The Safety of Erythropoiesis-Stimulating Agents for the Treatment of Anemia Resulting from Chronic Kidney Disease

Chronic kidney disease (CKD) anemia treatment was revolutionized in the late 1980s with the introduction of recombinant human erythropoietin. This and related erythropoiesis-stimulating agents (ESAs) greatly benefited patients by decreasing debilitating symptoms, improving their quality of life, and freeing them from dependence on blood transfusions with their associated complications such as infections, sensitization impeding transplantation, and secondary iron overload. However, even in the initial studies, untoward effects were noted in patients receiving ESAs, including worsening hypertension, seizures, and dialysis access clotting. Later, increased mortality, malignancy progression and even stroke were reported in renal patients. This review focuses on the safety issues of ESAs in CKD patients.

Association between polymorphisms in erythropoietin gene and upper limit haematocrit levels among regular blood donors

PURPOSE OF THE STUDY

Erythropoietin (EPO) is a glycoprotein hormone that functions primarily on the stimulation and control of erythropoiesis in bone marrow. In this study, polymorphisms in EPO gene; C3434T, G3544T (rs551238) and rs1617640 were evaluated to determine their frequencies and genotype distribution patterns among blood donors with upper-limit haematocrit level.

SUBJECTS AND METHODS

A total of 298 subjects, 181 blood donors with haematocrit level greater or equal to 48% and 117 donors with haematocrit between 42-47.5% as control were recruited. All subjects were genotyped for C3434T, rs551238 polymorphisms and for rs1617640 using restriction fragment length polymorphism method (PCR-RFLP) and sequencing techniques.

RESULTS

A significant difference was found in rs1617640 and rs551238 genotype frequencies in blood donors with upper-haematocrit compared to the control group (P<0.05). In accordance with genotype frequencies, G allele in these two polymorphisms were found at higher frequency among upper-haematocrit group compared to the control (P<0.05). On the other hand, C3434T polymorphism was not significantly different between the two groups, neither for genotype frequencies nor for allele frequencies.

CONCLUSION

Results suggest a strong association between rs551238 and rs1617640 polymorphisms in the EPO gene and upper-limit haematocrit level among blood donors.