In the present study, we evaluated the serum levels of interleukin (IL)‐1β, IL‐6, IL‐8, IL‐10, IL‐12p70, IL‐18 and tumour necrosis factor‐alpha (TNF‐α) in 76 adult SCA patients (homozygous haemoglobin SS genotype), all over 18 years of age, who attended the Haematology and Haemotherapy Centre in Northeast Brazil. Here, IL18 is linked to autosomal dominant cerebellar ataxia.