Histological reversibility of diabetic nephropathy after kidney transplantation from diabetic donor to non-diabetic recipient

Histological findings of diabetic kidneys transplanted in non-diabetic recipients: a case series

BACKGROUND

Diabetic donors are recognized as a reliable source of organs, although the discard rate of kidneys is still high. Few data are available on the histological evolution of these organs especially on kidneys transplanted into non-diabetic patients who remain euglycemic.

METHODS

We describe the histological evolution of ten kidney biopsies performed on non-diabetic recipients of diabetic donors.

RESULTS

Mean donor age was 69 ± 7 years, 60% were males. Two donors were treated with insulin, eight with oral antidiabetic drugs. Mean recipient age was 59.9 ± 7 years, 70% were males. The pre-existing diabetic lesions identified in the pre-implantation biopsies, encompassed all histological classes, and were associated with mild IF/TA and vascular damages. The median follow-up was 59.5 [IQR 32.5-99.0] months; at follow-up, 40% of cases did not change histologic classification, two patients with class IIb downgraded to IIa or I and one with class III downgraded to IIb. Conversely, three cases showed a worsening, from class 0 to I, I to IIb or from IIa to IIb. We also observed a moderate evolution of IF/TA and vascular damages. At follow-up visit, estimated GFR was stable (50.7 mL/min vs. 54.8 at baseline) and proteinuria was mild (51.1 ± 78.6 mg/day).

CONCLUSIONS

Kidneys from diabetic donors show variable evolution of the histologic features of diabetic nephropathy after transplant. This variability may be associated to recipients characteristics such as euglycemic milieu, in case of improvement, or obesity and hypertension, in case of worsening of histologic lesions.

Recoverability of Diabetic Nephropathy of Donor Kidney After Kidney Transplantation

Some kidney donors have diabetes, and little of their natural course of diabetic nephropathy (DN) is known. The aim of this study was to analyze the changes in pathologic lesions in the diabetic donor kidney after KT by performing protocol biopsy two weeks and one year after KT. This retrospective study included 103 patients who underwent KT, with kidneys from donors with a history of diabetes mellitus (DM). Among them, data of 34 patients who underwent biopsy two weeks and one year after KT were reviewed. Biopsy specimens were reviewed using light microscopy and electron microscopy. Glomerular basement membrane (GBM) thickness at 2 weeks and 1 year was compared. Biopsy showed that DN occurred in 29 of the 34 patients. Only trivial histological changes were observed in 22 patients (64.7%), including 5 patients who did not show DN. At one year after transplantation, there was no change in the DN histologic class in 26 patients (76.5%), and there was no statistically significant difference in the change in GBM thickness. This pattern was observed regardless of the recipient’s DM or glycemic control. With this understanding, clinicians can use kidneys from DM donors with more comfort, thereby reducing the kidney discard rate.

Biochemical mechanism underlying the pathogenesis of diabetic retinopathy and other diabetic complications in humans: the methanol-formaldehyde-formic acid hypothesis

Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to increased formation of endogenous methanol and/or formaldehyde, both of which are then metabolically converted to formic acid. These one-carbon metabolites are known to be present naturally in humans, and their levels are increased under diabetic conditions. Mechanistically, while formaldehyde is a cross-linking agent capable of causing extensive cytotoxicity, formic acid is an inhibitor of mitochondrial cytochrome oxidase, capable of inducing histotoxic hypoxia, ATP deficiency and cytotoxicity. Chronic increase in the production and accumulation of these toxic one-carbon metabolites in diabetic patients can drive the pathogenesis of ocular as well as other diabetic complications. This hypothesis is supported by a large body of experimental and clinical observations scattered in the literature. For instance, methanol is known to have organ- and species-selective toxicities, including the characteristic ocular lesions commonly seen in humans and non-human primates, but not in rodents. Similarly, some of the diabetic complications (such as ocular lesions) also have a characteristic species-selective pattern, closely resembling methanol intoxication. Moreover, while alcohol consumption or combined use of folic acid plus vitamin B is beneficial for mitigating acute methanol toxicity in humans, their use also improves the outcomes of diabetic complications. In addition, there is also a large body of evidence from biochemical and cellular studies. Together, there is considerable experimental support for the proposed hypothesis that increased metabolic formation of toxic one-carbon metabolites in diabetic patients contributes importantly to the development of various clinical complications.

Ongoing donor-transmitted diabetic kidney disease in kidney transplant recipients with fair sugar control: a single center retrospective study

Background

Transplantation with a diabetic donor kidney may have some benefits compared to remaining on the waitlist for selected patients. However, we found that some kidney transplant recipients have ongoing donor-transmitted diabetic kidney disease (DT-DKD) despite fair blood sugar control. This study aimed to survey the incidence and clinical pattern of DT-DKD in kidney transplant recipients.

Methods

We retrospectively reviewed the medical records of kidney transplantations in our hospital. We found 357 kidney transplantations from February 2006 to April 2018. Among these, 23 (6.4%) diabetic donor kidney transplantations were done in the study period.

Results

Among the 23 recipients, 6 (26.1%) displayed biopsy-proven DKD. Recipients with biopsy-proven DKD had longer dialysis vintage, higher proteinuria amount, lower last estimated glomerular filtration rate (eGFR), and a more rapid decline in the eGFR. The median fasting blood sugar level in the biopsy-proven DKD group was unexpectedly lower than the non-DKD group. Most of the pre-implantation frozen sections in biopsy-proven DKD group showed diabetic lesions worse than diabetic nephropathy (DN) class IIa. In the biopsy-proven DKD group, 5 recipients had no history of diabetes before or after transplantation. Among the 23 recipients, 5 (21.7%) were diagnosed with DT-DKD. Serial post-transplant biopsies showed the histological progression of allograft DN.

Conclusions

To the best of our knowledge, this is the first study to report the phenomenon of ongoing DT-DKD in kidney transplant recipients with fair blood sugar control. The zero-time pre-transplant kidney biopsy may be an important examination before the allocation of diabetic donor kidneys. Further study is needed to elucidate the possible mechanism of ongoing DT-DKD in non-diabetic recipients with fair blood sugar control as well as the impaction of pre-implantation diabetic lesion on the graft outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-020-02132-w.

Successful kidney transplantation from an expanded criteria donor with long-term extracorporeal membrane oxygenation treatment: A case report

BACKGROUND

Due to a shortage of donor kidneys, many centers have utilized graft kidneys from brain-dead donors with expanded criteria. Kidney transplantation (KT) from donors on extracorporeal membrane oxygenation (ECMO) has been identified as a successful way of expanding donor pools. However, there are currently no guidelines or recommendations that guarantee successful KT from donors undergoing ECMO treatment. Therefore, acceptance of appropriate allografts from those donors is solely based on clinician decision.

CASE SUMMARY

We report a case of successful KT from a brain-dead donor supported by ECMO for the longest duration to date. A 69-year-old male received a KT from a 63-year-old brain-dead donor who had been on therapeutic ECMO treatment for the previous three weeks. The recipient experienced slow recovery of graft function after surgery but was discharged home on post-operative day 17 free from hemodialysis. Allograft function gradually improved thereafter and was comparatively acceptable up to the 12 mo follow-up, with serum creatinine level of 1.67 mg/dL.

CONCLUSION

This case suggests that donation even after long-term ECMO treatment could provide successful KT to suitable candidates.

Mitochondria-related reversal of early-stage diabetic nephropathy in donor kidney after transplantation in mice

Background

Renal diabetic changes are frequent in kidney transplantation (KTx) donors. Whether these diabetic changes are reversible remains a topic of debate. This study aimed to test the hypothesized reversibility of diabetic changes after KTx.

Methods

C57BL/6J mice were randomly divided into three groups: the control group, early-stage group (ESG), and advanced-stage group (ASG). Diabetes mellitus (DM) was induced in mice by intraperitoneal injection of streptozotocin (STZ) at 50 mg/kg body weight for five consecutive days. Blood glucose levels ≥16.7 mmol/L were indicative of diabetic mice. The kidneys from ESG and ASG were transplanted to control mice 12 or 32 weeks after STZ injection. Kidney tissue, blood, and 24-hour urine specimens of donor and recipient mice were collected before KTx and 28 days after KTx, respectively. We measured the body weight, blood glucose, histological changes, reactive oxygen species (ROS), apoptosis. Electron microscopy was also performed to evaluate the mitochondrial morphology. The expression of NADPH oxidases (NOXs) was assessed by qRT-PCR.

Results

Kidneys from early-stage diabetic mice showed evidence of lesion reversal four weeks after KTx, including decreased urinary albumin and reversal of histological changes. Besides, mitochondrial swelling, oxidative stress, apoptosis, and overexpression of NOXs in the kidneys were also suppressed. Conversely, no changes were observed in kidneys from advanced-stage diabetic mice after KTx.

Conclusions

We confirmed that early-stage but not advanced-stage diabetic nephropathy (DN) is reversible, which is related to reduced NOX expression and improvement in mitochondrial function. These results indicated that kidneys with early-stage DN could be used for KTx in clinical practice, as the disease may be reversed following KTx.

Donor-related diabetic nephropathy: a comprehensive clinicopathological study

Knowledge on renal involvement in kidney donors with diabetes, that is, diabetic nephropathy (DN), is limited. During the 7 years (2010-2017), 921 postperfusion biopsies were performed for living donors (14%) or deceased donors (86%). The Renal Pathology Society classification schema for DN (class 0-IV) was used. Biopsies with light microscopic changes of DN (at least class IIa) were selected for study. Eleven biopsies (1.2%) showed DN, all from deceased donors (class IIa in 8, class IIb in 2, and class III in 1 biopsy). The glomerular basement membrane thickness ranged from 439 ± 52 to 725 ± 82 nm. These biopsies also displayed arterionephrosclerosis. They were from 9 deceased donors (fulfilling clinical criteria for acceptance in all, diabetes ;[>6 years] in 8, hypertension in 6, and proteinuria [1+] in all). Follow-up biopsies (5-342 weeks after transplant) showed DN of the same class (7 biopsies), probably progression (1), or progression (3). At follow-up (15-416 weeks), all recipients were alive. One graft was lost at 76 weeks because of progressive DN. The other 10 grafts were functioning, but the serum creatinine reached 2.0 to 2.7 mg/dL in 5 of them. Although diabetes is frequent in kidney donors, donor-related DN is unusual. It is observed only in deceased donors, but the risk factors for its development are not known. Donor-related DN may be stable or progress. Whether it resolves, especially for DN in early phase, remains unknown. It may adversely impact the graft outcome with a magnitude proportional to the severity of the tissue injury in the postperfusion biopsies.

Diabetic nephropathy after kidney transplantation in patients with pretransplantation type II diabetes: A retrospective case series study from a high-volume center in the United States

BACKGROUND

Patients with type II diabetes mellitus (DM) undergoing renal transplantation are at risk of diabetic nephropathy (DN) in the transplanted kidney. The true risk of developing post-transplantation DN is unknown, and post-transplantation DN is poorly characterized in the literature.

METHODS

The biopsy database at the University of Maryland Medical Center was queried for kidney transplant biopsies which demonstrated evidence of DN. The time from transplantation to biopsy-proven DN (time to diagnosis, TTD) was calculated and analyzed in the context of demographics, serum creatinine, and onset of diabetes. By extrapolating the total number of patients who developed DN in the last 2 years, we estimated the recurrence rate of DN.

RESULTS

Sixty patients whose renal biopsies met criteria were identified. The mean age was 56.6 (±1.58) years, and the mean creatinine level at time of biopsy was 1.65 (±0.12) mg/dL. Simultaneous pathological diagnoses were frequent on kidney biopsy; rejection was present at variable rates: classes I, IIA, IIB, and III were 5.0%, 66.7%, 18.4%, and 10%, respectively. The mean TTD was 1456 (±206) days. TTD was significantly shorter for patients receiving a cadaveric vs living donor renal transplant (1118 ± 184 vs 2470 ± 547 days, P = 0.004). Older patients (r = 0.378, P = 0.003) and patients with higher serum creatinine (r = 0.282, P = 0.029) had shorter TTDs. Extrapolations showed that 74.7% of patients would be free of DN 10 years after renal transplantation.

CONCLUSIONS

Diabetic nephropathy occurs after transplantation, and this appears to be due to both donor and recipient-derived factors. Encouragingly, our estimates suggest that as many as 75% of patients may be free of DN at 10 years following kidney transplantation.