Caracterização clínica, hematológica e molecular dos pacientes com anemia falciforme em Fortaleza, Ceará

Abstract

Introduction: The sickle cell anemia is the result of a point mutation in the β-globin gene, leading to a substitution of glutamic acid by valine at the sixth position of the polypeptide chain. The sickle cell anemia presents heterogeneous clinical manifestations, which may be related to the type of haplotype associated with the gene for HbS and HbF levels. Objective: Clinical characterization, molecular and haematological patients with sickle cell anemia in Fortaleza, Ceará. Methods: We analyzed 47 patients with sickle cell anemia, adults of both sexes. The determination of hematological values was performed on blood cells automated meter; the determination of the presence of HbSS was performed by alkaline hemoglobin electrophoresis on cellulose acetate tapes and by differentiation electrophoresis on agar-phosphate pH 6.2; the levels of HbF were determined by alkali denaturation technique; and the analysis of the haplotypes of the ßS mutation was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Statistical analysis was developed in the program GraphPad Prism (version 5.0) and the level of significance was set p <0.05. Results: The distribution of the haplotypes of βS-globin gene - 63% of the Bantu type, 25% of the Benin type and 12% atypical – was in conformity with that observed for the entire Brazilian population, in which the Bantu haplotype is most prevalent, followed by the Benin and Senegal. There was no significant difference between the results found in this study and those found for the cities of Rio de Janeiro, Porto Alegre, Campinas and Ribeirão Preto; but there was a significant difference with the results obtained for the cities of Salvador and Belém and the state of Amazonas, and by other researchers in Ceará. The distribution of haplotype frequencies of the βS-globin gene in the different studies is in line with the history of the formation of the Brazilian population, except for the results of a previous study carried out in Ceará, in which the Benin haplotype was found to be most prevalent. According to the historical information on the origins of the slave population brought to Ceará, the Bantu haplotype should be the most prevalent. In the comparison between the haplotypes and the haematological characteristics studied, only the values of HbF and Ht showed statistically significant difference. The levels of HbF were higher in the Benin haplotype, followed by the Bantu haplotype, which is in accordance with the literature. Was demonstrated greater presence of painful episodes and episodes of pneumonia in Benin haplotype/Atypical haplotype than in Bantu/Atypical and increased presence of urinary infection crises in Benin haplotype/Atypical haplotype than in Benin/Benin. There was no statistically significant difference between the haplotypes Bantu/Bantu and Benin/Benin for clinical complications, however it was observed that the haplotype Bantu/Bantu has a higher frequency in all studied clinical events when compared to Benin/Benin. Among the results was shown a trend of fewer patients with painful episodes and of leg ulcers with increased levels of HbF. There was no statistically significant difference in the comparison between the levels of HbF and the values of red blood cells, hemoglobin, hematocrit, leukocytes and platelets. Conclusions: The determination of haplotypes of sickle cell anemia is of great importance not only for monitoring and prognosis of patients, but also as a tool for anthropological studies which help in clarifying the origin of Africans who have contributed so much in training ethnological, economic, cultural and social Brazil.