ABSTRACT
With the clinical application of new technology and immunosuppressive drugs,the early acute graft rejection have been significantly decreased.However,chronic graft failure in long-term transplantation has become one of the most important reasons. As the same as body solid organ transplantation,chronic corneal allograft dysfunction is present after penetrating keratoplasty and has been one of the main reasons of causing repeat keratoplasty.Therefore,studying the mechanism of chronic allograft dysfunction will be of the most important significance in clinical prevention and treatment for chronic graft corneal transplant failure,especially in prolongation of corneal grafts survival rate.
ABSTRACT
Objective To study the expression of immune and non-immune related cytokine in corneal grafts of chronic graft dysfunction after penetrating keratoplasty and reveal the possible mechanism of it.Design Clinical experimental study.Participants Including two groups.In chronic corneal allograft dysfunction(CCAD) group,corneas of 8 patients fulfilling the diagnostic criteria for CCAD who underwent repeated PK operation.Three normal corneas supplied by Shandong provincial eye bank of China were used as control group.Methods The conreal graft were analyzed by immunohistochemical studies.Moreover,the comprehensive analysis was carried out combining the patient's clinical data.Main Outcome Measures CD4~+,CD8~+,F4/80,TGF-?,bFGF and?-SMA in cornea. Results The results of immnunohistochemical studies showed that compared with normal corneas,full-thickness corneal grafts of eight corneas which underwent repeated PK operation had no CD4~+ and CD8~+ T lymphocyte infiltration.F4/80 positive inflammatory cells were more abundant near the stroma of five corneal grafts which underwent once PK operation.Full-thickness corneal grafts of other three corneas which underwent no immune rejection had no F4/80 positive inflammatory cells.The TGF-?positive inflammatory cells were more abundant near the epithelium and stroma of all corneal grafts.The moderate bFGF positive inflammatory cells were present in stroma of all corneal grafts.The?-SMA positive inflammatory cells were more abundant near stroma and the elastic layer of all corneal grafts.Conclusions After PK operation,the results of immnunohistochemical studies of the corneal graft which underwent CCAD showed that there is no evidence of clinical acute rejection.The abnormal expression of antigen presenting cells and non-immune cell specific factors suggest that immune or non-immune factors maybe involve in the occurrence and development of CCAD.