Is analysis of the reticulocyte haemoglobin equivalent a useful test for the diagnosis of iron deficiency anaemia in geriatric patients?

BACKGROUND

Iron deficiency anaemia (IDA) and anaemia of chronic disease (ACD) are common in elderly patients but there are no standard diagnostic criteria. The reticulocyte haemoglobin equivalent (Ret-He) is routinely measured by modern automated blood analysers and is an early indicator of iron deficiency. The aim of this study was to investigate whether the Ret-He level as calculated by the Sysmex XE-5000 automated blood analyser is a useful parameter for the diagnosis of IDA in a geriatric hospitalized population.

METHODS

In a prospective study, blood samples were collected in 26 geriatric patients with IDA and 111 patients with ACD diagnosed according to generally accepted laboratory and clinical criteria. A blood count including Ret-He, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and standard iron parameters was performed in each patient.

RESULTS

Haemoglobin, Ret-He, MCV, MCH and MCHC levels were all significantly lower in IDA as compared to ACD patients. However, the area under the curve (AUC) was greater for MCH (0.87, 95% CI 0.78-0.95) and MCHC (0.86, 95% CI 0.76-0.96) then for Ret-He (0.828, 95% CI 0.73-0.93) and MCV (0.80, 95% CI 0.68-0.91). A Ret-He cut-off value of 26 pg had a sensitivity and specificity based on its optimal combination of 85% and 69% respectively.

CONCLUSION

Analysis of Ret-He does not perform better than the classical red cell indices such as MCH and MCHC in differentiating IDA and ACD in geriatric patients.