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.

Acute tubulointerstitial nephritis possibly caused by vedolizumab for ulcerative colitis in a kidney transplant recipient: A case report.

Vedolizumab, which is used to effectively treat ulcerative colitis (UC), is a humanized monoclonal antibody that specifically inhibits α4ß7 integrin on lymphocytes and prevents lymphocyte migration into the intestinal tissues. Herein, we report a case of acute tubulointerstitial nephritis (ATIN) probably caused by vedolizumab in a kidney transplant recipient (KR) with UC. Approximately 4 years after kidney transplantation, the patient developed UC and was treated initially with mesalazine. Treatment continued with the addition of infliximab later; however, he was hospitalized because of poor symptom control and treated with vedolizumab. His graft function declined rapidly after vedolizumab was administered. Allograft biopsy revealed ATIN. Since no evidence of graft rejection was found, vedolizumab-associated ATIN was diagnosed. The patient was treated with steroids, and his graft function improved. Unfortunately, he finally underwent total colectomy considering that UC was refractory to medical treatment. Previously, cases of vedolizumab-induced acute interstitial nephritis have been reported; however, none were associated with KRs. This is the first report of ATIN in KR which was possibly induced by vedolizumab.

Arteriovenous fistulas after ultrasound-guided needle biopsy of kidney allografts and treatment outcomes after transcatheter embolization: A single-center experience in Japan.

BACKGROUND: Arteriovenous fistula (AVF) is one of the vascular complications after allograft biopsy, and their reported incidence rates range widely. Transcatheter embolization (TE) is a common AVF treatment in kidney allografts. However, information on AVF incidence and features and TE outcomes in Japanese kidney transplant (KT) recipients is lacking. METHODS: This study investigated 270 protocol or clinically indicated kidney allograft biopsies in 129 KT recipients during 2010-2016 at a single-center using standardized methods (16-gauge needle and ultrasound guidance). We recorded the incidence and clinical features of AVF using currently recommended standardized methods of allograft biopsy and TE outcomes regarding allograft function up to 12 months after the procedure in Japanese KT recipients. RESULTS: AVF incidence was 2.6% (seven cases). The time from biopsy to AVF diagnosis was 7 (median, interquartile range: 5-117, range: 1-318) days. The time from biopsy to AVF diagnosis was significantly shorter in symptomatic cases (gross hematuria) than in asymptomatic cases (median 6 vs. 117 days, p = 0.034). Symptomatic patients underwent TE within a shorter time (0-6 days) than asymptomatic patients (25-104 days). There were no complications, and allograft function was stable up to 12 months after TE despite using contrast media and partial renal infarction. CONCLUSIONS: AVF does occur in certain probabilities. AVF formation can occur without apparent bleeding and exist for a long time after allograft biopsy. TE is a safe and immediate treatment for AVF in kidney allograft.

Clinical Outcomes of Monoclonal Gammopathy of Renal Significance Without Detectable Clones.

Introduction: Monoclonal gammopathy of renal significance (MGRS) is characterized by monoclonal immunoglobulin deposition in kidneys. However, monoclonal immunoglobulin and responsible clone(s) are not always detectable. Treatment response and kidney outcome of MGRS without detectable clones remain unclear. Methods: In this single-center, retrospective cohort study, we identified MGRS without detectable clones from our biopsy repository between 2010 and 2022. We investigated the correlations between treatment regimens and kidney outcomes defined by proteinuria and estimated glomerular filtration rate (eGFR), and the impact of repeat kidney biopsy. Results: Our study cohort included 29 cases (27 native kidney and 2 transplant allograft biopsies) of MGRS without detectable clones. At diagnosis, median serum creatinine was 1.8 mg/dl (interquartile range [IQR] 1.3-2.7), with proteinuria 4.6 g/gCr (IQR 2.3-7.9). Treatment regimens were variable: 6 (21%) received conservative therapy, 13 (45%) received plasma cell clone-directed therapy, 8 (28%) received lymphocytic clone-directed therapy, and 2 (7%) received nonclone-directed immunosuppressive therapy. Of 24 patients with proteinuria >0.5 g/gCr at diagnosis, 9 (38%) and 6 (25%) achieved complete response (CR) and partial response (PR), respectively. If interstitial fibrosis and tubular atrophy (IFTA) was >50% at the initial biopsy, less proportion of patients achieved CR. Six of 7 repeat biopsies showed progression of chronic changes (e.g., IFTA) but provided limited information on treatment response. Conclusion: Treatment regimens and outcomes of MGRS without detectable clones were extremely variable. Repeat biopsy provided limited information to assess disease activity or the need for additional treatment. More sensitive tools are needed to detect clones and to assess treatment response.

Renal hypouricemia in a recipient of living-donor kidney transplantation: a case report and literature review.

Hypouricemia in kidney transplant (KT) recipients is rare since they usually have subnormal kidney function which raises serum uric acid level. Recently, interests in pathogenesis of hypouricemia have been increasing due to the understanding of the role of uric acid transporter in renal hypouricemia (RHUC). We herein report the case of RHUC consequently developed in a KT recipient from a living donor with RHUC diagnosed by the detailed urinary and genetic test. A 73-year-old Japanese man underwent KT, and the donor was his wife who had hypouricemia [serum uric acid (S-UA) 0.6 mg/dL]. Nine months after KT, the recipient's S-UA was low (1.5 mg/dL) with serum creatinine (S-Cr) of 1.56 mg/dL, and fractional excretion of UA (FEUA) was high (59.7%; normal < 10%), indicating RHUC. Regarding the donor's information, S-Cr, S-UA, and FEUA were 0.95 mg/dL, 1.0 mg/dL, and 54.5%, respectively. To investigate further on the pathogenesis of RHUC in both the recipient and the donor, we performed genetic tests. The donor had a homozygous mutation of W258X in the SLC22A12 gene and the recipient had a wild type of W258X. Finally, we reviewed the previous literature on RHUC among KT recipients and discussed the strategy of follow-up for these patients.

Eculizumab for Severe Thrombotic Microangiopathy Secondary to Surgical Invasive Stress and Bleeding.

Atypical hemolytic uremic syndrome (aHUS) is an extremely rare condition caused by an excessive activation of the complement pathway based on genetic or acquired dysfunctions in complement regulation, leading to thrombotic microangiopathy (TMA). A complement-amplifying condition (CAC) can trigger aHUS occurrence along with complement abnormality. We herein report a case of severe TMA after laparoscopic myomectomy in a healthy woman. This case was eventually diagnosed as complement-mediated TMA secondary to surgical invasive stress as a CAC, with no definitive diagnosis of aHUS despite a genetic test. The patient fully recovered after several eculizumab administrations.

The Type of Vascular Access and the Incidence of Mortality in Japanese Dialysis Patients.

Objective The National Kidney Foundation (NKF) Kidney Disease Outcome Quality Initiative (KDOQI) guidelines have recommended the use of arteriovenous fistula (AVF) at the initiation of dialysis. However, there are significant differences in the dialysis environments of Japan and the United States, and there are few people who receive hemodialysis via a central venous catheter (CVC) in Japan. The aim of the present study was to examine the association between the type of vascular access at the initiation of dialysis and the incidence of mortality in Japan. Methods This study was a prospective, multicenter, cohort study. The data was collected by the Aichi Cohort study of Prognosis in Patients newly initiated into dialysis (AICOPP) in which 18 Japanese tertiary care centers participated. The present study enrolled 1,524 patients who were newly introduced to dialysis (the patients started maintenance dialysis between October 2011 and September 2013). After excluding 183 patients with missing data, 1,341 patients were enrolled. The Cox proportional hazards model was used to evaluate mortality based on the type of vascular access. The types of vascular access were divided into four categories: AVF, arteriovenous graft (AVG), CVC changed to AVF during the course (CAVF), CVC changed to AVG during the course (CAVG). Results A multivariate analysis revealed that AVG, CAVF and CAVG were associated with a higher risk of mortality in comparison to AVF [hazard ratio (HR), 1.60; p=0.048; HR, 2.26; p=0.003; and HR, 2.45; p=0.001, respectively]. Conclusion The research proved that the survival rate among patients in whom hemodialysis was initiated with AVF was significantly higher than that in patients in whom hemodialysis was initiated with AVG or CVC.