OBJECTIVE: To investigate the functionality of the Fas-induced apoptotic pathway in peripheral blood mononuclear cells (PBMC) from patients with systemic or pauciarticular juvenile idiopathic arthritis (JIA). METHODS: PBMC from 12 patients with systemic and 6 with pauciarticular JIA were activated with anti-CD3 and rhIL-2 and then incubated in the presence or absence of the anti-Fas MoAb CH11 inducing activation of the Fas apoptotic pathway. Apoptosis was evaluated by flow cytometry and fluorescence microscopy. RESULTS: The percentage of apoptotic cells following triggering of Fas did not differ between patients with systemic JIA (12.5 +/- 9.5%) or pauciarticular JIA (18.7 +/- 8.9%) and controls (16.1 +/- 6.8%). Evaluation of activation-induced cell death (AICD) in the absence of exogenous triggering of Fas showed that 44% (8/18) of the patients with JIA, compared to none of the controls (0/16), had a percentage of apoptotic cells higher than the mean + 2 SD of controls. The increased AICD was neutralized by the addition of an anti-TNF-alpha antibody. CONCLUSION: Patients with systemic or pauciarticular JIA do not show a defect in the Fas-dependent apoptotic pathway of T cells. The increased AICD present in some patients with JIA appears to be at least in part related to the inflammatory cytokine TNF-alpha.
OBJECTIVE: To investigate the functionality of the Fas-induced apoptotic pathway in peripheral blood mononuclear cells (PBMC) from patients with systemic or pauciarticular juvenile idiopathic arthritis (JIA). METHODS: PBMC from 12 patients with systemic and 6 with pauciarticular JIA were activated with anti-CD3 and rhIL-2 and then incubated in the presence or absence of the anti-Fas MoAb CH11 inducing activation of the Fas apoptotic pathway. Apoptosis was evaluated by flow cytometry and fluorescence microscopy. RESULTS: The percentage of apoptotic cells following triggering of Fas did not differ between patients with systemic JIA (12.5 +/- 9.5%) or pauciarticular JIA (18.7 +/- 8.9%) and controls (16.1 +/- 6.8%). Evaluation of activation-induced cell death (AICD) in the absence of exogenous triggering of Fas showed that 44% (8/18) of the patients with JIA, compared to none of the controls (0/16), had a percentage of apoptotic cells higher than the mean + 2 SD of controls. The increased AICD was neutralized by the addition of an anti-TNF-alpha antibody. CONCLUSION:Patients with systemic or pauciarticular JIA do not show a defect in the Fas-dependent apoptotic pathway of T cells. The increased AICD present in some patients with JIA appears to be at least in part related to the inflammatory cytokine TNF-alpha.