Long-term mycophenolate monotherapy in human leukocyte antigen (HLA)-identical living-donor kidney transplantation

Chronic Histologic Changes Are Present Regardless of HLA Mismatches: Evidence from HLA Identical Living Donor Kidney Transplants

BACKGROUND

At 5 and 10 years after kidney transplantation, chronic histologic changes such as arteriolar hyalinosis and mesangial expansion are common, however, determining etiology is difficult. We compared surveillance biopsies in living donor kidney transplants (LDKTx) from HLA matched siblings (termed HLA-identical (HLA-ID)) to HLA non-ID to investigate which histologic changes were likely due to alloimmune injury and which were due to non-alloimmune injury.

METHODS

We performed a retrospective, cohort study comparing HLA-ID sibling LDKTx (n=175) to HLA non-ID LDKTx (n=175; matched for age, sex and year of transplant +/- 2 years) performed at a single institution from 03/1999 to 11/2018.

RESULTS

Baseline characteristics and maintenance immunosuppression were similar. Mortality rates were similar, but in the HLA-ID group, 10-year death-censored graft survival was higher (93.8% vs 80.9% HLA non-ID LDKTx, p<0.001), rejection rates were lower (after 1 year 9.6% vs 27.1%; p<0.001) and Banff inflammation scores including glomerulitis and peritubular capillaritis were lower on surveillance biopsies at 1, 5 and 10 years. In contrast, chronic Banff scores (interstitial fibrosis, arteriolar hyalinosis, mesangial expansion, etc.) were similar in prevalence and severity on surveillance biopsies at 1, 5 and 10 years.

CONCLUSIONS

HLA-ID LDKTx have less inflammation and less transplant glomerulopathy, but most chronic histologic changes were similar to less-well matched LDKTx. We conclude that these types of chronic changes are not associated with HLA mismatches and may be due to non-immunologic causes (hypertension, obesity, etc.) suggesting that new management approaches to prevent these lesions may be needed.

Mycophenolate Monotherapy in HLA-Matched Kidney Transplant Recipients: A Case Series of 20 Patients

The ideal minimizing strategy for maintenance immunosuppression in HLA-matched kidney transplant recipients (KTR) is unknown. We hypothesized that mycophenolate (MPA) monotherapy is a safe and effective approach for maintenance therapy in this group of KTR.

Methods

Data were abstracted for 6-antigen HLA-matched KTR between 1994 and 2013. Twenty recipients receiving MPA monotherapy secondary to infection, cancer, calcineurin inhibitor (CNI) side effects, or immunosuppression minimization strategies were evaluated in this case series.

Results

MPA monotherapy had a low incidence of death-censored graft failure (3.19/100 person-y), rejection (0/100 person-y), hospitalization (1.62/100 person-y), malignancy (3.61/100 person-y), and infection (1.75/100 person-y). Further, 12-month mean or median serum creatinine (1.29 mg/dL), estimated glomerular filtration rate (64.3 mL/min/1.73 m2), urine protein creatinine ratio (143.2 mg/g), hemoglobin (13.9 g/dL), platelets (237.8 K/uL), and white blood cell count (9.04 K/uL) were favorable. There was a successful conversion rate of 90% (18 of 20) with 2 patients converting back to CNI-based regimens secondary to recurrence of membranous nephropathy and post-transplant lymphoproliferative disorder.

Conclusions

Our findings indicate that MPA monotherapy may be a promising immunosuppression minimization strategy for HLA-matched KTR.

Immunosuppression and Graft Rejection in Living-related HLA-identical Renal Transplantation: The RADOVFULL Study

BACKGROUND

We aimed to describe the immunosuppressive regimens and graft rejection rates in living-related HLA-identical (LR HLAid) renal transplantation.

METHODS

We performed a retrospective multicenter analysis of the French national database for LR HLAid renal transplantations performed between 2002 and 2012. Univariate and multivariate analysis were performed to determine risk factors for graft rejection in LR HLAid recipients.

RESULTS

A total of 27 218 renal transplantations were performed, of whom 163 had a LR HLAid donor. About immunosuppressive treatment, <60% of the cohort had induction therapy with polyclonal or monoclonal antibodies, 28% did not receive calcineurin inhibitors, and 36% did not receive steroids in maintenance. Biopsy-proven acute rejection was diagnosed in 21 patients (12.9%). Rejection occurred on an average of 24 months after transplantation, in 28.5% of the cases after minimization of immunosuppression. Factors associated with rejection were age of recipient (OR, 0.91 [0.84-0.96]; P = 0.003), the body mass index of donors (odds ratio [OR], 1.22 [1.04-1.46]; P = 0.01), and minimization of immunosuppression (OR, 26.2 [5.48-166.6]; P < 0.001). Overall and graft survival rates were not statistically different according to rejection at 1, 5, and 10 years posttransplantation.

CONCLUSIONS

Minimization of immunosuppression should be done with caution in LR HLAid renal transplantations.

The Privilege of Induction Avoidance and Calcineurin Inhibitors Withdrawal in 2 Haplotype HLA Matched White Kidney Transplantation

Background

White recipients of 2-haplotype HLA-matched living kidney transplants are perceived to be of low immunologic risk. Little is known about the safety of induction avoidance and calcineurin inhibitor withdrawal in these patients.

Methods

We reviewed our experience at a single center and compared it to Organ Procurement and Transplantation Network (OPTN) registry data and only included 2-haplotype HLA-matched white living kidney transplants recipients between 2000 and 2013.

Results

There were 56 recipients in a single center (where no induction was given) and 2976 recipients in the OPTN. Among the OPTN recipients, 1285 received no induction, 903 basiliximab, 608 thymoglobulin, and 180 alemtuzumab. First-year acute rejection rates were similar after induction-free transplantation among the center and induced groups nationally. Compared with induction-free transplantation in the national data, there was no decrease in graft failure risk over 13 years with use of basiliximab (adjusted hazard ratio [aHR], 0.86; confidence interval [CI], 0.68-1.08), Thymoglobulin (aHR, 0.92; CI, 0.7-1.21) or alemtuzumab (aHR, 1.18; CI, 0.72-1.93). Among induction-free recipients at the center, calcineurin inhibitor withdrawal at 1 year (n = 27) did not significantly impact graft failure risk (HR,1.62; CI, 0.38-6.89).

Conclusions

This study may serve as a foundation for further studies to provide personalized, tailored, immunosuppression for this very low-risk population of kidney transplant patients.

Long-term unexpected consequence of two kidney transplants with full-match grafts: a report of two cases

HLA typing is the cornerstone of kidney transplantation. Here, we present two full-match kidney transplants with early uneventful course but late c4d-mediated rejection and recurrent pauce-immune necrotizing crescentic glomerulonephritis, as each in one. Case 1: A 49 years old Caucasian female patient, received a six-matched cadaveric kidney and had nonspecific changes in 6th and 12th month protocol biopsies. The first and third year serum creatinin value was 1.8 and 2.0 mg/dl. Immunosuppressive drugs were gradually reduced due to recurrent infections at the 3rd year. She admitted with allograft dysfunction and serum creatinin 5.8 mg/dl. Kidney biopsy of graft dysfunction at the 4th year was diagnosed C4d-mediated rejection. Case 2: A 61 years old Caucasian female patient received a HLA-identical kidney 8.5 years ago from her sibling had a primary vasculitis mediated necrotizing crescentic glomerulonephritis. Her serum creatinin values in the 1st and 8th years were 1.3 and 1.7 mg/dl. In recent years, immunosuppressive dosage has been gradually reduced due to recurrent lower respiratory tract infections. She admitted with hematuria, purpuric rash, dyspnea. and serum creatinin 5.7 mg/dl. Renal biopsy revealed necrotizing crescentic glomerulonephritis. The patient was treated with pulse steroid, double filtration plasmapheresis and rituximab. She is being followed with a functioning graft and with serum creatinin 2.0 mg/dl. In case of recurrent infection, immunosuppressive drugs should be modified cautiously even in patients with full-match grafts to prevent late acute rejection or recurrence of the primary disease.