The CCR5Δ32 Polymorphism in Brazilian Patients with Sickle Cell Disease

Background. Previous studies on the role of inflammation in the pathophysiology of sickle cell disease (SCD) suggested that the CCR5Δ32 allele, which is responsible for the production of truncated C-C chemokine receptor type 5 (CCR5), could confer a selective advantage on patients with SCD because it leads to a less efficient Th1 response. We determined the frequency of the CCR5Δ32 polymorphism in 795 Afro-Brazilian SCD patients followed up at the Pernambuco Hematology and Hemotherapy Center, in Northeastern Brazil, divided into a pediatric group (3 months–17 years, n = 483) and an adult group (18–70 years, n = 312). The adult patients were also compared to a healthy control group (blood donors, 18–61 years, n = 247). Methods. The CCR5/CCR5Δ32 polymorphism was determined by allele-specific PCR. Results. No homozygous patient for the CCR5Δ32 allele was detected. The frequency of heterozygotes in the study population (patients and controls) was 5.8%, in the total SCD patients 5.1%, in the children 5.4%, in the adults with SCD 4.8%, and in the adult controls 8.1%. These differences did not reach statistical significance. Conclusions. Our findings failed to demonstrate an important role of the CCR5Δ32 allele in the population sample studied here.