Update on Anemia in ESRD and Earlier Stages of CKD: Core Curriculum 2018

Abstract

Anemia is a frequent complication during the later stages of chronic kidney disease. When present, it may cause symptoms such as fatigue and shortness of breath. The pathogenesis of anemia in chronic kidney disease is complex, but a central feature is a relative deficit of erythropoietin. New information has elucidated the critical role of the hypoxia-sensing system in mediating erythropoietin synthesis and release. Iron deficiency is a second important factor in the anemia of chronic kidney disease. New insights into the dynamics of iron metabolism have clarified the role of chronic inflammation and hepcidin as key mediators of impaired iron utilization. In this article, we review the epidemiology, pathobiology, clinical evaluation, and treatment of anemia in chronic kidney disease.

The role of iron repletion in adult iron deficiency anemia and other diseases

“…The prevalence of anemia in patients with chronic kidney disease (CKD) is 15.4% compared to 7.6% in the general population, but prevalence rises up to 53.4% in patients with End‐Stage Renal Disease (ESRD) . Major factors contributing to anemia in CKD include reduced EPO production, chronic inflammation leading to poor iron absorption and availability, blood loss (GI or hemodialysis associated), and nutritional iron deficiency . These factors may lead to functional and/or absolute iron deficiencies, which need to be clinically differentiated for optimal treatment.…”

“…Rates of acute infusion‐related hypersensitivity reactions are low with IV iron use in NDD‐ and PD‐CKD patients and the safety of short‐term IV iron is established by multiple trials . A trial of oral iron may however be considered in NDD‐CKD patients based on the severity of their anemia, previous response to oral iron, venous access, and cost considerations . Use of ESAs increases utilization of iron stores for hematopoiesis; they should only be used after functional or absolute iron deficiency has been corrected .…”

“…60 Major factors contributing to anemia in CKD include reduced EPO production, chronic inflammation leading to poor iron absorption and availability, blood loss (GI or hemodialysis associated), and nutritional iron deficiency. 61 These factors may lead to functional and/or absolute iron deficiencies, which need to be clinically differentiated for optimal treatment. While serum ferritin concentration <30 µg/L or TSAT <20% is indicative of an absolute iron deficiency, no current laboratory test accurately diagnoses functional iron deficiency in CKD patients.…”

Renal anemia and hydration status in non-dialysis chronic kidney disease: Is there a link?

“…Anemia is common in the course of chronic kidney disease (CKD) and end-stage kidney disease (ESKD), due to either disturbances induced by the glomerular filtration rate (GFR) decline (as erythropoietin deficiency, iron metabolism impairment, inflammation, uremic toxins retention, vitamin deficiencies, secondary hyperparathyroidism, reduced red cells survival) or the underlining disease or various chronic therapies [1]. Decreased renal production of erythropoietin (Epo) is its main mechanism, but increased iron losses and impaired absorption of dietary iron are also present.…”

“…Large interventional trials with recombinant human Epo, targeting near-normal hemoglobin levels, did not find any benefit on survival [1], while the risk for stroke, thromboembolic events and recurring cancers was higher [8]. On the other hand, intravenous iron (increasingly used in the last years) could lead to long-term complications related to triggering oxidative stress or tissue deposition, for example [8].…”