In previous studies genes encoding Angiotensin-Converting Enzyme (ACE) and IL-4 (Interleukin-4) were found to be associated with rheumatologic and autoimmune diseases.
Data from other studies show that the -589T/C polymorphism in IL-4 promoter may alter IL-4 expression and susceptibility of inflammatory or autoimmune diseases.
Associations have been reported between single nucleotide polymorphisms (SNPs) of IL-10 and the Ile50Val polymorphism of the IL-4 receptor gene (IL-4R) gene and atopy and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis.
Therefore, the attenuated autoimmunity following loss of IL-4 and IL-6 is dose-dependent, as higher doses of Hg are able to override the attenuation observed using lower doses.