Significance Of Non-HLA Antibodies In Active Antibody-mediated Rejection Of Kidney Transplantation

Background:Allogeneic kidney transplantation is currently the first choice for the treatment of end-stage renal disease,which brings hope to the majority of patients with end-stage renal disease.Antibody-mediated rejection after kidney transplantation is the main cause that affects the function of transplanted kidney and eventually leads to the failure of graft kidney.With the development of clinical testing technology,preoperative HLA matching reduces the occurrence of HLA mediated cellular rejection as well as HLA antibody mediated humoral rejection.Preoperative PRA detection and CDC test could early diagnose the sensitization state of patients and reduce the occurrence of hyper acute and accelerated rejection.The development of immune agents and the optimization of immunosuppressive regimen have improved the therapeutic effect of cell-mediated rejection,which have improved the short-term survival rate of grafts.However,the long-term survival rate of transplanted kidney has not been significantly improved.Studies have shown that most graft failure correlated with antibody mediated graft rejection.In addition to the role of HLA antibody in graft rejection,non-HLA antibody mediated graft rejection has attracted more and more attention in recent years.Compared with T cell-mediated rejection,antibody mediated rejection of renal transplantation has the characteristics of difficult treatment,poor prognosis and easy recurrence from clinical experience.At present,it has become an urgent problem to be solved in the field of organ transplantation.There are many kinds of non-HLA antibodies.At present,many kinds of non-HLA antibodies have been reported in kidney transplantation.Some non-HLA antibodies,such as thyroglobulin,have been reported in the field of heart transplantation,however not yet in the field of kidney transplantation.Clinically,in the field of renal transplantation,a perfect non-HLA antibody detection system has not been established,therefore it is not possible to carry out preventive preoperative detection and auxiliary postoperative diagnosis and treatment of active antibody mediated rejection through serum non-HLA antibody detection.Objective:Analyzing the non-HLA antibodies in serum of patients with ABMR but negative panel reactive antibody detection after kidney transplantation,and screening out nonHLA antibodies that are correlated with the occurrence of ABMR after kidney transplantation and have measurement value to provide theoretical basis for clinical screening of non-HLA antibodies.The expression of related non-HLA antigens in transplanted kidney was detected by immunohistochemical staining,so as to provide an experimental basis for studying the mechanism of non-HLA antibodies in the field of transplanted kidney.Methods:The clinical data of patients who underwent biopsy of transplanted kidney due to abnormal creatinine in the Second Department of Urology,First Hospital of Jilin University from January 1,2018 to June 30,2021 were retrospectively analyzed(the pathological diagnosis was based on Banff-2017 pathological classification scheme of transplanted kidney).According to the inclusion criteria,finally the ABMR group included 26 patients with active ABMR confirmed by pathology after surgery and with negative PRA at the time of rejection.The control group included 19 patients who underwent biopsy of the transplanted kidney due to abnormal creatinine and showed no rejection.The clinical data,serological samples before and after kidney transplantation,as well as the pathological tissue of the transplanted kidneys of the two groups were collected.The Luminex method was used to detect 60 kinds of non-HLA antibodies in serum(previously reported to be related to organ transplantation,including but not limited to the field of kidney transplantation).The differences of the number of positive non-HLA antibodies and the median value of fluorescence in the serum of the two groups of patients were analyzed.Univariate analysis was preformed to screen out nonHLA antibodies that related to the occurrence of active ABMR.By immunohistochemical staining of related non-HLA antigens in the transplanted kidney tissue,the differences in the expression and distribution of non-HLA antigens in the two groups of transplanted kidney species were compared.The ROC curve was drawn to evaluate the predictive value of the screened non-HLA antibodies on the occurrence of active ABMR.Results:(1)Statistical analysis was performed on the general data of the two groups of patients(including age,gender,puncture time,number of transplants,immunosuppressive agents,second-line medication regimen,preoperative induction,preoperative PRA test results,postoperative PRA test results,dialysis duration,dialysis method,BMI,transplantation type),there was no significant difference in all indicators between the ABMR group and the control group(P>0.05).(2)Comparing the number of positive non-HLA antibodies in the serum of the two groups of patients before and after operation tested by Luminex method,it was found that the number of positive non-HLA antibodies in the serum of patients in the ABMR group before and after the operation was higher than that in the control group(P<0.05).(3)Difference analysis was performed on the median fluorescence of all non-HLA antibodies,and it was found that the MFI of 6 kinds of antibodies before operation were significantly higher compared with control group(P<0.05),including PRKCH,PRKCZ,ATP5 B,SSB,SNRPB2 and STAT6 antibodies and there were 9 kinds of antibodies after operation were significant higher compared with control group(P<0.05),including CSF2,ATP5 B,LPHN1,PECR,CCP,STAT6,SSB,NCL and PRKCZ antibodies.(4)Univariate analysis was used to screen out 4 kinds of non-HLA antibodies that were significantly correlated with the occurrence of ABMR(P<0.05),including CSF2,CCP,SSB and Thyroglobulin,and the latter three have not been reported in the field of kidney transplantation before.9 kinds of antibodies potentially related to ABMR were also found,including CXCL9,P2RY11,PRKCZ,collagen I,collagen V,NCL,PTPRO,STAT6 and VIM,which need to be further clarified by expanding the sample size.(5)Histopathological staining also confirmed that the transplanted kidney tissue of ABMR expressed more CSF2 and Thyroglobulin antigens.(6)The screened CSF2,CCP,SSB and Thyroglobulin antibodies have certain predictive effects on the occurrence of ative ABMR after kidney transplantation.Conclusions:(1)Compared with the control group,patients in the ABMR group contained more numbers of non-HLA antibodies in serum before kidney transplantation,and 6kinds of non-HLA antibodies such as PRKCH,ATP5 B,SSB showed higher expression.(2)Compared with the control group,patients in the ABMR group contained more numbers of non-HLA antibodies in serum after kidney transplantation,and 9 kinds of non HLA antibodies such as CSF2,SSB and CCP showed higher expression.(3)This study screened out 4 non-HLA antibodies including CCP,SSB,CSF2 and TG antibodies that were significantly correlated with the occurrence of active ABMR after kidney transplantation,and 4 non-HLA antibodies have certain predictive value for the occurrence of active ABMR after kidney transplantation.(4)CSF2 and TG antigens were more expressed in transplanted kidney tissue in ABMR group.