Hello Autoimmune diseases (such as of the thyroid) are not associated with motor vehicle accidents. The cmv (cytomegalovirus infection) is not associated with autoimmune conditions either. Autoimmune conditions tend to have a hereditary aspect. Inquire with family members if any have autoimmune conditions. One autoimmune condition puts a person at risk for another (such as vitiligo, diabets, thyroid conditions, etc.). Weight fluctuations can be attributed to thyroid conditions. I hope this answer is helpful.