Use of exogenous erythropoietin in critically ill patients

Targeting the innate repair receptor axis via erythropoietin or pyroglutamate helix B surface peptide attenuates hemolytic-uremic syndrome in mice

Hemolytic-uremic syndrome (HUS) can occur as a systemic complication of infections with Shiga toxin (Stx)-producing Escherichia coli and is characterized by microangiopathic hemolytic anemia and acute kidney injury. Hitherto, therapy has been limited to organ-supportive strategies. Erythropoietin (EPO) stimulates erythropoiesis and is approved for the treatment of certain forms of anemia, but not for HUS-associated hemolytic anemia. EPO and its non-hematopoietic analog pyroglutamate helix B surface peptide (pHBSP) have been shown to mediate tissue protection via an innate repair receptor (IRR) that is pharmacologically distinct from the erythropoiesis-mediating receptor (EPO-R). Here, we investigated the changes in endogenous EPO levels in patients with HUS and in piglets and mice subjected to preclinical HUS models. We found that endogenous EPO was elevated in plasma of humans, piglets, and mice with HUS, regardless of species and degree of anemia, suggesting that EPO signaling plays a role in HUS pathology. Therefore, we aimed to examine the therapeutic potential of EPO and pHBSP in mice with Stx-induced HUS. Administration of EPO or pHBSP improved 7-day survival and attenuated renal oxidative stress but did not significantly reduce renal dysfunction and injury in the employed model. pHBSP, but not EPO, attenuated renal nitrosative stress and reduced tubular dedifferentiation. In conclusion, targeting the EPO-R/IRR axis reduced mortality and renal oxidative stress in murine HUS without occurrence of thromboembolic complications or other adverse side effects. We therefore suggest that repurposing EPO for the treatment of patients with hemolytic anemia in HUS should be systematically investigated in future clinical trials.

The role of erythropoietin in the acute phase of trauma management: evidence today

Trauma patients often present in a state of haemorrhagic shock. Blood products remain the gold standard of resuscitation, but allogeneic blood transfusions (ABTs) are associated with several risks. The stimulating effect of recombinant-erythropoietin (EPO-A) on erythropoiesis has raised interest in its administration as an alternative. The existing evidence on the early use of EPO-A in the acute phase of trauma patients management consists of only 14 publications. The level of evidence of these studies and the number of treated patients was not found to be adequate to support its generalised use, despite their favourable results. Its safety profile, the preliminary proofs of its efficacy, and the additional cyto-protective properties of EPO-A strongly encourage further controlled studies assessing its use in the acute setting of initial trauma management.

A meta-analysis of randomized controlled trials in critically ill patients to evaluate the dose-response effect of erythropoietin

The use of erythropoietin in critically ill patients has been investigated in multiple randomized clinical trials and its role in decreasing the number of units of blood transfused has been demonstrated in some trials. A meta-analysis was conducted to determine the pooled estimate of the decrease in number of units of blood transfused with the use of erythropoietin and investigated its dose-response effect. A systematic search was performed of the MEDLINE, EMBASE, and the Current Controlled Trials Register to identify randomized clinical trials investigating the role of erythropoietin in critically ill patients. Of 664 studies identified in the search, 5 randomized clinical trials met the inclusion criteria. The pooled estimate of the decrease of number of units of blood transfused was -1.64 (95% CI -2.6 to -0.67). Sensitivity analysis to establish the influence of temporal bias, quality of the study and comorbidities such as age and Acute Physiology and Chronic Health Evaluation (APACHE) II score were undertaken and did not reveal a significant difference. The inclusion of studies with higher doses of erythropoietin revealed a greater decrease in the number of units of blood transfused (-2.15; 95% CI -3.06 to -1.24). Despite the limitations of a meta-analysis we believe that the use of erythropoietin significantly decreases the number of units of blood transfused per patient. Our study also reveals the possibility of a dose-response effect of erythropoietin in decreasing the number of units of blood transfused.

Cost-effectiveness of recombinant human erythropoietin for reducing red blood cells transfusions in critically ill patients

OBJECTIVE

To examine the cost-effectiveness of using recombinant human erythropoietin (rHuEPO) to reduce red blood cells (RBC) transfusions in intensive care unit (ICU) patients.

METHODS

Decision analysis examining costs and effectiveness of using rHuEPO versus not using rHuEPO in a simulated adult medical/surgical/trauma (mixed) ICU. Two independent cost-effectiveness models were created based on the results of two multicenter studies that investigated the use of rHuEPO. Base case assumptions and estimates of effectiveness were obtained from these two studies. Mean cumulative doses of rHuEPO were 190,900 units and 102,400 units for studies 1 and 2, respectively. The models accounted for the deferral rate for allogeneic RBC transfusions, rHuEPO efficacy (the reduction in allogeneic RBC use), and adverse effects of rHuEPO and allogeneic RBC transfusions. Model estimates were obtained from published sources. Costs were expressed in 2002 US dollar (dollars) and effectiveness was measured using discounted quality-adjusted life-years (QALYs). A 3% discount rate was used. Probabilistic sensitivity analysis was conducted using second-order Monte Carlo simulation.

RESULTS

Incremental costs of using rHuEPO to reduce RBC transfusions amounted to 1918 dollars and 1439 dollars; incremental effectiveness values were 0.0563 QALYs and 0.0305 QALYs; and the cost-effectiveness ratios were 34,088 dollars and 47,149 dollars per QALY for studies 1 and 2, respectively. The model was most sensitive to the attributable risk of nosocomial bacterial infections per RBC unit. rHuEPO was cost-effective in 52.0% of the Monte Carlo simulations for a willingness to pay of 50,000 dollars/QALY.

CONCLUSION

rHuEPO appears to be cost-effective for reducing RBC transfusions in heterogeneous ICU populations, assuming RBC transfusions increase the risk of nosocomial bacterial infections.