MEFV gene p.Met694Val variation is not associated with subacute thyroiditis in Turkish patients

Abstract

Subacute thyroiditis (SAT) is a self-limited, granulomatous inflammatory thyroid disorder associated with neck pain and systemic inflammatory findings such as fever and acute phase response. Familial Mediterranean fever (FMF), an autosomal recessively inherited autoinflammatory disorder, is characterized by recurrent inflammatory attacks in serosal and synovial tissues. Heterozygous carrier state is quite prevalent in Eastern Mediterranean countries, especially the most penetrant p.Met694Val variant, has been found to be a risk factor for other inflammatory disorders due to a tendency to higher IL-1 production. We herein aimed to investigate the possible role of p.Met694Val variant in the pathogenesis of subacute thyroiditis in Turkish patients, in which the prevalence of the variation in healthy individuals is around 3%. We genotyped 58 SAT patients with typical clinical and laboratory features, and we could not identify any individual with p.Met694Val variant among them. On the other hand, 7 heterozygous individuals were found among healthy controls, who were matched to the study group according to the their birth places. Two of the patients were on anti-TNF agents for the treatment of rheumatoid arthritis and ankylosing spondylitis, and additional two patients, one with systemic lupus erythematosus and another with eosinofilic granulomatosis with polyangiitis (Churg-Strauss syndrome) were on immunosuppressive drugs. Additionally, another patient with ankylosing spondylitis was receiving sulphasalazine. In conclusion, we did not find an association between the MEFV gene p.Met694Val variant and subacute thyroiditis in Turkish patients, which may suggest no contribution of pyrin inflammasome in the pathogenesis. Increased proportion of patients on immunosuppressive agents supports further the triggering role of infections, and investigations of genetic polymorphisms associated with infection susceptibility are warranted.