Importance of RDW value in differential diagnosis of hypochrome anemias

Red cell distribution width (RDW) was studied in adults carrying - thalassemia traits (-TT) who were 20-40 years of age (n = 29), thalassemia traits (-TT) with an age range of 18-60 years (n = 49), iron deficiency anemia (IDA) in individuals aged 1-18 years (n = 27), and in controls with an age range of 20-40 years (n = 20). Although red blood cell count, MCV, and MCH values showed no statistically significant differences between -TT and -TT, the mean RDW value was significantly higher in -TT (20.14 ± 1.21) compared to -TT (14.88 ±1.77) (P < 0.001). No difference was observed between the means of RDW in -TT and IDA (18.00 ± 1.94) (P > 0.05). A significant rise in RDW in IDA 5-7 days after initiation of iron therapy (P = 0.00) which was continued to rise up to the 4th week of therapy was suggested as an important tool in differentiation of IDA from -TT. These observations could be kept in mind in the differential diagnosis of -TT from -TT and IDA by determining the red blood cell count, red cell indices, and RDW only.