Role of the IL8 rs4073 polymorphism in central nervous system toxicity in patients receiving multidrug-resistant tuberculosis treatment.

OBJECTIVE: To determine the role of the IL8 rs4073 polymorphism in predicting the risk of central nervous system (CNS) toxicity in patients receiving standard pharmacological treatment for multidrug-resistant tuberculosis (MDR-TB). METHODS: A cohort of 85 consenting MDR-TB patients receiving treatment with second-line antituberculosis drugs had their blood samples amplified for the IL8 (rs4073) gene and genotyped. All patients were clinically screened for evidence of treatment toxicity and categorized accordingly. Crude and adjusted associations were assessed. RESULTS: The chief complaints fell into the following categories: CNS toxicity; gastrointestinal toxicity; skin toxicity; and eye and ear toxicities. Symptoms of gastrointestinal toxicity were reported by 59% of the patients, and symptoms of CNS toxicity were reported by 42.7%. With regard to the genotypes of IL8 (rs4073), the following were identified: AA, in 64 of the study participants; AT, in 7; and TT, in 11. A significant association was found between the dominant model of inheritance and CNS toxicity for the crude model (p = 0.024; OR = 3.57; 95% CI, 1.18-10.76) and the adjusted model (p = 0.031; OR = 3.92; 95% CI, 1.13-13.58). The AT+TT genotype of IL8 (rs4073) showed a 3.92 times increased risk of CNS toxicity when compared with the AA genotype. CONCLUSIONS: The AT+TT genotype has a tendency to be associated with an increased risk of adverse clinical features during MDR-TB treatment.

Role of the IL8 rs4073 polymorphism in central nervous system toxicity in patients receiving multidrug-resistant tuberculosis treatment / Papel do polimorfismo rs4073 do gene IL8 na toxicidade do sistema nervoso central em pacientes em tratamento para tuberculose multirresistente

ABSTRACT Objective: To determine the role of the IL8 rs4073 polymorphism in predicting the risk of central nervous system (CNS) toxicity in patients receiving standard pharmacological treatment for multidrug-resistant tuberculosis (MDR-TB). Methods: A cohort of 85 consenting MDR-TB patients receiving treatment with second-line antituberculosis drugs had their blood samples amplified for the IL8 (rs4073) gene and genotyped. All patients were clinically screened for evidence of treatment toxicity and categorized accordingly. Crude and adjusted associations were assessed. Results: The chief complaints fell into the following categories: CNS toxicity; gastrointestinal toxicity; skin toxicity; and eye and ear toxicities. Symptoms of gastrointestinal toxicity were reported by 59% of the patients, and symptoms of CNS toxicity were reported by 42.7%. With regard to the genotypes of IL8 (rs4073), the following were identified: AA, in 64 of the study participants; AT, in 7; and TT, in 11. A significant association was found between the dominant model of inheritance and CNS toxicity for the crude model (p = 0.024; OR = 3.57; 95% CI, 1.18-10.76) and the adjusted model (p = 0.031; OR = 3.92; 95% CI, 1.13-13.58). The AT+TT genotype of IL8 (rs4073) showed a 3.92 times increased risk of CNS toxicity when compared with the AA genotype. Conclusions: The AT+TT genotype has a tendency to be associated with an increased risk of adverse clinical features during MDR-TB treatment.

RESUMO Objetivo: Determinar o papel do polimorfismo rs4073 do gene IL8 na previsão do risco de toxicidade do sistema nervoso central (SNC) em pacientes em tratamento farmacológico padrão para tuberculose multirresistente (TBMR). Métodos: Amostras de sangue de uma coorte de 85 pacientes com TBMR que assinaram um termo de consentimento livre e esclarecido e que estavam recebendo tratamento com medicamentos antituberculosos de segunda linha foram amplificadas para o gene IL8 (rs4073) e genotipadas. Todos os pacientes foram avaliados clinicamente quanto a evidências de toxicidade do tratamento e categorizados de acordo com os achados. Foram avaliadas as associações brutas e ajustadas. Resultados: As principais queixas enquadraram-se nas seguintes categorias: toxicidade do SNC; toxicidade gastrointestinal; toxicidade cutânea; e toxicidade ocular e ototoxicidade. Sintomas de toxicidade gastrointestinal foram relatados por 59% dos pacientes, e sintomas de toxicidade do SNC foram relatados por 42,7%. Foram identificados os seguintes genótipos de IL8 (rs4073): AA, em 64 dos participantes; AT, em 7; TT, em 11. Houve associação significativa entre o modelo dominante de herança e toxicidade do SNC no modelo bruto (p = 0,024; OR = 3,57; IC95%: 1,18-10,76) e no ajustado (p = 0,031; OR = 3,92; IC95%: 1,13-13,58). O genótipo AT+TT do gene IL8 (rs4073) apresentou risco 3,92 vezes maior de toxicidade do SNC que o genótipo AA. Conclusões: O genótipo AT+TT tende a se associar a um maior risco de características clínicas adversas durante o tratamento da TBMR.