Ham test

The Ham test is a test used in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). The 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. The Ham test is a test used in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). The 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. Ham's test is occasionally positive in aplastic anemia.