Reticulocyte hemoglobin content in hemodialysis patients with acute infection.

BACKGROUND: Reticulocyte hemoglobin content (CHr) has recently become available as a direct marker of the iron status in hemodialysis patients undergoing recombinant human erythropoietin (rHuEPO) therapy. This study evaluated the stability of CHr in hemodialysis patients with acute infectious disease. METHODS: We retrospectively selected 22 hemodialysis patients who had acute respiratory tract infection and who showed transient elevation of C-reactive protein (CRP), and we investigated changes in parameters for erythropoiesis, iron status, and inflammation, i.e., hematocrit (Ht), transferrin saturation (TSAT), CHr, serum ferritin, and CRP, in the preinfection, infection, and postinfection phases. Throughout the observation period, doses of rHuEPO and iron supplements had not been changed. We divided the patients into two groups, those who showed a decrease in Ht in the infection phase (group 1; n = 12) and those who did not show a change in Ht in this phase (group 2; n = 10). We defined the differences between the parameters in the preinfection phase and the infection phase as Delta, and performed correlation analysis between them. RESULTS: CRP in group 1 was significantly higher than that in group 2 in the infection phase. In group 1, TSAT significantly decreased, from 32.9 +/- 8.8% (preinfection phase) to 16.9 +/- 5.0% (infection phase), and CHr also significantly decreased, from 33.1 +/- 1.5 pg to 30.4 +/- 2.0 pg. In group 2, however, although TSAT significantly decreased, from 34.8 +/- 4.6% to 27.0 +/- 9.3%, CHr showed no significant change (from 33.4 +/- 0.9 pg to 33.0 +/- 1.4 pg). There was a significantly high correlation between DeltaHt and DeltaCHr, but there was a low correlation between DeltaHt and DeltaTSAT ( r = 0.505; P = 0.0153 versus r = 0.175; P = 0.4420). Furthermore, the correlation between DeltaCRP and DeltaCHr was quite high ( r = -0.722; P = 0.0001). CONCLUSIONS: TSAT overreacts to inflammation, failing to reveal the correct status of available iron for erythropoiesis in acute inflammatory disease, but the use of CHr is expected to avoid these disadvantages, providing a reliable direct marker of iron status in the acute infection phase.

Assessment of iron deficiency in chronic hemodialysis patients: investigation of cutoff values for reticulocyte hemoglobin content.

BACKGROUND: Recently, the usefulness of reticulocyte hemoglobin content (CHr) as a ferrokinetic marker in hemodialysis patients who receive recombinant human erythropoietin (rHuEPO) has been reported. However, a definite index for iron deficiency has not been established. In this study, a CHr cutoff value was investigated. METHODS: We retrospectively selected 27 hemodialysis patients by the following criteria: (1) hematocrit (Ht) values less than 30%, (2) patients receiving a stable dose of rHuEPO for at least 3 months, (3) patients who had not received iron supplements for at least 3 months, and had begun receiving iron supplements, (4) the doses of rHuEPO and iron supplements were unchanged for 8 weeks following the start of iron administration. The iron supplement was administered at a dose of 40 mg/week, and Ht, CHr, transferrin saturation (TSAT), and serum ferritin were measured. The difference between the peak Ht value obtained at weeks 4-8 and Ht at baseline was calculated (DeltaHt). Patients with a DeltaHt of 3% or more were categorized as iron-deficient at baseline (group 1; n = 17). Patients with a DeltaHt of less than 3% were categorized as iron-sufficient at baseline (group 2; n = 10). Each parameter was compared between the groups. RESULTS: Significant negative correlations between DeltaHt and CHr at baseline, and DeltaHt and TSAT at baseline were observed. CHr and TSAT were significantly lower in group 1 than in group 2 at baseline. CHr was less than 32 pg in all patients in group 1, and greater than 32 pg in nine of the ten patients in group 2. If the CHr cutoff value was 32 pg, sensitivity was 100% and specificity was 90%. CONCLUSIONS: It is considered that 32 pg is appropriate for the CHr cutoff value.