[Cytokines release related to cardiopulmonary bypass in patients with prosthetic valve replacement]

To examine cytokines release related to cardiopulmonary bypass(CPB), the anthers investigated the possible differences in cytokines responses between patients undergoing prosthetic valve replacement (study group, n = 10) and those receiving closure of patent ductus arteriosus or pericardiectomy(control group, n = 9). Venous levels of interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10) were measured at multiple time points before, during and after operation. As compared with pre-operative values, IL-2 levels in both groups decreased significantly (P < 0.05), and the levels of sIL-2R, IL-6, TNF-alpha, and IL-10 in both groups increased significantly at multiple time points post-operative (P < 0.01). All the values of cytokines returned to pre-operative levels at 7th post-operative day. Although there were no pre-operative differences in these cytokines between the two groups (P > 0.05), the post-operative changes of cytokines in study group was more obvious than that in control group (P < 0.01). In study group IL-10 rose to a peak value of around 620 pg/ml at the end of CPB while IL-6 and TNF-alpha levels reached their peak values of around 88 pg/ml and 52 pg/ml respectively at 1st post-operative day. IL-10 has been reported as an antiinflammatory cytokine. The preceding IL-10 peak value, as compared with the peak values of IL-6 and TNF-alpha, could be associated with the interplay and regulation of cytokine network. On the other hand, in control group the levels of IL-6, TNF-alpha, and IL-10 reached their peak values at 1st post-operative day simultaneously. The values were 34 pg/ml, 36 pg/ml, and 162 pg/ml respectively. This result suggests that besides surgical stress mediated cytokines production or suppression, CPB itself also results in obvious changes of cytokine metabolism. However further studies are needed to elucidate the underlying mechanisms and clinical value of post-operative cytokines production or suppression related to CPB in patients with prosthetic valve replacement.