| Ham test |
The Ham test is a blood test used in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). Patient red blood cells (RBCs) are placed in mild acid; a positive result (increased RBC fragility) indicates PNH or congenital dyserythropoietic anemia.[1] This is now an obsolete test for diagnosing PNH due to its low sensitivity and specificity.[2]
As one fourth of PNH cases progress to aplastic anemia, Ham's test is occasionally positive in AA.[3]