Interleukin-2 in relation to T cell subpopulations in rheumatic heart disease

Interleukin-2 (IL-2) and T cell subpopulations were evaluated in children with rheumatic heart disease (RHD). Three groups were included: 13 patients with active RHD, 12 with non-active RHD, and 14 control children. Serum IL-2 and T cell subpopulations were measured by radioimmunoassay and monoclonal antibodies respectively. Patients with active RHD showed a significant increase in IL-2 concentrations and helper:suppressor (H:S) ratio compared with controls with a mean (SEM) IL-2 of 3.48 (0.62) v 1.26 (0.16) U/ml and H:S ratio 2.31 (0.14) v 1.66 (0.04). There was a significant decrease in T suppressor (CD8+) and pan T (CD3+) cells compared with controls with a mean (SEM) for CD8+ of 23.75 (1.19) v 32.23 (0.56)% and CD3+ of 79.55 (0.94) v 85.00 (0.11)%. Patients with non-active RHD showed a significant decrease only in the CD3+ cells (78.20 (0.20)%) when compared with controls. A deficiency of CD3+ cells is a constant finding in patients with RHD, whether the disease is active or not. There was a significant increase in IL-2 concentration with a significant decrease in CD8+ cells in patients with active RHD in comparison with the non-active group (mean (SEM) IL-2 of 3.48 (0.62) v 1.85 (0.24) U/ml and CD8+ of 23.75 (1.19) v 28.83 (1.91)%). Thus an increase in IL-2 and a decrease in CD8+ cells may be related to rheumatic activity. T helper (CD4+) cells did not differ significantly between groups.