Combined cell index in assessing blood donor iron stores

The aim of this study was to assess the appropriateness of using combined cell index (CCI) in the assessment of iron stores in blood donors. This index is calculated by the formula: red blood cell distribution width (RDW) × 10⁴ × mean corpuscular volume (MCV)^-1 × mean corpuscular haemoglobin (MCH)^-1 .

Ferritin measurement is a reliable method for estimating iron stores in blood donors. The sensitivity of red blood cell (RBC) parameters of complete blood count in detecting non-anaemic iron deficiency is significantly lower. Consequently, there were several attempts to increase the detection sensitivity by combining these parameters in different indices.

This study included 1084 male and 792 female whole blood donors accepted for blood donation. For six RBC parameters with the highest level of correlation relative to ferritin [Hgb, MCV, MCH, mean corpuscular haemoglobin concentration (MCHC), RDW and CCI], diagnostic efficacy in the detection of iron depletion (ferritin <12 µg L^-1 ) was assessed using receiver operating characteristic (ROC) analysis.

CCI showed the highest degree of correlation with ferritin (r = -0·373 for men and r = -0·590 for women) and the highest area under the curve (0·961 for men and 0·864 for women). Using the cut-off value of 52·6 for men and 50·6 for women, the corresponding Youden index was the highest for CCI in both genders (0·851 for men and 0·612 for women). The sensitivity and specificity of CCI in the population of male donors were higher in comparison to female donors (0·941 and 0·910 vs 0·851 and 0·761, respectively).

Study results confirmed the satisfactory diagnostic value of CCI in detecting depleted iron stores in blood donors.