[Studies on interferon in Behçet's disease].

The serum levels of interferon (IFN-gamma) were investigated in patients with Behçet's disease. The origin of IFN-producing cells was also studied to understand the immunopathological roles of IFN-gamma in this disease better. It was shown that the IFN titer was 38.5 +/- 3.4 IU/ml in the patients and 6.6 +/- 0.9 IU/ml in the controls. The patients had significantly higher levels of IFN compared to the controls (P less than 0.0001). The IFN activity was shown to be IFN-gamma by acid treatment, heating at 56 degrees C for 30 min, and neutralization with anti-human IFN-alpha and-gamma sera. Peripheral blood mononuclear leukocytes of the patients produced IFN-gamma spontaneously in vitro without any stimulations. The average IFN titers in leukocyte cultures were significantly increased in patients in the ocular convalescent stage compared to those in the exacerbation stage (P less than 0.0001), as was the case with the serum IFN titers. By leukocyte fractionation procedures, the generated IFN-gamma was shown to originate from the T gamma cells of the patients. IFN-gamma may therefore play some significant role in the pathophysiology of Behçet's disease.