemia and unexplained thrombocytopenia
(reduced platelet levels). Alexion is encouraging the use of standardized diagnostic
pathways through educational programs.
Physicians can determine the exact proportion of PNH cells in a patient's blood
by using flow cytometry, a sophisticated laboratory technique that identifies and
sorts blood cells and their components. Flow cytometry is considered to be the standard
diagnostic test for confirming a PNH diagnosis and in most cases has replaced the
need for older tests including the Ham test or sucrose hemolysis test.21
FLAER technology, a specific type of flow cytometry test, is becoming more and more
popular because it is highly sensitive to PNH.22
Alexion continues to conduct research to better understand diagnosis of the PNH.