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 4 30 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 pati ents 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 dec rease in mean ferritin between 1981-1985 and 1991-1995, despite a significa nt change in the patients' mean age; (ii) When patients of same age were co mpared 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 wit h ferritin > 4000 mug/L, with a parallel increase in the proportion of pati ents who had ferritin < 2000 mug/L; (ill) When the same patients were follo wed 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 compl iance with chelation therapy has improved with time and therefore, a favour able influence in survival could be expected. (C) 2001 Wiley-Liss, Inc.