Methimazole prevents induction of experimental systemic lupus erythematosus in mice

Experimental SLE can be induced in mice by immunization with a human mAb to DNA (16/6Id). Immunized mice develop Abs to the 16/6Id immunogen, DNA, and nuclear Ags. Subsequently, clinical manifestations of disease develop, including leukopenia, proteinuria, and immune complex deposits in the kidney. MHC class I Ags play a critical role in the induction of experimental SLE, as demonstrated by the finding that class I-deficient mice are resistant to disease induction. This finding suggested that agents that reduce MHC class I expression might mitigate experimental SLE in normal mice. These studies report that methimazole, which has been shown to repress class I transcription in some cell lines, reduces class I expression on PBLs in vivo and prevents the development of clinical manifestations of SLE in 16/6Id-immunized mice. These data suggest that methimazole, which has been used in the treatment of Graves' disease, may be useful in the clinical treatment of SLE and other autoimmune diseases.