Red cell indices as predictors of iron depletion in blood donors.

The objective of this study was to investigate whether red cell indices mean cell volume (MCV) and mean cell haemoglobin (MCH) were lower in frequent blood donors and hence, indirectly, able to predict impending iron depletion. Serum ferritin and/or soluble transferrin receptor levels can be used to evaluate iron status but are not practical for routinely screening blood donors prior to donation. Hb, MCV and MCH were measured on venous blood from 886 blood donors using a Sysmex E-5000. Full details were obtained for all donors of each earlier donation over the previous 3 years. MCV and MCH levels were lowest in donors with the highest frequency of previous blood donation. There was a significant negative correlation between MCV and number of donations in males and females and between MCH and number of donations in females, over the 3 year period 1995-97. Similar trends were observed when only the previous year's donations (1997) were considered with all categories showing significant negative correlations and additionally, Hb levels in females showed negative correlation with number of donations in 1997. In conclusion, increased frequency of blood donations is associated with lower MCV and MCH. These red cell indices, or more sophisticated parameters such as percentage hypochromic cells, should be used to monitor early onset of iron depletion in frequent blood donors.