Operational Tolerance in Living-Related Renal Transplantation: A Single-Center Experience

Thrombotic microangiopathy in a renal allograft: Single-center five-year experience

Thrombotic microangiopathy (TMA) is devastating for renal transplantation (RT) causing graft/ patient loss. We present 5-year experience of TMA in RT in retrospective study of indicated renal allograft biopsies with TMA. Patient-donor demographics and associated histological findings with respect to transplants under tolerance induction protocol (Group 1) were compared with patients transplanted under triple immunosuppression (Group 2). Statistical analysis was performed using IBM SPSS Statistics version 20. Sixty-one (4.1%) of 1520 biopsies [Group 1:17 (1.9%)/882, Group 2:44 (6.9%)/638] revealed TMA. Tacrolimus trough levels were normal. There was no evidence of systemic involvement in any patient. Mean age was 36.8 years with 70.6% males, HLA-match, 2.6/6, and the most common original disease unknown (41.2%) in Group 1, and 35.9 years with 86.4% males, HLA-match, 2.1/6, and the most common original disease unknown (50%) in Group 2. Biopsies were performed at mean 5.1-year posttransplant in Group 1 and 2.3 years in Group 2. Acute TMA constituted 47% Group 1 and 43.2% Group 2 biopsies; of these, antibody-mediated rejections were observed in 58.8%, T-cell mediated rejections in 11.8%, tacrolimus toxicity in 76.5%, and other findings in 35.3% Group 1; and 61.4%, 25%, 50%, and 18.2%, respectively, in Group 2 biopsies. Higher rejection activity scores were more in Group 2. Postbiopsy 1- and 5- year patient survival was 94.1%, 86.9% in Group 1 and 92.1%, 88.3% in Group 2; 1- and 4-year graft survival was 52.9%, 15.9% in Group 1 and 20.3%, 5.4% in Group 2. TMA was poor prognosticator for RT, especially under triple immunosuppression. Antibody- mediated rejection and tacrolimus toxicity were more prone to TMA.

Kidney transplantation for treatment of end-stage kidney disease after haematopoietic stem cell transplantation: case series and literature review

BACKGROUND

The safety of kidney transplantation (KT) for end-stage kidney disease (ESKD) after haematopoietic stem cell transplantation (HSCT) for haematological disease has not been investigated thoroughly.

METHODS

In this retrospective multicentre study, we investigated the clinical courses of six ESKD patients that received KT after HSCT for various haematological diseases. Data for six such patients were obtained from three institutions in our consortium.

RESULTS

Two patients with chronic myeloid leukaemia, one with refractory aplastic anaemia and another one with acute lymphocytic leukaemia received bone marrow transplantation. One patients with acute lymphocytic leukaemia received umbilical cord blood transplantation, and one with mantle cell lymphoma received peripheral blood stem cell transplantation. The patients developed ESKD at a median of 133 months after HSCT. Two patients who received KT and HSCT from the same donor were temporarily treated with immunosuppressive drugs. The other patients received KT and HSCT from different donors and were treated with antibody induction using our standard regimens. For one patient with ABO-incompatible transplantation, we added rituximab, splenectomy, and plasmapheresis. In the observational period at a median of 51 months after KT, only one patient experienced acute T-cell-mediated rejection. Four patients underwent hospitalization because of infection and fully recovered. No patient experienced recurrence of their original haematological disease. All patients survived throughout the observational periods, and graft functions were preserved.

CONCLUSIONS

Despite the high infection frequency, survival rates and graft functions were extremely good in patients compared with previous studies. Therefore, current management contributed to favourable outcomes of these patients.

Co-infusion of donor adipose tissue-derived mesenchymal and hematopoietic stem cells helps safe minimization of immunosuppression in renal transplantation - single center experience

BACKGROUND

Stem cell therapy (SCT) is used for immunosuppression minimization in renal transplantation (RT). We carried out a prospective study to evaluate the benefits of co-infusion of donor adipose-derived mesenchymal stem cells (AD-MSC) + hematopoietic stem cells (HSC) in living donor RT (LDRT) under non-myeloablative conditioning.

METHODS

In a demographically balanced three-armed LDRT trial with 95 patients in each arm, group-1 received portal co-infusion of AD-MSC + HSC, group-2 received HSC and group-3 received no SCT. Lymphoid irradiation and anti-thyroglobulin were used for conditioning.

RESULTS

SCT was safe. At 1 and 5 years post-transplant, patient survival was 100% and 94.7% in group-1, 100% and 95.7% in group-2, and 94.7% and 84% in group-3, death-censored graft survival was 100% and 94.6% in group-1, 100% and 91.3% in group-2, and 98.9% and 94.4% in group-3 with mean serum creatinine (mg/dL) of 1.38 and 1.39 in group-1, 1.48 and 1.51 in group-2, and 1.29 and 1.42 and in group-3. Rejection episodes and immunosuppression requirement were lesser in SCT groups versus controls with best results noted in group-1.

CONCLUSION

Coinfusion of donor AD-MSC +HSC in portal circulation pre-transplant under non-myeloablative conditioning is safe and effective for immunosuppression minimization in LDRT.

Transplantation tolerance; myth or reality?

Implication for health policy/practice/research/medical education: Transplantation is now a well-accepted therapy for end organ failure. However the recipients are required to take life-long immunosuppression to prevent rejection. This leads to immunosuppression associated morbidity in the form of viral/ fungal/ bacterial infections in addition to causing financial burden on the system. Over a long run these patients are at high risk to develop malignancies.In spite of all these efforts, the graft is lost over 7-10 years to chronic graftattrition/ rejection. The only answer to this problem is "Transplant tolerance" which means stable allograft function while maintaining third party immuneresponse intact in absence of rejections on no immunosuppression. Since last 60 years transplanters across the globe are in search of this "Mackenna's gold". The following editorial discusses how far have we progressed in our search for the promised land of "Transplant Tolerance."

Pre-transplant co-infusion of donor-adipose tissue derived mesenchymal stem cells and hematopoietic stem cells may help in achieving tolerance in living donor renal transplantation

Transplantation tolerance is still a Utopian dream for many transplanters. Mesenchymal stem cells (MSC) have shown immuno-modulatory and tolerogenic effects in experimental models. We present a 29-year-old male with end stage renal disease (ESRD) who was transplanted with HLA 4/6 matched kidney from 51-year-old father in June 2010 preceded by co-infusion of donor-adipose tissue derived mesenchymal stem cells (AD-MSC) and bone marrow derived hematopoietic stem cells (BM-HSC) under non-myeloablative conditioning for deleting rejecting T and B-cells. He has maintained fairly stable graft function with serum creatinine (SCr) between 1.5 and 1.8 mg/dL at 3 years post-transplant with absence of donor specific antibodies (DSA), normal protocol graft biopsy, and peripheral T-regulatory cell levels (pTregs) (CD127(low/-)CD25(high)CD4+) of 4.57% on zero immunosuppression since 6 months.

Stable graft function on low-dose steroid monotherapy in spite of donor-specific antibodies in renal transplantation combined with stem cell infusion

Transplantation using immunosuppression/induction therapies has controlled acute rejections; however, there is no answer for chronic graft attrition. Donor-specific antibodies (DSA) are believed to cause antibody mediated rejections eventually causing chronic graft loss. Regulatory T cells (T-regs) are believed to protect the graft from immune injury. We report a 53-year-old woman transplanted with her son's kidney using donor-specific transfusion and stem cells (SC) under non-myeloablative conditioning of cyclophosphamide, anti-T and anti-B-cell antibodies and Bortezomib. The patient was on low-dose steroid monotherapy under immune monitoring of DSA and serum creatine. Graft biopsy at 1 and 3.5 years post-transplant was unremarkable in spite of the presence of DSA. Peripheral T-regs (pTregs) at 3.5 years post-transplant were 3.54%. This case shows that DSA are not necessarily detrimental to the renal allograft. We further hypothesise that pTregs were induced from SC and sustained to protect this graft from cytotoxic T cells and DSA.

Stem cells versus donor specific transfusions for tolerance induction in living donor renal transplantation: a single-center experience

BACKGROUND

We undertook this study to define the role of stem cell transplantation (SCT) versus donor-specific transfusion (DST) in tolerance induction and sustenance in living donor renal transplantation (LDRT).

METHODS

In this prospective three-armed trial in LDRT with 13 patients each in demographically well-balanced groups, tolerance induction protocol (TIP) was used with SCT in group 1, DST in group 2, and no induction in group 3. Tolerance induction protocol consisted of SCT/DST under conditioning with bortezomib, methylprednisone, rituximab, and rabbit antithymocyte globulin. Transplantation was performed with prednisone in groups 1 and 2 and with triple immunosuppression in group 3, if lymphocyte/flow crossmatch was negative; and if donor-specific antibodies (DSAs) were absent in the first 2 groups. Posttransplant monitoring included serum creatinine (SCr), peripheral T-regulatory cells (pTregs)(127/CD4+/25), and DSA for groups 1 and 2; DSA was eliminated in group 3. Rescue IS was started with rise of SCr/DSA/ rejection.

RESULTS

Tolerance induction protocol was safe. Over a mean follow-up of 2 years, no patient/graft was lost in groups 1 and 2. One patient of group 3 lost graft to noncompliance. Protocol biopsies were unremarkable. Rejections were noted in six patients of group 1, five of group 2, and seven of group 3. Donor-specific antibodies were elevated in three patients of both groups. Mean SCr of all groups was similar; however, pTregs were increased posttransplant in groups 1 and 2 versus group 3. Group 1 had sustained rise in pTregs.

CONCLUSION

Stem cell transplantation and DST are useful for immunosuppression minimization in LDRT with sustained generation of pTregs with SCT.

Renal transplantation in hepatitis C positive patients: a single centre experience

Introduction. Hepatitis C virus (HCV) infection is an independent risk factor for renal transplantation (RTx). Immunosuppression minimization can render better quality of life to these patients. Methods. We analyzed 132 HCV-positive RTx patients (group A) transplanted under tolerance induction protocol (TIP) and compared them with 79 controls (group B) transplanted using standard triple drugs. TIP consisted of 1 donor-specific transfusion, peripheral blood stem cell infusion, portal infusion of bone marrow, and target-specific irradiation. Their immunosuppression was cyclosporin, 2 ± 1 mg/kg BW/day + prednisone, 10 mg/day. Results. TIP had no side effects. Although unequal in size, the groups were well balanced. Group A patient survival at 1, 5, and 10 years was 92.4%, 70.4%, and 63.7%, respectively, versus 75.6%, 71.7%, and 55.7% in later, and graft survival was 92.9%, 81.5%, and 79.1% versus 91.7%, 75.7%, and 67.7%, respectively. Mean serum creatinine (mg/dL) at these time periods in former was 1.38, 1.72, and 1.87, versus 1.3, 1.75, and 2.1 in later. Altered liver functions were noted in 22% patients in former versus 31% in later. Group A had lesser rejection episodes. Conclusion. RTx using TIP in HCV-positive patients is a viable option with acceptable outcome.