RESUMO
Phagocytosis and peroxidase activity of PMNLs were evaluated in eleven polytransfused patients [mean age 6.5 +/- 2.5 years] with high serum ferritin [mean 1390 ng/ml S.D. 219.3 ng/ml] and high serum iron [mean 196.9 ug/100ml, S.D. 20.5 ug/100 ml] and in 10 normal controls of matched age and sex. The patients were, 6 cases of B. thalassemia major, 2 cases with diamond-Blackfan anaemia, one case of sickle cell thalassemia, one case of sidroblastic anaemia and one case of chronic renal failure. Phagocytic index [P.I.], phagocytic percentage [P.P] and peroxidase activity were highly significantly reduced in patients than controls. Also patient's serum exerted highly significant inhibitory effect on phagocytic functions of patient's and control's PMNLs. After 10 - 12 weeks of desferrioxamin treatment, the studied PMNL function parameters were returned to normal in all patient's and the inhibitory effect of patient's serum was lost. These data suggest that patients receiving multiple blood transfusions have a reversible impairment of their neutrophil functions which is most probably due to iron overload