[Prevention of sickle cell crises with multiple phlebotomies]. / Prévention des crises douloureuses drépanocytaires par saignées itératives.

OBJECTIVES: Sickle cell disease patients suffering from frequent painful crises were submitted to phlebotomies in order to reduce hospitalization days due to pain, through hemoglobin (Hb) level reduction and iron deficiency in patients with an hemoglobin level equal to or above 9.5 g/dL. PATIENTS: Seven sickle cell disease patients (four SC, three SS), aged four to 24 years, were submitted to sequential phlebotomies during periods from 18 months to four years. METHODS: The number of hospitalization days for crises was considered. The volumes and frequencies of phlebotomies were adjusted according to the patients ages, the hemoglobin concentrations and the serum ferritin levels. RESULTS: One hundred and forty-four hospitalization days were recorded in the seven patients in the year preceding the treatment. During the study period, the annual numbers of hospitalization days were respectively 20, five, six and one. Mean hemoglobin concentration was 10.7 g/dL before phlebotomies and 8.8 to 9.2 g/dL during the four years of treatment. Mean corpuscular volume, mean corpuscular hemoglobin concentration and serum ferritin were also reduced. The volume of phlebotomies was 116 to 39 mL/kg/year according to the patients. COMMENTS AND CONCLUSION: The striking decrease of the number of hospitalization days for all the patients suggests a closed relationship between therapy and clinical improvement. The mechanism of this effect is probably multifactorial: a) the concentration of Hb level is known to influence the blood viscosity and its decrease always improved rheology in sickle cell disease patients; b) the mean corpuscular hemoglobin concentration is a critical factor concerning the HbS molecule polymerization in sickle cell disease, and its slight reduction may have an important biological effect. We observed these two biological modifications in our patients and suggest that they mediate the clinical effects. The iron deficiency induced by phlebotomies has no evident deleterious consequence either on height and weight in the children or on intellectual performance in any patients.