Incidence of high erythrocyte count in infants and young children with iron deficiency anemia: re-evaluation of an old parameter.

Purpose: To investigate the frequency of high erythrocyte count (red blood cell count >or=5.0 x 106/microL) in infants and young children with iron deficiency anemia and to document the differences in hematologic parameters at diagnosis and during iron therapy in IDA patients with and without a high erythrocyte count.

Patients And Methods: A total of 140 infants and young children aged 6 to 48 months with nutritional IDA without a history of any bleeding disorder were the subjects of this study. The patients were divided into three groups according to the severity of anemia. Group A1 children had Hb values 8.0 g/dL or less (severe anemia); group A2, 8.1 to 10.0 g/dL (moderate anemia); and group A3, 10.1-11.0 g/dL (mild anemia). All children received oral iron (3-5 mg/kg per day) for 12 weeks. Complete blood counts were done weekly during treatment.

Results: A total of 36 of the 140 patients (26%) had a high erythrocyte count. Of the 140 patients, 37 were in group A1, 80 in A2, and 23 in A3. The frequency of high erythrocyte count was 11%, 23%, and 61% in groups A1, A2, and A3, respectively. The patients with a high erythrocyte count had significantly higher Hb and Hct but significantly lower mean corpuscular volume and mean corpuscular hemoglobin (MCH) values than those with a low erythrocyte count (n = 104). A continuous elevation in the erythrocyte count has been observed in patients with a high red cell count, as in those with a low red cell count, after the institution of iron therapy.

Conclusions: A high erythrocyte count is a common feature of iron deficiency anemia in infants and young children, with an increasing frequency from severe to moderate to mild anemia. High erythrocyte count cannot be regarded as a reliable preliminary parameter in differentiating iron deficiency from thalassemias in infants and children aged up to 48 months.