Eculizumab costs at least US$440,000 for a single year of treatment and has been reported as one of the worlds most expensive drugs. Signs and symptoms
The classic sign of PNH is red discoloration of the urine due to the presence of hemoglobin  and hemosiderin from the breakdown of red blood cells. As the urine is more concentrated in the morning, this is when the color is most pronounced. This phenomenon mainly occurs in those who have the primary form of PNH, who will notice this at some point in their disease course. The remainder mainly experience the symptoms of anemia, such as tiredness, shortness of breath, and palpitations.A small proportion of patients report attacks of abdominal pain, difficulty swallowing and pain during swallowing, as well as erectile dysfunction in men; this occurs mainly when the breakdown of red blood cells is rapid, and is attributable to spasm of smooth muscle due to depletion of nitric oxide by red cell breakdown products.Forty percent of people with PNH develop thrombosis (a blood clot) at some point in their illness. This is the main cause of severe complications and death in PNH.
In this case, anemia may be caused by insufficient red blood cell production in addition to the hemolysis.Historically, the sucrose lysis test, in which a patients red blood cells are placed in low-ionic-strength solution and observed for hemolysis, was used for screening. If this was positive, the Hams acid hemolysis test (after Dr Thomas Ham, who described the test in 1937) was performed for confirmation. The Ham test involves placing red blood cells in mild acid; a positive result (increased RBC fragility) indicates PNH or Congenital dyserythropoietic anemia. This is now an obsolete test for diagnosing PNH due to its low sensitivity and specificity.Today, the gold standard is flow cytometry for CD55 and CD59 on white and red blood cells. Based on the levels of these cell proteins, erythrocytes may be classified as type I, II, or III PNH cells. Type I cells have normal levels of CD55 and CD59; type II have reduced levels; and type III have absent levels. The fluorescein-labeled proaerolysin (FLAER) test is being used more frequently to diagnose PNH. FLAER binds selectively to the glycophosphatidylinositol anchor and is more accurate in demonstrating a deficit than simply for CD59 or CD55. Classification
PNH is classified by the context under which it is diagnosed:
Classic PNH. Evidence of PNH in the absence of another bone marrow disorder. PNH in the setting of another specified bone marrow disorder such as aplastic anemia and myelodysplastic syndrome (MDS). Subclinical PNH. PNH abnormalities on flow cytometry without signs of hemolysis.