Method of treating autoimmune conditions are disclosed comprising
administering to a mammalian subject IL-12 or an IL-12 antagonist. In
certain preferred embodiments the autoimmune condition is one which is
promoted by an increase in levels of IFN-.gamma. or TNF-.alpha.. Suitable
conditions for treatment include multiple sclerosis, systemic lupus
erythematosus, rheumatoid arthritis, autoimmune pulmonary inflammation,
Guillain-Barre syndrome, autoimmune thyroiditis, insulin dependent
diabetes melitis and autoimmune inflammatory eye disease.