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.