RESUMEN
This study was undertaken to investigate the immunological mechanism of Behqet s syndrome, considered to be important in the pathogenesis of the disease. Seventy- three patients with complete, incomplete and suspected types of Behget's syndrotne were tested for leukocyte migration ingibition factor(LIF), one of the lymphokines. The results were as follows : 1. There was no difference between the average LIF activity of all the patients and that of eontrol. 2. LIF activity of complete type, according to Shirnizus classification, was significaritly lower than the control value. 3. LIF activity of ocular type, according to Lehners classification, was signficantly lower than the control value. 4. LIF activity for patients with 4 clinical symptoms was well below the value for patients with less symptomes 5. For patients with single clinical symptom, LIF activity of complete type was well below the values of incomplete and suspected types. 6. In suspected and mucocutaneous types, LIF activity was low when the patients showed two clinical symptoms than one. Thus, LIF activity was low for patients with complete, ocular and neurological types and with multiple symptorns.