Publication

Interpretation of erythropoietin levels in patients with various degrees of renal insufficiency and anemia

Journal Paper/Review - Sep 1, 2004

Units
PubMed
Doi

Citation
Fehr T, Ammann P, Garzoni D, Korte W, Fierz W, Rickli H, Wüthrich R. Interpretation of erythropoietin levels in patients with various degrees of renal insufficiency and anemia. Kidney international 2004; 66:1206-11.
Type
Journal Paper/Review (English)
Journal
Kidney international 2004; 66
Publication Date
Sep 1, 2004
Issn Print
0085-2538
Pages
1206-11
Brief description/objective

BACKGROUND: Chronic renal failure leads to hyporegenerative anemia due to erythropoietin deficiency. The creatinine clearance and hemoglobin levels, at which anemia treatment with recombinant erythropoietin should be started, are unclear. Interpretation of serum erythropoietin levels in the context of renal insufficiency remains controversial and was addressed in this study. METHODS: Three hundred and ninety-five patients were randomly chosen out of over 5000 consecutive patients investigated by coronary angiography at a single center between 1997 and 2001. Laboratory values and clinical information were prospectively collected in a central registry. Serum samples were frozen before angiography and now used to measure serum erythropoietin levels and evaluate the relationship between erythropoietin and hemoglobin levels in the context of various degrees of renal insufficiency. RESULTS: The patients with the lowest renal function (creatinine clearance <20 mL/min) had significantly lower hemoglobin levels than the group with normal renal function. However, erythropoietin levels were identical indicating a lower set point for erythropoietin regulation. Above a creatinine clearance of 40 mL/min a significant inverse correlation between erythropoietin and hemoglobin levels was observed and described with the formula erythropoietin [U/L]= 2.5 x (140 - hemoglobin [g/L]) or alternatively Deltaerythropoietin (U/L) =-2.5 xDeltahemoglobin (g/L). Below 40 mL/min no significant correlation was found. CONCLUSION: A cut-off level for an altered set point of erythropoietin regulation was determined at 40 mL/min creatinine clearance. Above this cut-off hemoglobin negatively regulates erythropoietin. Below the cut-off erythropoietin levels remain stable. Pathophysiologic concepts for this finding and clinical implications in patients with moderate renal failure are discussed.