That sounds incorrect. Lupus and Hashimoto's can coexist. It's not something I know all that much about, but if anything, Hashimoto's, like many autoimmune dise

That sounds incorrect. Lupus and Hashimoto's can coexist. It's not something I know all that much about, but if anything, Hashimoto's, like many autoimmune diseases, is associated positively with others: http://www.mdconsult.com/das/article/body/203965646-2/jorg=journal&source=&sp=22862642&sid=0/N/733434/1.html?issn=0002-9343 http://www.mdconsult.com/das/article/body/203965646-2/jorg=j... Among those with Hashimoto's, the relative risk for having lupus is 6.23-20.0. Thus, Hashimoto's is positively predictive. There is no reason that an inflammatory thyroiditis should mask ANA, anti-Ro, anti-La, etc. (If there is, though, please do tell me about it because that would be some very useful knowledge.)