Development and nationwide validation of kidney graft injury markers using urinary exosomes and microvesicles (complete English translation of the Japanese version).

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.

Relationship Between Physical Activity and Estimated Glomerular Filtration Rate in Renal Transplant Recipients: A Cross-sectional Study Analyzing Isotemporal Substitution Model.

OBJECTIVES: Successful renal transplantation reduces mortality rates. However, the decline in the estimated glomerular filtration rate (eGFR) after transplantation is strongly associated with premature mortality in renal transplant recipients (RTRs). Physical activity (PA) is a modifiable lifestyle factor with the potential to maintain or improve eGFR. However, the effects of the type or intensity of PA and sedentary behavior (SB) on eGFR in RTRs remain unclear. The purpose of this study was to clarify the association between accelerometry-measured PA and SB and eGFR in RTRs using isotemporal substitution (IS) analysis. METHODS: A total of 82 renal transplant outpatients participated in this cross-sectional study, of which 65 (average age, 56.9 years; average time post-transplant, 83.0 months) were finally analyzed. All RTRs wore a triaxial accelerometer to measure PA for 7 consecutive days. The measured PA was classified based on intensity into light PA, moderate-to-vigorous PA (MVPA), and SB. The association of each type of PA with eGFR was examined using multi-regression analyses of single-factor, partition, and IS models. The IS model was applied to examine the estimated effects of substituting 30 minutes of SB with an equal amount of time of light PA or MVPA on eGFR. RESULTS: The partition model showed that MVPA was an independent explanatory variable for eGFR (ß = 5.503; P < .05), and the IS model identified that the substitution of time spent in SB with MVPA led to improvements in eGFR (ß = 5.902; P < .05). CONCLUSIONS: The present study suggests that MVPA has an independent and positive association with eGFR, and replacing 30 minutes of SB with MVPA after renal transplantation might lead to the maintenance or improvement of eGFR in RTRs.

Incidence and mortality of post-transplant lymphoproliferative disorders after kidney transplantation: A real-world retrospective analysis in Japan.

OBJECTIVES: Post-transplant lymphoproliferative disorder is a potentially life-threatening complication that has a greater risk of occurrence in the setting of immunosuppression and oncogenic viral infections after transplant surgery. Few studies have reported the cumulative incidence, histological subtypes and clinical outcomes of this disorder in kidney transplant recipients. METHODS: We retrospectively investigated 34 post-transplant lymphoproliferative disorder patients diagnosed out of the 1210 kidney transplant recipients who had undergone the surgery at the two largest centers in Japan between January 1983 and December 2017. RESULTS: A total of 32 patients (94.1%) developed late-onset post-transplant lymphoproliferative disorder (diagnosed 1 year after transplantation). The cumulative incidence rates were 0.76% and 1.59% at 5 and 10 years post-transplantation, respectively. The central nervous system was the most common site (35.3%, 12/34). Overall survival was similar between patients with and without central nervous system lesions (P = 0.676). Of all of the cases, 23.5% (8/34) were detected through cancer screening. Importantly, patients with screening-detected post-transplant lymphoproliferative disorder had better overall survival than those with the disorder who had been symptom detected (P = 0.0215). Overall survival was significantly reduced in patients who developed the disorder compared with those who did not (P = 0.0001). CONCLUSIONS: Post-transplant lymphoproliferative disorder was more likely to occur in the late post-transplantation period, which showed that long-term medical examination for transplant recipients is required. Based on our findings, we propose vigilant, long-term, cancer screening in kidney transplant recipients.

[Ectopic Ureterocele of Adult Male with Urination Difficulty : A Case Report].

Ectopic ureteroceles is sometimes noted in children as an incidental finding in antenatal ultrasonography results or because of symptoms related to a urinary tract infection. In contrast, it is rarely noted in adults, with only 18 cases in Japan presented in literature. We report here a 30-year-old adult male with an ectopic ureterocele discovered due to urination difficulty. The patient noted a poor urine stream and macroscopic hematuria after exercise, and over time needed manual compression on the lower abdomen for urination. Computed tomography results revealed a 35 mm right ureterocele containing a 7.0 mm stone. Cystoscopy showed the ureterocele protruding into the prostatic urethra, which was thought to be the cause of urination difficulty. Transurethral resection of the ureterocele and lithotripsy for the stone were performed. The right ureteral orifice was not visualized during the operation. Resection was performed from the bladder neck side so that the ureterocele wall did not interfere with urination and the calculus was crushed with a pneumatic lithotripter (LithoClast®). Urination difficulty was improved following the procedures. Urinary cystourethrography performed two weeks postoperatively confirmed no vesicoureteral reflux. No symptoms of dysuria or fever were noted at a follow-up visit two months after the operation.

Difference in IgA1 O-glycosylation between IgA deposition donors and IgA nephropathy recipients.

IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis, and disease recurrence often occurs after transplantation. On the other hands, Asymptomatic IgA deposition (IgAD) is occasionally observed in donated kidney. It is recognized that IgAD does not progress to IgAN, but the mechanism has not demonstrated yet. In IgAN, aberrant IgA1 O-glycan structure in the hinge region (HR) of serum IgA is suggested as one of the most convincing key mediators. However, little is known about IgA1 O-glycan structure in IgAD patients. Herein, we investigated the prevalence of IgAD in living renal transplant donors in our cohort. IgAD was observed in 21(13.0%) among 161 renal transplant donors and have statistically significant blood relationship with IgAN recipients (28.6% in relatives vs. 9.8% in non-relatives, respectively; p = 0.0073). Next, we evaluated the IgA1 O-glycan structure of serum IgA from IgAN recipients (n = 26), IgAD donors (n = 17), and non-IgAD helthy donors (n = 27) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The numbers of GalNAc and Gal and the Gal/GalNAc ratio in the HR of the IgAN recipients had significantly lower comparing to the IgAD and non-IgAD healthy donors. The decreased Gal/GalNAc ratio in IgAN recipients means the increased ratio of galactose-deficient IgA1. To the best of our knowledge, this is the first report to compare the O-glycan structures in IgAN recipients and IgAD donors using MALDI-TOF MS. We concluded that IgAD was more common in IgAN related donors. Overall, decreased GalNAc and Gal contents in HR could play a material pathogenic role in IgAN.

[Disturbance of Consciousness in a Patient with an Indwelling Lumbar-Peritoneal Shunt Following Retroperitoneal Laparoscopic Radical Right Nephrectomy : A Case Report].

An 83-year-old man with an indwelling lumbar-peritoneal (L-P) shunt (for idiopathic normal-pressure hydrocephalus) underwent retroperitoneal laparoscopic radical right nephrectomy for renal cell carcinoma (pT1aN0M0). Peritoneal perforation occurred intraoperatively, and he developed postoperative disturbance of consciousness. Computed tomography showed mild ventricular enlargement, which was attributed to L-P shunt failure secondary to increased pneumoperitoneum pressure. His level of consciousness was improved when we raised his head. Few reports have discussed complications observed during retroperitoneal laparoscopic surgery in patients with an indwelling L-P shunt. This case report discusses this topic along with a discussion of previously reported findings.

[Empyema in Left Ureteral Stump Following Bilateral Nephrectomy and Living Renal Transplant-Case Report].

A 34-year-old male came to us with congenital spina bifida, vesicoureteral reflux and scoliosis. He had been on hemodialysis for chronic renal failure caused by reflux nephropathy since the age of 23 years. At the age of 24, he received bilateral nephrectomy and underwent living renal transplantation from his mother. Hemodialysis was started again at the age of 26, because the renal graft was not functioning. At the age of 34, the patient developed a fever that persisted for a few days. He received antibiotic medication from his physician, but since his condition did not improve he was refered to our hospital. A computed tomography scan examination revealed abscess formation in the left retroperitoneum. Magnetic resonance imaging findings also showed the abscess in the left retroperitoneum. The patient was diagnosed with empyema of the residual ureter and underwent a left ureterectomy procedure.

[A Case of Hypoplastic Kidney and an Ectopic Ureter Treated by Laparoscopic Nephroureterectomy in an Adult Woman].

A 20-year-old woman had urinary incontinence since childhood. She self-managed her symptoms by using incontinence pads and she admitted never having been to a urologist. When she consulted a urologist for cystitis, ultrasonography could not locate the presence of a right kidney. She was suspected of having a contracted kidney and was referred to our hospital for further examinations and treatment. An enhanced computed tomography scan showed a contracted right kidney, which was located on the surface of the inferior vena cava. Magnetic resonance imaging showed that the right ureter extended into the vagina. Cystoscopy showed the absence of a right ureteral orifice, and an ectopic orifice was identified in the vagina. Laparoscopic nephroureterectomy was performed based on the diagnosis of a hypoplastic kidney with an ectopic ureter. We removed the ureter as far as the vagina because a residual ureteral segment could cause infection. Postoperatively, the patient had no complications, and her uterine artery was successfully saved. The patient achieved complete continence after the operation.

[Development of Ectopic Adrenocorticotropic Hormone Syndrome in a Patient with Prostate Cancer during Combined Androgen Blockade Therapy].

A 74-year old man presented to us with difficulty urinating. The laboratory examinations revealed an elevated prostate-specific antigen (PSA) level. A prostate biopsy revealed prostate adenocarcinoma. The computed tomography scan showed metastasis to lymph nodes in the pelvic cavity and both adrenal glands. Combined androgen blockade therapy was started, and PSA levels began to decrease gradually. However, 2 months later, he was hospitalized for treatment of cellulitis and was found to have hypertension, hyperglycemia, and hypokalemia. Endocrinological studies showed elevated serum adrenocorticotropic hormone (ACTH) and serum and urinary cortisol levels. The plasma cortisol level was not reduced by either the 1 mg or 8 mg dexamethasone suppression test, and the plasma cortisol and ACTHlevels did not respond to the corticotropin-releasing hormone test. Computed tomography indicated increased metastasis, and endocrinological studies and other examinations suggested a diagnosis of ectopic ACTHsyndrome. Combined androgen blockade therapy was continued, and inhibitors of adrenocortical synthesis were also administered. However, 16 weeks later, he died of prostate cancer. On autopsy, the histological examination revealed small cell carcinoma in the prostate and adrenal glands and other sites of metastasis, while immunohistochemistry findings revealed that the tumors in the prostate and adrenal glands were strongly positive for ACTH.

[Recurrence of Well Differentiated Intrascrotal Liposarcoma in Retroperitoneum Five Years after Resection : A Case Report].

A 68-year-old man underwent an inguinal orchiectomy for a right testicular tumor and the pathological diagnosis was atypical lipomatous tumor. Nine years later, a resection procedure was performed for local recurrence. Five years after that second surgery, abdominal computed tomography (CT) findings revealed a low density mass 40 mm in size on the back side of the right kidney and enlarged fat in the retroperitoneal space. We performed a laparoscopic tumor resection under a diagnosis of lipoma or liposarcoma recurrence, and the pathological diagnosis was well differentiated liposarcoma. Treatment with pazopanib was started, as a CT examination showed that the tumor remained, after which we performed an open nephroureterectomy and resected the remaining tumor portion. Pazopanib treatment was continued and no obvious signs of recurrence were seen at 8 months after the most recent surgery. Although well differentiated liposarcoma usually recurs in the original tumor region, multicentric recurrence in other parts is possible.

[Nutcracker Syndrome with Left Inferior Vena Cava : A Case Report].

A 37-year-old male with a history of intermittent gross hematuria visited our hospital with asymptomatic macrohematuria. Cystoscopy findings revealed bloody urine from the left ureteric orifice and the cytodiagnosiswasclas sII. Contrast-enhanced computed tomography imaging revealed the inferior vena cava (IVC) running upward along the left side of the aorta, then crossing the aorta between the aorta and superior mesenteric artery (SMA). The crossing portion of the IVC was severely compressed by the SMA, causing the left-sided IVC (LIVC), and two left renal veins (LRV) were entered at the dilated portion of LIVC. On suspicion of nutcracker syndrome (NCS) with LIVC, color doppler ultrasonography and venography examinationswere performed. Although the resultsdid not meet criteria reported for NCS, venography revealed reflux from the IVC to the upper branch of the left renal vein. LIVC is a rare vessel anomaly, with a rate of incidence ranging from 0.2-0.5%, while NCS with LIVC isextremely rare, with only 7 case reports in the English literature. Herein. we report the first known case in Japan and review previous reports.

[A Case of Tubercular Prostatic Abscess Following Intravesical Bacillus Calmette-Guerin Therapy].

We report a case of tubercular prostatic abscess. A 65-year-old man had undergone intravesical Bacillus Calmette-Guerin therapy for a non-muscle invasive bladder carcinoma. One year 8 months later, the prostate-specific antigen concentration in serum was elevated (18. 58 ng/ml). Results of magnetic resonance imaging (MRI) of the pelvis led us to suspect a prostatic abscess, and transurethral resection of the prostate for drainage was performed. A culture of fluid obtained from the latter procedure revealed a tubercular prostatic abscess. We administered the antituberculous agents, isoniazid (300 mg) and rifampicin(450 mg) daily, for 6 months. One year after surgery, the patient had no urinary symptoms or evidence of recurrence.

[Posterior reversible encephalopathy syndrome (PRES) after kidney transplantation: a case report].

A 60-year-old woman with chronic renal failure due to a polycystic kidney underwent living kidney transplantation. Initial immunosuppressive therapy consisted of tacrolimus (TAC), mycophenolate mofetil (MMF), prednisolone, and basiliximab. Furthermore, rituximab was administered, and double filtration plasmapheresis and plasma exchange were utilized because of ABO-incompatible transplantation, while intravenous immune serum globulin (IVIG) was given because donor specific antibody was positive. Four days after the renal transplantation, the patient developed visual abnormalities, a headache, and paralysis. Then, he became unconscious. Magnetic resonance imaging of the brain demonstrated bilateral posterior vasogenic edema. Our diagnosis was posterior reversible encephalopathy syndrome due to TAC neurotoxicity. After converting TAC to reduced cyclosporine and everolimus, the symptoms rapidly disappeared.

[Sertoli cell tumor of the testis : a case report and questionnaire survey on the reported cases in Japan].

We report a case of Sertoli cell tumor of the testis. A 33-year-old man visited our hospital with the complaints of macroscopic hematuria and fever. The left testis was swollen on palpation. Serum levels of human chorionic gonadotropin-ß and lactate dehydrogenase were not elevated, while α fetoprotein was slightly over the normal range. Ultrasonography showed a hypoechoic lesion in the left testis. There was no evidence of retroperitoneal lymph node enlargement or distant metastasis on computed tomography. A left orchietectomy was performed under the diagnosis of left testicular tumor. The tumor, measuring 20 mm in size was histologically diagnosed as benign Sertoli cell tumor. No adjuvant therapy was performed. Neither recurrence nor evidence of metastasis has been detected for 6 months postoperatively.

[Complete atrioventricular block due to cardiac metastasis from bladder cancer: case report].

A 72-year-old woman was diagnosed with bladder cancer (cT3bN0M0). After 2 cycles of GC (gemcitabine，cisplatin) neoadjuvant chemotherapy, the patient underwent a cystectomy and ileal conduit construction. Pathological findings showed urothelial carcinoma, high grade, G2＞G3, pT3a, INFß, ly0, v1. Six months after the operation, metastases to the liver, lung, left adrenal gland, rib, multiple lymph nodes, and peritoneum were revealed. Under palliative care, she suffered from palpitation and general fatigue. Electrocardiogram findings showed a complete atrioventricular block, while echocardiography and computed tomography revealed cardiac metastasis. We diagnosed her with complete atrioventricular block due to cardiac metastasis from bladder cancer. She died 7 days after onset of the complete atrioventricular block without use of a pacemaker.

[A case of urachal carcinoma with multiple lung metastases treated by TS-1/CDDP chemotherapy].

A 67-year-old woman presented with macroscopic hematuria and lower abdominal pain. Cystoscopy revealed a broad-stalk non-papillary tumor at the bladder dome. Computed tomography (CT) showed a tumor extending from the umbilicus to the bladder dome, together with multiple lung metastases. Serum carcinoembryonic antigen and cancer antigen (CA19-9) levels were elevated at 7.0 ng/ml and 180 U/ml, respectively. Transurethral resection of the tumor was performed and histopathology revealed adenocarcinoma. Therefore, the tumor was diagnosed as a stage IVB (Sheldon's category) urachal carcinoma. En bloc segmental resection of the urachal carcinoma with the bladder dome was performed, followed by chemotherapy with tegafur, gimestat, and otastat potassium (TS-1) and cisplatin. The disease remained stable for 8 months. However, a follow up CT scan after 11 chemotherapy cycles showed progression of the lung metastases. In spite of the change to a second-line gemcitabine and cisplatin chemotherapy regimen, the disease continued to progress after 4 cycles.

Assessment of Tumor Markers in Renal Transplant Recipients.

Background/Aim: Malignant tumors are diagnosed using various methods, including diagnostic imaging methods. The measurement of tumor markers is commonly used because of its noninvasiveness and convenience. Furthermore, it is known that the excretion and metabolism of some tumor markers are affected by impaired renal function. In the present study, we investigated the effect of improved renal function on pre-and post-transplantation changes in tumor marker levels [carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), and prostate-specific antigen (PSA)] in renal transplant recipients. Patients and Methods: A total of 116 renal transplant recipients, who had not been diagnosed with malignancies between January 2012 and December 2019, were included, and tumor markers were investigated. Results: CEA showed a significant decrease after kidney transplantation, regardless of the dialysis type (3.6→2.6 ng/ml, p<0.001), while other tumor markers showed a significant increase (AFP: 3.6→3.7 ng/ml; CA19-9: 16.2→19.5 U/ml; PSA: 0.95→1.05 ng/ml; all p<0.05). Pre- and postoperative eGFR ratios and postoperative liver function were identified as factors influencing the postoperative CEA and CA19-9 values, while PSA was influenced by the duration of dialysis. No statistically significant factors were found for AFP levels. Conclusion: Caution should be exercised when investigating tumor markers in patients with renal dysfunction, as tumor marker levels may vary depending on the pathophysiology of each patient.

MYH9-related disorder with sole presentation of end-stage kidney disease and long-term, recurrence-free living after living donor renal transplantation: a case report.

MYH9-related disorders are a group of autosomal dominant disorders caused by mutations in MYH9, and are characterized by thrombocytopenia, sensorineural hearing loss, cataracts, and renal failure. Here, we report a case of chronic renal failure due to MYH9-related disorder with renal symptoms in a patient who underwent living-donor renal transplantation. The patient was diagnosed with proteinuria during a health checkup at the age of 12 years. Her renal function gradually deteriorated, and hemodialysis was initiated at 34 years of age. No definitive diagnosis of renal disease was made through renal biopsy. At the age of 35, she underwent living-donor renal transplantation from her mother as the donor. Six years after transplantation, her renal function remained stable, and no evidence of recurrent nephritis was found during renal biopsies. The family history revealed that her father, uncle, and younger brother had end-stage kidney disease. Genetic testing revealed a mutation (p.E1653D) related to the MYH9 gene. As her father had a history of renal biopsy and was diagnosed with focal segmental glomerulosclerosis (FSGS), we diagnosed chronic renal failure due to FSGS associated with MYH9 disorder. There were no findings suggestive of hearing loss, cataracts, or thrombocytopenia in the recipient or their family members with renal failure, and no symptoms other than renal failure were noted.

Fat Necrosis Mimicking Local Recurrence With Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) Positivity After Partial Nephrectomy for Renal Cell Carcinoma.

We report a case of fat necrosis with positive results on fluorodeoxyglucose positron emission tomography (FDG-PET)-CT imaging after partial nephrectomy. A 77-year-old man underwent a partial nephrectomy for a right renal mass. The histopathological results showed clear cell renal cell carcinoma, G1>G2, pT1a. Four and a half years after surgery, a nodule appeared in the retroperitoneal space on CT. FDG-PET CT showed increased uptake in the nodule, indicating local recurrence of carcinoma. A right nephrectomy was performed. The histopathological diagnosis was fat necrosis.

Immunohistochemical features of BK virus nephropathy in renal transplant recipients.

BK virus nephropathy (BKVN) is one of the factors that reduces renal graft function after transplantation. However, BKVN and rejection present similar pathological findings, as both are accompanied by cellular infiltration to the interstitium and tubulitis, thus they are difficult to distinguish for diagnosis and medical treatment. In the present study, we examined immunohistochemical pathological features of BKVN in four cases treated in our hospital from 2007 to 2010. Common immunohistological finding is that tubulitis in these cases was primarily EMA and 34ßE12-positive and existed predominantly from the collecting duct to the distal convoluted tubule. The majority of infected cells existed in EMA and 34ßE12-positive tubules, which were also located mainly from the collecting duct to the distal tubule. In addition, a large number of SV40-positive infected cells were similarly seen. Dylon staining clearly revealed eosinophils. We concluded that the main pathological features of BKVN are the presence of tubulitis and infected cells predominantly from the collecting duct to distal tubule and the appearance of eosinophils.