title: The relationship between reticulocyte hemoglobin content with C-reactive protein and conventional iron parameters in dialysis patients.
abstract: Adequate iron stores are a prerequisite for successful erythropoietin (EPO) therapy in hemodialysis (HD) patients. Nevertheless, iron status estimation in HD patients remains problematic, as most parameters are influenced by inflammation. The reticulocyte hemoglobin content (CHr) has recently been proposed as a useful tool in iron status assessment. However, the effect of inflammation on CHr remains unstudied. This study aimed to assess the relationship between CHr with other parameters of iron status as well as with C-reactive protein (CRP). This relationship was studied in all the patients (n=61) at our dialysis unit. CHr was significantly and positively related to transferrin saturation (TS) (rho=0.26; p<0.05) and inversely to the percentage of hypochromic red blood cells (%Hypo) (rho=-0.63; p<0.0001), but not to serum ferritin. CHr was strongly and inversely related to log CRP (rho=-0.50; p<0.0001). Despite the use of maintenance intravenous (i.v.) iron doses and relatively high serum ferritin levels, a large percentage of patients were in a state of functional iron deficiency (%Hypo > or = 6 in 41% of patients and CHr < or = 29 pg in 13% of patients). This percentage was far lower in patients with CRP levels below the detection limit (2 mg/L) (26% and 0%, respectively). In conclusion, CHr is related to both TS and %Hypo, but not to serum ferritin, and is strongly influenced by the presence of inflammation (as determined by CRP). In patients with elevated CRP levels, it is very difficult to reach target iron status levels without exceeding the upper limits for serum ferritin.
authors.affiliation: Department of Clinical Chemistry, University Hospital Maastricht, The Netherlands.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Hackeng
authors.forename: Charles M
authors.initials: CM
authors.lastname: Beerenhout
authors.forename: Marc
authors.initials: M
authors.lastname: Hermans
authors.forename: P Hugo M
authors.initials: PH
authors.lastname: Van der Kuy
authors.forename: Henk
authors.initials: H
authors.lastname: Van der Dussen
authors.forename: Marja P
authors.initials: MP
authors.lastname: Van Dieijen-Visser
authors.forename: Karly
authors.initials: K
authors.lastname: Hamulyák
authors.forename: Frank M
authors.initials: FM
authors.lastname: Van der Sande
authors.forename: Karel M
authors.initials: KM
authors.lastname: Leunissen
authors.forename: Jeroen P
authors.initials: JP
authors.lastname: Kooman
mesh_terms: D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis*; D004921:Erythropoietin / Q000627:therapeutic use; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007249:Inflammation; D007501:Iron / Q000008:administration & dosage; D000090463:Iron Deficiencies; D008297:Male; D011994:Recombinant Proteins; D006435:Renal Dialysis; D012156:Reticulocytes / Q000737:chemistry*
chemical_list: D006454:Hemoglobins; D011994:Recombinant Proteins; D004921:Erythropoietin; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron