Renal outcome of living kidney donors aged more than 70 years.

BACKGROUND: The number of marginal living kidney donors has increased. Medically complex donors who have hypertension, older age, or low estimated glomerular filtration rate (eGFR) have been more likely to be used. METHODS: We conducted a retrospective cohort study of living kidney donors at a single center. We analyzed 309 living donors and divided them into three groups: group with older donors (aged ≥70 years) (n = 41), middle-aged (aged 46-69 years) (n = 239), and young donors (aged <46 years) (N = 29). Donor factors associated with chronic kidney disease (CKD) stage 3b or worse within 5 years post-donation were investigated. RESULTS: Of the 309 live donors, 86 (27.8%) developed CKD stage3b or worse within 5 years post-donation. The incidence of CKD stage3b or worse within 5 years post-donation was significantly higher in older donor (p < 0.01). Cox regression models revealed that older donor ages and lower eGFR were significantly related to the development of CKD stage3b or worse, independent of comorbidities such as obesity and hypertension [hazard ratio (95% CI); 4.59 (1.02-20.6), p = 047, 0.95 (0.94-0.96), p ≤ 0.01, respectively]. However, recovery of eGFR 4-5 years after donation was noted in the middle-aged and older donor groups, whereas the level of eGFR remained unchanged in the young group. CONCLUSIONS: Older donors tend to develop CKD stage3b within 5 years post-donation but with the potential of recovery. Healthy older people (aged ≥70 years) could be candidates for living donors under careful monitoring of kidney function after donation.

Safety of Docetaxel in a Patient with Metastatic Castration-Resistant Prostate Cancer After Kidney Transplantation: A Case Report.

BACKGROUND: There are limitations in treating advanced prostate cancer (PC), especially castration-resistant (CR) cases, in renal transplant recipients (RTRs). We describe the case of RTR with metastatic CRPC (mCRPC) treated with docetaxel. CASE REPORT: A 60-year-old man with end-stage renal disease due to autosomal-dominant polycystic kidney disease (ADPKD) underwent living-related kidney transplantation. A year later, he was diagnosed with PC (prostate-specific antigen level: 998 ng/mL). Prostate biopsy revealed prostatic adenocarcinoma with a Gleason score of 4 + 4 = 8. Radiographic examination revealed seminal vesicle invasion and multiple bone and lymph node metastases. Combined androgen blockade therapy was initiated; however, the patient was diagnosed with CRPC 6 months later. Triweekly docetaxel therapy was administered 28 months after diagnosis. The patient successfully completed 7 cycles of this therapy without major adverse events. However, after the 7th cycle, he developed a high fever caused by an infection of ADPKD-associated renal cysts. Therefore, docetaxel was discontinued, and enzalutamide was started, followed by abiraterone, but without any effect. We then introduced cabazitaxel but discontinued it because of hepatic dysfunction. Hence, the patient underwent a docetaxel rechallenge. He was administered the PEGylated form of the recombinant human granulocyte colony-stimulating factor for neutropenia prophylaxis. After 6 cycles of rechallenge docetaxel therapy, the patient accidentally fell, resulting in a cervical spine fracture and subsequent death due to respiratory failure. CONCLUSIONS: Docetaxel can be safely delivered to patients with CRPC after renal transplantation who are taking oral immunosuppressants. It can be a good treatment option for them.

Higher Donor Age and Severe Microvascular Inflammation Are Risk Factors for Chronic Rejection After Treatment of Active Antibody-Mediated Rejection.

Recent developments in intensive desensitization protocols have enabled kidney transplantation in human leukocyte antigen (HLA)-sensitized recipients. However, cases of active antibody-mediated rejection (AABMR), when they occur, are difficult to manage, graft failure being the worst-case scenario. We aimed to assess the impact of our desensitization and AABMR treatment regimen and identify risk factors for disease progression. Among 849 patients who underwent living-donor kidney transplantation between 2014 and 2021 at our institution, 59 were diagnosed with AABMR within 1 year after transplantation. All patients received combination therapy consisting of steroid pulse therapy, intravenous immunoglobulin, rituximab, and plasmapheresis. Multivariable analysis revealed unrelated donors and preformed donor-specific antibodies as independent risk factors for AABMR. Five-year death-censored graft survival rate was not significantly different between patients with and without AABMR although 27 of 59 patients with AABMR developed chronic AABMR (CABMR) during the study period. Multivariate Cox proportional hazard regression analysis revealed that a donor age greater than 59 years and microvascular inflammation (MVI) score (g + ptc) ≥4 at AABMR diagnosis were independent risk factors for CABMR. Our combination therapy ameliorated AABMR; however, further treatment options should be considered to prevent CABMR, especially in patients with old donors and severe MVI.

Clinical Course of Candidate Renal Transplant Recipients Diagnosed With Prostate Cancer During Pre-transplant Screening Test.

BACKGROUND/AIM: Occasionally, candidate renal transplant recipients (RTRs) are incidentally diagnosed with prostate cancer (PCa) during pre-transplant screening examinations; however, their clinical course remains unclear. This study aimed to clarify the clinical course of RTR diagnosed with PCa during pre-transplant screening tests. PATIENTS AND METHODS: Between April 2008 and April 2022, 15 candidates for RTRs were newly diagnosed with PCa during the screening test. We analyzed the patients' treatment choices, initial treatment results, waiting duration for renal transplantation, and whether they finally underwent transplantation. RESULTS: The median patient age was 64 years (range=52-75 years). The median prostate-specific antigen level was 6.9 ng/ml (5.2-56.9 ng/ml). According to D'Amico risk stratification, one, 10, and four patients were at low, intermediate, and high risk, respectively. As for treatment choice, 13 patients chose surgery. Moreover, intensity-modulated radiotherapy and hormone therapy were chosen by one patient each. Of these, seven patients underwent transplantation, with a median waiting time from initial treatment to transplantation of 20.3 months (9.2-40.0 months). One patient discontinued transplantation owing to poor cancer control, four patients had donor issues (change in mind, aging, or disease), and one patient waited because pathological findings revealed locally invasive cancer. CONCLUSION: PCa diagnosis in candidate RTRs during the pre-transplant screening test impacts the candidate's clinical course.

Case Report: Suspected Hyperacute Rejection During Living Kidney Transplantation.

BACKGROUND: We report a case of suspected hyperacute rejection during living kidney transplantation. CASE REPORT: A 61-year-old man underwent kidney transplantation in November 2019. Before the transplantation, immunologic tests revealed the presence of anti-HLA antibodies but not donor-specific HLA antibodies. The patient was intravenously administered 500 mg of methylprednisolone (MP) and basiliximab before perioperative blood flow reperfusion. After blood flow restoration, the transplanted kidney turned bright red and then blue. Hyperacute rejection was suspected. After the intravenous administration of 500 mg of MP and 30 g of intravenous immunoglobulin, the transplanted kidney gradually changed from blue to bright red. The initial postoperative urine output was good. On the 22nd day after the renal transplantation, the patient was discharged with a serum creatinine level of 2.38 mg/dL, and the function of the transplanted kidney gradually improved. CONCLUSIONS: In this study, non-HLA antibodies may have been a cause of the hyperacute rejection, which was managed with additional perioperative therapies.

Clinicopathological Analyses of Chronic Renal Allograft Arteriopathy after Kidney Transplantation.

INTRODUCTION: Herein, we discuss clinicopathological analyses of cases of chronic renal allograft arteriopathy (CRA) after renal transplantation and clarify the mechanisms underlying the development and prognostic significance of CRA. METHODS: CRA was diagnosed in 34 renal allograft biopsy specimens (BSs) obtained from 27 renal transplant patients who were followed up at the Department of Urology and Transplant Surgery, Toda Chuo General Hospital, between January 2010 and December 2020. RESULTS: CRA was diagnosed at a median of 33.4 months post-transplantation. Of the 27 patients, 16 had a history of rejection. Among the 34 BSs showing evidence of CRA, CRA was mild (cv1 in Banff's classification) in 22, moderate (cv2) in 7, and severe (cv3) in 5 patients. We then classified the 34 BSs showing evidence of CRA based on their overall histopathological features as follows: cv alone seen in 11 (32%) BSs, cv + antibody-mediated rejection (AMR) in 12 (35%), and cv + T-cell-mediated rejection (TCMR) in 8 (24%). Loss of the renal allograft occurred during the observation period in 3 patients (11%). Of the remaining patients with functioning grafts, deterioration of renal allograft function after biopsies occurred in 7 cases (26%). CONCLUSIONS: Our study results suggest that AMR contributes to CRA in 30-40% of cases, TCMR in 20-30% of cases, isolated v lesions in 15% of cases, and cv lesions alone in 30%. The intimal arteritis was a prognostic factor in CRA.

Long-term prolonged-release tacrolimus outcomes in living donor kidney transplantation: The Japan Academic Consortium of Kidney Transplantation study-II.

OBJECTIVES: To evaluate the 10-year efficacy and safety of a prolonged-release tacrolimus-based combination immunosuppressive regimen on longer-term outcomes in living donor kidney transplantation. METHODS: Data from Japanese living donor kidney transplant recipients (n = 410) maintained on continuous prolonged-release tacrolimus-based immunosuppression from 2009-2013 were analyzed with a median follow-up of 9.9 years. RESULTS: A prolonged-release, tacrolimus-based combination regimen provided death-censored graft failure and all-cause death rates at 10 years of 7.0% and 6.8%, respectively. In multivariable analyses, acute and chronic rejection and 'throughout' (new-onset plus preexisting) diabetes mellitus were risk factors for death-censored graft failure. Recipient age ≥ 65 years, throughout diabetes mellitus and malignancy were common risk factors for all-cause death. Throughout diabetes mellitus was the most common risk factor for both death-censored graft failure and all-cause death. Additional analyses showed 10-year cumulative rates of death-censored graft failure were 14.0% and 5.4% for recipients with or without preexisting diabetes mellitus, respectively (log-rank test: p = 0.009). All-cause death rates were 12.7% and 5.4% in the preexisting and non-diabetes mellitus groups, respectively (log-rank test: p = 0.023). CONCLUSIONS: In this real-world, retrospective, living donor kidney transplantation study, a prolonged-release tacrolimus-based immunosuppressive combination regimen provided 10-year death-censored graft failure rates of 14.0% and 5.4% in diabetes mellitus and non-diabetes mellitus patients, respectively; Similarly, 10-year all-cause death rates were 12.7% and 5.4% in diabetes mellitus and non-diabetes mellitus patients, respectively. To our knowledge, the data in this study are the first to provide 10-year transplant outcomes in living donor kidney transplant recipients under prolonged-release tacrolimus-based regimen.

A Comparative Study on the Variation in Seropositivity Rates After 2-Dose COVID-19 Vaccination Before or After Transplant: A Single-Center Analysis.

OBJECTIVES: Many researchers have demonstrated that the seropositivity rate after SARS-CoV-2 coronavirus vaccination is lower in patients receiving oral immunosuppressants. In this article, we report on a comparative study on the seropositivity rate after 2 doses of coronavirus vaccine before or after kidney transplant. MATERIALS AND METHODS: We studied 111 recipients vaccinated after transplant, 19 patients vaccinated before transplant, and 10 healthy patients. We retrospectively measured antibody titers using preserved serum samples. The antibody testing was performed 1 month and 3 months after vaccination. The measurement was via LABScreen COVID Plus, which enables simultaneous determination of 5 coronavirus protein antigens. RESULTS: Seropositivity to coronavirus antibodies was observed in all 19 patients vaccinated before transplant (100%) and in all the 10 healthy patients (100%). Forty- six of the 111 recipients (42%) vaccinated after transplant developed seropositivity. Analyzed at each time point after vaccination, the mean fluorescence intensity of antibodies was unchanged between 1 month and 3 months after vaccination in transplant recipients who were vaccinated after transplant and developed seropositivity. On the other hand, the antibody mean fluorescence intensity in patients vaccinated before transplant was markedly lower at 3 months (posttransplant). CONCLUSIONS: All patients with renal failure who were vaccinated before transplant showed a high seropositivity rate, similar to that in healthy patients. The seropositivity rate for each of the viral fragment antibodies in patients vaccinated before transplant was maintained, as seen in healthy patients. However, in patients vaccinated before transplant who tested positive for antibody production at 1 month after vaccination,the antibody mean fluorescence intensity at 3 months after vaccination (posttransplant) was remarkedly lower than the mean fluorescence intensity at 1 month, which was probably caused by the types of immunosuppressive regimens used atthe time of transplant.

A case of novel coronavirus disease after combination therapy with nivolumab and ipilimumab for metastatic renal cell carcinoma.

INTRODUCTION: We present a case of novel coronavirus disease-2019 that underwent combination therapy with nivolumab and ipilimumab for metastatic renal cell carcinoma. CASE PRESENTATION: A 50-year-old man complained of anorexia and weight loss. Contrast-enhanced computed tomography revealed a solid mass of 57 mm in diameter with cysts in the right kidney, along with liver, lung, and multiple bone metastases. Computed tomography-guided biopsy of the right kidney was performed, and a diagnosis of clear cell renal cell carcinoma was made. Three weeks after nivolumab and ipilimumab administration, the patient contracted coronavirus disease-2019. Anticoagulation therapy (dalteparin) was administered for 4 days once infection was confirmed, after which dexamethasone was administered for 10 days. The patient survived without experiencing worsened respiratory symptoms. CONCLUSION: We administered nivolumab and ipilimumab combination therapy as treatment for metastatic renal cell carcinoma. No side effects or immune-related adverse events were observed for a short time.

Safe Renal Transplantation to the Extraperitoneal Cavity in Children Weighing Less Than 15 kg.

Pediatric renal transplantation is associated with various surgical complications due to the complexity of the technique and the often-fragile condition of patients with end-stage renal disease. We evaluated the surgical complications associated with renal transplantation via the extraperitoneal approach in pediatric recipients. This retrospective study enrolled 280 patients younger than 16 years old who underwent renal transplantation via the extraperitoneal approach: 216 patients underwent transplant placement in the iliac fossa like in adults, and 64 underwent transplant placement in the distal part of the original renal lower pole (the extraperitoneal cavity). On the basis of the Clavien-Dindo classification, 30 patients (10.7%) showed grade 2 complications and 12 patients (4.3%) showed grade 3 or higher complications. None of the patients showed gastrointestinal complications. In a Cox regression analysis, grade 2 or higher complications were significantly associated with weight less than 15 kg (P = .027) and operative times longer than 245 minutes (P = .029). Among the 49 patients weighing less than 15 kg with an allograft placed in a distal portion of the original renal lower pole, only 3 patients (6.1%) developed surgical complications. Thus, allograft placement in the extraperitoneal cavity can be performed safely in children weighing less than 15 kg.

Case Report of COVID-19 Infection After Kidney Transplant Treated With Casirivimab-Imdevimab and Mycophenolate Mofetil Changed to Everolimus.

BACKGROUND: Casirivimab-imdevimab is a cocktail of 2 monoclonal antibodies designed to prevent infection by SARS-CoV-2, the virus that causes COVID-19. Casirivimab-imdevimab has been approved in Japan for treating mild to moderate COVID-19; however, to our knowledge, there are no reports of its use after kidney transplant from a live donor. Everolimus, an antineoplastic chemotherapy drug, is expected to be effective in inhibiting the spread of SARS-CoV-2 and preventing its replication, which may facilitate treatment. Here, we report a case of COVID-19 infection after kidney transplant that was initially treated with casirivimab-imdevimab and mycophenolate mofetil but was later changed to everolimus. CASE REPORT: A 47-year-old man underwent living donor kidney transplant from his mother in 2017. Immunosuppression therapy was underway through the administration of tacrolimus, mycophenolate mofetil, and methylprednisolone. In early September 2021, he was diagnosed as having COVID-19 and was hospitalized on day 3. On hospitalization, mycophenolate mofetil was discontinued and casirivimab-imdevimab and heparin were started. The patient started an everolimus regimen on day 5. The clinical course was successful without rejection. There was no exacerbation of COVID-19; the patient's serum creatinine levels and renal function had otherwise remained stable. CONCLUSIONS: We could safely treat a patient with casirivimab-imdevimab after kidney transplant. It is suggested that casirivimab-imdevimab can prevent COVID-19 from becoming severe and can be administered without worsening renal function. In addition, everolimus may have inhibited the spread of the virus and prevented it from replicating.

Japanese Single-Center Experience of Kidney Transplant: Experience in a Japanese Private Hospital.

BACKGROUND: We reviewed the results of cases of kidney transplant (KTx) that were conducted at the Toda Chuo General Hospital, a private hospital located in Saitama, Japan. METHODS: A total of 312 patients with end-stage renal failure underwent KTx between January 1992 and December 2019 at Toda Chuo General Hospital. There were 191 men and 121 women. Their mean age was 45.7 years. Of the 312 cases, 310 were living-related KTx, while 2 were deceased donor KTx. The immunosuppressive treatment protocol mainly consisted of 4-drug therapy with methylprednisolone, tacrolimus, mycophenolate mofetil, and basiliximab. RESULTS: Patient survival was 99.7% at 1 year, 99.3% at 5 years, and 97.3% at 10 years. Renal allograft survival was 98.4% at 1 year, 91.7% at 5 years, and 86.5% at 10 years. However, death-censored renal allograft survival was 98.7% at 1 year, 92.4% at 5 years, and 89.0% at 10 years. Among the 312 patients, 33 grafts were lost during the observation period. The loss was because of chronic antibody-mediated rejection in 19 patients, death with function in 6 patients, and acute antibody-mediated rejection in 2 patients. CONCLUSIONS: The prognosis of patients and their grafts, which were managed following the immunosuppression protocol at our institute, was relatively good. KTx in a private hospital in Japan is at par with the global standard.

Suspected Pneumonia Caused by Coronavirus Disease 2019 After Kidney Transplantation: A Case Report.

BACKGROUND: Coronavirus disease 2019 (COVID-19) infection may become more severe in those who have undergone kidney transplantation than in the general population. False-negative reverse transcription-polymerase chain reaction (RT-PCR) results have been reported for COVID-19 infection. Patients might carry infection even though RT-PCR results are negative. CASE REPORT: A 65-year-old man with a 19-year history of ABO-incompatible kidney transplantation presented with fever and arthralgia. Although the RT-PCR result was negative, a focal slit-glass shadow in the left upper lobe on computed tomography (CT) suggested COVID-19 pneumonia. His symptoms did not improve until after 10 days, and CT showed multiple slit-glass shadows in the bilateral lung fields. However, RT-PCR remained negative. The patient was admitted, and mycophenolate mofetil was discontinued. Anticoagulants were administered on the third day of hospitalization. Because of poor oxygenation, the patient was intubated in the intensive care unit on the fifth day, and sivelestat sodium was administered. The patient was extubated on the 12th day after improvement in oxygenation. There was no exacerbation, and CT showed improvements on day 51. CONCLUSION: We report a case of pneumonia with suspected COVID-19 infection 18 years after living donor kidney transplantation. If COVID-19 is suspected, infection control and aggressive therapeutic interventions should be undertaken while considering the possibility of a positive result.

Allogeneic Kidney Transplantation After COVID-19: A Case Report.

BACKGROUND: Patients undergoing organ transplantation are immunosuppressed and already at risk of various diseases. We report about a patient who underwent ABO-incompatible kidney transplantation after coronavirus disease 2019 (COVID-19) without a recurrence of infection. CASE REPORT: A 68-year-old woman presented with end-stage renal failure owing to primary autosomal dominant polycystic kidney disease; accordingly, hemodialysis was initiated in September 2020. Her medical history included bilateral osteoarthritis, lumbar spinal stenosis, hypertension, and hyperuricemia. In mid-January 2021, she contracted severe acute respiratory syndrome coronavirus 2 infection from her husband. Both of them were hospitalized and received conservative treatment. Because their symptoms were mild, they were discharged after 10 days. The patient subsequently underwent ABO-incompatible kidney transplantation from her husband who recovered from COVID-19 in March 2021. Before kidney transplantation, her COVID-19 polymerase chain reaction test was negative, confirming the absence of pre-existing COVID-19 immediately before the procedure. Computed tomography revealed no pneumonia. Initial immunosuppression was induced by administering tacrolimus, mycophenolate mofetil, methylprednisolone, basiliximab, rituximab, and 30 g of intravenous immunoglobulin. Double-filtration plasmapheresis and plasma exchange were performed once before ABO-incompatible kidney transplantation. The renal allograft functioned immediately, and the postoperative course was normal without rejection. COVID-19 did not recur. In addition, her serum creatinine levels and renal function had otherwise remained stable. CONCLUSION: Living kidney transplantation was safely performed in a patient with COVID-19 without postoperative complications or rejection. During the COVID-19 pandemic, the possibility of severe acute respiratory syndrome coronavirus 2 infection during transplantation surgery must be considered.

Two Laparotomy Surgeries to Achieve Hemostasis After Kidney Transplantation in a Patient With Frailty: A Case Report.

BACKGROUND: The assessment of frailty before and after kidney transplantation is becoming more important in the aging population. It is recommended to recognize the post-transplant risks and establish a treatment strategy. We report the case of a patient who underwent 2 laparotomy hemostasis procedures due to frailty after kidney transplantation. CASE REPORT: A 72-year-old woman presented with end-stage renal failure due to an unknown primary disease. She was also found to be frail when assessed using the physical frailty phenotype. She underwent ABO-incompatible kidney transplantation from her husband at the end of March 2020. On the first postoperative day, re-operation for hematoma evacuation was performed. The bleeding point could not be identified at that time. Progression of anemia was observed on the sixth postoperative day, and computed tomography showed no obvious bleeding. Subsequently, the renal allograft started functioning immediately, without rejection. However, emergency laparotomy for hematoma removal was performed on the 22nd postoperative day. Bleeding had occurred from the anastomotic region of the renal allograft artery and the external iliac artery. Her serum creatinine levels and renal function remained stable one month after surgery. CONCLUSIONS: We encountered a case of living-donor kidney transplantation in a frail older woman who underwent 2 laparotomies due to hemorrhage. Perioperative risk management is necessary for patients with a high risk of postoperative bleeding. To ensure a good outcome, preoperative and postoperative rehabilitation is important for patients with frailty.

Fluorescence In Situ Hybridization for the Origin of De Novo Renal Cell Carcinoma in a Kidney Allograft: A Case Report.

BACKGROUND: We present a rare case of de novo renal cell carcinoma that developed in an allograft kidney 14 years after transplantation. CASE REPORT: A 39-year-old man underwent living donor kidney transplantation from his mother. After 14 years, routine screening ultrasonography revealed a solid mass of 30-mm diameter in the kidney allograft. Partial nephrectomy was performed by clamping the renal artery under in situ cooling. Tissue histology revealed clear cell carcinoma with negative surgical margins. We explored the tumor's genetic origin using fluorescence in situ hybridization to analyze the X and Y chromosomes of the tumor cells. Postoperative hemodialysis was avoided, and the patient's serum creatinine level remained stable. CONCLUSIONS: Fluorescence in situ hybridization clearly indicated that the tumor originated from the donor and that the tumor vasculature originated from the recipient. The patient recovered well and remains without any tumor recurrence.

Living-Donor Kidney Transplantation Performed in a Low-Volume Center by Visiting Surgeons From a High-Volume Center and Managed Clinically Solely by Nephrologists: 1-Year Outcomes.

BACKGROUND: Little is known about the outcome of living-donor kidney transplantation (LDKT) performed in low-volume centers lacking the services of full-time transplant surgeons. This retrospective cohort study assessed the outcome of LDKT performed in a low-volume center by visiting transplant surgeons from a high-volume center and managed perioperatively by transplant nephrologists. METHODS: We compared Japanese adult patients who had no donor-specific antibodies and underwent LDKT between 2006 and 2015 either in a low-volume (n = 31) or high-volume (n = 481) center. In the low-volume center, visiting transplant surgeons from the high-volume center conducted LDKT and transplant nephrologists managed the recipients peri- and postoperatively. The primary outcome was the composite of infection, cardiovascular disease, or cancer during 1-year follow-up. The outcomes of the low- and high-volume centers were compared using 1:2 propensity score matching. RESULTS: After matching, 9 of 29 patients in the low-volume center (31.0%) and 16 of 58 patients in the high-volume center (27.6%) experienced the primary composite outcome (risk ratio = 1.13; 95% confidence interval, 0.57-2.23). There were no significant differences between the 2 groups in graft function at 1 year, all-cause graft loss, biopsy-proven rejection, and urological complications. However, the median duration of post-LDKT hospitalization was significantly longer in the low-volume center than in the high-volume center (23 and 16 days, respectively). CONCLUSIONS: Among Japanese patients without preformed donor-specific antibodies, LDKT conducted at a low-volume center by visiting transplant surgeons from a high-volume center and managed clinically by transplant nephrologists was not associated with significantly higher risk of postoperative complications.

Influence of a low-dose tacrolimus protocol on the appearance of de novo donor-specific antibodies during 7 years of follow-up after renal transplantation.

BACKGROUND: Tacrolimus (TAC) is a key immunosuppressant drug for kidney transplantation (KTx). However, the optimal serum trough level of TAC for good long-term outcomes remains unclear. This study aimed to investigate the relationship between the maintenance TAC trough level and the appearance of de novo donor-specific anti-human leukocyte antigen (HLA) antibodies (dnDSAs). METHODS: A total of 584 KTx recipients were enrolled in this study, of whom 164 developed dnDSAs during the follow-up period and 420 did not. RESULTS: We found no significant relationship between TAC trough level during the follow-up period and dnDSA incidence. Patients who developed dnDSAs had a significantly greater number of HLA-A/B/DR mismatches (3.4 ± 1.3 versus 2.8 ± 1.5; P < 0.001), were more likely to have preformed DSAs (48.2% versus 27.1%; P < 0.001) and showed poor allograft outcome. CONCLUSIONS: There was no clear relationship between TAC trough level and dnDSA incidence for KTx recipients whose TAC trough levels were kept within the narrow range of 4-6 ng/mL during the immunosuppression maintenance period.

Clinical and Pathological Analyses of Borderline Changes Cases after Kidney Transplantation.

AIM: We aimed to perform a clinicopathological analysis of cases presenting with borderline changes (BC) after renal transplantation and discuss whether BC might be clinically or pathologically important. MATERIALS AND METHODS: BC was diagnosed in 22 renal allograft biopsy specimens obtained from 20 renal transplant recipients between April 2010 and March 2019 after follow-up at the Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital. RESULTS: BC was diagnosed at a median of 500 days following transplantation. Among the 22 renal allograft biopsy specimens showing evidence of BC, tubulitis was observed in all specimens. Interstitial inflammation was present in 18 specimens (82%), peritubular capillaritis in 14 (64%), interstitial fibrosis (ci) and tubular atrophy (ct) in 4 (18%), and C4d deposition in the peritubular capillary was present in 6 specimens (27%). Glomerulitis and intimal arteritis were not observed. There was no renal graft loss during the observation period, but deterioration of renal allograft function after biopsy occurred in 9 patients (45%). CONCLUSIONS: In BC, tubulitis and interstitial inflammation were the main constituents. Because glomerulitis was not observed in our study, we suspect that BC contributes to acute T-cell-mediated rejection. Although BC did not lead to renal graft loss, renal graft function deterioration was seen in nearly half of the patients after the renal graft biopsy. We conclude that BC is important clinically and pathologically and needs to be monitored and treated appropriately.