Blood donors’ genetic background affects hemolysis

RBCs from high-intensity donors had significantly higher storage hemolysis (P<0.0001) and lower oxidative hemolysis (P<0.0001) than Caucasian RBCs. There was no significant difference in osmotic hemolysis (P=0.84)

Gender and age

As in other studies, Dr Kanias and his colleagues found that RBCs from females hemolyzed significantly less than RBCs from males. This was true for storage hemolysis, osmotic hemolysis, and oxidative hemolysis (P<0.0001 for all).

“Just to note, the gender effect was more dramatic in storage and osmotic rather than oxidative, which suggests that the gender effect is more on the membrane or membrane integrity rather than antioxidant capacity,” Dr Kanias said.

He and his colleagues then looked at donor age and observed the gender effect at every age analyzed (18 to 65+). He noted that hemolysis fluctuated throughout the age groups, so the investigators couldn’t draw any concrete conclusions about hemolysis and donor age.

“One interesting thing to note is that, in all the assays, in young males—like around 20—there’s an increase in hemolysis where there’s a decrease in females,” Dr Kanias said. “This may be related to the effect of sex hormones.”

Genetic modifiers

The investigators also assessed how the 3 hemolytic assays relate to each other and found very weak correlations between them. Pearson correlations were 0.12 between storage and osmotic hemolysis, 0.0041 between storage and oxidative hemolysis, and 0.058 between osmotic and oxidative hemolysis.

“This is kind of cool because it may mean that there is a different genetic modifier affecting each of these phenomena,” Dr Kanias said.

He and his colleagues are now working to identify genetic and metabolic modifiers of hemolysis.