De novo Inflammatory Bowel Disease in Kidney Transplant Recipients: A Single-Center Case Series Study.

Introduction: Gastrointestinal complications are common after solid organ transplantation. New-onset inflammatory bowel disease (IBD) after transplantation (de novo) is a major differential diagnosis of diarrhea after liver transplantation (LT) because of its high incidence in the field. However, the incidence of IBD after kidney transplantation (KT) remains unknown. Methods: This case series comprised six de novo IBD patients who had undergone KT at our hospital from April 1998 to December 2020. In this period, 232 KT recipients were identified. Participants were analyzed based on their colonoscopy diagnoses. Detailed clinical information regarding both KT- and IBD-related symptoms or outcomes was obtained, and we calculated the incidence of de novo IBD from the date of KT. Results: Of the 232 recipients in the median observation period of 6.1 (interquartile range: 2.6, 10.8) years, six recipients (one with Crohn's disease and five with ulcerative colitis) were diagnosed with de novo IBD. The incidence of de novo IBD after KT was 355.8/100,000 person-years (95% confidence interval, 159.8-791.9 per 100,000 person-years). Bloody stools and diarrhea did not always occur, with bloody stools occurring in three and diarrhea in 2 patients at the time of diagnosis. No recipient developed graft failure or extraintestinal complications (e.g., IBD-related nephritis or arthritis). Conclusion: Despite a small sample size, this study's results indicate that the incidence of de novo IBD after KT may be similar to that after LT and higher than that in the general population. Larger studies are required to validate these preliminary findings.

Consequences of kidney donation by age in Japanese living kidney donors: a single-center study.

BACKGROUND: Elderly living kidney donors (LKDs) are becoming increasingly important in countries with a high prevalence of living-donor kidney transplants and an aging society. This study explored the features of elderly LKDs, focusing on their subsequent outcomes. METHODS: This single-center, retrospective, observational study included eligible LKDs who donated their kidneys between April 2008 and July 2022. LKDs were categorized into an elderly (≥70 years at donation) or a non-elderly group (<70 years). We examined pre-operative characteristics and post-operative outcomes, such as kidney function, complications, development of end-stage kidney disease (ESKD), and mortality. RESULTS: Of the 188 LKDs observed for a median of 5.7 years, 31 were in the elderly group (16.5%) and 157 (83.5%) were in the non-elderly group (mean age 72.5 ± 2.7 and 58.2 ± 7.3 years, respectively). No significant differences were observed in hospital stay length or peri-operative complications between groups. Both groups experienced a similar decline in post-donation estimated glomerular filtration rate (eGFR)-approximately 37%. In the elderly group, four LKDs died, and one progressed to ESKD. In the non-elderly group, two LKDs died, and none progressed to ESKD. The cause of death was not strongly suspected to be associated with the donation. CONCLUSIONS: eGFR was maintained even in elderly LKDs post-donation. Prioritizing LKDs' safety is paramount; however, donations from elderly people would be acceptable, considering their life expectancy. This can expand the pool of living kidney donors and address the growing demand for kidney transplants.

Mesangiolysis in Pathological Chronic Active Antibody-Mediated Rejection in Kidney Transplant Biopsies.

INTRODUCTION: This study aimed to determine if immune or nonimmune and acute or chronic lesions associated with mesangiolysis (MGLS) occurred in biopsy-proven pathological chronic active antibody-mediated rejection (P-CAABMR) in kidney transplant biopsies. METHODS: We evaluated MGLS in 41 patients with biopsy findings of P-CAABMR from January 2016 to December 2019. Histological scoring was evaluated by Banff classification. Multivariate logistic regression analysis was performed using a forward selection method. RESULTS: Fifteen of the 41 P-CAABMR biopsies (36.6%) cases showed MGLS. The estimated glomerular filtration rate (eGFR) was significantly lower in the MGLS-positive compared with the MGLS-negative group, and proteinuria was significantly higher in the MGLS-positive compared with the MGLS-negative group. In the clinical model, multivariate analysis was performed using covariates of eGFR and duration after transplantation significantly correlated with MGLS by simple analysis, in addition to type of calcineurin inhibitor use (tacrolimus or cyclosporine), donor-specific antibodies, diabetes, and hypertension grade defined by use of antihypertensive therapy or/and blood pressure level. Only hypertension grade was significantly correlated with MGLS. In the pathological model, multivariate analysis was performed using the presence of FSGS and the aah and cg scores significantly correlated with MGLS by simple analysis, in addition to g and ptc scores. The cg score was significantly correlated with hypertension grade, duration after transplantation, g, ah, and aah. CONCLUSION: Lower graft function and higher proteinuria was observed in MGLS of P-CAABMR. The Banff cg score was independently related to MGLS in multivariate analysis. Sustained glomerulitis, calcineurin inhibitor nephrotoxicity, and hypertension may cause Banff cg lesions, leading to MGLS in P-CAABMR.

Prognostic value of the 7-year protocol biopsy of adult kidney allografts: impact of mesangiosclerosis and proteinuria.

AIM: The aim of the present study was to clarify the relationship between the Banff score of the 7-year protocol biopsy and the allograft outcome. METHODS: One-hundred-and-eighty-four patients received kidney transplantation from 2002 to 2008. We excluded patients aged <20 years at transplantation (n = 24), those who did not undergo a 7-year protocol biopsy (n = 66), and those who underwent for-cause biopsy (n = 5). Consequently, 89 patients who underwent a 7-year protocol biopsy were enrolled. We analyzed the relationship between the clinicopathological findings 7 years after transplantation and the estimated glomerular filtration rate (eGFR) change per year and allograft survival. Histological evaluation was performed using the Banff 2015 classification. RESULTS: Among the clinicopathological findings, each Banff mesangial matrix increase (mm) score ≥1 and proteinuria ≥1+ was independently associated with the eGFR decline per year during a median follow-up of 73 months. Furthermore, in the model of the clinicopathological findings including the presence of mm with proteinuria, mm ≥1 alone and mm ≥1 with proteinuria were each independently associated with the eGFR decline. The graft survival was significantly worse for those with mm ≥1 with proteinuria than those with mm ≥1 without proteinuria. CONCLUSION: Among the 7-year protocol biopsy findings, the presence of mm alone and mm with proteinuria were each significant predictors of eGFR decline. The presence of both proteinuria and mm had a negative impact on graft survival. These results underscore the significance of the Banff mm score and proteinuria at the time of the 7-year protocol biopsy to predict the allograft outcome.

Allograft adenovirus nephritis accompanied by Crohn's disease in a kidney transplant recipient: a novel case report.

Excessive immunosuppression after kidney transplantation (KT) is often encountered in patients undergoing therapy for anti-rejection or autoimmune disease that requires further treatment using immunosuppressive medications (IMs), including biologic agents. We report a novel case wherein a kidney transplant recipient developed severe acute allograft injury and hemorrhagic cystitis at 4.5 years after KT due to adenovirus nephritis after treatment with infliximab for Crohn's disease. The diagnosis was made based on adenovirus immunohistochemistry staining and urine polymerase chain reaction tests. The patient was successfully treated by reducing IMs and administration of immunoglobulin even though allograft function was eventually partially recovered. When new immunosuppressive agents, particularly biologic agents, are initiated for other diseases in addition to maintenance IMs, the following points need to be regarded: (1) pay attention to opportunistic infections even in the late phase of KT, and (2) maintain communication with other specialists who prescribe biologics to ensure appropriate administration of IMs.

Deep venous thrombosis in a kidney transplant recipient with COVID-19: a case report.

The outcomes of COVID-19 in kidney transplant recipients have shown high mortality. In addition to their immunocompromised states, kidney transplant recipients frequently have certain exacerbation risk comorbidities of COVID-19, such as diabetes mellitus, hypertension, and chronic kidney disease. Several concomitant diseases develop during the course of COVID-19, one of which is thromboembolism, which can potentially lead to a critical condition. However, thromboembolic complications in kidney transplant recipients with COVID-19 have not been fully addressed in previous studies. A 62-year-old man, who underwent kidney transplantation 17 years ago, was diagnosed with COVID-19 and was admitted to our hospital. Although the patient was in remission at the start of the hospitalization, his condition became severe on day 7 after admission, with fever, elevated white blood cell counts (10,000/µL) and a high C-reactive protein level (6.9 mg/dL). Although the patient was not under forced bed rest, an ultrasound study on day 10 detected deep venous thrombosis (DVT), with an elevated D-dimer level (6.2 µg/dL). We withdrew the mycophenolate mofetyl and the tacrolimus dosage but did not administer any specific treatment for COVID-19. The patient achieved successful clearance of SARS-CoV-2 on day 16. The DVT disappeared after systematic heparin treatment and oral rivaroxaban for 2 months. DVT occurred in a kidney transplant recipient with COVID-19 who was not bedridden and might manifest when the clinical status was exacerbated during hospitalization.

Outcome of ABO-incompatible kidney transplantation using a modified desensitization protocol without plasmapheresis.

OBJECTIVES: Several controversies regarding desensitization strategies for successful ABO-incompatible (ABOi) kidney transplantation still exist. This study aimed to investigate whether pretransplant anti-A/B antibody removal is mandatory in an ABOi kidney transplant recipient with low baseline isoagglutinin titers. METHODS: We adopted a modified desensitization protocol with two doses of rituximab (RTX, 100 mg/body) without pretransplant antibody removal for ABOi kidney transplant recipients with a titer of ≤1:64 (group A; n = 35) and investigated the feasibility of this protocol by comparing it with the clinical outcomes of patients undergoing standard pretransplant plasmapheresis (group B; n = 21). RESULTS: There was no significant difference in the rate of antibody-mediated rejection within the first month after transplantation between the two groups (11.4% in group A vs. 2% in group B, p = 0.6019). Moreover, no differences were observed in the short- and long-term graft outcomes between the groups. However, two major critical acute antibody-mediated events occurred in group A; one patient lost the graft due to hyperacute rejection, and the other patient developed thrombotic microangiopathy after surgery. Risk factors predicting these perioperative complications were not identified. CONCLUSIONS: We conclude that not only B-cell depletion using RTX but also pretransplant antibody removal is still recommended even for patients with low isoagglutinin titers. In addition, a new diagnostic tool is needed for accurate risk stratification.

Clinicopathological Analysis of Acute/Active Antibody-Mediated Rejection in Renal Allografts According to the Banff 2013 Classification.

AIM: This study evaluated the clinicopathological findings of acute/active antibody-mediated rejection (AABMR) according to the Banff 2013 classification. METHODS: We analyzed 345 biopsies of 269 kidney transplant recipients. Pathological AABMR (PAABMR) was defined as histological evidence of acute tissue injury and endothelial injury by light microscopy regardless of donor-specific antibodies (DSAs). RESULTS: Among the 345 biopsies, 29 (8.4%) were diagnosed as PAABMR. The mean g score was 1.17 ± 0.60, the mean ptc score was 1.97 ± 1.32, and DSA positivity was found in 69% of PAABMR. The mean duration after transplantation was 22.9 ± 26.7 months. Among 3 groups (DSA-high, mean fluorescence intensity (MFI) ≥ 5,000; DSA-low, MFI < 5,000 to ≥1,000; below cutoff), ABO incompatibility in DSA-high was significantly lower and second transplantation in DSA-high was significantly higher. We found 83% of PAABMR by the protocol biopsy (subclinical AABMR [SAABMR]). The short-term clinical and light microscopical changes in 8 cases of SAABMR did not show worsening during follow-up period (9-24 months). However, ultrastructural finding, including glomerular endothelial swelling, subendothelial electron-lucent widening, and early glomerular basement duplication, were found by electron microscopy (EM) in the first biopsies, and half of the SAABMR cases developed de novo circular peritubular capillary multilayering in the follow-up biopsies. CONCLUSION: PAABMR was mainly found by the protocol biopsy. The short-term follow-up of SAABMR patients did not show worsening clinically and light microscopically, but ultrastructural examination by EM was useful to detect early lesions of endothelial injury and progression of glomerular and peritubular capillary basement membrane alterations.

Pathological Analysis of Early Transplant Glomerulopathy in Renal Allografts Using Low-Vacuum Scanning Electron Microscopy.

AIM: Low-vacuum scanning electron microscopy (LVSEM) has been reported to aid in diagnosis of renal biopsy. This study evaluated early transplant glomerulopathy in kidney transplant recipients using LVSEM. METHODS: We selected 4 biopsies of cg0, 5 biopsies of cg1a, 5 biopsies of cg1b, and 4 biopsies of cg2 lesions that had been evaluated by light microscopy (LM) and transmission electron microscopy from recipients with acute/active or chronic, active antibody-mediated rejection (AABMR or CAABMR). Renal allograft paraffin sections (1 µm thickness) were stained with periodic acid-methenamine silver and observed using LVSEM. The cg score was based on the Banff classification. The parameter "percentage of duplicated capillary number" was calculated as follows: in 1 glomerulus with glomerular basement membrane (GBM) duplication, the total duplicated capillary number/the total number of capillaries ×100. RESULTS: In all 4 biopsy specimens with AABMR showing cg0, LVSEM revealed GBM duplication not identified by LM. The average percentage of duplicated capillary number per glomerulus with GBM duplication was higher when observed by LVSEM than when observed by LM in all cg1b and cg2 biopsy specimens. CONCLUSION: LVSEM revealed early GBM duplication in AABMR. Early GBM duplication might progress in the very early phase of AABMR. GBM duplication was more frequently detected by LVSEM than by LM in biopsy specimens with early chronic, active antibody mediated rejection. Thus, LVSEM may be useful in diagnosis of early transplant glomerulopathy.

Dehydroxymethylepoxyquinomicin, a novel nuclear factor-κB inhibitor, prevents the development of cyclosporine A nephrotoxicity in a rat model.

BACKGROUND: Cyclosporine A (CsA) is an essential immunosuppressant in organ transplantation. However, its chronic nephrotoxicity is an obstacle to long allograft survival that has not been overcome. Nuclear factor-κB (NF-κB) is activated in the renal tissue in CsA nephropathy. In this study, we aimed to investigate the effect of the specific NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), in a rat model of CsA nephrotoxicity. METHODS: We administered CsA (15 mg/kg) daily for 28 days to Sprague-Dawley rats that underwent 5/6 nephrectomy under a low-salt diet. We administered DHMEQ (8 mg/kg) simultaneously with CsA to the treatment group, daily for 28 days and evaluated its effect on CsA nephrotoxicity. RESULTS: DHMEQ significantly inhibited NF-κB activation and nuclear translocation due to CsA treatment. Elevated serum urea nitrogen and creatinine levels due to repeated CsA administration were significantly decreased by DHMEQ treatment (serum urea nitrogen in CsA + DHMEQ vs CsA vs control, 69 ± 6.4 vs 113.5 ± 8.8 vs 43.1 ± 1.1 mg/dL, respectively, p < 0.0001; serum creatinine in CsA + DHMEQ vs CsA vs control, 0.75 ± 0.02 vs 0.91 ± 0.02 vs 0.49 ± 0.02 mg/dL, respectively, p < 0.0001), and creatinine clearance was restored in the treatment group (CsA + DHMEQ vs CsA vs control, 2.57 ± 0.09 vs 1.94 ± 0.12 vs 4.61 ± 0.18 ml/min/kg, respectively, p < 0.0001). However, DHMEQ treatment did not alter the inhibitory effect of CsA on urinary protein secretion. The development of renal fibrosis due to chronic CsA nephrotoxicity was significantly inhibited by DHMEQ treatment (CsA + DHMEQ vs CsA vs control, 13.4 ± 7.1 vs 35.6 ± 18.4 vs 9.4 ± 5.4%, respectively, p < 0.0001), and these results reflected the results of renal functional assessment. DHMEQ treatment also had an inhibitory effect on the increased expression of chemokines, monocyte chemoattractant protein-1, and chemokine (c-c motif) ligand 5 due to repeated CsA administration, which inhibited the infiltration of macrophages and neutrophils into the renal tissue. CONCLUSIONS: These findings suggest that DHMEQ treatment in combination therapy with CsA-based immunosuppression is beneficial to prevent the development of CsA-induced nephrotoxicity.

Comparison of live donor predonation and post-transplant kidney volumes and glomerular size in pediatric patients weighing less than 15 kg - a retrospective study.

Renal transplantation of adult-size kidneys presents a size mismatch in small children. This study presents a comparison of live donor predonation and recipient post-transplant kidney volumes (k-vol) and glomerular size at 1 year after transplantation. We analyzed 47 pediatric renal transplant recipients weighing <15 kg between 2009 and 2017. The k-vol before and 1 year after transplantation and glomerular size at implant and 1 year post-transplant were evaluated. We estimated the relationships between these changes and graft function, and the factors associated with k-vol. Pretransplant k-vol was 158.1 ± 25.1 ml, and the k-vol at 1 year post-transplant was significantly reduced by -17.2% to 132.3 ± 27.3 ml (P < 0.001). Implant glomerular size showed the diameter was 165.3 ± 15.1 µm and the area 20 737.1 ± 3230.6 µm2 . One-year post-transplant, the glomerular diameter was 150.6 ± 11.4 µm and the area 17 428.3 ± 2577.9 µm2 , significantly reduced compared with implantation values (both P < 0.001). The change in k-vol was affected by pretransplant abdominal cavity (ml/200 ml cavity volume, partial regression coefficient = 0.029, SE = 0.009, P = 0.004) and recipient's weight gain (ml/5% of weight gain, partial regression coefficient = 0.020, SE = 0.006, P = 0.002). In small pediatric transplants, an adult-size kidney is acceptable with reduction in k-vol. Moreover, the post-transplant k-vol might be regulated by pretransplant physique and post-transplant somatic growth.

Successful Treatment of End-stage Renal Disease in a Patient With Chronic Myeloid Leukemia by Kidney Transplantation and Tyrosine Kinase Inhibitors: A Case Report.

Consensus regarding kidney transplantation feasibility in patients with chronic myeloid leukemia (CML) well controlled by tyrosine kinase inhibitors has not yet been achieved. Here, we report a patient with CML well controlled by tyrosine kinase inhibitors who developed end-stage renal disease during treatment and underwent kidney transplantation. CML activity has been carefully and successfully controlled for 4 years post-transplant. Very cautious dose adjustment and temporary cessation of nilotinib were required because kidney function fluctuated in reference to the doses of nilotinib.

A comparison of laparoendoscopic single-site surgery versus conventional procedures for laparoscopic donor nephrectomy: a Japanese multi-institutional retrospective study.

PURPOSE: Laparoendoscopic single-site donor nephrectomy (LESSDN) is a feasible and effective procedure because of its non-invasiveness and better cosmetic outcomes. However, there have been few multi-institutional studies conducted by multiple surgeons on LESSDN. We retrospectively compared the clinical data and outcomes between LESSDN and conventional laparoscopic donor nephrectomy (LDN) at multiple institutes in Japan. MATERIALS AND METHODS: From 2009 to 2015, the clinical data of 223 donors who underwent LESSDN and 151 donors who underwent LDN were collected from 10 institutes. All LESSDNs were performed transperitoneally, whereas LDNs were performed transperitoneally (P-LDN) in 75 patients and retroperitoneally (R-LDN) in 76 patients. RESULTS: In the LESSDN group, the single-incision site was pararectal in 155 (69.5%) patients and umbilical in 65 (29.1%) patients. Multiple surgeons (one to eight per institute) performed the LESSDN. No significant differences were observed between the three groups regarding estimated blood loss and warm ischemic time. The operative time was significantly shorter in the LESSDN group than in the R-LDN group (p = 0.018). No significant differences were observed regarding the rates of blood transfusion, open conversion, visceral injuries, and postoperative complications. Furthermore, no significant differences were observed regarding the dose of analgesic and the rate of delayed graft function. One patient required open conversion due to injury to the renal artery. Selection of LESS procedure was not an independent risk factor for the median serum creatinine level of above 1.27 mg/dL in recipients at 1 year after kidney transplantation. CONCLUSION: The results showed the technical feasibility of LESSDN compared with the standard LDNs in a multi-institutional and multi-surgeon setting. A few observed non-negligible complications and the significantly higher levels of serum creatinine in patients who underwent LESSDN indicate that this procedure should be employed cautiously when performed by surgeons without ample experience in performing LESS procedures.

Plasmacytoid Dendritic Cell-driven Induction of Treg Is Strain Specific and Correlates With Spontaneous Acceptance of Kidney Allografts.

BACKGROUND: DBA/2J kidney allografts, but not heart allografts, are spontaneously accepted indefinitely in C57BL/6 (B6) mice, through regulatory tolerance mechanism dependent on Foxp3 cells. In contrast, B6 kidneys are rejected within a week in DBA/2J recipients. We hypothesized that the tolerogenic difference of the kidneys might be due to differences in number or function of plasmacytoid dendritic cells (pDCs), because these cells are potent inducers of Foxp3 cells. METHODS: pDCs from murine bone marrow, native kidneys, and spontaneously accepted kidney allografts were analyzed using flow cytometry and immunohistochemical staining. Naive T cells were cocultured with pDCs in specific strain combinations and analyzed for FoxP3 induction and functionality. MEK/ERK and NFκB inhibitors were used to assess the regulatory T-cell induction pathways. pDCs and T-cell cultures were adoptively transferred before heterotopic heart transplantation to assess allograft survival. RESULTS: DBA/2J pDCs were more potent in inducing Foxp3 in B6 T cells than the reverse combination, correlating with survival of the kidney allografts. Foxp3 induction by pDCs in vitro was dependent on pDC viability, immaturity, and class II MHC mismatch and blocked by MEK/ERK and NFκB inhibition. pDC-induced Foxp3 T cells suppressed proliferation of B6 T cells in vitro, and adoptive transfer into B6 recipients 2 weeks before heterotopic DBA/2J heart transplantation resulted in prolonged allograft survival. CONCLUSIONS: These data suggest that pDC-induced regulatory T cells are dependent on downstream signaling effects and on strain-dependent, MHC class II disparity with naive T cells, which may explain organ- and strain-specific differences in spontaneous tolerance.

Donor-Recipient Body Weight Mismatch May Affect Glomerular Basement Membrane Thinning in Electron Microscopic Examination of 1-Hour Renal Allograft Biopsy Specimens.

BACKGROUND: Although an association between body weight mismatch and impaired graft function has been reported, few histologic studies have evaluated this issue, especially using electric microscopic analysis. During routine observations, we have noted a thin glomerular basement membrane (GBM) in the 1-hour biopsy specimen in cases with an overweight recipient and a lightweight donor. Therefore, we hypothesized that donor-recipient body weight mismatch affects the GBM thickness in the 1-hour biopsy specimen. The aim of the present study was to clarify the effect of donor-recipient body weight mismatch on the GBM thickness of the 1-hour biopsy specimen measured using electron microscopy. METHODS: We used an electron microscope to measure the GBM thickness of specimens at 1-hour post-transplantation (n = 24) and at 1 year post-transplantation (n = 17). The GBM thickness of cases with donor-recipient body weight mismatch was compared with those without mismatch. In accordance with a previous study, we defined a donor/recipient body weight ratio of less than 0.9 as donor-recipient body weight mismatch and a ratio of more than 0.9 as no mismatch. RESULTS: At 1-hour post-transplantation, the mean GBM was significantly thinner in the mismatch group than in the nonmismatch group. However, at 1-year post-transplantation, the mean GBM thickness did not significantly differ between the 2 groups. CONCLUSIONS: The GBM thickness at 1-hour post-transplantation is thinner in cases with donor-recipient body weight mismatch than in cases without mismatch. This implies that donor-recipient body weight mismatch may have to be considered when assessing donor-derived thin GBM disease using the 1-hour biopsy specimen.

Can Lipofuscin Deposition on Renal Allograft Tubular Epithelium Be a Surrogate Marker for Kidney Allograft Aging?

BACKGROUND: Lipofuscin is an indicator of aging. We examined the clinicopathologic significance of lipofuscin deposition in the renal tubules of renal allografts. METHOD: We analyzed allograft biopsy specimens from living kidney transplantations from January to December 2015. For controls, we analyzed native kidney biopsy specimens obtained from January 2015 to December 2016. We identified granules with a yellow-to-tan shade in renal tubules as lipofuscin. RESULTS: The donor age at transplantation was significantly older in lipofuscin deposition biopsy specimens than in those without, whereas the time after transplantation age was not different between the 2 groups with renal allografts. In native kidney biopsies, age at biopsy was significantly older in lipofuscin deposition biopsy specimens than in those without. We compared "massive lipofuscin deposition," defined as lipofuscin deposition on both sides of 3 or more renal tubules, and donor-age matched control allograft biopsies without lipofuscin deposition. Comparing these 2 groups, recipient age at transplantation was significantly older in the massive lipofuscin deposition group. CONCLUSION: Lipofuscin deposition on tubular epithelium is not a surrogate marker of aging of kidneys allografts, although lipofuscin deposition was significantly greater in older tissues from native kidneys. The older age of recipients may be associated with massive lipofuscin deposition in renal allografts.

Preserved Kidney Volume, Body Mass Index, and Age Are Significant Preoperative Factors for Predicting Estimated Glomerular Filtration Rate in Living Kidney Donors at 1 Year After Donation.

BACKGROUND: Securing postdonation renal function in the lifetime of donors is a consequential subject for physicians, and precise prediction of postdonation renal function would be considerably beneficial when judging the feasibility of kidney donation. The aim of this study was to investigate the optimum model for predicting eGFR at 1 year after kidney donation. METHODS: We enrolled 101 living-related kidney donors for the development cohort and 44 for the external validation cohort. All patients in each cohort underwent thin-sliced (1 mm) enhanced computed tomography (CT) scans. We excluded individuals with diabetes, glucose intolerance, or albuminuria from this study. We evaluated preoperative factors including age, sex, hypertension, body mass index (BMI), serum uric acid, baseline eGFR, and body surface area (BSA)-adjusted preserved kidney volume (PKV) by using 3-dimensional reconstruction of thin-sliced enhanced CT images. To detect independent predictors, we performed multivariable regression analysis. RESULTS: The multivariable regression analysis revealed that age, BMI, predonation eGFR, and BSA-adjusted PKV were independent predictors of eGFR at 1 year after kidney donation (correlation coefficient: -0.15, -0.476, 0.521, 0.127, respectively). A strong correlation between predicted eGFR and observed eGFR was obtained in the development cohort (r = 0.839, P < .0001). The significance of this predictive model was also confirmed with the external validation cohort (r = 0.797, P < .0001). CONCLUSIONS: Age, BMI, predonation eGFR, and BSA-adjusted PKV may be useful for precisely predicting eGFR at 1 year after living kidney donation and be helpful to determine the feasibility of kidney donation from marginal donors.

Small intestinal perforation due to a huge gastrointestinal stromal tumor in a kidney transplant recipient: a case report and literature review.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) in transplant recipients are very rare and only a handful of cases have been reported to date. Here we present the first known case of a huge GIST in a kidney transplant recipient with perforation of small intestine. CASE PRESENTATION: A 64-year-old male presented at our hospital with right colic pain; he had received an ABO incompatible kidney transplant 6 years earlier and was treated with cyclosporine, mycophenolate mofetil, and methylprednisolone. Radiological evaluation revealed a huge (11 cm in diameter) solitary tumor at the small intestine without distant metastasis. The small intestinal wall at the tumor location was perforated one week after diagnosis and the patient underwent emergency surgery. The pathological findings were compatible with GIST and the tumor consisted of spindle cells with positive staining for KIT, CD34, and DOG1 and negative or weak staining for desmin and S-100 protein. A mutation in exon 11 of the c-kit gene was also detected. Cyclosporine was withdrawn and imatinib mesylate (400 mg daily) was introduced. However, thereafter, we needed to decrease the dose at 300 mg daily due to severe hyponatremia. Reduced imatinib treatment was well tolerated and recurrence was not observed for 18 months after surgery. CONCLUSIONS: The occurrence of GISTs in transplant patients is rare, and huge GISTs should be resected immediately after diagnosis because gastrointestinal tract at the tumor site could be perforated. Imatinib treatment is feasible in transplant recipients under immunosuppression, although immunosuppressive drugs metabolized by CYP3A4 should be used at a reduced dosage or withdrawn.