This work was planned to evaluate the role of interferon gamma (IFNy) and IL-12 in tuberculous children and their relation to hypersensitivity and disease susceptibility. For this pur­pose we studied 19 children with new­ly diagnosed tuberculosis; 12 with pul­monary TB and 7 with tuberculous lymphadenopathy; in addition to 12 asymptomatic contacts with positive tuberculin test and 13 healthy tuber­culin negative children with matched age and sex. Both serum and in vitro production of IFNy and IL-12 by FBMCs were estimated in all subjects by ELISA technique. Our results re­vealed that tuberculous patients had significantly higher serum IFNy and IL-12 than both tuberculin positive and negative control (P<0.001). Similarly, tuberculin positive contacts had signif­icantly higher serum levels of both cy-
tokines compared with healthy nega­tive group. However, in vitro produc­tion of IFNy and IL-12 were signifi­cantly higher in patients and tubercufin positive contacts than hea­lthy tuberculin negative subjects (P<0.001) and did not differ signif-cantly between patients and tubercu­lin positive contacts (P = 0.056, 0.86). Significant positive correlation was found between tuberculin diameter and the studied cytokines. Conclu­sion: serum levels of IFNy and IL-12 are elevated in tuberculous children than control with correlation to tuber­culin reaction denoting a protective role for these cytokines. The relatively depressed in vitro production of IL-12-IFNyaxis in tuberculous patients may predispose to disease progression. Recommendations: adjuvant cytokine therapy using IFNy and IL-12 espe­cially in advanced and resistant tuber-