CD28 expression was unaltered on either CD4 or CD8 T cell subsets following stimulation over this time-period. There was, however, a significant increase in the production of IFN-γ by both CD28null/CD4+ and CD28null/CD8+ T cells in patients with BOS compared with stable transplant patients and controls (Fig. 3a). The percentage Aloxistatin mw of CD28null/IFN-γ/CD8+ T cells was also increased in all groups compared to the CD28null/CD4+ subset (Fig. 3a). There were no significant differences in the percentage of IFN-γ-producing CD28+/CD8+ or CD28+/CD4+ T cells in any of the groups studied 12·5 ± 8·3%, 10·1 ± 7·6% and 11·6 ± 9·1%; and 15·1 ± 8·9%, 15·4 ± 7·1% and 14·6 ± 6·3%
CD28+/CD4+/IFN-γ+ and CD28+/IFN-γ+/CD8+ [mean ± standard deviation (s.d.)] for controls, stable patients and patients with BOS, respectively (all P < 0·05). There was an increase in the percentage of both CD28nullCD4+ and CD28null/CD8+ T cells producing TNF-α in patients with BOS compared with stable transplant patients and controls (Fig. 3b). The percentage of CD28null/TNF-α/CD8+
T cells was increased compared to CD28null/CD4+ cells in all groups (Fig. 3b). There were no significant changes in the percentage of CD28+/CD8+ or CD28+/CD4+ producing TNF-α between any of the groups studied [12·5 ± 8·9%, 10·1 ± 7·4% and 11·6 ± 6·2%; and −15·1 ± 8·0%, 15·4 ± 9·3% and 14·6 ± 8·4% (mean ± s.d.) CD28+/TNF-α+/CD4+ and CD28+/TNF-α+/CD8+ for controls, stable patients and patients with BOS, respectively] (all P > 0·05). For IL-2, there was an decrease in the percentage of cytokine-producing MLN0128 cell line CD28null/CD4+ and CD28null/CD8+ T cells in stable transplant patients compared with controls (Fig. 3c), but an increase for both
CD4 and CD8+ subsets in patients with BOS compared with both stable transplant patients and controls (Fig. 3c). There was a decrease in the percentage of IL-2-producing CD28+/CD4+ and CD28+/CD8+ cells in stable transplant patients compared with controls and an increase in patients with BOS compared with stable transplant Farnesyltransferase patients [58 ± 19·2%, 18·3 ± 15·5% and 36·6 ± 19·8%; and 19·7 ± 6·4%, 6·9 ± 6·3% and 14·1 ± 17·2% (mean ± s.d.) CD28+/IL-2/CD4+ and CD28+/IL-2/CD8+ for controls, stable patients and patients with BOS, respectively] (all P < 0·05). Longitudinal studies were performed on three stable lung transplants that subsequently developed BOS (Fig. 4). The percentages of CD28null/CD4+ and CD28null/CD8+ T cells producing IFN-γ and TNF-α for these patients are shown. In brackets are the upper 90% confidence intervals (CI) for the percentage of cells producing cytokine in the stable transplant group. Note the increasing percentages of both CD28null/CD4+ and CD28null/CD8+ T cells producing IFN-γ and TNF-α in all patients preceding BOS compared with the stable patient group.