Choosing the larger kidney on CT volumetry: a study on the early post-donation kidney function of living donors.

BACKGROUND: Selecting the smaller kidney for donation has been advocated if there is a size difference of > 10% between the 2 kidneys but has never been prospectively evaluated. With increase in donor nephrectomies, it is important to evaluate this to minimize loss of renal function to donors. METHODS: 75 consecutive donor nephrectomy patients were included in our longitudinal study. The Split Renal Volume (SRV) of bilateral kidneys were measured using contrasted computer tomography scans and patients segregated into 2 groups depending on donated kidney having more (Group 1) or less than (Group 2) 52.5% of SRV. RESULTS: Patients in Group 1 (n = 19) and 2 (n = 56) were of similar age (43.8 vs. 48.3), BMI (22.4 vs. 25.2), sex (57.9 vs. 55.4% women), respectively. Although total kidney volumes were similar in both groups, Group 1 had significantly smaller right kidney volumes (120.4 ± 24.9 vs. 142.7 ± 28.4 mls, p = 0.003). EGFR pre-operatively (116.3 ± 20.8 vs. 106.3 ± 23.8 mL/min/1.73 m2) and at 6-months (65.7 ± 13.3 vs. 66.9 ± 15.5 mL/min/1.73 m2) were not different between groups. However, patients in Group 1 had significantly greater absolute (50.6 ± 14.9 vs. 39.5 ± 14.7 mL/min/1.73 m2) and relative decline (43.0 ± 8.6 vs. 36.3 ± 10.6%) in eGFR at 6 months (p = 0.06, 0.009). CONCLUSION: With a SRV difference of 5% between the 2 sides, removal of the larger kidney for living kidney donation resulted in greater early decline of renal function than kidney donors whose larger or equivalent kidney is preserved.

Polymorphism in autophagy gene ATG2B is not associated with bladder cancer recurrence after intravesical Bacillus Calmette-Guerin (BCG) immunotherapy in Asian patients.

OBJECTIVES: Optimal patient stratification is critical in the era of personalized medicine. Germline polymorphisms play an important role in the treatment response of various human diseases, including bladder cancer. Intravesical BCG therapy is widely-used for bladder cancer. However, tumor recurrence and progression are very common. Stratification based on germline polymorphisms may contribute to circumvent this clinical challenge. Autophagy pathway plays an important role in the nonspecific protective effects of BCG. Patients that carry C allele of rs3759601 in autophagy gene ATG2B showed increased risk of recurrence and progression in European population. We thus sought to analyze rs3759601 and its relevance in BCG response in Asian NMIBC patients. METHOD: Functional impact of rs3759601 ATG2B (p.Gln1383Glu) was analyzed by bioinformatics programs including NCBI Conserved Domain Search, Clustal Omega, Polyphen and SIFT. NMIBC patients who received intravesical BCG at multiple hospitals in Singapore from 1995 to 2016 were included. These patients were genotyped for rs3759601 using high resolution melt analysis. The rs3759601 polymorphism was studied in correlation with the bladder cancer recurrence rate and disease progression rate in our cohort. Statistical analysis was conducted using Kaplan-Meier plots and the Chi-squared analysis. RESULTS: In total, 307 individules were included in the study including 161 NMIBC patients and 146 healthy controls, predominately Chinese. The rs3759601 genotype distributions in our NMIBC patients were (GG 72.1%; GC 27.9%; CC 0%), which were distinct from the Dutch report (GG 32.8%; GC 47.4% and CC 19.8%, Buffen K et al, 2014). Consistently, the C allele frequencies of rs3759601 are 0.171 in our controls and 0.177 in East Asians from 1,000 Genome, but 0.406 in Europeans from 1,000 Genome. In silico analysis suggested rs3759601 ATG2B (p.Gln1383Glu) alteration is unlikely to be functionally deleterious. Statistical analysis revealed no significant association between ATG2B rs3759601 C allele and risk of bladder cancer recurrence (P= 0.353, GC vs. GG: hazard ratio [HR]= 1.324), or cancer progression (P= 0.454, GC vs. GG: HR = 0.658). CONCLUSION: In contrast to European NMIBC patients, ATG2B rs3759601 C allele is much less common in Asians and it not associated with BCG response in Asian NMIBC patients.

Tryptophan-kynurenine ratio as a biomarker of bladder cancer.

OBJECTIVES: To investigate plasma and urinary kynurenine (KYN)-tryptophan (TRP) ratios in bladder cancer, expression of indoleamine 2,3-dioxygenase 1 (IDO1) in relation to tryptophan 2,3-dioxygenase (TDO2) in bladder tumour, and the correlation of KYN-TRP ratio with bladder tumour burden. METHODS: Metabotyping of the TRP-KYN metabolic axis was performed via a clinical case-control study. Expression of IDO1 and TDO2 was measured in human biopsied tissues. Correlational experiments between KYN-TRP ratio and bladder tumour were performed using a murine orthotopic prostate-specific antigen (PSA)-secreting MB49 bladder cancer model. RESULTS: We established for the first time that plasma TRP level was significantly decreased, while both plasma and urinary KYN-TRP ratios were significantly higher in bladder cancer patients, and expression level of IDO1 but not TDO2 was increased in human bladder tumour. We reported the positive correlation between IDO1 expression, KYN-TRP ratio, normalized PSA to creatinine, and bladder tumour burden in the murine model. CONCLUSION: Kynurenine-tryptophan ratio is a promising surveillance biomarker for bladder cancer, but would require further validation before clinical translation.

Detection of Clinical Mesenchymal Cancer Cells from Bladder Wash Urine for Real-Time Detection and Prognosis.

Bladder cancer (BC) is a disease that requires lifelong surveillance due to its high recurrence rate. An efficient method for the non-invasive rapid monitoring of patient prognosis and downstream phenotype characterization is warranted. Here, we develop an integrated procedure to detect aggressive mesenchymal exfoliated bladder cancer cells (EBCCs) from patients in a label-free manner. Using a combination of filtration and inertial focusing principles, the procedure allowed the focusing of EBCCs in a single stream-line for high-throughput separation from other urine components such as large squamous cells and blood cells using a microfluidic sorting device. Characterization of enriched cells can be completed within hours, suggesting a potential utility for real-time detection. We also demonstrate high efficiency of cancer cell recovery (93.3 ± 4.8%) and specific retrieval of various epithelial to mesenchymal transition (EMT) phenotype cell fractions from respective outlets of the microfluidic device. EMT is closely associated with metastasis, drug resistance and tumor-initiating potential. This procedure is validated with clinical samples, and further demonstrate the efficacy of bladder wash procedure to reduce EBCCs counts over time. Overall, the uniqueness of a rapid and non-invasive method permitting the separation of different EMT phenotypes shows high potential for clinical utility. We expect this approach will better facilitate the routine screening procedure in BC and greatly enhance personalized treatment.

Visceral obesity in Asian living kidney donors significantly impacts early renal function after donor nephrectomy.

INTRODUCTION: Obesity may be a risk factor for kidney donors to develop reduced renal function. The Framingham heart study suggested that visceral adipose tissue (VAT) confers a more adverse metabolic profile compared with subcutaneous adipose tissue (SAT). Asians tend to have a higher VAT composition and it is unclear if their kidney function is affected differently. We hypothesized that Asian living kidney donors who have visceral obesity are at a higher risk of renal function deterioration 1 year after donation. METHODS: Between 2011 and 2014, we retrospectively evaluated data from 73 consecutive patients (52% male; mean age 44.9 ± 11.7 years) before they underwent donor nephrectomy and at their 1 year routine follow-up. VAT and SAT were measured at the level of the umbilicus on pre-operative computerized tomography (CT). Visceral obesity (VO) was defined as a VAT > 100 cm [2] and patients were then further divided and compared in two subgroups: VAT > 100 and < 100 cm [2]. Estimated glomerular filtration rate (eGFR, mL/min per 1.73 m [2]) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation pre-operatively and 1 year post-operatively. RESULTS: Both subgroups had similar baseline kidney function (P = NS) pre-operatively. At the 1 year follow-up, patients with VO experienced a more significant decline of renal function (109 ± 9 to 89 ± 8 mL/min per 1.73 m2), compared to those without VO (111 ± 12 to 96 ± 11 mL/min per 1.73 m2, P = 0.013). VO was associated with a body mass index (BMI) > 25 kg/m2 (P < 0.001), male gender (P < 0.001) and older age at the time of donor nephrectomy (48.0 vs 39.5 years, P = 0.01). The presence of hypertension or hyperlipidaemia pre-operatively, choice of surgical approach, and post-operative complication rates, did not differ significantly between the subgroups. CONCLUSIONS: Visceral obesity as defined by VAT > 100 cm2 at the level of the umbilicus on cross-sectional imaging, may have a significant impact on early renal function after donor nephrectomy. Adiposity markers, as measured by cross-sectional CT imaging, may be incorporated into routine pre-operative kidney donor workup.

Premenopausal women with recurrent urinary tract infections have lower quality of life.

OBJECTIVES: To examine the impact on quality of life of recurrent acute uncomplicated urinary tract infection among premenopausal Singaporean women, and to determine the risk factors for lower quality of life among these patients. METHODS: A total of 85 patients with recurrent acute uncomplicated urinary tract infection who were referred to the Urology Department at the National University Hospital, Singapore, were prospectively recruited over a 3-year period to complete the validated Short Form 36 Health Survey version 1. In addition, demographic and clinical details including symptomology and medical history were analyzed for factors impacting quality of life. Short Form 36 Health Survey version 1 results were compared with published population norms. RESULTS: After adjusting for age, gender and race, recurrent acute uncomplicated urinary tract infection patients had significantly lower quality of life on seven out of eight Short Form 36 Health Survey version 1 domains when compared with age-, gender- and race-adjusted population norms for Singapore. Among those with recurrent acute uncomplicated urinary tract infection, those who also reported caffeine consumption had significantly lower Short Form 36 Health Survey version 1 scores than those who did not. Those who reported chronic constipation also had consistently lower Short Form 36 Health Survey version 1 scores across all domains. CONCLUSIONS: Recurrent acute uncomplicated urinary tract infection has a negative impact on the quality of life of premenopausal, otherwise healthy women. Recurrent acute uncomplicated urinary tract infection patients who also have chronic constipation or consume caffeine have lower quality of life than those who do not. More studies are required to understand the relationships between these common problems and risk factors.

Screening for asymptomatic bacteruria at one month after adult kidney transplantation: Clinical factors and implications.

OBJECTIVE: Urinary tract infections (UTIs) account for significant morbidity after kidney transplantation (KT). Screening for asymptomatic bacteruria (AB) has proven to be beneficial in certain population including pregnant women; however, it is not well-studied in KT population. We reviewed the incidence, clinical features, and implications of asymptomatic bacteruria one month after KT. METHODS: A total of 171 adult KT patients (86 [50.3%] living transplants, 87 [50.9%] males, mean age 47.3 ± 13.7 years), between 2005 and 2012, were analyzed. Immunosuppression induction and maintenance were as per protocol. Protocol urine cultures were taken at 1 month post-transplantation. Patients were stratified for presence of AB and analyzed for demographics and clinical parameters. Outcomes of hospitalization for symptomatic UTIs, graft, and patient survival were ascertained. RESULTS: Forty-one (24%) KT recipients had AB at 30 days post-transplant. Multiresistant organisms accounted for 43.9% of these infections. Logistic regression confirms female sex and deceased donor recipients as independent predictors of 30-day bacteruria, which predicts subsequent hospitalization for symptomatic UTI. One-year patient and graft survival were similar in recipient with or without AB. CONCLUSION: Asymptomatic bacteruria 30 days post-transplant can be predicted in female recipients and kidneys from deceased donors probably due to anatomical and functional differences respectively. There is increased morbidity of subsequent hospitalization for symptomatic UTI and more research in prevention of UTI is needed, particularly non-antibiotic prophylaxis.

Nephrectomy-induced reduced renal function and the health-related quality of life of living kidney donors.

OBJECTIVE: To evaluate the health impact of nephrectomy on living kidney donors (LKDs) by comparing the health-related quality of life (HrQOL) scores measured by Short Form-36 (SF36) between those with and without postdonation renal function impairment (PRFI). METHODS: Eighty-two LKDs (47 females, mean age=50.2±11.2 years) were prospectively recruited to participate in a SF-36 HrQOL survey. Chart review, individual baseline, and postoperative renal function (eGFR) was determined using the Modification of Diet in Renal Disease formula. PRFI was defined as eGFR<60 mL/min/1.73 m2 or proteinuria. Mean SF-36 domain scores were compared between those with and without PRFI. RESULTS: After a median follow-up of 5.7 years, the prevalence of postdonation comorbidities was 29.3% (n=24) PRFI, 25.6% (n=21) hypertension, 6.1% (n=5) diabetes, and 3.7% (n=3) heart disease, and no LKDs developed end-stage renal disease. Mean eGFR before and after donor nephrectomy was 95.5±23.4 and 71.0±17.3 mL/min/1.73 m2 (P<.01). Mean SF-36 scores of LKDs were not significantly different between those with and without PRFI in all the domains (all P>.05). Similarly, the proportion of LKDs with PRFI did not differ significantly between the patients with SF-36 domain scores above and below the published reference values. CONCLUSION: Nephrectomy-induced PRFI may not have a significant impact on the HrQOL of the LKD population with a low proportion of other major comorbidities such as diabetes and ischemic heart disease.

Preoperative Renal Volume: A Surrogate Measure for Radical Nephrectomy-Induced Chronic Kidney Disease.

OBJECTIVES: Surgically induced chronic kidney disease (CKD) has been found to have less impact on survival as well as function when compared to medical causes for CKD. The aim of this study is to evaluate whether preoperative remaining kidney volume correlates with renal function after nephrectomy, which represents an individual's renal reserve before surgically induced CKD. METHODS: A retrospective review of 75 consecutive patients (29.3% females) who underwent radical nephrectomy (RN) (2000-2010) was performed. Normal side kidney parenchyma, excluding renal vessels and central sinus fat, was manually outlined in each transverse slice of CT image and multiplied by slice thickness to calculate volume. Estimated glomerular filtration rate (eGFR) was determined using the Modification of Diet in Renal Disease equation. CKD is defined as eGFR < 60 mL/min/1.73 m(2). RESULTS: Mean preoperative normal kidney parenchymal volume (mean age 55 [SD 13] years) is 150.7 (SD 36.4) mL. Over median follow-up of 36 months postsurgery, progression to CKD occurred in 42.6% (n = 32) of patients. On multivariable analysis, preoperative eGFR and preoperative renal volume <144 mL are independent predictors for postoperative CKD. On Kaplan-Meier analysis, median time to reach CKD postnephrectomy is 12.7 (range 0.03-43.66) months for renal volume <144 mL but not achieved if renal volume is >144 mL. CONCLUSIONS: Normal kidney parenchymal volume and preoperative eGFR are independent predictive factors for postoperative CKD after RN and may represent renal reserve for both surgically and medically induced CKD, respectively. Preoperative remaining kidney volume may be an adjunct representation of renal reserve postsurgery and predict later renal function decline due to perioperative loss of nephrons.

Molecular profiling reveals a tumor-promoting phenotype of monocytes and macrophages in human cancer progression.

Monocytes and macrophages are major components of the tumor microenvironment, but their contributions to human cancer are poorly understood. We used molecular profiling combined with functional assays to investigate the role of these cells in human renal cell carcinoma (RCC). Blood monocytes from RCC patients displayed a tumor-promoting transcriptional profile that supported functions like angiogenesis and invasion. Induction of this protumor phenotype required an interleukin-1 receptor (IL-1R)-dependent mechanism. Indeed, targeting of IL-1-IL-1R axis in a human RCC xenograft model abrogated the protumor phenotype of tumor-associated macrophages (TAMs) and reduced tumor growth in vivo. Supporting this, meta-analysis of gene expression from human RCC tumors showed IL1B expression to correlate with myelomonocytic markers, protumor genes, and tumor staging. Analyzing RCC patient tumors confirmed the protumor phenotype of TAMs. These data provide direct evidence for a tumor-promoting role of monocytes and macrophages in human cancer and indicate IL-1-IL-1R as a possible therapeutic target.

Postoperative risk of chronic kidney disease in radical nephrectomy and donor nephrectomy patients: a comparison and analysis of predictive factors.

INTRODUCTION: To compare baseline renal function and identify predictive factors in patients undergoing radical nephrectomy (RN) or donor nephrectomy (DN) and their risk of subsequent chronic kidney disease (CKD) after surgery. MATERIALS AND METHODS: A retrospective review of patients with no baseline CKD undergoing RN (n = 88) and DN (n = 58) from 2000 to 2008 was performed. Baseline and postoperative renal function (eGFR) was determined using the Modification of Diet in Renal Disease (MDRD) formula. CKD was defined as eGFR < 60 mL/min/1.73 m2 according to the National Kidney Foundation guidelines. RESULTS: Before surgery, patients undergoing RN and DN had a mean eGFR (+/- SD) of 83.5 +/- 17.4 and 92.9 +/- 17.0 mL/min/1.73 m2 respectively (p = 0.002). Patients with RN had significantly greater morbidities including hypertension (47.7%), diabetes (14.8%) and ischemic heart disease (12.5%) than DN (5.2%, 0% and 1.7% respectively) (all p < 0.05). Median follow up was 3.5 years. The relative hazard of developing CKD post RN compared with DN was 1.91 (95% CI 1.01 to 3.61, p = 0.040). The median time to CKD was 77 months (range 2-107) for RN and 100 months (range 11-105) for DN. Age, gender, comorbidities, radical nephrectomy and baseline kidney function were individual risk factors for CKD post nephrectomy. However, preoperative eGFR was the only independent prognostic factor on multi-variable analysis. CONCLUSIONS: Patients undergoing RN are distinctly different from kidney donors in terms of age, renal function and comorbidities. RN is not an independent predictive factor for CKD but the lower baseline renal function in RN patients significantly accelerates renal senescence in the uninephrectomy state.

Comparison of creatinine based and kidney volume based methods of estimating glomerular filtration rates in potential living kidney donors.

PURPOSE: Accurate assessment of kidney function is critical to evaluate living kidney donors. Direct glomerular filtration rate measurement using isotopes is currently the gold standard but it is complex and costly. We evaluated the performance of surrogate markers of the glomerular filtration rate in living kidney donors by comparing direct measurement of the rate to the creatinine based equation estimated rate, the kidney volume based estimated rate using a newly developed equation and creatinine clearance. MATERIALS AND METHODS: We first statistically compared direct glomerular filtration rate measurement to the results of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) creatinine based equations, and to creatinine clearance in 54 potential renal donors from 2006 to 2010. In 32 donors with cross-sectional computerized tomography available we used measured functional renal volume with age, gender, weight and serum creatinine to estimate the rate based on kidney volume according to a previously reported model. Kidney volume based measurement was compared to direct glomerular filtration rate measurement and assessed against the results of the best performing creatinine based equation. RESULTS: In the first group of 54 donors the correlation index of the estimated glomerular filtration rate according to MDRD and CKD-EPI creatinine based equations, and to creatinine clearance was low compared to direct measurement. In the subset of 32 potential donors the kidney volume based estimated rate correlated better with direct measurement than MDRD equation results with higher accuracy (estimated 87.5% and 75.0% within 30% and 10% of direct rate measurement, respectively). CONCLUSIONS: To estimate the glomerular filtration rate in healthy individuals a volume based model correlated better than the MDRD equation, which is the best performing creatinine based equation used to estimate the rate. By providing a more robust estimation of the glomerular filtration rate in healthy potential kidney donors, the volume based model adds value to routine preoperative computerized tomography above that of anatomical evaluation.

Impact of Kidney Disease Outcomes Quality Initiative guidelines on the prevalence of chronic kidney disease after living donor nephrectomy.

PURPOSE: We evaluated the prevalence of chronic kidney disease stage 3 or worse based on the National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines after living kidney donation at a single institution. MATERIALS AND METHODS: The collected data of 86 consecutive patients who underwent uneventful donor nephrectomy between 1987 and 2008 were evaluated retrospectively. Estimated glomerular filtration rate was determined using the Modification of Diet in Renal Disease from serum creatinine levels collected before and after surgery in kidney donor followup clinics. Chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 ml/minute/1.73 m(2) according to the Kidney Disease Outcomes Quality Initiative guidelines. Cox regression analyses were then used to determine the impact of predictors on the development of chronic kidney disease. RESULTS: All donors (mean age 41.2, SD 9.9 years) had a mean preoperative estimated glomerular filtration rate of 88.7 ml/min/1.73 m(2) (SD 16.3). Median followup was 6.4 years (range 0.9 to 21.0). Progression to stage 3 or worse chronic kidney disease was seen in 24.4% (95% CI 15.2-33.7) of patients. There were 2 patient deaths secondary to cancer and none required dialysis. Multivariable analysis showed that preoperative estimated glomerular filtration rate less than 82 ml/minute/1.73 m(2) was an independent risk factor for post-donation chronic kidney disease. For every 1 ml/minute/1.73 m(2) increase in baseline estimated glomerular filtration rate, the hazard of postoperative chronic kidney disease was reduced by 7% (HR 0.93, 95% CI 0.89-0.97, p = 0.001). CONCLUSIONS: Kidney Disease Outcomes Quality Initiative stage 3 chronic kidney disease or worse occurs in 24.4% of kidney donors. Long-term prospective studies and closer followup of donors are needed to identify its implications, given the associated risk of cardiovascular diseases with chronic kidney disease in the general population.

Road traffic accident mortality in Singapore.

The aim of this study was to identify factors that contribute to road traffic accident mortality and the patterns of injuries sustained by these victims, with a view to identifying areas for future intervention. All road traffic accident deaths that occurred in Singapore over a period of 1 year were reviewed. A total of 226 deaths occurred: 82.3% of the victims were male. The median age was 31 years. Blood alcohol was detected in 42 (18.7%) victims. In general, head (86.7%), followed by thoracic (67.7%) and abdominal (31.4%) injuries, were the most common injuries. Severe lower extremity trauma was most common among pedestrians and pedal cyclists (20.6% and 11.0%, respectively). The mean Injury Severity Score was 38.7. The relative risk of mortality between motorcyclists and motorcar drivers was 18.8:1. Suggestions for future prevention and intervention include stricter enforcement of speed limits, more severe penalties for drunk driving, helmet use among pedal cyclists, and the introduction of pre-hospital advanced airway management.