Defective production of interferon-alpha associated with HLA-DW2 antigen in stable multiple sclerosis.

Interferon (IFN) production by peripheral blood mononuclear cells after induction with one purified and three crude viral antigens was studied in 29 patients with stable multiple sclerosis (MS) and 29 healthy controls. Antiviral substance produced was characterized as interferon-alpha. MS patients produced significantly less IFN-alpha after induction with mumps and purified measles virus antigens and the same tendency was seen after induction with rubella virus antigen. However, when herpes simplex virus antigen was used as the stimulating agent, no difference was seen between MS patients and controls. The decreased ability to produce IFN-alpha was associated with the histocompatibility antigen Dw2. Control subjects positive for Dw2 also produced less IFN-alpha than Dw2-negative controls. In conclusion, we suggest that the observed impaired interferon-alpha production in MS is at least partially due to a high prevalence of Dw2 antigen in this disease.