Use of Droplet Digital Polymerase Chain Reaction to Identify Biomarkers for Differentiation of Benign and Malignant Renal Masses.

Several microRNAs (miRNAs) have been identified as cell-free biomarkers for detecting renal cell carcinoma (RCC). Droplet digital polymerase chain reaction (ddPCR) is a unique technology for nucleic acid quantification. It has the potential for superior precision, reproducibility, and diagnostic performance in identifying circulating miRNA biomarkers compared to conventional quantitative real-time PCR (qRT-PCR). This study aims to evaluate the performance of ddPCR compared to qRT- PCR in identifying miRNA biomarkers that differentiate malignant from benign renal masses. Potential biomarkers of RCC were identified from a literature review. RNA was extracted from the plasma of 56 patients. All the samples underwent analysis via ddPCR as well as qRT-PCR, and expression levels were recorded for the following miRNAs: miR-93, -144, -210, -221, and -222. Tumors were grouped into low-grade ccRCC, high-grade ccRCC, papillary RCC, and benign masses (primarily angiomyolipoma). The miRNA miR-210 (p = 0.034) and the combination of miRs-210 and miR-222 (p = 0.003) were expressed at significantly higher rates among those with RCC than those with benign masses, as measured by ddPCR. Using the combination of miR-210 and miR-222, ddPCR identified significant differences between the subgroups: papillary RCC versus benign (p = 0.03), low-grade ccRCC versus benign (p = 0.026), and high-grade ccRCC versus benign (p = 0.002). The only significant difference between these subgroups using qRT-PCR was between high-grade ccRCC and benign (p = 0.045). All the AUCs were significant when comparing each RCC subgroup with benign for both PCR technologies. Using a combination of miR-210 and miR-222, ddPCR identified significant differences between benign and malignant renal masses that were not identified as significant by conventional qRT-PCR.

Optimal carcinoembryonic antigen (CEA) cutoff values in the diagnosis of neoplastic mucinous pancreatic cysts differ among assays.

AIM: Pancreatic cyst fluid carcinoembryonic antigen (CEA) is a pivotal test in the diagnosis and management of neoplastic mucinous cysts (NMC) of the pancreas. Cyst fluid CEA levels of 192 ng/mL have been widely used to identify NMC. However, CEA values are unique to and significantly differ between individual assays with various optimal cutoffs reported in the literature for NMC. Here, we investigate the optimal CEA cut-off value of pancreatic cysts from two different assays to identify differences in thresholds. METHODS: Pancreatic cyst fluid CEA levels, CEA assay platform (Beckman Dxl (BD) or Siemens Centaur XP (SC)), and clinical/pathological information were retrospectively collected. Cases were categorised into either NMC or non-NMC. Optimal CEA cut-off values were calculated via a receiver operator characteristic curve. Cut-off values were then identified separately by assay platform. RESULTS: In total, 149 pancreatic cystic lesions with concurrent CEA values (SC: n=47; BD: n=102) were included. Histological correlation was available for 26 (17%) samples. The optimal CEA cut-off value for all samples at the study institution was 45.9 ng/mL (area under the curve (AUC)=86, Sn=85.7%, Sp=73.8%). When analysed separately by CEA assay, the cut-off values were 45.9 ng/mL (AUC=84.27, Sn=89.7%, Sp=71.4%) for BD and 24.4 ng/mL (AUC=77, Sn=81.8%, Sp=75%) for SC (p=0.48). CONCLUSIONS: This study showed an optimal pancreas cyst CEA cut-off threshold of 45.9 ng/mL, which is lower than commonly cited literature with different cutoffs on the two separate platforms (BD: 45.9 ng/mL, SC: 24.4 ng/mL).

A Phenylboronic Acid-Based Transition State Analogue Yields Nanomolar Inhibition of Mandelate Racemase.

Mandelate racemase (MR) catalyzes the Mg2+-dependent interconversion of (R)- and (S)-mandelate by stabilizing the altered substrate in the transition state (TS) by ∼26 kcal/mol. The enzyme has been employed as a model to explore the limits to which the free energy of TS stabilization may be captured by TS analogues to effect strong binding. Herein, we determined the thermodynamic parameters accompanying binding of a series of bromo-, chloro-, and fluoro-substituted phenylboronic acids (PBAs) by MR and found that binding was predominately driven by favorable entropy changes. 3,4-Dichloro-PBA was discovered to be the most potent inhibitor yet identified for MR, binding with a Kdapp value of 11 ± 2 nM and exceeding the binding of the substrate by ∼72,000-fold. The ΔCp value accompanying binding (-488 ± 18 cal·mol-1 K-1) suggested that dispersion forces contribute significantly to the binding. The pH-dependence of the inhibition revealed that MR preferentially binds the anionic, tetrahedral form of 3,4-dichloro-PBA with a pH-independent Ki value of 5.7 ± 0.5 nM, which was consistent with the observed upfield shift of the 11B NMR signal. The linear free energy relationship between log(kcat/Km) and log(1/Ki) for wild-type and 11 MR variants binding 3,4-dichloro-PBA had a slope of 0.8 ± 0.2, indicating that MR recognizes the inhibitor as an analogue of the TS. Hence, halogen substitution may be utilized to capture additional free energy of TS stabilization arising from dispersion forces to enhance the binding of boronic acid inhibitors by MR.

Application of circular dichroism-based assays to racemases and epimerases: Recognition and catalysis of reactions of chiral substrates by mandelate racemase.

Racemases and epimerases have attracted much interest because of their astonishing ability to catalyze the rapid α-deprotonation of carbon acid substrates with high pKa values (∼13-30) leading to the formation of d-amino acids or various carbohydrate diastereomers that serve important roles in both normal physiology and pathology. Enzymatic assays to measure the initial rates of reactions catalyzed by these enzymes are discussed using mandelate racemase (MR) as an example. For MR, a convenient, rapid, and versatile circular dichroism (CD)-based assay has been used to determine the kinetic parameters accompanying the MR-catalyzed racemization of mandelate and alternative substrates. This direct, continuous assay permits real time monitoring of reaction progress, the rapid determination of initial velocities, and immediate recognition of anomalous behaviors. MR recognizes chiral substrates primarily through interactions of the phenyl ring of (R)- or (S)-mandelate with the hydrophobic R- or S-pocket at the active site, respectively. During catalysis, the carboxylate and α-hydroxyl groups of the substrate remain fixed in place through interactions with the Mg2+ ion and multiple H-bonding interactions, while the phenyl ring moves between the R- and S-pockets. The minimal requirements for the substrate appear to be the presence of a glycolate or glycolamide moiety, and a hydrophobic group of limited size that can stabilize the carbanionic intermediate through resonance or strong inductive effects. Similar CD-based assays may be applied to determine the activity of other racemases or epimerases with proper consideration of the molar ellipticity, wavelength, overall absorbance of the sample, and the light pathlength.

AACC Guidance Document on the Clinical Use of Procalcitonin.

BACKGROUND: Procalcitonin (PCT), a peptide precursor of the hormone calcitonin, is a biomarker whose serum concentrations are elevated in response to systemic inflammation caused by bacterial infection and sepsis. Clinical adoption of PCT in the United States has only recently gained traction with an increasing number of Food and Drug Administration-approved assays and expanded indications for use. There is interest in the use of PCT as an outcomes predictor as well as an antibiotic stewardship tool. However, PCT has limitations in specificity, and conclusions surrounding its utility have been mixed. Further, there is a lack of consensus regarding appropriate timing of measurements and interpretation of results. There is also a lack of method harmonization for PCT assays, and questions remain regarding whether the same clinical decision points may be used across different methods. CONTENT: This guidance document aims to address key questions related to the use of PCT to manage adult, pediatric, and neonatal patients with suspected sepsis and/or bacterial infections, particularly respiratory infections. The document explores the evidence for PCT utility for antimicrobial therapy decisions and outcomes prediction. Additionally, the document discusses analytical and preanalytical considerations for PCT analysis and confounding factors that may affect the interpretation of PCT results. SUMMARY: While PCT has been studied widely in various clinical settings, there is considerable variability in study designs and study populations. Evidence to support the use of PCT to guide antibiotic cessation is compelling in the critically ill and in some lower respiratory tract infections but is lacking in other clinical scenarios, and evidence is also limited in the pediatric and neonatal populations. Interpretation of PCT results requires guidance from multidisciplinary care teams of clinicians, pharmacists, and clinical laboratorians.

The Roles of miRNAs in Predicting Bladder Cancer Recurrence and Resistance to Treatment.

Bladder cancer (BCa) is associated with significant morbidity, with development linked to environmental, lifestyle, and genetic causes. Recurrence presents a significant issue and is managed in the clinical setting with intravesical chemotherapy or immunotherapy. In order to address challenges such as a limited supply of BCG and identifying cases likely to recur, it would be advantageous to use molecular biomarkers to determine likelihood of recurrence and treatment response. Here, we review microRNAs (miRNAs) that have shown promise as predictors of BCa recurrence. MiRNAs are also discussed in the context of predicting resistance or susceptibility to BCa treatment.

Biomarkers in Urethral Stricture Disease and Benign Lower Urinary Tract Disease.

Increased understanding of molecular pathophysiology has led to the detection of clinically applicable biomarkers across medicine, which allow for minimally invasive detection, management, and monitoring of disease processes. Although biomarkers have traditionally played a more significant role in malignancy, these goals also pertain to benign disease. Herein, the authors review ongoing research into biomarker investigation and application in urethral stricture disease, benign prostatic hyperplasia, bladder outlet obstruction, and overactive bladder. No biomarkers for these entities are currently in clinical use; however, numerous physiologic pathways provide targets for current and future study.

Outcomes of an Algorithmic, Multidisciplinary Approach to Rectourethral Fistula Repair: A Pre- and Postintervention Quasi-Experimental Study.

BACKGROUND: Rectourethral fistulas are a rare yet severe complication of prostate surgery, pelvic irradiation therapy, or both. Multiple surgical repairs exist with widely varying success rates. OBJECTIVE: This study aimed to present our institutional multidisciplinary algorithm for rectourethral fistula repair and its outcomes. DESIGN: This was a retrospective, pre- and postintervention, quasi-experimental design, comparing the frequency of fistula healing and reversal of urinary and fecal diversion before and after implementation of our algorithm. SETTING: All patients who presented to the Duke University with rectourethral fistula between 2002 and 2019 were included. PATIENTS: This study included 79 patients treated for rectourethral fistula: 36 prealgorithm and 43 postalgorithm. INTERVENTIONS: Our multidisciplinary algorithm was implemented in 2012. Patients with fistulas <2 cm and without history of radiation therapy underwent York-Mason repair, whereas those with fistulas 2-3 cm or with prior irradiation underwent transperineal repair with gracilis flap interposition. Those with nonrepairable fistulas (>3 cm or fixed tissues) underwent pelvic exenteration. Before repair, the algorithm recommended all patients to undergo urinary and bowel diversion. MAIN OUTCOME MEASURES: The 2 primary outcomes were rectourethral fistula healing, defined as both radiographic and clinical resolutions, and reversal of urinary and fecal diversions. RESULTS: Frequency of fistula healing improved in the post- versus prealgorithm subgroups (93.1% vs 71.9%; p = 0.04). The relative risk of fistula healing pre- versus postintervention was 0.77 (0.61-0.98; p = 0.04) among the overall cohort. Eighteen patients (22.8%) underwent pelvic exenteration for nonrepairable fistulas and were not included in primary outcome measures. LIMITATIONS: Limitations include the study's retrospective nature, possible selection bias because of algorithmic patient selection, and small sample size. CONCLUSIONS: Implementation of a multidisciplinary institutional algorithm improved rectourethral fistula repair success with high rates of ostomy reversal. Proper patient selection and multidisciplinary involvement are paramount to this success. See Video Abstract at http://links.lww.com/DCR/B955 . RESULTADOS DE UN ABORDAJE ALGORTMICO Y MULTIDISCIPLINARIO PARA LA REPARACIN DE FSTULAS RECTOURETRALES UN ESTUDIO CUASIEXPERIMENTAL PREVIO Y POSTERIOR A LA INTERVENCIN: ANTECEDENTES:Las fístulas rectouretrales son una complicación rara pero grave de la cirugía de próstata, la radiación pélvica o ambas. Existen múltiples reparaciones quirúrgicas con tasas de éxito muy variables.OBJETIVO:Presentar el algoritmo multidisciplinario de nuestra institución para la reparación de fístulas rectouretrales y sus resultados.DISEÑO:Este fue un diseño retrospectivo, previo y posterior a la intervención, cuasiexperimental, que comparó la frecuencia de curación de la fístula y la reversión de la derivación urinaria y fecal antes y después de la implementación de nuestro algoritmo.ESCENARIO:Se incluyeron todos los pacientes que acudieron a Duke con fístula rectouretral entre 2002 y 2019.PACIENTES:Setenta y nueve pacientes fueron tratados por fístula rectouretral; 36 pre-algoritmo y 43 post-algoritmo.INTERVENCIONES:Nuestro algoritmo multidisciplinario se implementó en 2012. Los pacientes con fístulas <2 cm y sin antecedentes de radiación se sometieron a reparación de York-Mason, mientras que aquellos con fístulas de 2-3 cm o radiación pélvica previa se sometieron a reparación transperineal con interposición de colgajo de gracilis. Aquellos con fístulas no reparables (> 3 cm o tejidos fijos) fueron sometidos a exenteración pélvica. Antes de la reparación, el algoritmo recomomendó que todos los pacientes se sometieran a una derivación urinaria y fecal.PRINCIPALES MEDIDAS DE RESULTADO:Los dos resultados primarios fueron la curación de la fístula rectouretral, definida como la resolución radiográfica y clínica, y la reversión de las derivaciones urinaria y fecale.RESULTADOS:La frecuencia de curación de la fístula mejoró en el subgrupo post-algoritmo vs. pre-algoritmo (93.1% vs. 71.9%, p = 0.04). El riesgo relativo de curación de la fístula antes de la intervención en comparación con después de la intervención fue de 0.77 (0.61-0.98, p = 0.04) entre la cohorte general. Dieciocho pacientes (22.8%) se sometieron a exenteración pélvica por fístulas no reparables y, por lo tanto, no se incluyeron en las medidas de resultado primarias.LIMITACIONES:Las limitaciones de este estudio incluyen su naturaleza retrospectiva, posible sesgo de selección debido a la selección algorítmica de pacientes y un tamaño de muestra pequeño.CONCLUSIONES:La implementación de un algoritmo institucional multidisciplinario mejoró el éxito en la reparación de la fístula rectouretral con altas tasas de reversión de la ostomía. La selección adecuada de pacientes y la participación multidisciplinaria son fundamentales para este éxito. Consulte Video Resumen en http://links.lww.com/DCR/B955 . (Traducción-Dr. Jorge Silva Velazco ).

Patient-Reported and Physiologic Outcomes Following Pelvic Exenteration for Non-Repairable Radiated Rectourethral Fistula.

OBJECTIVE: To investigate the impact of pelvic exenteration (PelvEX) on patient-reported pain, distress, and quality of life along with physiologic indicators of health in cancer survivors with radiated, non-repairable rectourethral fistula (RUF). MATERIALS AND METHODS: We reviewed a prospectively maintained quality improvement database of RUF patients at our institution from 2012 to 2020. Patients with radiated, non-repairable RUF who underwent PelvEX and had follow up to 1 year were included. Pain and distress scores were collected preoperatively and at 1-year follow up. Number of narcotic prescriptions in the 3 months before surgery and the year after surgery were abstracted. Short Form 12 surveys were administered in the postoperative period. Serum albumin, creatinine, carbon dioxide, hematocrit, and glucose were abstracted from electronic health records. Statistical analysis was performed using Wilcoxon signed-rank and Mann-Whitney tests. RESULTS: Eleven patients met inclusion criteria. Patient-reported pain significantly decreased at 1 year follow-up compared to preoperative scores (median pre: 4 vs 1 year post: 0, P = .0312). Patient-reported distress significantly decreased pre- versus post-PelvEX (median pre: 5 vs post: 0, P = .0156). At the time of postoperative pain and distress surveys, 9 (82.8%) patients did not have narcotic prescriptions. Postoperative Short Form 12 scores were similar to an age-matched United States population (mental: P = .3125; physical: P = .1484). Serum-based indicators of health were not different in the pre- versus postoperative period (all P >.05). CONCLUSION: PelvEX may be a valuable treatment option to decrease patient-reported pain and distress without compromising quality of life or physiologic health in patients with radiated, non-repairable RUF.

Challenged comparison of tacrolimus assays.

Monitoring tacrolimus trough concentrations is important for optimal immunosuppression in solid organ transplant recipients. Available assays generally correlate well with each other but little attention is given to patients in whom tacrolimus metabolite concentrations might be elevated, which could lead to artificially increased tacrolimus concentrations assessed by cross-reacting immunoassays. We addressed this hypothesis by investigating the correlation between four different assays (two immunoassays and two mass-spectrometry assays) in both a population with normal and a population with high dose requirements. Routine blood samples were collected in 37 control (CO) and 72 high dose patients (HD). Tacrolimus was measured with a CMIA, an ECLIA and two LCMS assays. Results were investigated using Deming regression analysis, Pearson correlation coefficients, Bland-Altman plots and by calculating bias. The CMIA demonstrated a positive bias of 23-26% compared with both LCMS assays. The correlation between CMIA and LCMS assays was good for the CO (r = 0.96) but less so for the HD group (r = 0.91). The ECLIA showed a positive bias of 11-13% compared with both LCMS assays. The correlation between ECLIA and LCMS assays was also good for the CO (r = 0.95) but again less for the HD group (r = 0.93). The correlation for both LCMS assays was excellent for either group (r > 0.99) with no bias. CMIA, ECLIA and LCMS assays for tacrolimus therefore correlate well for trough concentrations from solid organ transplant recipients. However, inter-assay differences exist, which seem more pronounced in patients who need a high dose of tacrolimus to reach a trough concentration in the therapeutic range.

A diagnostic platform for rapid, simultaneous quantification of procalcitonin and C-reactive protein in human serum.

BACKGROUND: Early and accurate determination of bacterial infections as a potential cause for a patient's systemic inflammatory response is required for timely administration of appropriate treatment and antibiotic stewardship. Procalcitonin (PCT) and C-reactive protein (CRP) have both been used as biomarkers to infer bacterial infections, particularly in the context of sepsis. There is an urgent need to develop a platform for simultaneous quantification of PCT and CRP, to enable the potential use of these biomarkers at the point-of-care. METHODS: A multiplexed lateral flow assay (LFA) and a fluorescence optical reader were developed. Assay performance was validated by testing spiked antigens in the buffer, followed by a validation study comparing results with conventional assays (Roche Cobas e411 Elecsys PCT and Siemens ADVIA XPT CRP) in 25 archived remnant human serum samples. FINDINGS: A linear regression correlation of 0·97 (P < 0·01) was observed for PCT, and a correlation of 0·95 (P < 0·01) was observed for CRP using direct patient samples. We also validated our platform's ability to accurately quantify high-dose CRP in the hook effect range where excess unlabeled analytes occupy binding sites at test lines. INTERPRETATION: A fluorescence reader-based duplex LFA for simultaneous quantification of PCT and CRP was developed and successfully validated with clinical samples. The rapid, portable, and low-cost nature of the platform offers potential for differentiation of bacterial and viral infections in emergency and low-resource settings at the point-of-care. FUNDING: NIH/NIBIB Award 1R01EB021331, and Academic Venture Fund from the Atkinson Center for a Sustainable Future at Cornell University.

Altering the binding determinant on the interdigitating loop of mandelate racemase shifts specificity towards that of d-tartrate dehydratase.

The enolase superfamily (ENS) has served as a paradigm for understanding how enzymes that share a conserved structure, as well as a common partial reaction (i.e., metal-assisted, Brønsted base-catalyzed enol(ate) formation), evolved from a common progenitor to catalyze mechanistically diverse reactions. Enzymes of the mandelate racemase (MR)-subgroup of the ENS share interdigitating loops between adjacent, 2-fold symmetry-related protomers of the tightly associated homodimers that comprise their quaternary structures. For the MR-subgroup members MR and d-tartrate dehydratase (TarD), the tip of the loop contributes a binding determinant to the adjacent active site (i.e., Leu 93 and Lys 102, respectively). To assess the role of Leu 93 of MR in substrate specificity and catalysis, we constructed L93 variants bearing hydrophobic (L93A, L93F, and L93W), polar neutral (L93N), acidic (L93D), or basic (L93K and L93R) residues at position 93. Gel filtration-HPLC revealed that wild-type MR and all L93 MR variants, apart from L93R MR (dimeric), were tetrameric in solution. The catalytic efficiency (kcat/Km) was reduced in the R→S and S→R reaction directions for all variants, primarily due to reduced turnover (kcat). Substitution of Leu 93 by Lys or Arg to mimic Lys 102 of TarD enhanced the binding of malate and tartrate, with meso- and d-tartrate exhibiting linear mixed-type inhibition of L93K MR. Despite the striking 500-fold increase in the binding affinity of d-tartrate, relative to (S)-mandelate, L93K MR exhibited no TarD activity. MD simulations suggested that the failure of L93K MR to catalyze α-deprotonation (i.e., H-D exchange) arises from inappropriate positioning of the Brønsted base (Lys 166). Thus, a change in binding determinant on the interdigitating loop can play a significant role in governing substrate specificity within the ENS, but does not necessarily confer 'new' catalytic activity despite similarities in catalytic machinery.

Peritoneal Effluent Cell-Free DNA Sequencing in Peritoneal Dialysis Patients With and Without Peritonitis.

RATIONALE & OBJECTIVE: Conventional culture can be insensitive for the detection of rare infections and for the detection of common infections in the setting of recent antibiotic usage. Patients receiving peritoneal dialysis (PD) with suspected peritonitis have a significant proportion of negative conventional cultures. This study examines the utility of metagenomic sequencing of peritoneal effluent cell-free DNA (cfDNA) for evaluating the peritoneal effluent in PD patients with and without peritonitis. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We prospectively characterized cfDNA in 68 peritoneal effluent samples obtained from 33 patients receiving PD at a single center from September 2016 to July 2018. OUTCOMES: Peritoneal effluent, microbial, and human cfDNA characteristics were evaluated in culture-confirmed peritonitis and culture-negative peritonitis. ANALYTICAL APPROACH: Descriptive statistics were analyzed and microbial cfDNA was detected in culture-confirmed peritonitis and culture-negative peritonitis. RESULTS: Metagenomic sequencing of cfDNA was able to detect and identify bacterial, viral, and eukaryotic pathogens in the peritoneal effluent from PD patients with culture-confirmed peritonitis, as well as patients with recent antibiotic usage and in cases of culture-negative peritonitis. LIMITATIONS: Parallel cultures were not obtained in all the peritoneal effluent specimens. CONCLUSIONS: Metagenomic cfDNA sequencing of the peritoneal effluent can identify pathogens in PD patients with peritonitis, including culture-negative peritonitis.

Slow-Onset, Potent Inhibition of Mandelate Racemase by 2-Formylphenylboronic Acid. An Unexpected Adduct Clasps the Catalytic Machinery.

o-Carbonyl arylboronic acids such as 2-formylphenylboronic acid (2-FPBA) are employed in biocompatible conjugation reactions with the resulting iminoboronate adduct stabilized by an intramolecular N-B interaction. However, few studies have utilized these reagents as active site-directed enzyme inhibitors. We show that 2-FPBA is a potent reversible, slow-onset inhibitor of mandelate racemase (MR), an enzyme that has served as a valuable paradigm for understanding enzyme-catalyzed abstraction of an α-proton from a carbon acid substrate with a high pKa. Kinetic analysis of the progress curves for the slow onset of inhibition of wild-type MR using a two-step kinetic mechanism gave Ki and Ki* values of 5.1 ± 1.8 and 0.26 ± 0.08 µM, respectively. Hence, wild-type MR binds 2-FPBA with an affinity that exceeds that for the substrate by ∼3000-fold. K164R MR was inhibited by 2-FPBA, while K166R MR was not inhibited, indicating that Lys 166 was essential for inhibition. Unexpectedly, mass spectrometric analysis of the NaCNBH3-treated enzyme-inhibitor complex did not yield evidence of an iminoboronate adduct. 11B nuclear magnetic resonance spectroscopy of the MR·2-FPBA complex indicated that the boron atom was sp3-hybridized (δ 6.0), consistent with dative bond formation. Surprisingly, X-ray crystallography revealed the formation of an Nζ-B dative bond between Lys 166 and 2-FPBA with intramolecular cyclization to form a benzoxaborole, rather than the expected iminoboronate. Thus, when o-carbonyl arylboronic acid reagents are employed to modify proteins, the structure of the resulting product depends on the protein architecture at the site of modification.

Medical Management of Penile and Urethral Lichen Sclerosus with Topical Clobetasol Improves Long-Term Voiding Symptoms and Quality of Life.

PURPOSE: We evaluated the success of minimally invasive management of lichen sclerosus with topical and intraurethral clobetasol, as defined by improvement in patient reported outcome measures and nonprogression to surgery. MATERIALS AND METHODS: We conducted a review of our prospective ongoing quality improvement study to determine outcomes of our current standard practice for males with penile and urethral biopsy proven lichen sclerosus. Data were collected between 2011 and 2019, and included patient demographic information, medical and surgical histories, and location and extent of lichen sclerosus related pathology. The primary outcomes for this study were voiding function and voiding related quality of life, and were assessed using the AUASS (American Urological Association Symptom Score) and quality of life bother index, respectively. RESULTS: We identified 42 patients with biopsy proven lichen sclerosus related urethral stricture disease. Of these patients 85.7% were treated with intraurethral steroids alone and did not require surgical intervention. Median AUASS significantly improved from 12 to 8, and median quality of life bother index improved from 4 ("mostly dissatisfied") to 2 ("mostly satisfied"). Average stricture length of those with penile urethral disease and bulbar urethral disease was 4.8 cm (SD 3.0) and 16.2 cm (SD 6.5), respectively. Median followup was 8.4 months (IQR 2.6-26.4). CONCLUSIONS: Lichen sclerosus related urethral stricture disease can be effectively managed with intraurethral steroids. This minimally invasive management strategy improves patient reported voiding symptoms and voiding quality of life.

Pharmacokinetics and Efficacy of Ceftazidime-Avibactam in the Treatment of Experimental Pneumonia Caused by Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae in Persistently Neutropenic Rabbits.

Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is an emerging global public health threat that causes life-threatening pneumonia and bacteremia. Ceftazidime-avibactam (CZA) represents a promising advance for the treatment of serious infections caused by KPC-Kp We investigated the pharmacokinetics and efficacy of ceftazidime-avibactam in the treatment of experimental KPC-Kp pneumonia in persistently neutropenic rabbits. For single-dose and multidose (administration every 8 h) pharmacokinetics, rabbits received ceftazidime-avibactam intravenous infusions at 60/15, 90/22.5, and 120/30 mg/kg of body weight. Ceftazidime mean area under the concentration-time curves (AUCs) ranged from 287 to 608 µg·h/ml for a single dose and from 300 to 781 µg·h/ml for multiple doses. Avibactam AUCs ranged from 21 to 48 µg·h/ml for a single dose and from 26 to 48 µg·h/ml for multiple doses. KPC-Kp pneumonia was established by direct endotracheal inoculation. Treatments consisted of ceftazidime-avibactam at 120/30 mg/kg every 6 h, a polymyxin B (PMB) loading dose of 2.5 mg/kg followed by 1.5 mg/kg every 12 h q12h, or no treatment (untreated controls [UC]). There were significant reductions in the residual bacterial burden, lung weights, and pulmonary hemorrhage scores in CZA- and PMB-treated rabbits for a 7-day or a 14-day (P ≤ 0.01) course in comparison with those in the UC. These results corresponded to significant decreases in the bacterial burden in bronchoalveolar lavage fluid after a 7-day or a 14-day treatment (P ≤ 0.01). The outcomes demonstrated an improved response at 14 days versus that at 7 days. There was significantly prolonged survival in rabbits treated with CZA for 14 days in comparison with that in the PMB-treated or UC rabbits (P ≤ 0.05). This study demonstrates that ceftazidime-avibactam displays linear dose-proportional exposures simulating those seen from human plasma pharmacokinetic profiles, is active for the treatment of experimental KPC-Kp pneumonia in persistently neutropenic rabbits, and provides an experimental foundation for the treatment of severely immunocompromised patients with this life-threatening infection.

Procalcitonin utilization in the real world: An observational study of antibiotic prescribing practices.

OBJECTIVES: This study aims to better understand and describe antibiotic prescribing practices and adherence to a procalcitonin (PCT)-guided algorithm in patients undergoing serum PCT testing in adult hospitalized patients. METHODS: We performed an observational, retrospective study of 201 randomly selected patients who are aged ≥18 years, admitted to the general medicine floors or step-down unit between 1 January 2017 and 31 December 2017, and had serum PCT testing. Physician adherence to a PCT-guided algorithm was assessed through chart review. RESULTS: We found an overall adherence of 64.7%. Adherence was highest for PCT values above 0.25 ng/mL (82.8% for 0.25-0.50 ng/mL and 83.6% for >0.50 ng/mL). Adherence was lower for PCT values less than 0.25 ng/mL (59% for <0.1 ng/mL and 38% for 0.1-0.24 ng/mL). Serial testing was performed in 10% of patients. CONCLUSIONS: Hospital-based providers are more likely to overrule the algorithm and either initiate or continue antibiotics when guidelines encourage discontinuing antibiotics. These findings have important implications for antimicrobial stewardship and patient care and suggest that hospital-based providers may benefit from targeted didactics regarding the interpretation of the serum PCT assay.

Center-related Bias in MELD Scores Within a Liver Transplant UNOS Region: A Call for Standardization.

BACKGROUND: Model for End-Stage Liver Disease (MELD) score-based liver transplant allocation was implemented as a fair and objective measure to prioritize patients based upon disease severity. Accuracy and reproducibility of MELD is an essential assumption to ensure fairness in organ access. We hypothesized that variability in laboratory methodology between centers could impact allocation scores for individuals on the transplant waiting list. METHODS: Aliquots of 30 patient serum samples were analyzed for creatinine, bilirubin, and sodium in all transplant centers within United Network for Organ Sharing (UNOS) region 9. Descriptive statistics, intraclass correlation coefficients (ICCs), and linear mixed-effects regression were used to determine the relationship between center, bilirubin, and calculated MELD-sodium (MELD-Na) score. RESULTS: The mean MELD-Na score per sample ranged from 14 to 38. The mean range in MELD-Na per sample was 3 points, but 30% of samples had a range of 4-6 points. Correlation plots and intraclass correlation coefficient analysis confirmed bilirubin interfered with creatinine, with worsening agreement in creatinine at high bilirubin levels. Center and bilirubin were independently associated with creatinine reported in mixed-effects models. Unbiased hierarchical clustering suggested that samples from specific centers have consistently higher creatinine and MELD-Na values. CONCLUSIONS: Despite implementation of creatinine standardization, centers within a single UNOS region report clinically significant differences in MELD-Na on an identical sample, with differences of up to 6 points in high MELD-Na patients. The bias in MELD-Na scores based upon center choice within a region should be addressed in the current efforts to eliminate disparities in liver transplant access.