Variations of ferritin levels over a period of 15 years as a compliance chelation index in thalassemic patients.

We studied the changing pattern of the distribution of ferritin levels in 430 regularly-transfused patients with thalassemia in an attempt to evaluate compliance of chelation with deferoxamine. The study covered 15 years and was divided in three periods: 1981-1985, 1986-1990, and 1991-1995. The patients were stratified in age-groups. The mean ferritin levels of each period were calculated for each patient individually. The study showed that: (i) When all the patients were compared as a group, there was a significant decrease in mean ferritin between 1981-1985 and 1991-1995, despite a significant change in the patients' mean age; (ii) When patients of same age were compared between periods, there was a decrease in mean ferritin between 1981-1985 and 1991-1995, as well as a decrease in the proportion of patients with ferritin >4000 microg/L, with a parallel increase in the proportion of patients who had ferritin <2000 microg/L; (iii) When the same patients were followed longitudinally, they showed a decrease in their ferritin levels in all age groups with the exception of the late adolescence period. The decrease in iron overload observed in patients on close follow up implies that compliance with chelation therapy has improved with time and therefore, a favourable influence in survival could be expected. Copyright 2001 Wiley-Liss, Inc.