Dynamics of sickle cell disease as one of the determinants of quality of life

Sickle cell disease (SCD) is a genetic disorder belonging to a group characterized by the predominance of abnormal hemoglobin S (Hb S). Under conditions of deoxygenation, Hb S polymerizes causing vaso-occlusion and tissue injury. Clinical manifestations occur in the course of the disease and infections can also affect patients throughout their lives (1,2). Even though the incidence varies, sickle cell disease is present all over the world (3). In regions where the S gene predominates, such as in sub-Saharan Africa, the birth rate of homozygotes is high. In contrast, the migration phenomenon is responsible for the emergence of the disease in non-endemic regions (4). Ireland saw an increase in the disease affecting children because of a flow of refugees from Nigeria, Angola and the Congo (5). In 1993, Cyprus hosted the joint meeting of the World Health Organization and the International Federation of Thalassemia. Recommendations were made on the need for exact and regular updated information and possible strategies to control the situational of thalassemia and sickle cell disease worldwide (4). Among the countries that attended the meeting, Greece´s response was the creation of a national record of all patients with thalassemia and sickle cell disease, newborns affected and hemoglobinopathy-related deaths (6). Knowing the dynamics of sickle cell disease and its prevalence among communities poses a major challenge to the effective and equitable management of the disease in view of the scarcity of epidemiological data (7). With this knowledge it is possible to contribute to the planning of more effective therapeutic regimens (6). In Brazil, the prevalence of heterozygotes for Hb S is higher in the north and northeast of the country (6% to 10%), while the rates in the south and southeast are 2% and 3%, respectively (8). In the Midwest, especially in Mato Grosso do Sul, in the period 2000-2005, after the introduction of the State Neonatal Screening Program, there has been no record of mortality in children screened for sickle cell disease. In 2005 the coverage was 90.78% (9). In Bahia, an evaluation of the neonatal screening program in 2003 showed coverage of 71.52%, with an incidence of 1:650 newborns (257 patients) with sickle cell anemia (10). Another study conducted in Bahia of 99 patients throughout the State, with mean age of 30.2 ± 10.8 years and mean time of diagnosis of 12.7 ± 12.1 years, showed that the majority was diagnosed after an acute event (11). …