Yes, autoimmunity is in large part from adrenal dysfunction. The corticosteroids from the adrenals help to regulate the immune response, which includes the formation of the proper high affinity (specific) antibodies. Lack of the corticosteroids leads to immune suppression and the over production of low affinity (nonspecific) antibodies that inadvertently tag healthy tissue for destruction by the white blood cells. So the tissues end of being attacked by the white blood cells since the tissues are antibody tagged. So there is no hyperactive immune system as the doctors claim, but rather immune suppression through the adrenals.
And the worst things for your adrenals are stress, stimulants (caffeine, nicotine, etc.) and steroids including steroidal medications. The stress and stimulants will flare up an autoimmune condition. The steroids can cover up the symptoms but will make the underlying condition worse.