[Iron overload in sickle cell anemia : a study of 94 patients]

Abstract

Background: Sickle cell disease is an autosomal, recessive hemoglobinopathy characterized by hemolytic anemia. Red blood cell transfusions are uncommon therapeutic mainstay in sickle cell disease and repeated transfusions can result in iron overload. The predicted risks of iron overload and organ failure increase with both the duration of disease requiring transfusion therapy and the number of transfusions.

Aim: To assess the state of iron overload in patients with sickle ce anemia according to their number of transfusions.

Methods: The medical records of 94 patients with sickle cell anemia (46 had homozygous sickle cell disease, 41 had sickle-ß thalassemia, 7 had compound heterozygous hemoglobin: 4 SC and 3 SOArab) were retrospectively reviewed for the following: clinical exam, serum ferritin level, liver function tests, abdominal ultrasound exam and heart Doppler.

Results: 61% of our patients are from the Northern- west of the country. The average age is 18.29 years (2 to 62 years) and the sexratio is 0.62. In addition to parental consanguinity which is found in 28.72% of the cases. The average level of ferritin is 660.35 ng/ml. 41.5% of the patients have a high status of ferritin witch ranged from 521.4 to 3360 ng/ml. There is not a significant difference of ferritin level according to age, sex and a phenotype of sickle cell anemia. However, it is higher among the transfused patients with a same phenotype (p<0.05). We found a correlation between serum ferritin levels and the number of transfusions (r =+0.74). Splenectomy has a preventive role because it allowed stopping the transfusion in 65% of the cases. The evaluation of organ dysfunction has found a hepatomegaly in 29% of the cases, half of witch were have a high status of serumferritin (> 1000 ng/ml). Left ventricular hypertrophy associated to valvulopathy was classified in 10 % of the cases.

Conclusion: Iron overload in sickle cell anemia, though relying on transfusion, remains moderate. The repetitive assessment of serum ferritin level is considered as the best test though it does not evaluate an organic dysfunction. To evaluate them better, other tests are requiring: magnetic resonance imaging and Tc-Squid biosusceptometers.