Comparison of Urine Flow Cytometry on the UF-1000i System and Urine Culture of Urine Samples from Urological Patients

<b><i>Introduction:</i></b> The aims of this study were to evaluate urine flow cytometry (UFC) as a tool to screen urine samples of urological patients for bacteriuria and to compare UFC and dipstick analysis with urine culture in a patient cohort at a urological department of a university hospital. <b><i>Methods and Material:</i></b> We screened 662 urine samples from urological patients (75.2% male; 80.7% inpatients; mean age 58 years). UFC results were compared to microbiological urine culture. <b><i>Results:</i></b> The accuracy in using the UFC-based parameters for detecting cultural bacteriuria was 91.99% and 88.97% for ≥10⁵ colony-forming units (CFU)/mL and ≥10⁴ CFU/mL, respectively. UFC and leukocyte dipstick analysis measured leukocyturia similarly (Pearson correlation coefficient 0.87, <i>p</i> value &#x3c;0.01%), but dipstick analysis scored less accurately on bacteriuria (accuracy 59.37% and 62.69%). UFC remained effective in subgroup analysis of patients of both sexes and with different urological conditions with its overall use only slightly impaired when assessing gross hematuria (NPV 84.62% for ≥10⁴ CFU/mL). UFC also reliably removed those urine samples below cutoffs with negative predictive values of 99.28% for ≥10⁵ CFU/mL and 95.86% for ≥10⁴ CFU/mL. <b><i>Conclusion:</i></b> Counting bacteria with UFC is an accurate and rapid method to determine significant bacteriuria in urological patients and is superior to dipstick analysis or indirect surrogate parameters such as leukocyturia. When UFC is available, we recommend it to be used for the diagnosis of bacteriuria over findings obtained by dipstick analysis.

Possibilities of peripheral magnetic neuromodulation in the treatment of lower urinary tract symptoms in men

Introduction. Lower urinary tract symptoms (LUTS) are common in men and are associated with a significant decrease in quality of life. To date, there is no universal approach to the treatment of LUTS, which determines the need to search for new methods for influencing the lower urinary tract.Purpose of the study. To test the hypothesis that the use of peripheral magnetic neuromodulation (PMN) in male patients with LUTS will reduce the severity of LUTS.Materials and methods. Sixty-eight men with LUTS were enrolled in a prospective, randomized study. Patients were randomized in a 1:1 ratio for PMN or drug therapy with an alpha-1-blocker (tamsulosin). The primary endpoint was a reduction the LUTS severity such as urinary frequency during the day, nocturia and urgency as assessed using the IPSS questionnaire and urination diary. Improvements in urodynamic parameters such as maximum urine flow rate (Q max), mean urine flow rate (Q ave), and residual urine volume (PVR) were the secondary endpoint of the study. The results were evaluated on equal terms (10 days and 1 month) in both groups.Results. Sixty-seven (98.5%) subjects were included in the final base. Ten days after the start of therapy in the magnetic stimulation group, symptom relief was noted by 21 people (61.7%), the mean IPSS score showed a decrease from 18.1 ± 2.1 to 16.9 ± 3.2 points (p = 0.037). The number of urinations per day decreased from 14 (6 - 20) to 10 (6 - 14) times (p < 0.001). Objective indicators of urodynamics did not change in both groups. At a period of 1 month, PMN occurred in 22 (64.7%) patients, the IPSS score was 16.6 ± 3.7 points (p = 0.032), the number of urinations 9 (6 - 14) times (p < 0.001). Objective indicators have not changed. In the tamsulosin group, IPSS score changed from 19.27 ± 5.08 to 15.4 ± 4.85 (p < 0.001), Q max 14.36 ± 2.82 ml/s increased to 15.94 ± 2.71 ml/s (p = 0.032), while the Q ave did not change (p = 0.17). The number of urinations decreased from 13 (6 - 19) times to 10 (6 - 14) times (p <0.001).Conclusion. The study demonstrated the promise of PMN in men with LUTS in terms of improving the quality of life. The proposed method may be preferable for patients dissatisfied with drug therapy. Further placebo-controlled studies are required to help determine the role of PMN in the management of patients with LUTS.

Mathematical postprocessing analysis of contrast-enhanced computed tomography data of the kidneys in evaluation of split renal function in patients with kidney stone disease

Introduction. An original research work was performed to assess split kidney function by glomerular filtration rate (GFR) with mathematical analysis of the kidneys computed tomography (CT) data in patients with kidney stone disease (KSD). Objective was to evaluate the GFR and the parenchyma structure of each kidney and identify the possible patterns of contrast medium intrarenal transport with mathematical analysis of the kidneys CT data in patients with KSD.Materials and methods. Data of 27 patients of both genders with KSD were retrospectively analyzed. To evaluate GFR separately for each kidney we analyzed the data of contrast-enhanced CT (GFR reference values are 0.55 % of contrast medium per second). Inclusion criteria are as follows: 1) newly diagnosed SKD; 2) stone size ≤1,5-2,0 cm, no obstruction of the urine flow registered; 3) no kidney or upper urinary tract surgical history; 4) age - ≤45 years; 5) no severe chronic diseases. All of these allowed to minimize influence of any other disorders on split renal function except for SKD and conduct per se research.Results. The mathematic analysis of the contrast-enhanced CT data revealed GFR changes in 26 (96.3 %) out of 27 patients. Hyperfiltration was found in 12 (44.4 %) patients: right kidney GFR - 0.6-0.77 %, mean value - 0.65 %; left kidney GFR - 0.59-0.79 %, mean value - 0.67 %. Hypofiltration was found in 13 (48.1 %) patients: right kidney GFR - 0.2-0.54 %, mean value - 0.37 %; left kidney GFR - 0.2-0.53 %, mean value - 0.4 %. The GFR values significantly differed between the groups both for the right (p = 0.000014) and left (p = 0.000045) kidneys. We found no significant age-related difference between the groups (p = 0.895). As well as that no significant differences in Resistance Index both in magistral (right kidney: p = 0.221; left kidney: p = 0.850) and segmental (right kidney: p = 0.306; left kidney: p = 0.957) arteries between the groups with hyperfiltration and hypofiltration were observed. One patient demonstrated no changes in GFR, and the other one had hyperfiltration (0,62 %) in one kidney and hypofiltration (0,48 %) in another.Conclusion. Most of the patients (92.6 %) with SKD demonstrate GFR changes (either hyperfiltration or hypofiltration) that may indicate the disturbed intrarenal blood and urine flow through the kidney.

PBPK Simulation-Based Evaluation of Ganciclovir Crystalluria Risk Factors: Effect of Renal Impairment, Old Age, and Low Fluid Intake

Dosing guidance is often lacking for chronic kidney disease (CKD) due to exclusion of such patients from pivotal clinical trials. Physiologically based pharmacokinetic (PBPK) modelling supports model-informed dosing when clinical data are lacking, but application of these approaches to patients with impaired renal function is not yet at full maturity. In the current study, a ganciclovir PBPK model was developed for patients with normal renal function and extended to CKD population. CKD-related changes in tubular secretion were explored in the mechanistic kidney model and implemented either as proportional or non-proportional decline relative to GFR. Crystalluria risk was evaluated in different clinical settings (old age, severe CKD and low fluid intake) by simulating ganciclovir medullary collecting duct (MCD) concentrations. The ganciclovir PBPK model captured observed changes in systemic pharmacokinetic endpoints in mild-to-severe CKD; these trends were evident irrespective of assumed pathophysiological mechanism of altered active tubular secretion in the model. Minimal difference in simulated ganciclovir MCD concentrations was noted between young adult and geriatric populations with normal renal function and urine flow (1 mL/min), with lower concentrations predicted for severe CKD patients. High crystalluria risk was identified at reduced urine flow (0.1 mL/min) as simulated ganciclovir MCD concentrations exceeded its solubility (2.6–6 mg/mL), irrespective of underlying renal function. The analysis highlighted the importance of appropriate distribution of virtual subjects’ systems data in CKD populations. The ganciclovir PBPK model illustrates the ability of this translational tool to explore individual and combined effects of age, urine flow, and renal impairment on local drug renal exposure. Graphical Abstract

Use of Sysmex UF-5000 flow cytometry in rapid diagnosis of urinary tract infection and the importance of validating carryover rates against bacterial count cut-off

Introduction. Urinary tract infections are common bacterial infections worldwide. Urine culture is the gold standard method to identify and quantify the presence or absence of bacteria in urine. Flow cytometry, which can differentiate and quantify multiple particles (including bacteria) in the urine, presents an alternative method for rapid screening to rule out bacteriuria. Hypothesis. Adding flow cytometry to identify urine samples without bacteriuria could substantially reduce the number of urine samples that need to be cultured as well as the response time for negative results. However, the level of instrument rinsing between samples could affect sample-to-sample carryover rate, a concept given little attention in previous studies. Aim. We aimed to evaluate urine flow cytometry as a rapid screening method to identify urine samples without significant bacterial growth, including analyses of cross-contamination and sample-to-sample carryover rate. Methodology. We analysed 3919 urine samples by quantitative urine culture and flow cytometry screening (Sysmex UF-5000). Receiver operator characteristic (ROC) curve analyses were used to test method agreement to identify: (a) positive vs. negative culture and (b) mixed vs. pure culture. In addition, we performed carryover and cross-contamination studies. Results. ROC curve analyses identified bacterial count (BACT ml−1) and leucocyte count (WBC µl−1) as possible predictors of bacterial growth in the total material and subpopulations, except pregnant women (n=451). This subgroup was excluded from further analyses, leaving a final 3468 urine samples. Area under the ROC curve was 0.94 (95 % CI 0.93–0.95) and 0.81 (95 % CI 0.79–0.82) for bacterial and leucocyte count, respectively. A bacterial count cut-off of 30 BACT ml−1 resulted in 95.2 % sensitivity and 91.2 % negative predictive value, resulting in approximately 30 % of urine samples that could be reported as negative without culture. Use of high-level rinse modes was necessary to ensure carryover rates <0.05 %. Conclusion. Flow cytometry is a suitable and rapid method to rule out urine samples without significant bacterial growth. Rinses between samples should be adjusted, depending on the cut-off used, to prevent sample-to-sample carryover, whereas cross-contamination can be eliminated by the use of separate urine aliquots for flow cytometry analysis and urine culturing respectively.

Role of Renal Sympathetic Nerves in GLP‐1 (Glucagon‐Like Peptide‐1) Receptor Agonist Exendin‐4‐Mediated Diuresis and Natriuresis in Diet‐Induced Obese Rats

Background The gut‐derived hormone GLP‐1 (glucagon‐like peptide‐1) exerts beneficial effects against established risk factors for chronic kidney disease. GLP‐1 influences renal function by stimulating diuresis and natriuresis and thus lowering arterial blood pressure. The role of the sympathetic nervous system has been implicated as an important link between obesity with elevated arterial pressure and chronic kidney disease. The primary aim of this study was to determine the contribution of renal sympathetic nerves on intrapelvic GLP‐1‐mediated diuresis and natriuresis in high‐fat diet (HFD)‐induced obese rats. Methods and Results Obesity was induced in rats by HFD for 12 weeks, followed by either surgical bilateral renal denervation or chronic subcutaneous endopeptidase neprilysin inhibition by sacubitril for a week. Diuretic and natriuretic responses to intrapelvic administration of the GLP‐1R (GLP‐1 receptor) agonist exendin‐4 were monitored in anesthetized control and HFD rats. Renal GLP‐1R expression and neprilysin expression and activity were measured. The effects of norepinephrine on the expression of GLP‐1R and neprilysin in kidney epithelial LLC‐PK1 cells were also examined. We found that diuretic and natriuretic responses to exendin‐4 were significantly reduced in the HFD obese rats compared with the control rats (cumulative urine flow at 40 minutes, 387±32 versus 650±65 µL/gkw; cumulative sodium excretion at 40 minutes, 42±5 versus 75±10 µEq/gkw, P <0.05). These responses in the HFD rats were restored after ablation of renal nerves (cumulative urine flow at 40 minutes, 625±62 versus 387±32 µL/gkw; cumulative sodium excretion at 40 minutes, 70±9 versus 42±5 µEq/gkw, P <0.05). Renal denervation induced significant reductions in arterial pressure and heart rate responses to intrapelvic GLP‐1 in the HFD rats. Renal denervation also significantly increased the GLP‐1R expression and reduced neprilysin expression and activity in renal tissues from the HFD rats. Chronic subcutaneous neprilysin inhibition by sacubitril increased GLP‐1–induced diuretic and natriuretic effects in the HFD rats. Finally, exposure of the renal epithelial cells to norepinephrine in vitro led to downregulation of GLP‐1R expression but upregulation of neprilysin expression and activity. Conclusions These results suggest that renal sympathetic nerve activation contributes to the blunted diuretic and natriuretic effects of GLP‐1 in HFD obese rats. This study provides significant novel insight into the potential renal nerve–neprilysin–GLP‐1 pathway involved in renal dysfunction during obesity that leads to hypertension.

Improved diagnostics of infectious diseases in emergency departments: a protocol of a multifaceted multicentre diagnostic study

BackgroundThe major obstacle in prescribing an appropriate and targeted antibiotic treatment is insufficient knowledge concerning whether the patient has a bacterial infection, where the focus of infection is and which bacteria are the agents of the infection. A prerequisite for the appropriate use of antibiotics is timely access to accurate diagnostics such as point-of-care (POC) testing.The study aims to evaluate diagnostic tools and working methods that support a prompt and accurate diagnosis of hospitalised patients suspected of an acute infection. We will focus on the most common acute infections: community-acquired pneumonia (CAP) and acute pyelonephritis (APN). The objectives are to investigate (1) patient characteristics and treatment trajectory of the different acute infections, (2) diagnostic and prognostic accuracy of infection markers, (3) diagnostic accuracy of POC urine flow cytometry on diagnosing and excluding bacteriuria, (4) how effective the addition of POC analysis of sputum to the diagnostic set-up for CAP is on antibiotic prescriptions, (5) diagnostic accuracy of POC ultrasound and ultralow dose (ULD) computerized tomography (CT) on diagnosing CAP, (6) diagnostic accuracy of specialist ultrasound on diagnosing APN, (7) diagnostic accuracy of POC ultrasound in diagnosing hydronephrosis in patients suspected of APN.Methods and analysisIt is a multifaceted multicentre diagnostic study, including 1000 adults admitted with suspicion of an acute infection. Participants will, within the first 24 hours of admission, undergo additional diagnostic tests including infection markers, POC urine flow cytometry, POC analysis of sputum, POC and specialist ultrasound, and ULDCT. The primary reference standard is an assigned diagnosis determined by a panel of experts.Ethics, dissemination and registrationApproved by Regional Committees on Health Research Ethics for Southern Denmark, Danish Data Protection Agency and clinicaltrials.gov. Results will be presented in peer-reviewed journals, and positive, negative and inconclusive results will be published.Trial registration numbersNCT04661085, NCT04681963, NCT04667195, NCT04652167, NCT04686318, NCT04686292, NCT04651712, NCT04645030, NCT04651244.

Abstract P247: Elastin Insufficiency Impairs Renal Hemodynamics And Accelerates Aging-associated Structural And Functional Remodeling Of Preglomerular Arterioles

Elastin degradation and fragmentation are hallmarks of arterial stiffness and renal dysfunction associated with aging. However, it is unclear whether elastin insufficiency contributes to the changes in the structure and function of the resistance vasculature of the kidney during aging. Here we determined how increased vascular stiffness due to elastin insufficiency alters renal hemodynamics and mechanical properties of preglomerular arterioles. We assessed renal hemodynamics under anesthesia in 14-16-month-old female wild type (WT) and elastin heterozygous ( Eln +/- ) mice. Renal autoregulation was assessed by a stepwise increase in renal perfusion pressure (RPP) by simultaneously occluding the superior mesenteric and celiac arteries. Myogenic constriction and arterial stiffness were assessed by pressure myography of isolated renal interlobar arteries. Baseline renal vascular resistance (RVR) was elevated in Eln +/- mice (13.8 ± 2.9 vs 11.2 ± 1.4 mmHg/μL/min/g left kidney weight), while systolic blood pressure (SBP; 75.1 ± 7.4 vs 91 ± 4.2mmHg), renal blood flow (RBF; 6.3 ± 1.2 vs 7.4 ± 1.7 μL/min/g left kidney weight), renal plasma flow (RPF; 3.4 ± 0.8 vs 5 ± 1.2 mL/min/g/ left kidney weight) and urine flow rate, all trended lower in Eln +/- mice compared to WT mice. Glomerular filtration rate (GFR) and filtration fraction (FF) were similar between the two groups. A stepwise increase in RPP caused a slower decline and rise in RBF and RVR, respectively, in Eln +/- relative to WT mice. The maximal changes in RBF (5 ± 1.1 vs 4.7 ± 0.8 μL/min/g left kidney weight), RVR (17.6 ± 7.3 vs 22.5 ± 2.1 mmHg/μL/min/g left kidney weight), urine flow rate,GFR, and FF were less robust in Eln +/- mice. RPF decreased in WT mice in response to raising RPP, whereas it remained unchanged in Eln +/- mice. Myogenic response and increases in elastic modulus and wall tension following stepwise changes in intraluminal pressure were all augmented in interlobar arteries from Eln +/- relative to WT mice. However, there was no difference in kidney weight/tibia length ratio between the two genotypes. We conclude that elastin insufficiency impairs renal hemodynamics by exacerbating age associated increase in vascular stiffness.