SHBG gene polymorphisms and their influence on serum SHBG, total and free testosterone concentrations in men.

CONTEXT: Genetic variation in sex hormone-binding globulin (SHBG) structure may affect estimates of sex steroid exposure by altering the affinity of the protein for its ligand. Consequently, free hormone calculations assuming constant binding affinity may, for certain genetic variations, lead to incorrect diagnoses if genetic variation is not taken into consideration. OBJECTIVE: To investigate the effects of genetic variation in SHBG on calculated and measured serum free testosterone (T) in men. DESIGN, SETTING AND PARTICIPANTS: Population-based sibling-pair study in 999 healthy men aged 25 to 45 (mean: 34.5) years. MAIN OUTCOME MEASURES: Genotyping using microarray (Illumina®) for SNPs suggested to affect binding affinity and/or concentration of SHBG or T. SHBG concentrations were measured using immunoassay and in a subset (n = 32) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Total T was measured using LC-MS/MS. Free T was calculated and in a subset (n = 314) measured directly using LC-MS/MS after equilibrium dialysis. RESULTS: Allelic frequencies of analyzed SNPs ranged from 0.5% to 58.2%. Compared to wild-type, SHBG concentrations were lower in rs6258 heterozygotes (-24.7%; p < 0.05) and higher in rs6259 heterozygotes, rs727428 homozygotes, and carriers of rs1799941 (+10.8 to 23.1%; all p < 0.05). Total T was higher in rs727428 homozygotes and carriers of rs5934505, rs1799941and rs6259 (+3.9 to 21.4%; all p < 0.05). No clear effects on measured free T were found, except for a trend towards higher values in rs6259 homozygotes, significant for calculated free T (+18.7%; p < 0.05) in the larger global study population. CONCLUSION: In these men, analyzed SNPs were relatively prevalent and affected serum concentrations of total T and SHBG but not calculated or measured free T except for a higher trend in rs6259 homozygotes.

An Unexpected Finding of an Aggressive Pleural Hemangiopericytoma/Solitary Fibrous Tumor in a Patient With Recurrent Meningioma: A Case Report.

Pleural hemangiopericytoma/solitary fibrous tumor (HPC/SFT) is a rare form of mesenchymal tumor arising from pericytes, which predominantly occurs intrathoracically. HPC/SFT can be suspected on imaging, but radiographic features are non-specific. Therefore, histological confirmation remains the gold standard. Due to the rarity of the tumor, specific anatomical pathological expertise is necessary to make the diagnosis, which is not available in every hospital. Here, we report the case of a 51-year-old female with a medical history of recurrent meningiomas. A chest CT scan revealed extensive subpleural soft tissue lesions in the left hemithorax with histological characteristics suggestive of a pleural malignancy. A specialized analysis of the sample led to the final diagnosis of HPC/SFT. Unfortunately, in the meantime, the patient's condition worsened rapidly, and she passed away before the final diagnosis was made and any decisions about therapeutic options were taken. In our case, we want to highlight the importance of having knowledge about the existence of this type of tumor in order to make the correct diagnosis in a timely manner.

Hypertrophic cardiomyopathy dysfunction mimicked in human engineered heart tissue and improved by sodium-glucose cotransporter 2 inhibitors.

AIMS: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy, often caused by pathogenic sarcomere mutations. Early characteristics of HCM are diastolic dysfunction and hypercontractility. Treatment to prevent mutation-induced cardiac dysfunction is lacking. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a group of antidiabetic drugs that recently showed beneficial cardiovascular outcomes in patients with acquired forms of heart failure. We here studied if SGLT2i represent a potential therapy to correct cardiomyocyte dysfunction induced by an HCM sarcomere mutation. METHODS AND RESULTS: Contractility was measured of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) harbouring an HCM mutation cultured in 2D and in 3D engineered heart tissue (EHT). Mutations in the gene encoding ß-myosin heavy chain (MYH7-R403Q) or cardiac troponin T (TNNT2-R92Q) were investigated. In 2D, intracellular [Ca2+], action potential and ion currents were determined. HCM mutations in hiPSC-CMs impaired relaxation or increased force, mimicking early features observed in human HCM. SGLT2i enhance the relaxation of hiPSC-CMs, to a larger extent in HCM compared to control hiPSC-CMs. Moreover, SGLT2i-effects on relaxation in R403Q EHT increased with culture duration, i.e. hiPSC-CMs maturation. Canagliflozin's effects on relaxation were more pronounced than empagliflozin and dapagliflozin. SGLT2i acutely altered Ca2+ handling in HCM hiPSC-CMs. Analyses of SGLT2i-mediated mechanisms that may underlie enhanced relaxation in mutant hiPSC-CMs excluded SGLT2, Na+/H+ exchanger, peak and late Nav1.5 currents, and L-type Ca2+ current, but indicate an important role for the Na+/Ca2+ exchanger. Indeed, electrophysiological measurements in mutant hiPSC-CM indicate that SGLT2i altered Na+/Ca2+ exchange current. CONCLUSION: SGLT2i (canagliflozin > dapagliflozin > empagliflozin) acutely enhance relaxation in human EHT, especially in HCM and upon prolonged culture. SGLT2i may represent a potential therapy to correct early cardiac dysfunction in HCM.

Simultaneous quantification of the 22-kDa isoforms of human growth hormone 1 and 2 in human plasma by multiplexed immunocapture and LC-MS/MS.

An LC-MS/MS method is presented for the simultaneous quantification of two structurally closely related protein biomarker isoforms, the 22-kDa isoforms of human growth hormone 1 and human growth hormone 2, in human plasma. It is based on multiplexed immunocapture using two monoclonal antibodies immobilized on magnetic beads, tryptic digestion and quantification of two specific signature peptides plus an additional peptide for estimation of total growth hormone related concentrations. A full validation according to international guidelines was performed across the clinically relevant concentration ranges of 0.5 to 50 ng/mL for growth hormone 1, and 2 to 50 ng/mL for growth hormone 2 and demonstrated satisfactory method performance in terms of accuracy, precision, stability and absence of interference. The method's applicability for routine analysis and its ability to effectively distinguish between GH1 and GH2 was demonstrated by the analysis of plasma samples from pregnant individuals to study the changes in growth hormone levels during pregnancy.

Simultaneous and independent topological control of identical microparticles in non-periodic energy landscapes.

Topological protection ensures stability of information and particle transport against perturbations. We explore experimentally and computationally the topologically protected transport of magnetic colloids above spatially inhomogeneous magnetic patterns, revealing that transport complexity can be encoded in both the driving loop and the pattern. Complex patterns support intricate transport modes when the microparticles are subjected to simple time-periodic loops of a uniform magnetic field. We design a pattern featuring a topological defect that functions as an attractor or a repeller of microparticles, as well as a pattern that directs microparticles along a prescribed complex trajectory. Using simple patterns and complex loops, we simultaneously and independently control the motion of several identical microparticles differing only in their positions above the pattern. Combining complex patterns and complex loops we transport microparticles from unknown locations to predefined positions and then force them to follow arbitrarily complex trajectories concurrently. Our findings pave the way for new avenues in transport control and dynamic self-assembly in colloidal science.

Quantitative bioanalysis of proteins by digestion and LC-MS/MS: the use of multiple signature peptides.

The use of multiple signature peptides for the quantification of proteins by digestion and LC-MS/MS is reviewed and evaluated here. A distinction is made based on the purpose of the use of multiple peptides: confirmation of the protein concentration, discrimination between different protein forms or species and in vivo biotransformation. Most reports that describe methods with at least two peptides use these for confirmation, but it is not always mentioned how the peptides are used and how possible differences in concentration between the peptides are handled. Differences in concentration are often reported in the case of monitoring different protein forms or in vivo biotransformation, and this offers insight into the biological fate of the protein.

Local measures of fluctuations in inhomogeneous liquids: statistical mechanics and illustrative applications.

We show in detail how three one-body fluctuation profiles, namely the local compressibility, the local thermal susceptibility, and the reduced density, can be obtained from a statistical mechanical many-body description of classical particle-based systems. We present several different and equivalent routes to the definition of each fluctuation profile, facilitating their explicit numerical calculation in inhomogeneous equilibrium systems. This underlying framework is used for the derivation of further properties such as hard wall contact theorems and novel types of inhomogeneous one-body Ornstein-Zernike equations. The practical accessibility of all three fluctuation profiles is exemplified by grand canonical Monte Carlo simulations that we present for hard sphere, Gaussian core and Lennard-Jones fluids in confinement.

Determination of Binding Sites on Trastuzumab and Pertuzumab to Selective Affimers Using Hydrogen-Deuterium Exchange Mass Spectrometry.

Hydrogen-deuterium exchange mass spectrometry (HDX-MS) is a method to probe the solvent accessibility and conformational dynamics of a protein or a protein-ligand complex with respect to exchangeable amide hydrogens. Here, we present the application of HDX-MS to determine the binding sites of Affimer reagents to the monoclonal antibodies trastuzumab and pertuzumab, respectively. Intact and subunit level HDX-MS analysis of antibody-affimer complexes showed significant protection from HDX in the antibody Fab region upon affimer binding. Bottom-up HDX-MS experiments including online pepsin digestion revealed that the binding sites of the affimer reagents were mainly located in the complementarity-determining region (CDR) 2 of the heavy chain of the respective antibodies. Three-dimensional models of the binding interaction between the affimer reagents and the antibodies were built by homology modeling and molecular docking based on the HDX data.

Comparing Oncological and Perioperative Outcomes of Open versus Laparoscopic versus Robotic Radical Nephroureterectomy for the Treatment of Upper Tract Urothelial Carcinoma: A Multicenter, Multinational, Propensity Score-Matched Analysis.

OBJECTIVES: To identify correlates of survival and perioperative outcomes of upper tract urothelial carcinoma (UTUC) patients undergoing open (ORNU), laparoscopic (LRNU), and robotic (RRNU) radical nephroureterectomy (RNU). METHODS: We conducted a retrospective, multicenter study that included non-metastatic UTUC patients who underwent RNU between 1990-2020. Multiple imputation by chained equations was used to impute missing data. Patients were divided into three groups based on their surgical treatment and were adjusted by 1:1:1 propensity score matching (PSM). Survival outcomes per group were estimated for recurrence-free survival (RFS), bladder recurrence-free survival (BRFS), cancer-specific survival (CSS), and overall survival (OS). Perioperative outcomes: Intraoperative blood loss, hospital length of stay (LOS), and overall (OPC) and major postoperative complications (MPCs; defined as Clavien-Dindo > 3) were assessed between groups. RESULTS: Of the 2434 patients included, 756 remained after PSM with 252 in each group. The three groups had similar baseline clinicopathological characteristics. The median follow-up was 32 months. Kaplan-Meier and log-rank tests demonstrated similar RFS, CSS, and OS between groups. BRFS was found to be superior with ORNU. Using multivariable regression analyses, LRNU and RRNU were independently associated with worse BRFS (HR 1.66, 95% CI 1.22-2.28, p = 0.001 and HR 1.73, 95%CI 1.22-2.47, p = 0.002, respectively). LRNU and RRNU were associated with a significantly shorter LOS (beta -1.1, 95% CI -2.2-0.02, p = 0.047 and beta -6.1, 95% CI -7.2-5.0, p < 0.001, respectively) and fewer MPCs (OR 0.5, 95% CI 0.31-0.79, p = 0.003 and OR 0.27, 95% CI 0.16-0.46, p < 0.001, respectively). CONCLUSIONS: In this large international cohort, we demonstrated similar RFS, CSS, and OS among ORNU, LRNU, and RRNU. However, LRNU and RRNU were associated with significantly worse BRFS, but a shorter LOS and fewer MPCs.

Is conservative management safe in patients with acute ureterolithiasis and perirenal stranding?

In patients presenting with ureterolithiasis, perirenal stranding is frequently observed in non-contrast computed tomography. Because perirenal stranding may be caused by tears in the collecting system, previous studies have described an increased risk of infectious complications and suggested broad empiric antibiotic therapy and immediate decompressing of the upper urinary tract. We hypothesized that these patients can also be managed conservatively. Therefore, we retrospectively identified patients with ureterolithiasis and perirenal stranding and compared diagnostic and treatment characteristics as well as treatment outcomes between patients undergoing conservative versus interventional management by ureteral stenting, percutaneous drainage or primary ureteroscopic stone removal. We classified perirenal stranding as mild, moderate or severe based on its radiological extent. Of 211 patients, 98 were managed conservatively. Patients in the interventional group had larger ureteral stones, more proximal ureteral stone location, more severe perirenal stranding, higher systemic and urinary infectious parameters, higher creatinine levels, and received more frequent antibiotic therapy. The conservatively managed group experienced a spontaneous stone passage rate of 77%, while 23% required delayed intervention. In the interventional and conservative groups, 4% and 2% of patients, respectively, developed sepsis. None of the patients in either group developed a perirenal abscess. Comparison of perirenal stranding grade between mild, moderate and severe in the conservatively treated group showed no difference in the spontaneous stone passage and infectious complications. In conclusion, conservative management without prophylactic antibiotics for ureterolithiasis and perirenal stranding is a valid treatment option as long as no clinical or laboratory signs of renal failure or infections are observed.

An antibody-free LC-MS/MS method for the quantification of sex hormone binding globulin in human serum and plasma.

OBJECTIVES: Sex hormone binding globulin (SHBG) is a hormone binding protein which plays an important role in regulating the transport and availability of biologically active androgens and estradiol to target cells and used to calculate free testosterone concentrations. METHODS: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed, featuring an albumin removal step followed by a tryptic digestion. After a reduction step with dithiothreitol and alkylation with iodoacetamide three signature peptides were used for the quantification of SHBG. RESULTS: The method enables the quantification of serum and plasma SHBG over the clinically relevant range of 200-20,000 ng/mL and was validated according to the most recent guidelines. The LC-MS/MS method correlates well with the Abbott Alinity immunoassay (R2>0.95), but the LC-MS/MS results are on average 16-17% lower than the immunoassay results, which is consistent for all three signature peptides. CONCLUSIONS: The LC-MS/MS method which includes an albumin depletion step allows quantification of SHBG in serum and plasma without an immunocapture step at clinically relevant SHBG levels, thus contributing to better lab-to-lab consistency of results.

Pertuzumab Charge Variant Analysis and Complementarity-Determining Region Stability Assessment to Deamidation.

Pertuzumab is a monoclonal antibody used for the treatment of HER2-positive breast cancer in combination with trastuzumab. Charge variants of trastuzumab have been extensively described in the literature; however, little is known about the charge heterogeneity of pertuzumab. Here, changes in the ion-exchange profile of pertuzumab were evaluated by pH gradient cation-exchange chromatography after stressing it for up to 3 weeks at physiological and elevated pH and 37 °C. Isolated charge variants arising under stress conditions were characterized by peptide mapping. The results of peptide mapping showed that deamidation in the Fc domain and N-terminal pyroglutamate formation in the heavy chain are the main contributors to charge heterogeneity. The heavy chain CDR2, which is the only CDR containing asparagine residues, was quite resistant to deamidation under stress conditions according to peptide mapping results. Using surface plasmon resonance, it was shown that the affinity of pertuzumab for the HER2 target receptor does not change under stress conditions. Peptide mapping analysis of clinical samples showed an average of 2-3% deamidation in the heavy chain CDR2, 20-25% deamidation in the Fc domain, and 10-15% N-terminal pyroglutamate formation in the heavy chain. These findings suggest that in vitro stress studies are able to predict in vivo modifications.

Predictive and Prognostic Role of the Neutrophil-to-Lymphocyte Ratio in Muscle Invasive Bladder Cancer Treated With Neoadjuvant Chemotherapy and Radical Cystectomy.

INTRODUCTION: There is a persistent lack of validated biomarkers that identify patients most likely to benefit from neoadjuvant chemotherapy (NAC) in urothelial carcinoma of the bladder (UCB). Therefore, the purpose of this study was to investigate the predictive and prognostic impact of the pretreatment neutrophil-to-lymphocyte ratio (NLR) in UCB patients treated with NAC and radical cystectomy (RC). PATIENTS AND METHODS: We conducted a retrospective analysis of an international-multicenter database comprising 404 UCB patients staged cT2-4N0-3M0. The cohort was split into low and high NLR using an optimal cutoff value determined by maximizing Youden's index. Logistic and Cox regression analyses were performed with respect to several clinical endpoints. The discriminative ability of the models and the additive discriminative value of NLR was assessed by calculating the area under receiver operating characteristics curves, C-index, and decision curve analysis (DCA). RESULTS: A total of 169 patients (41.8%) had a high NLR, which was associated with a decreased probability of complete response (CR, OR: 0.24 [95% CI, 0.13-0.42], P < .001) and/or partial response (PR, OR: 0.33 [95% CI, 0.21-0.49], P < .001). Adding the NLR to predictive reference models significantly improved their accuracy for the prediction of both CR and PR. A high NLR was associated with poor survival outcomes in the pretreatment setting, however, it didn't meaningfully change the C-index based on the model. CONCLUSION: We confirmed that an elevated NLR is an independent and clinically significant predictor of response to NAC and adverse pathological features in UCB treated with NAC plus RC. The accuracy of this biomarker in the age of immunotherapy warrants further evaluation.

A Quantitative LC-MS/MS Method for Distinguishing the Tau Protein Forms Phosphorylated and Nonphosphorylated at Serine-396.

Hyperphosphorylated tau protein is well-known to be involved in the formation of neurofibrillary tangles and the progression of age-related neurodegenerative diseases (tauopathies), including Alzheimer's Disease (AD). Tau protein phosphorylated at serine-396 (pS396-tau) is often linked to disease progression, and we therefore developed an analytical method to measure pS396-tau in cerebrospinal fluid (CSF) in humans and animal models of AD. In the S396-region, multiple phosphorylation sites are present, causing structural complexity and sensitivity challenges for conventional bottom-up mass spectrometry approaches. Here, we present an indirect LC-MS/MS method for quantification of pS396-tau. We take advantage of the reproducible miscleavage caused by S396 being preceded by a lysine (K395) and the proteolytic enzyme trypsin not cleaving when the following amino acid is phosphorylated. Therefore, treatment with trypsin discriminates between the forms of tau with and without phosphorylation at S396 and pS396-tau can be quantified as the difference between total S396-tau and nonphosphorylated S396-tau. To qualify the method, it was successfully applied for quantification of pS396-tau in human CSF from healthy controls and patients with Mild Cognitive Impairment and AD. In addition, the method was applied for rTg4510 mice where a clear dose dependent decrease in pS396-tau was observed in CSF following intravenous administration of a monoclonal antibody (Lu AF87908, hC10.2) targeting the tau epitope containing pS396. Finally, a formal validation of the method was conducted. In conclusion, this sensitive LC-MS/MS-based method for measurement of pS396-tau in CSF allows for quantitative translational biomarker applications for tauopathies including investigations of potential drug induced effects.

Revealing charge heterogeneity of stressed trastuzumab at the subunit level.

Trastuzumab is known to be heterogeneous in terms of charge. Stressing trastuzumab under physiological conditions (pH 7.4 and 37 °C) increases charge heterogeneity further. Separation of charge variants of stressed trastuzumab at the intact protein level is challenging due to increasing complexity making it difficult to obtain pure charge variants for further characterization. Here we report an approach for revealing charge heterogeneity of stressed trastuzumab at the subunit level by pH gradient cation-exchange chromatography. Trastuzumab subunits were generated after limited proteolytic cleavage with papain, IdeS, and GingisKHAN®. The basic pI of Fab and F(ab)2 fragments allowed to use the same pH gradient for intact protein and subunit level analysis. Baseline separation of Fab subunits was obtained after GingisKHAN® and papain digestion and the corresponding modifications were determined by LC-MS/MS peptide mapping and middle-down MALDI-ISD FT-ICR MS. The described approach allows a comprehensive charge variant analysis of therapeutic antibodies that have two or more modification sites in the Fab region.

Biological and prognostic implications of biopsy upgrading for high-grade upper tract urothelial carcinoma at nephroureterectomy.

OBJECTIVES: Technical limitations of ureteroscopic (URS) biopsy has been considered responsible for substantial upgrading rate in upper tract urothelial carcinoma (UTUC). However, the impact of tumor specific factors for upgrading remain uninvestigated. METHODS: Patients who underwent URS biopsy were included between 2005 and 2020 at 13 institutions. We assessed the prognostic impact of upgrading (low-grade on URS biopsy) versus same grade (high-grade on URS biopsy) for high-grade UTUC tumors on radical nephroureterectomy (RNU) specimens. RESULTS: This study included 371 patients, of whom 112 (30%) and 259 (70%) were biopsy-based low- and high-grade tumors, respectively. Median follow-up was 27.3 months. Patients with high-grade biopsy were more likely to harbor unfavorable pathologic features, such as lymphovascular invasion (p < 0.001) and positive lymph nodes (LNs; p < 0.001). On multivariable analyses adjusting for the established risk factors, high-grade biopsy was significantly associated with worse overall (hazard ratio [HR] 1.74; 95% confidence interval [CI], 1.10-2.75; p = 0.018), cancer-specific (HR 1.94; 95% CI, 1.07-3.52; p = 0.03), and recurrence-free survival (HR 1.80; 95% CI, 1.13-2.87; p = 0.013). In subgroup analyses of patients with pT2-T4 and/or positive LN, its significant association retained. Furthermore, high-grade biopsy in clinically non-muscle invasive disease significantly predicted upstaging to final pathologically advanced disease (≥pT2) compared to low-grade biopsy. CONCLUSIONS: High tumor grade on URS biopsy is associated with features of biologically and clinically aggressive UTUC tumors. URS low-grade UTUC that becomes upgraded to high-grade might carry a better prognosis than high-grade UTUC on URS. Tumor specific factors are likely to be responsible for upgrading to high-grade on RNU.

Diagnostic Accuracy of Clinical Lymph Node Staging for Upper Tract Urothelial Cancer Patients: A Multicenter, Retrospective, Observational Study.

PURPOSE: Treatment options for the management of upper tract urothelial cancer are based on accurate staging. However, the performance of conventional cross-sectional imaging for clinical lymph node staging (N-staging) remains poorly investigated. This study aims to evaluate the diagnostic accuracy of conventional cross-sectional imaging for upper tract urothelial cancer N-staging. MATERIALS AND METHODS: This study was a multicenter, retrospective, observational study. We included 865 nonmetastatic (M0) upper tract urothelial cancer patients treated with curative intended surgery and lymph node dissection who had been staged with conventional cross-sectional imaging before surgery. We compared clinical (c) and pathological (p) N-staging results to evaluate the concordance of node-positive (N+) and node-negative (N0) disease and calculate cN-staging's diagnostic accuracy. RESULTS: Conventional cross-sectional imaging categorized 750 patients cN0 and 115 cN+. Lymph node dissection categorized 641 patients pN0 and 224 pN+. The cN-stage was pathologically downstaged in 6.8% of patients, upstaged in 19%, and found concordant in 74%. The sensitivity and specificity of cN-staging were 25% (95% CI 20; 31) and 91% (95% CI 88; 93). Positive and negative likelihood ratios were 2.7 (95% CI 2.0; 3.8) and 0.83 (95% CI 0.76; 0.89). The area under the receiver operating characteristics curve (0.58, 95% CI 0.55; 0.61) revealed low diagnostic accuracy. CONCLUSIONS: Conventional cross-sectional imaging had low sensitivity in detecting upper tract urothelial cancer pN+ disease. However, cN+ increased the likelihood of pN+ by almost threefold. Thus, conventional cross-sectional imaging is a rule-in but not a rule-out test. Lymph node dissection should remain the standard during extirpative upper tract urothelial cancer surgery to obtain accurate N-staging. cN+ could be a strong argument for early systemic treatment.

Clinical Outcomes of Patients With Metastatic NSCLC After Discontinuation of Immunotherapy Because of Immune-Related Adverse Effects.

Introduction: Immune checkpoint inhibition (ICI) is an important treatment modality in metastatic NSCLC and management of immunotherapy-related adverse effects (irAEs) can be challenging. Retreatment after discontinuation of ICI because of irAEs is a frequent clinical dilemma with limited available data. Methods: This single-center retrospective observational study reviewed the clinical course of 30 patients with metastatic NSCLC in whom ICI had to be discontinued owing to a serious irAE after an initial objective response to therapy. Results: After ICI discontinuation, 14 patients (47%) developed a durable response of more than 6 months, seven patients (23%) developed oligoprogression treated with local radiotherapy leading to disease control, six patients (20%) had progression of disease within 6 months, and three patients (10%) died owing to a severe irAE. Conclusions: A watchful waiting approach is justified after discontinuation of ICI owing to irAEs in patients with metastatic NSCLC with an initial response to therapy.

Biotransformation of Trastuzumab and Pertuzumab in Breast Cancer Patients Assessed by Affinity Enrichment and Ion-Exchange Chromatography.

Therapeutic proteins (TPs) are known to be heterogeneous due to modifications that occur during the production process and storage. Modifications may also occur in TPs after their administration to patients due to in vivo biotransformation. Ligand binding assays, which are widely used in the bioanalysis of TPs in body fluids, are typically unable to distinguish such modifications. Liquid chromatography coupled to mass spectrometry is being increasingly used to study modifications in TPs, but its use to study in vivo biotransformation has been limited until now. We present a novel approach that combines affinity enrichment using Affimer reagents with ion-exchange chromatography (IEX) to analyze charge variants of the TPs trastuzumab and pertuzumab in plasma of patients undergoing therapy for HER2-positive breast cancer. Affimer reagents were immobilized via engineered Cys tags to maleimide beads, and the TPs were eluted under acidic conditions followed by rapid neutralization. The enriched TPs were analyzed by cation-exchange chromatography (IEX) using pH-gradient elution, resulting in the separation of about 20 charge variants for trastuzumab and about five charge variants for pertuzumab. A comparison between in vitro stressed TPs spiked into plasma, and TPs enriched from patient plasma showed that the observed profiles were highly similar. This indicates that in vitro stress testing in plasma can mimic the situation in patient plasma, as far as the generation of charge variants is concerned. SIGNIFICANCE STATEMENT: This research attempts to elucidate the modifications that occur in therapeutic proteins (TPs) after they have been administered to patients. This is important because there is little knowledge about the fate of TPs in this regard, and certain modifications could affect their efficiency. Our results show that the modifications discovered are most likely due to a chemical process and are not patient specific.

The Role of Additional Epididymis Resection during Hydrocelectomy: Is It of Any Benefit in Comparison to Simple Hydrocelectomy?

INTRODUCTION: Open hydrocelectomy via scrotal incision is the standard approach for secondary hydroceles. Traditionally, the Swiss urologic community offer hydrocelectomy with additional resection of the epididymis in elderly men with completed family planning. It is believed that the additional resection of the epididymis reduces the postoperative recurrence rate of hydroceles. However, there is no evidence supporting this theory. Therefore, the aim of this study was to compare the recurrence and complication rates for patients with secondary hydroceles undergoing either pure hydrocelectomy (puH) or hydrocelectomy with additional resection of the epididymis (HRE). MATERIALS AND METHODS: We reviewed all male patients who underwent surgical therapy for secondary hydroceles between May 2003 and February 2019 at our institution. Patient's baseline and perioperative characteristics as well as postoperative characteristics including complications and recurrence rates were gathered and compared between different surgical techniques. RESULTS: A total of 234 patients were identified. puH was performed in 93 (40%) cases and HRE in 141 (60%) patients. Patients in the HRE group were older (median age: 62 vs. 38 years, p < 0.001), had a higher ASA-Score (p < 0.001), were more often on platelet aggregation inhibitors (19% vs. 7.5%, p = 0.01), and had a longer median operative time (75 vs. 64 min, p < 0.001). During a median follow-up of 46 months, a similar number of recurrent hydroceles were found for puH (7 [7.5%]) and HRE (6 [4.5%]) (p = 0.3). Complications were observed in 19 (20%) cases after puH compared to 25 (18%) cases after HRE (p = 0.6). Patients after puH experienced more often severe complications (Clavien-Dindo Grade 3b) compared to the HRE group (5 vs. 12%, p = 0.046). CONCLUSION: puH and HRE showed similar results in terms of overall low recurrence rates and also in terms of postoperative complications, even though patients who underwent puH experienced slightly higher severe complications. Both procedures are safe and effective, but it seems that HRE does not provide a relevant clinical benefit in comparison to puH for the management of men with secondary hydroceles.