Teppei Okamoto

Core2 O-glycan-expressing prostate cancer cells are resistant to NK cell immunity.

Core2 β-1,6-N-acetylglucosaminyltransferase (C2GnT) forms an N-acetylglucosamine branch in the O-glycans (core2 O-glycans) of cell surface glycoproteins. We previously revealed that the expression of C2GnT is positively correlated with poor prognosis in prostate cancer patients. However, the detailed mechanisms underlying their poor prognosis remain unclear. In the current study, we report that the core2 O-glycans carried by the surface MUC1 glycoproteins of prostate cancer cells play an important role in the evasion of NK cell immunity. In C2GnT-expressing prostate cancer cells, the MUC1 core2 O-glycans are modified with poly-N-acetyllactosamine. MUC1 glycoproteins carrying poly-N-acetyllactosamine attenuated the interaction of the cancer cells with NK cells, resulting in decreased secretion of granzyme B by the NK cells. Poly-N-acetyllactosamine also interfered with the ability of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to access the cancer cell surface. These effects of poly-N-acetyllactosamine on NK cells render C2GnT-expressing prostate cancer cells resistant to NK cell cytotoxicity. By contrast, C2GnT-deficient prostate cancer cells carrying a lower amount of poly-N-acetyllactosamine than the C2GnT-expressing prostate cancer cells were significantly more susceptible to NK cell cytotoxicity. Our results strongly suggest that C2GnT-expressing prostate cancer cells evade NK cell immunity and survive longer in the host blood circulation, thereby resulting in the promotion of prostate cancer metastasis.

Effect of an Oral Adsorbent, AST-120, on Dialysis Initiation and Survival in Patients with Chronic Kidney Disease

The oral adsorbent AST-120 has the potential to delay dialysis initiation and improve survival of patients on dialysis. We evaluated the effect of AST-120 on dialysis initiation and its potential to improve survival in patients with chronic kidney disease. The present retrospective pair-matched study included 560 patients, grouped according to whether or not they received AST-120 before dialysis (AST-120 and non-AST-120 groups). The cumulative dialysis initiation free rate and survival rate were compared by the Kaplan-Meier method. Multivariate analysis was used to determine the impact of AST-120 on dialysis initiation. Our results showed significant differences in the 12- and 24-month dialysis initiation free rate (P < 0.001), although no significant difference was observed in the survival rate between the two groups. In conclusion, AST-120 delays dialysis initiation in chronic kidney disease (CKD) patients but has no effect on survival. AST-120 is an effective therapy for delaying the progression of CKD.

Skin perfusion pressure is a prognostic factor in hemodialysis patients.

Peripheral arterial disease (PAD) is common in hemodialysis patients and predicts a poor prognosis. We conducted a prospective cohort study to identify risk factors for PAD including skin perfusion pressure (SPP) in hemodialysis patients. The cohort included 373 hemodialysis patients among 548 patients who received hemodialysis at Oyokyo Kidney Research Institute, Hirosaki, Japan from August 2008 to December 2010. The endpoints were lower limb survival (peripheral angioplasty or amputation events) and overall survival of 2 years. Our results showed that <70 mmHg SPP was a poor prognosis for the lower limb survival and overall survival. We also identified age, history of cardiovascular disease, presence of diabetes mellitus, smoking history, and SPP < 70 mmHg as independent risk factors for lower limb survival and overall survival. Then, we constructed risk criteria using the significantly independent risk factors. We can clearly stratify lower limb survival and overall survival of the hemodialysis patients into 3 groups. Although the observation period is short, we conclude that SPP value has the potential to be a risk factor that predicts both lower limb survival and the prognosis of hemodialysis patients.

Efficacy of SMART Stent Placement for Salvage Angioplasty in Hemodialysis Patients with Recurrent Vascular Access Stenosis

Vascular access stenosis is a major complication in hemodialysis patients. We prospectively observed 50 patients in whom 50 nitinol shape-memory alloy-recoverable technology (SMART) stents were used as salvage therapy for recurrent peripheral venous stenosis. Twenty-five stents each were deployed in native arteriovenous fistula (AVF) and synthetic arteriovenous polyurethane graft (AVG) cases. Vascular access patency rates were calculated by Kaplan-Meier analysis. The primary patency rates in AVF versus AVG at 3, 6, and 12 months were 80.3% versus 75.6%, 64.9% versus 28.3%, and 32.3% versus 18.9%, respectively. The secondary patency rates in AVF versus AVG at 3, 6, and 12 months were 88.5% versus 75.5%, 82.6% versus 61.8%, and 74.4% versus 61.8%, respectively. Although there were no statistically significant difference in patency between AVF and AVG, AVG showed poor tendency in primary and secondary patency. The usefulness of SMART stents was limited in a short period of time in hemodialysis patients with recurrent vascular access stenosis.

The influence of serum uric acid on renal function in patients with calcium or uric acid stone: A population-based analysis

Objectives To determine the influence of serum uric acid (UA) levels on renal impairment in patients with UA stone. Materials and methods We retrospectively analyzed 463 patients with calcium oxalate and/or calcium phosphate stones (CaOx/CaP), and 139 patients with UA stones. The subjects were divided into the serum UA-high (UA ≥ 7.0 mg/dL) or the UA-low group (UA < 7.0 mg/dL). The control group comprised 3082 community-dwelling individuals that were pair-matched according to age, sex, body mass index, comorbidities, hemoglobin, serum albumin, and serum UA using propensity score matching. We compared renal function between controls and patients with UA stone (analysis 1), and between patients with CaOx/CaP and with UA stone (analysis 2). Logistic regression analysis was used to evaluate the impact of the hyperuricemia on the development of stage 3 and 3B chronic kidney disease (CKD) (analysis 3). Results The renal function was significantly associated with serum UA levels in the controls and patients with CaOx/CaP and UA stones. In pair-matched subgroups, patients with UA stone had significantly lower renal function than the control subjects (analysis 1) and patients with CaOx/CaP stones (analysis 2) regardless of hyperuricemia. Multivariate logistic regression analysis revealed that patients with UA stone, CaOx/CaP, hyperuricemia, presence of cardiovascular disease, higher body mass index, older age and lower hemoglobin had significantly higher risk of stage 3 and 3B CKD (analysis 3). Conclusion Patients with UA stones had significantly worse renal function than controls and CaOx/CaP patients regardless of hyperuricemia. Urolithiasis (CaOx/CaP and UA stone) and hyperuricemia had an association with impaired renal function. Our findings encourage clinicians to initiate intensive treatment and education approaches in patients with urolithiasis and/or hyperuricemia in order to prevent the progression of renal impairment.

Surgery without Blood Transfusion for Giant Paraganglioma in a Jehovah's Witness Patient

A retroperitoneal tumor was identified in a 57-year-old female belonging to Jehovahs Witnesses during a health check. Subsequent examination led to the suspicion of a right pheochromocytoma. The patient wished to be treated by bloodless surgery and consulted our hospital after being refused surgery by several hospitals. She signed a liability waiver for blood transfusion refusal. After obtaining consent for diluted autotransfusion and preoperative administration of erythropoietin, the surgery was scheduled. The tumor was attached to the inferior vena cava and left renal vein and engulfed the right renal artery and vein. The tumor and right kidney were removed en bloc. Operative time was 8 h and 18 min, with 1,770 ml of blood loss. The histopathological diagnosis was paraganglioma with the normal adrenal gland within the border of the tumor. The patient was discharged from the hospital with no postoperative complications.

Clinical implication of a quantitative frailty assessment tool for prognosis in patients with urological cancers

Objectives Optimal tools for evaluating frailty among urological cancer patients remain unclear. We aimed to develop a quantitative frailty assessment tool comparing healthy individuals and urological cancer patients, and investigate the clinical implication of quantitative frailty on prognosis in urological cancer patients. Results Gait speed, hemoglobin, serum albumin, exhaustion, and depression were significantly worse in patients with all types of cancers than in pair-matched controls. Frailty discriminant score (FDS) showed clear separation between controls and urological cancer patients, and significant association with the Fried criteria. Overall survivals were significantly shorter in patients with a higher score (>2.30) than in those with a lower score among nonprostate cancer (bladder, upper tract urothelial carcinoma, and renal cell carcinoma) patients. In prostate cancer patients, overall survivals were significantly shorter in patients with a higher score (>3.30) than in those with a lower score. Conclusions FDS was significantly associated with frailty and prognosis in urological cancer patients. This tool for frailty assessment can help patients and physicians make more informed decisions. Further validation study is needed. Materials and Methods Total 605 urological cancer patients presenting to our hospital underwent a prospective frailty assessment. Controls were selected from 2280 community-dwelling subjects. Frailty was assessed via physical status, blood biochemical tests, and mental status. We compared frailty variables between pair-matched controls and urological cancer patients. We developed FDS using frailty variables, and compared with the Fried criteria. The influence of FDS on overall survivals was investigated by Kaplan-Meier analysis and Cox regression analysis.

Slow Gait Speed and Rapid Renal Function Decline Are Risk Factors for Postoperative Delirium after Urological Surgery.

Objectives The aim of this study was to identify risk factors associated with postoperative delirium in patients undergoing urological surgery. Methods We prospectively evaluated pre- and postoperative risk factors for postoperative delirium in consecutive 215 patients who received urological surgery between August 2013 and November 2014. Preoperative factors included patient demographics, comorbidities, and frailty assessment. Frailty was measured by handgrip strength, fatigue scale of depression, fall risk assessment, and gait speed (the timed Get-up and Go test). Postoperative factors included types of anesthesia, surgical procedure, renal function and serum albumin decline, blood loss, surgery time, highest body temperature, and complications. Uni- and multivariate logistic regression analyses were performed to assess pre- and postoperative predictors for the development of postoperative delirium. Results Median age of this cohort was 67 years. Ten patients (4.7%) experienced postoperative delirium. These patients were significantly older, had weak handgrip strength, a higher fall risk assessment score, slow gait speed, and greater renal function decline compared with patients without delirium. Multivariate analysis revealed slow gait speed (>13.0 s) and rapid renal function decline (>30%) were independent risk factors for postoperative delirium. Conclusions Slow gait speed and rapid renal function decline after urological surgery are significant factors for postoperative delirium. These data will be helpful for perioperative patient management. This study was registered as a clinical trial: UMIN: R000018809.

Blood group antigen-targeting peptide suppresses anti-blood group antibody binding to antigen in renal glomerular capillaries after ABO-incompatible blood reperfusion.

Background Antibody-mediated rejection after ABO-incompatible kidney transplantation (ABO-I KTx) is a major barrier to transplantation success. The advent of immunosuppressive therapy has markedly improved graft survival in ABO-I KTx. However, compared with normal KTx, clinical conditions during ABO-I KTx are difficult to control because of overimmunosuppression. To reduce the need for immunosuppression, we aimed to develop a novel blood group antigen-neutralizing therapy. Methods We screened for an ABO blood group antigen-targeting peptide (BATP) by screening of T7 phage-displayed peptide library. After screening, hemagglutination inhibition assays, enzyme-linked immunosorbent assay, and cytotoxicity assay were used to analyze the blood group antigen-blocking effect and toxicity of BATP. We also tested the inhibitory effects on anti-blood group antibody binding in normal human kidney tissues blocked with BATP and excised kidneys perfused ex vivo with BATP. Results We identified six peptide sequences that efficiently suppressed hemagglutination of red blood cells by anti-ABO blood group antibodies and binding of these antibodies to ABO histo-blood group antigens in kidney tissues. Surprisingly, ex vivo perfusion of BATP in kidneys excised from renal cell carcinoma patients caused significant suppression of anti-blood group antibody binding to antigen and IgG and IgM deposition in renal glomerular capillaries after ABO-I blood reperfusion. Conclusions These data indicate that A/B blood group antigens on red blood cells and in kidney tissues may be neutralized by BATP. This approach may enable the development of a novel blood group antigen-neutralizing therapy to overcome the challenges of ABO-I KTx.

The relationship between poor nutritional status and progression of aortic calcification in patients on maintenance hemodialysis

BackgroundAlthough aortic calcification has a significant negative impact on prognosis in patients on hemodialysis (HD), risk factors for aortic calcification progression remain unclear. The aim of this study was to investigate the relationship between malnutrition and aortic calcification progression in patients on HD.MethodsBetween April 2015 and October 2016, we treated 232 patients on HD. Of those, we retrospectively evaluated data from 184 patients who had had regular blood tests and computed tomography (CT) scans. The abdominal aortic calcification index (ACI) was quantitatively measured by abdominal CT. Nutritional status was evaluated using the Geriatric Nutritional Risk Index (GNRI). A normalized treatment ratio of functional urea clearance was evaluated by Kt/V. The difference in ACI values between 2015 and 2016 was evaluated as a ΔACI, and patients were stratified into two groups according to ΔACI value: high (≥75th percentile, ΔACI-high group) and low (<75th percentile, ΔACI-low group). Variables such as age, sex, comorbidities, dialysis vintage, serum data, and GNRI were compared between ΔACI-high and ΔACI-low patients. Factors independently associated with a higher ΔACI progression (ΔACI ≥75th percentile) were determined using multivariate logistic analysis.ResultsMedian values of ACIs in 2015 and 2016 were 40.8 and 44.6%, respectively. Of 184 patients, 125 (68%) patients experienced ACI progression for 1 year. The median ΔACI and 75th percentile of ΔACI were 2.5% and 5.8%, respectively. The number of patients in the ΔACI-low and ΔACI-high groups were 128 (70%) and 56 (30%), respectively. There were significant differences in sex, presence of diabetic nephropathy, HD vintage, serum albumin, serum phosphate, C-reactive protein, intact parathyroid hormone, Kt/V, and GNRI. Multivariate logistic regression analysis revealed that independent factors associated with a higher ΔACI progression were male sex, serum phosphate levels, HD vintage, and GNRI of < 90.ConclusionsOur results suggest that poor nutritional status is an independent risk factor for the progression of aortic calcification. Nutrition management may have the potential to improve progression of aortic calcification in patients on HD.Trial registrationUMIN Clinical Trials Registry UMIN000028050.