Researchers may have discovered why African Americans on dialysis sometimes require higher doses of erythropoietin-stimulating agents (ESAs) than dialysis patients of other ethnicities.
The team found that sickle cell trait was more common in African Americans on dialysis than in the general African American population.
And patients with sickle cell trait required higher ESA doses than other African American dialysis patients to reach the same hemoglobin level.
The researchers reported these findings in the Journal of the American Society of Nephrology.
The team noted that kidney abnormalities have been reported in some individuals with sickle cell trait. And studies have shown that African Americans with kidney failure require higher doses of ESAs to treat anemia during dialysis. So researchers wondered if there was a correlation.
To find out, Vimal Derebail, MD, of the University of North Carolina at Chapel Hill, and his colleagues examined laboratory and clinical data concerning 5319 adult African American hemodialysis patients.
But the researchers looked at the presence of hemoglobin C trait as well as sickle cell trait.
In the entire study cohort, 542 (10.2%) patients had sickle cell trait, and 129 (2.4%) had hemoglobin C trait. There were no other hemoglobinopathy traits present.
Sickle cell trait was more common among dialysis patients than the general African American population—10.2% and 6.5%-8.7%, respectively (P<0.05).
Among the 5002 patients receiving ESAs, 10.3% had sickle cell trait and 2.4% had hemoglobin C trait.
The patients with hemoglobinopathy traits received higher median ESA doses than patients with normal traits—4737.4 units/treatment and 4364.1 units/treatment, respectively (P=0.02).
Having either hemoglobinopathy trait was associated with a 13.2% increase in ESA dose (P=0.001). And patients with either trait had a 30% increased risk of falling into the highest quartile of ESA dosing.
There was no significant difference in the dose increase according to trait type (P=0.10).
The researchers therefore said these findings suggest the presence of hemoglobinopathy traits, particularly sickle cell trait, may explain why greater ESA doses are administered to African American dialysis patients relative to Caucasian patients.
“While we don’t know whether there are any adverse consequences to this higher dose of medication yet, further policies and decisions regarding management of anemia in dialysis patients should take into account these findings,” Dr Derebail said.
He added that future research should also explore whether sickle cell trait is more common in dialysis patients because it contributes to kidney disease.
