Variant hemoglobin phenotypes may account for differential erythropoiesis-stimulating agent dosing in African-American hemodialysis patients.

African-American patients with end-stage renal disease have historically lower hemoglobin concentrations and higher requirements of erythropoiesis-stimulating agent (ESA). While disparities in health-care access may partially explain these findings, the role of variant hemoglobin, such as sickle trait, has not been investigated. To clarify this, we evaluated 154 African-American patients receiving in-center hemodialysis with available hemoglobin phenotyping. The primary exposure was any abnormal hemoglobin variant and the primary outcome of higher-dose ESA was defined as a dose of 6500 or more units per treatment. Logistic regression assessed the association between variant hemoglobin and higher-dose ESA. Covariates included age, gender, diabetes, iron parameters, intravenous iron dose, parathyroid hormone, albumin, phosphorus, body mass index, vascular access type, hospitalization/missed treatments, smoking status, alcohol abuse, and gastrointestinal bleeding. Of 33 patients with variant hemoglobin, 24 had HbAS and 9 had HbAC. Univariate odds of higher-dose ESA among those with hemoglobin variants were twice that of those with the normal HbAA phenotype (odds ratio 2.05). In multivariate models, the likelihood of higher-dose ESA had an odds ratio of 3.31 and the nature of this relationship did not change in Poisson regression or sensitivity analyses. Hence, our findings may explain, in part, the difference in ESA dosing between Caucasians and African-Americans with end-stage renal disease but await further study.

[Hemoglobinopathies. Current therapeutic possibilities]. / Haemoglobinopatier. Aktuelle behandlingsmuligheder.

In recent years, the number of immigrants has increased considerably in Denmark. Consequently, a series of new clinical pictures has appeared in the Danish health care system. Typical examples are the genetic diseases, the haemoglobinopathies. Most of the immigrants come from areas, where the gene frequency of these disorders is widely distributed, for instance the Mediterranean countries, the Middle East, Southeast Asia and Africa. Most frequent are the heterozygous thalassaemias, but also the number of patients with severe thalassaemia and other clinically important haemoglobinopathies such as sickle cell anaemia has also increased in recent years. The clinical problems concerning these patients focus on two important topics, namely genetic counselling of heterozygous individuals (in some cases combined with prenatal diagnostics) and the treatment of patients with clinically severe haemoglobinopathy. The only curative treatment of the haemoglobinopathies is allogeneic bone marrow transplantation, but this treatment can only be offered to a few of these patients. However, a variety of therapeutic options exist which can improve their prognosis and quality of life. Since the number of patients with these diseases will probably increase over the next years we find it relevant, based on typical case stories, to give a review of the present therapeutic possibilities for these disorders.