[Effect of anti-ICOS monoclonal antibody combined with low-dose CsA on chronic rejection of heart grafts in rats].

OBJECTIVE: To evaluate the effect of anti-inducible costimulator monoclonal antibody (anti-ICOS-Ab) combined with low-dose cyclosporine (CsA) on the survival quality and chronic rejection of heart allografts in rats. METHODS: The rats' heterotopic cardiac transplantation model was established by Ono's method. The recipient rats were randomly divided into an isotransplantation control group and an allotransplantation experiment group. The experiment group was re-classified into a placebo group, a normal-dose CsA group, an anti-ICOS-Ab group, a low-dose CsA group, and an anti-ICOS-Ab combined with low-dose CsA group. The survival time of grafts was monitored. The cardiac grafts were harvested for histological analysis. Flow cytometric analysis was employed to detect the population of CD25+CD4+ in peripheral lymphocytes from recipients with a long-term surviving graft. RESULTS: The survival time of the cardiac allografts in CsA-treated groups was significantly longer than that in placebo group (P<0.05). The survival time of the cardiac allografts in anti-ICOS-Ab combined with low-dose CsA group was significantly longer than that in low dose CsA-treated group (P<0.05). There was no significant difference in the survival time of the cardiac grafts between the anti-ICOS-Ab group and the placebo group (P>0.05). Compared with the normal-dose CsA group, the chronic rejection lesions of the anti-ICOS-Ab combined with low-dose CsA treatment group significantly were alleviated in the long-term survival grafts, and the proportion of CD4+CD25+ regulatory T cell increased in peripheral blood. CONCLUSION: The anti-ICOS-Ab combined with low-dose CsA can prolong the survival of cardiac allografts and alleviate the chronic rejection significantly. The high expression level of CD4+CD25+ regulatory T cell is beneficial to the long-term survival of grafts.

[Effect of mono and combination therapy with FTY720 and ICAM-1 mAb for mouse-to-rat cardiac xenotransplantation].

OBJECTIVE: To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in mouse-to-rat cardiac xenotransplantation. METHODS: Cardiac xenotransplantation was performed in abdominal site with micro-surgical technique. Recipients with xenografts were treated with different doses of FTY720 and/or ICAM-1 mAb. Graft survival, histopathology, infiltration of CD4+, and CD8+ T cells and levels of serum IL-2, IFN-gamma, IL-4, and IgM were investigated. RESULTS: Survival time of xenografts was (2.75+/- 0.43)d in the controls, survival of grafts treated with ICAM-1 mAb did not significantly improve. Treatment with large dose FTY720 led to a survival of (4.25+/- 0.71)d (P<0.01). Combination therapy with large dose FTY720 and ICAM-1 mAb achieved a significant prolongation of graft survival with (10.25+/- 2.12)d (P<0.01). Levels of serum IL-2, IFN-gamma and rat-anti-mouse IgM decreased in the combined therapy group. Pathologic lesion and infiltration of T cells in xenografts showed mitigated in the large dose combined therapy group. There was a significant negative correlation between the antibody level and the graft survival time (R=-0.754, P<0.01). CONCLUSION: The combined therapy of FTY720 and ICAM-1 mAb can achieve a significant effect in the prolongation of heart xenograft survival and inhibition of xenoantibodies.

[Immune tolerance induced by combined heart-thymus transplantation for heart allograft in rats].

OBJECTIVE: To explore the role of combined heart-thymus transplantation for heart allograft in rats. METHODS: Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology, infiltration of CD4+, CD8+ T cells, level and mRNA expressions of IL-2 and IL-4 in the serum and cardiac grafts were investigated. RESULTS: Heart allograft in the controls had a survival time of (6.0+/-0.76) d. heart-thymus combined transplantation in non-thymectomized rats had a survival time of (6.88+/-0.64)d (P<0.05). Heart-thymus combined transplantation in thymectomized rats led to an evident survival time of (14.13+/-5.82)d (P<0.01) for cardiac graft, which further obtained long term survival after short course of treatment with cyclosporine. Pathologic lesion and infiltration of CD4+ and CD8+ T cells in cardiac grafts showed mitigated in the long term survival group. IL-2 level in the serum and cardiac grafts maintained low level in the long term survival group, whereas IL-4 maintained high level. CONCLUSION: Whether thymectomized or not in recipient rats, heart-thymus combined transplantation has a positive effect to protect cardiac graft. Furthermore, in thymectomized rats heart-thymus combined transplantation may lead to evident survival prolongation of the heart grafts, which induces immune tolerance in short course of treatment with cyclosporine.

Preoperative risk factor analysis in orthotopic liver transplantation with pretransplant artificial liver support therapy.

AIM: To assess the value of pre-transplant artificial liver support in reducing the pre-operative risk factors relating to early mortality after orthotopic liver transplantation (OLT). METHODS: Fifty adult patients with various stages and various etiologies undergoing OLT procedures were treated with molecular adsorbent recycling system (MARS) as preoperative liver support therapy. The study included two parts, the first one is to evaluate the medical effectiveness of single MARS treatment with some clinical and laboratory parameters, which were supposed to be the therapeutical pre-transplant risk factors, the second part is to study the patients undergoing OLT using the regression analysis on preoperative risk factors relating to early mortality (30 d) after OLT. RESULTS: In the 50 patients, the statistically significant improvement in the biochemical parameters was observed (pre-treatment and post-treatment). Eight patients avoided the scheduled Ltx due to significant relief of clinical condition or recovery of failing liver function, 8 patients died, 34 patients were successfully bridged to Ltx, the immediate outcome of this 34 patients within 30 d observation was: 28 kept alive and 6 patients died. CONCLUSION: Pre-operative SOFA, level of creatinine, INR, TNF-alpha, IL-10 are the main preoperative risk factors that cause early death after operation, MARS treatment before transplantation can relieve these factors significantly.

[Immune tolerance induced by combined heart-thymus transplantation with intrathymic inoculation of thymocytes in rats].

OBJECTIVE: To explore the role of allo heart and thymus transplantation by intrathymic inoculation of thymocytes. METHODS: Wistar recipients were given intrathymic injection of allo thymocytes (2 x 10(7)) 14 days before the heart and/or thymus transplantation. Graft survival, histopathology, levels and mRNA expressions of IL-2, IL-4 in serum and cardiac-grafts were investigated. RESULTS: Heart transplantation and heart-thymus composite transplantation with the treatment of CysA for 7 or 14 days prolonged graft survival. Heart transplantation and heart-thymus composite transplantation with intrathymic thymocytes injection induced the long-term survival of allo-grafts transiently immunosuppressed with CysA; IL-4 maintained at high levels but IL-2 kept at low levels in grafts in long-term survivals. CONCLUSION: Intrathymic inoculation of allo thymoctyes can induce immune tolerance for both cardiac transplantation and heart-thymus combined transplantation in rats. Thymus graft may play a role in the induction and maintenance of central tolerance.