scientist are lately looking to the involvement of retroviruses
and autoimmune disorders, because many of the
HIV-infected people show in the course of their illness, AI-disorders. In their search, they have found most of the people infected with the "Human Intracisternal A-Type Particle" or HIAP-virus.
More information can be found here:
http://www.autoimmune.com/
or here:
http://www.ncbi.nlm.nih.