FATORES CLÍNICOS, LABORATORIAIS E GENÉTICOS ASSOCIADOS AO TABAGISMO EM UMA COORTE BRASILEIRA DE DOENÇA FALCIFORME

Abstract

Smoking is associated with increased morbidity in individuals with sickle cell disease (SCD). Genetic factors are known to influence smoking behavior in other populations but have not been investigated in individuals with SCD. Our aim was to assess the impact of smoking on clinical and laboratory findings in a large cohort of SCD and to identify genetic variations that may be associated with smoking in this population. Methods: The Brazil SCD cohort of the Recipient Epidemiology and Donor Evaluation Study (REDS-III) was established in 6 Brazilian cities to investigate clinical outcomes. Adult participants were interviewed and asked if they had smoked 100 cigarettes in their lifetime. Participants who answered “yes” were classified as smokers (active smokers and ex-smokers) and non-smokers. Clinical and laboratory data of 'smokers' and 'non-smokers' participants were compared. All participants were genotyped using a custom matrix and a Genome Wide Association Study (GWAS) was conducted to assess which single nucleotide variations (SNVs) were associated with smoking. Results: Of the 1,231 adults enrolled with smoking data, 332 (26.97%) were classified as 'Smokers' and 899 (73.03%) as 'Non-smokers'. Male gender, age ≥ 40 years, less education and hemoglobin above the 75th percentile were associated with having ever smoked. In GWAS, no SNP reached genome-wide significance (p < 5x10 -8). However, SNVs rs11087854 and at position 1059991 on chromosome 20, located in the AL110114.1 gene, and SNV rs701023 in the NCOR2 gene were nominally significant (p < 10-7), suggesting a possible association with smoking. Conclusion: Gender, age and education are related to smoking in patients with SCD and smoking is associated with higher levels of hemoglobin in this same group. Our analysis suggests that new loci are associated with smoking in patients with sickle cell anemia. Keywords: Sickle cell anemia, genetic variation, smoking, nicotine.