Tolerance protocol of living kidney transplant for developing countries through basic strategy of lymphocyte depletion

End-stage kidney failure(ESKD)is a global issue where kidney replacement therapy imposes enormous economic burden to people of developing countries,in addition to the severe limitations to the availability of hemodialysis and peritoneal dialysis technique.The best option of kidney transplantation also requires lifelong combination immunosuppressive medicines,the cost of which is equally comparable to lifelong dialysis.A strategy of achieving transplant tolerance that requires minimum immunosuppressive medicines,although in experimental stage,also requires state-of-art technology with costly medicines and interventions.This is evidently beyond the reach of ESKD patients of developing countries.Hence,globally in developing countries,a need for an innovative but cost-effective tolerance protocol is a burning need for a successful transplant program.In brief,transplant tolerance is defined as a state of donorspecific unresponsiveness to the allograft antigens without the need for ongoing pharmacologic immunosuppression or with a minimal need.Current state-of-art techniques involves:(1)A state of hematological chimera,for complete tolerance;(2)Prope or partial tolerance where immune-reactive T-lymphocytes are inhibited using monoclonal antibodies;and(3)Chimeric antigen receptor for T-regulatory(T-reg)cell therapy using genetically engineered T-reg cells targeting specific Tlymphocyte receptors for inducing anergy.From our real-world experience in transplant management in post-transplant lympho-proliferative disorders(PTLD),we noticed frequently a drastic reduction in the need of immunosuppressive medicines following lympho-ablative therapy for PTLD.We recently published a case study on a real-world experience transplant case where we explained a partial or prope tolerance that developed after lymphocyte ablation therapy,following which the allograft was maintained with low dose dual standard immunosuppressive medicines.Based on this publication,we propose here an innovative tolerance protocol for living related low risk kidney transplantation for developing countries,in this opinion review.

Effect of Alemtuzumab on Intestinal Intraepithelial Lymphocytes and Intestinal Barrier Function in Cynomolgus Model

Background：Alemtuzumab has been used in organ transplantation and a variety of hematologic malignancies （especially for the treatment of B-cell chronic lymphocytic leukemia）.However,serious infectious complications frequently occur after treatment.The reason for increased infections postalemtuzumab treatment is unknown at this stage.We explore the effect ofalemtuzumab on intestinal intraepithelial lymphocytes （IELs） and intestinal barrier function in cynomolgus model to explain the reason of infection following alemtuzumab treatment.Methods：Twelve male cynomolguses were randomly assigned to either a treatment or control group.The treatment group received alemtuzumab （3 mg/kg,intravenous injection） while the control group received the same volume of physiological saline.Intestinal IELs were isolated from the control group and the treatment group （on day 9,35,and 70 after treatment） for counting and flow cytometric analysis.Moreover,intestinal permeability was monitored by enzymatic spectrophotometric technique and enzyme-linked immunosorbent assay.Results：The numbers of IELs were decreased significantly on day 9 after treatment compared with the control group （0.35 ± 0.07 × 10^8 and 1.35 ± 0.09 × 10^8,respectively; P 〈 0.05） and were not fully restored until day 70 after treatment.There were significant differences among four groups considering IELs subtypes.In addition,the proportion ofapoptotic IELs after alemtuzumab treatment was significantly higher than in the control group （22.01 ± 3.67 and 6.01 ± 1.42,respectively; P 〈 0.05）.Moreover,the concentration of D-lactate and endotoxin was also increased significantly on day 9 after treatment.Conclusions：Alemtuzumab treatment depletes lymphocytes in the peripheral blood and intestine of cynomolgus model.The induction of apoptosis is an important mechanism of lymphocyte depletion after alemtuzumab treatment.Notably,intestinal barrier function may be disrupted after alemtuzumab treatment.