Polymorphisms of interleukin (IL)-4 receptor alpha and signal transducer and activator of transcription-6 (Stat6) are associated with increased IL-4Ralpha-Stat6 signalling in lymphocytes and elevated serum IgE in patients with Graves' disease

Summary Activated interleukin (IL)-4Rα stimulates production of IgE through signal transducer and activator of transcription-6 (Stat6) activation in lymphocytes. Genetic studies have shown an association between polymorphisms in the genes encoding IL-4Rα and Stat6 and elevated serum IgE in patients with atopic disease. Some authors, including us, have reported an association of Graves' disease and elevated serum IgE. To analyse the relationship between IL-4Rα and Stat6 polymorphisms and elevated serum IgE in patients with Graves' disease, 169 patients with Graves' disease were studied. We investigated whether these polymorphisms affect IL-4Rα–Stat6 signalling in cultured human lymphocytes. A high frequency of both the Ile50 polymorphism in IL-4Rα and 13GT repeat variants of the Stat6 gene was observed in patients with Graves' disease and elevated serum IgE (Ile50 allele; P