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Background: Non-invasive, prompt, and proper detection tools for kidney graft injuries (KGIs) are awaited to ensure graft longevity. We screened diagnostic biomarkers for KGIs following kidney transplantation using extracellular vesicles (EVs; exosomes and microvesicles) from the urine samples of patients., Methods: One hundred and twenty-seven kidney recipients at 11 Japanese institutions were enrolled in this study; urine samples were obtained prior to protocol/episode biopsies. EVs were isolated from urine samples, and EV RNA markers were assayed using quantitative reverse transcription polymerase chain reaction. Diagnostic performance of EV RNA markers and diagnostic formulas comprising these markers were evaluated by comparison with the corresponding pathological diagnoses., Results: EV CXCL9, CXCL10, and UMOD were elevated in T-cell-mediated rejection samples compared with other KGI samples, while SPNS2 was elevated in chronic antibody-mediated rejection (cABMR) samples. A diagnostic formula developed through Sparse Logistic Regression analysis using EV RNA markers allowed us to accurately (with an area under the receiver operator characteristic curve [AUC] of 0.875) distinguish cABMR from other KGI samples. EV B4GALT1 and SPNS2 were also elevated in cABMR, and a diagnostic formula using these markers was able to distinguish between cABMR and chronic calcineurin toxicity accurately (AUC 0.886). In interstitial fibrosis and tubular atrophy (IFTA) urine samples and those with high Banff chronicity score sums (BChS), POTEM levels may reflect disease severity, and diagnostic formulas using POTEM detected IFTA (AUC 0.830) and high BChS (AUC 0.850)., Conclusions: KGIs could be diagnosed with urinary EV mRNA analysis with relatively high accuracy., (© 2023. The Author(s).)

Introduction: Laparoscopic surgery has been a standard procedure of living donor nephrectomy (LDN). Transperitoneal hand-assisted laparoscopic LDN (HALDN) has been commonly reported by many centers with excellent outcome. However, there are few studies reporting retroperitoneoscopic LDN (RPLDN)., Materials and Methods: Four hundred four consecutive kidney donors (124 men, 280 women) were enrolled in this study. Age of the donors was 55.0 ± 10.7 years. RPLDN was performed for 294 donors, and HALDN for 110 donors. We compared perioperative donor outcome and early complication rates between RPLDN and HALDN to evaluate the safety and efficacy of RPLDN., Results: Intraoperative blood loss was significantly less in RPLDN than in HALDN (p < 0.05). The conversion rate to open surgery was similar between the two groups. The intraoperative complication rate was 1.0% (two vascular injuries and one bowel injury) in RPLDN and 0.9% (one vascular injury) in HALDN. The postoperative complication rate was 3.4% (six surgical site infections, two postoperative bleeding, one colon perforation, one ileus, one rhabdomyolysis) in RPLDN and 1.8% (two surgical site infections) in HALDN. Although warm ischemic time was significantly longer in RPLDN than in HALDN (p < 0.01), the incidence of delayed graft function was similar between the two groups. Furthermore, there was no difference in 1-year graft survival between the two groups., Conclusions: Both RPLDN and HALDN procedures were well tolerated with minimal complication rates, and both procedures showed similar impact on recipient graft function. These results suggest that RPLDN could be a feasible option for LDN as well as HALDN.

Objectives: To evaluate the risk for urological complications after kidney transplantation at a single medical center in Japan., Methods: In the present study, 408 kidney recipients (255 men, 153 women) were enrolled. There were 349 living and 59 deceased donors. The average age of the recipients was 42.5 ± 13.5 years, and the average pretransplant dialysis period was 71.8 ± 88.2 months. Ureteroneocystostomy was carried out on 347 patients, and ureteroureterostomy on 61 patients. We investigated the relationship between pretransplant duration of dialysis and bladder capacity, and examined the risk factors for urological complication. We also evaluated the incidence of vesicoureteral reflux in 191 recipients who underwent ureteroneocystostomy during transplantation., Results: The preoperative duration of dialysis therapy showed a significant negative correlation with bladder capacity (R 2  = 0.33, P < 0.001). The overall urological complication rate was 3.4% (14 patients), including urinary leakage (12 patients) and ureteral stricture (two patients). Univariate analysis showed that atrophic bladder, long-term dialysis therapy, deceased donor and ureteroureterostomy were associated with a higher incidence of urological complications (odds ratio 8.05, 4.43, 3.42 and 3.35; P < 0.01, P = 0.01, P = 0.04 and P = 0.04, respectively). Furthermore, multivariate analysis showed that atrophic bladder was the only significant factor associated with urological complications (odds ratio 10.37; P = 0.01). Among 191 recipients, vesicoureteral reflux was observed in 32 (16.8%). The incidence of vesicoureteral reflux was significantly higher in patients with atrophic bladder., Conclusions: Bladder atrophy in renal transplant recipients after long-term dialysis therapy is associated with a higher risk of urological complications., (© 2017 The Japanese Urological Association.)

Aim: Chronic active antibody-mediated rejection (chronic ABMR) is one important cause of late-stage renal allograft loss. However, few reports have used protocol biopsy to observe changes over time in cases that develop chronic ABMR. The aim of this study was to use protocol biopsy to clarify the histological features of cases that develop chronic ABMR., Methods: We recruited 379 ABO compatible patients who underwent protocol biopsy at our hospital from 2010 to 2014. Seventeen of these patients were diagnosed with chronic ABMR (chronic ABMR group), and 12 patients were class 2 donor-specific antibody (DSA) positive and were not diagnosed with chronic ABMR (class 2 DSA-positive group). With the addition of a control group consisting of 30 DSA negative patients, these three groups were compared for Banff factors in protocol biopsies taken 3 months, 6 months, 1 year, 3 years, and 5 years after the transplant., Results: Three months post transplant, the chronic ABMR group had a significantly higher number of patients exhibiting g + ptc > 0 than that in the control group (P = 0.01). At 1, 3, and 5 years post transplant, significantly more subjects in the chronic ABMR and class 2 DSA-positive groups compared with the control group exhibited g + ptc > 0 (P < 0.03). Five years post transplant, the chronic ABMR group exhibited a significantly higher mean c4d score than that in the control group (P = 0.02). The only significant difference observed between the chronic ABMR group and the class 2 DSA-positive group was in cg scores at 5 years post transplant, which were significantly higher in the chronic ABMR group (P = 0.03)., Conclusions: These results suggest that cases exhibiting microvascular inflammation in the early post-transplant period may develop chronic ABMR, and it would be highly beneficial to perform focused electron microscope surveillance of these cases., (© 2015 Asian Pacific Society of Nephrology.)