Red Blood Cell Phenotype Mosaicism in Paroxysmal Nocturnal Hemoglobinuria (RBC Types)

 

If the red blood cells are stained with labeled anti-CD59 or other red blood cell marker and examined in a flow cytometer, then the intensity of fluorescent signal is proportionate to the density of the surface protein.

 

There are 3 potential types of deficiency in the surface proteins. A patient may show from 1, 2 or all 3 of the different types depending on the clonal mix.

 

Intensity of Fluorescence	Deficiency in Surface Proteins	Phenotype
high	none (normal)	Type I
intermediate	partial	Type II
none to low	complete	Type III

 

If the concentration of Type III cells is high, then the risk of hemolysis is high.

 

A high concentration of Type I or Type II cells is associated with a low rate of hemolysis.

 

Limitations:

• A patient with PNH may have normal RBC phenotype but abnormal clones in the granulocyte and/or monocyte series.