ASN Kidney Week
SAN DIEGO—The presence of variant hemoglobin (Hb)–sickle cell trait and hemoglobin C trait (HbAc) in African-American hemodialysis patients is associated with an increase in erythropoiesis-stimulating agent (ESA) dose, researchers reported here at the American Society of Nephrology (ASN) Kidney Week 2012 (TH-OR098).
“It's been observed in the past that African-Americans on hemodialysis receive more ESAs,” said Vimal K. Derebail, MD, MPH, of the UNC Kidney Center, who presented the information at the meeting on behalf of his team.
“At every category of hemoglobin achieved, as we reach the higher percentiles of EPO [erythropoietin] dosing, African-Americans are in a higher proportion than Caucasian counterparts, suggesting that no matter the achieved hemoglobin, African-Americans receive more ESA.”
Variant hemoglobin was common, found in 671 (12.6%) of the 5,323 African-American adult prevalent hemodialysis patients in the study. Of the total study population, 542 patients (10.2%) had the sickle cell trait and 129 (2.4%) had the hemoglobin C trait.
Demographic characteristics and laboratory values were similar across the groups of patients regardless of whether they did or did not have variant hemoglobin.
In a univariate analysis, the median ESA dose was about 10% higher in those with variant hemoglobin and was consistent for the two traits. In multivariate models, this percentage jumped to about 13% but only reached statistical significance for the sickle cell trait.
While recognizing that the cross-sectional study is subject to potential confounders, Dr. Derebail noted potential implications of the findings.
“Could these higher ESA doses in this patient population lead to higher morbidity and mortality, both in terms of thrombotic risks and cardiovascular outcomes?” he said.