Lab tests

Flow cytometry is widely considered the most informative way to confirm a PNH diagnosis.

It detects if red blood cellsred blood cellsThe most common type of blood cell. Their job is to carry oxygen using an important molecule, hemoglobin, around the body. are missing their protective shield, a key sign of PNH. It also calculates the quantity of blood cells impacted by PNH, which is called your “clone size.” If you have a large clone size, it means you have a high percentage of blood cells that may be destroyed, which may lead to more severe symptoms.

Making sense of the numbers

The goal of treatment in PNH is to prevent destruction of red blood cells. While there is no formal standard for exactly what numbers reflect red blood cell destruction, many doctors consider a combination of factors to be the best gauge.

For example, your doctor may consider lab results for hemoglobin, LDH and ARC levels in combination with the number of transfusions in the past 12 months.

If you’d like to track your lab results to see changes over time, download the This is PNH app.

Speaking with a physician who specializes in PNH may be helpful. The Aplastic Anemia and MDS International Foundation offers support finding and connecting with specialists here.