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1.
Blood Adv ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38861273

ABSTRACT

Venetoclax is the first example of personalized medicine for multiple myeloma (MM), with meaningful clinical activity as a monotherapy and in combination in myeloma patients harboring the t(11:14) translocation. However, despite the high response rates and prolonged PFS, a significant proportion of patients eventually relapse. Here, we aimed to study adaptive molecular responses after the acquisition of venetoclax resistance in sensitive t(11:14) MM cell models. We therefore generated single-cell venetoclax-resistant t(11:14) MM cell lines and investigated the mechanisms contributing to resistance as well as the cells' sensitivity to other treatments. Our data suggests that acquired resistance to venetoclax is characterized by reduced mitochondrial priming and changes in BCL-2 family proteins' expression in MM cells, conferring broad resistance to standard-of-care anti-myeloma drugs. However, our results show that the resistant cells are still sensitive to immunotherapeutic treatments, highlighting the need to consider appropriate sequencing of these treatments following venetoclax-based regimens.

2.
Int J Legal Med ; 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38619573

ABSTRACT

PURPOSE: The skeletal survey X-ray series is the current 'gold standard' when investigating suspected physical abuse (SPA) of children, in addition to a non-contrast computed tomography (CT) brain scan. This systematic literature review synthesised findings of published research to determine if low dose computed tomography (LDCT) could detect subtle fractures and therefore replace the skeletal survey X-ray series in the investigation of SPA in children aged under 3 years. METHODS: Five electronic databases and grey literature were systematically searched from their inception to 28 April 2022. Primary studies were included where the population comprised paediatric patients up to 16 years and LDCT was used to detect fractures associated with SPA. Studies involving imaging investigations of the head, standard dose CT examinations or accidental trauma were excluded. RESULTS: Three studies met the inclusion criteria, all of which were case series. These studies did not report many of the criteria required to compare the accuracy of LDCT to X-ray, i.e. they did not meet the criteria for a diagnostic accuracy test. Therefore, it is difficult to conclude from the case series if LDCT is accurate enough to replace X-rays. CONCLUSION: Due to the gap in current literature, a phantom study and subsequent post-mortem CT study are recommended as the primary investigative methods to assess the ability of low-dose CT to identify the subtle fractures associated with SPA and to calculate how low the achievable CT dose can be.

3.
Article in English | MEDLINE | ID: mdl-38579156

ABSTRACT

Undifferentiated embryonal sarcoma of the liver (UESL) is an extremely rare and aggressive malignancy in adults.1 Adults with UESL have a worse prognosis compared to pediatric population.2 Due to the rarity of this disease in adults, there has been a lack of information that assists in treatment decisions within this group. Improved understanding of UESL in adults might assist in understanding biological differences compared to pediatric cohorts as well as tailor treatments to improve their overall outcome. We described the management and outcome of a young adult managed at our center with metastatic relapsed UESL. For comparison, a PubMed search for adolescent and young adult (AYA) and adults with UESL was performed with the aim to review and address any distinct clinical features, different aspects of management and survival outcomes within this population. A 21-year-old male underwent right hepatectomy for a large 16 cm localized UESL with clear surgical margin and did not receive adjuvant chemotherapy. Seven months postsurgery, he relapsed with both local and metastatic disease and underwent chemotherapy with vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide and etoposide achieving a complete metabolic response. This was followed by Stereotactic Ablative Radiation Therapy and surgical resection of residual disease. He remains free of disease 3 years since his diagnosis. We subsequently reviewed 42 AYA and adults (aged >15) with UESL (median age, 33 years) between 1991 and 2022. Most patients presented with localized UESL and for those treated with surgery alone, 67% developed recurrences. Those receiving multimodality treatment, better outcomes, and reduced relapse rate was achieved. Twenty-seven patients developed recurrences, 13 with local recurrences and 14 with metastatic relapse. The median time to relapse was 12 months. We reported a successful outcome in multimodality treatment which resulted in long remission in a young adult with relapsed UESL. Combination of perioperative chemotherapy with locoregional treatment is important to improve long-term survival in adults with metastatic UESL.

4.
Cureus ; 16(2): e54399, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38375057

ABSTRACT

Granular cell tumours (GCTs) are rare soft tissue tumours of neural origin. They have been reported in multiple anatomical sites. However, only 14 cases worldwide have been reported arising from the abdominal wall. While they can clinically manifest in a variety of ways, often they present as a small, slow-growing nodule with benign features. They can, however, be malignant, and in rare cases, they have been reported to metastasise. Here, we present a case of a rare abdominal wall GCT, which was managed with local excision. The purpose of this paper is to report the patient's clinical history, presentation, and surgical management, as well as to review the current literature to highlight the existence of this rare entity and the possibility that this may occur and should be considered a differential diagnosis in clinical practice.

5.
Cell Mol Life Sci ; 81(1): 42, 2024 Jan 13.
Article in English | MEDLINE | ID: mdl-38217709

ABSTRACT

Neprilysin (NEP) is an emerging biomarker for various diseases including heart failure (HF). However, major inter-assay inconsistency in the reported concentrations of circulating NEP and uncertainty with respect to its correlations with type and severity of disease are in part attributed to poorly characterized antibodies supplied in commercial ELISA kits. Validated antibodies with well-defined binding footprints are critical for understanding the biological and clinical context of NEP immunoassay data. To achieve this, we applied in silico epitope prediction and rational peptide selection to generate monoclonal antibodies (mAbs) against spatially distant sites on NEP. One of the selected epitopes contained published N-linked glycosylation sites at N285 and N294. The best antibody pair, mAb 17E11 and 31E1 (glycosylation-sensitive), were characterized by surface plasmon resonance, isotyping, epitope mapping, and western blotting. A validated two-site sandwich NEP ELISA with a limit of detection of 2.15 pg/ml and working range of 13.1-8000 pg/ml was developed with these mAbs. Western analysis using a validated commercial polyclonal antibody (PE pAb) and our mAbs revealed that non-HF and HF plasma NEP circulates as a heterogenous mix of moieties that possibly reflect proteolytic processing, post-translational modifications and homo-dimerization. Both our mAbs detected a ~ 33 kDa NEP fragment which was not apparent with PE pAb, as well as a common ~ 57-60 kDa moiety. These antibodies exhibit different affinities for the various NEP targets. Immunoassay results are dependent on NEP epitopes variably detected by the antibody pairs used, explaining the current discordant NEP measurements derived from different ELISA kits.


Subject(s)
Antibodies, Monoclonal , Heart Failure , Humans , Epitopes , Neprilysin/metabolism , Enzyme-Linked Immunosorbent Assay , Immunoassay/methods
6.
J Mol Diagn ; 25(10): 771-781, 2023 10.
Article in English | MEDLINE | ID: mdl-37544359

ABSTRACT

For patients with BRAF wild-type stage III and IV melanoma, there is an urgent clinical need to identify prognostic biomarkers and biomarkers predictive of treatment response. Circulating tumor DNA (ctDNA) is emerging as a blood-based biomarker and has shown promising results for many cancers, including melanoma. The purpose of this study was to identify targetable, tumor-derived mutations in patient blood that may lead to treatment alternatives and improved outcomes for patients with BRAF-negative melanoma. Using a CAncer Personalized Profiling by deep Sequencing (CAPP-seq) pan-cancer gene panel, ctDNA from 150 plasma samples (n = 106 patients) was assessed, including serial blood collections for a subset of patients (n = 16). ctDNA variants were detected in 85% of patients, all in targetable pathways, such as vascular endothelial growth factor receptor, epidermal growth factor receptor, phosphatidylinositol 3-kinase/AKT, Bcl2/mammalian target of rapamycin (mTOR), ALK/MET, and cyclin-dependent kinase 4/6. Patients with stage IV melanoma with low ctDNA concentrations, <10 ng/mL, had significantly better disease-specific survival and progression-free survival. Patients with both a high concentration of ctDNA and any detectable ctDNA variants had the worst prognosis. In addition, these results indicated that longitudinal changes in ctDNA correlated with treatment response and disease progression determined by radiology. This study confirms that ctDNA may be used as a noninvasive liquid biopsy to identify recurrent disease and detect targetable variants in patients with late-stage melanoma.


Subject(s)
Circulating Tumor DNA , Melanoma , Humans , Circulating Tumor DNA/genetics , Proto-Oncogene Proteins B-raf/genetics , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/therapeutic use , Melanoma/diagnosis , Melanoma/genetics , Biomarkers, Tumor/genetics , Mutation
7.
Anesthesiol Clin ; 41(3): 671-691, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37516502

ABSTRACT

With the increase in life expectancy in the United States, octogenarians and nonagenarians are more frequently seen in clinical practice. The elderly patients have multiple preexisting comorbidities and are on multiple medications, which can make pain management complex. Moreover, the elderly population often suffers from chronic pain related to degenerative processes, making medical management challenging. In this review, the authors collated available evidence for best practices for pain management in the elderly.


Subject(s)
Chronic Pain , Pain Management , Aged, 80 and over , Humans , Aged , United States , Chronic Pain/therapy , Comorbidity
8.
Sci Immunol ; 8(84): eadd9232, 2023 06 08.
Article in English | MEDLINE | ID: mdl-37267382

ABSTRACT

Group A Streptococcus (GAS) infection is associated with multiple clinical sequelae, including different subtypes of psoriasis. Such post-streptococcal disorders have been long known but are largely unexplained. CD1a is expressed at constitutively high levels by Langerhans cells and presents lipid antigens to T cells, but the potential relevance to GAS infection has not been studied. Here, we investigated whether GAS-responsive CD1a-restricted T cells contribute to the pathogenesis of psoriasis. Healthy individuals had high frequencies of circulating and cutaneous GAS-responsive CD4+ and CD8+ T cells with rapid effector functions, including the production of interleukin-22 (IL-22). Human skin and blood single-cell CITE-seq analyses of IL-22-producing T cells showed a type 17 signature with proliferative potential, whereas IFN-γ-producing T cells displayed cytotoxic T lymphocyte characteristics. Furthermore, individuals with psoriasis had significantly higher frequencies of circulating GAS-reactive T cells, enriched for markers of activation, cytolytic potential, and tissue association. In addition to responding to GAS, subsets of expanded GAS-reactive T cell clones/lines were found to be autoreactive, which included the recognition of the self-lipid antigen lysophosphatidylcholine. CD8+ T cell clones/lines produced cytolytic mediators and lysed infected CD1a-expressing cells. Furthermore, we established cutaneous models of GAS infection in a humanized CD1a transgenic mouse model and identified enhanced and prolonged local and systemic inflammation, with resolution through a psoriasis-like phenotype. Together, these findings link GAS infection to the CD1a pathway and show that GAS infection promotes the proliferation and activation of CD1a-autoreactive T cells, with relevance to post-streptococcal disease, including the pathogenesis and treatment of psoriasis.


Subject(s)
CD8-Positive T-Lymphocytes , Psoriasis , Humans , Mice , Animals , Skin , Inflammation/pathology , Streptococcus pyogenes , Mice, Transgenic , Lipids
9.
Blood ; 141(23): 2841-2852, 2023 06 08.
Article in English | MEDLINE | ID: mdl-36877894

ABSTRACT

Therapeutic targeting of CDK7 has proven beneficial in preclinical studies, yet the off-target effects of currently available CDK7 inhibitors make it difficult to pinpoint the exact mechanisms behind MM cell death mediated by CDK7 inhibition. Here, we show that CDK7 expression positively correlates with E2F and MYC transcriptional programs in cells from patients with multiple myeloma (MM); its selective targeting counteracts E2F activity via perturbation of the cyclin-dependent kinases/Rb axis and impairs MYC-regulated metabolic gene signatures translating into defects in glycolysis and reduced levels of lactate production in MM cells. CDK7 inhibition using the covalent small-molecule inhibitor YKL-5-124 elicits a strong therapeutic response with minimal effects on normal cells, and causes in vivo tumor regression, increasing survival in several mouse models of MM including a genetically engineered mouse model of MYC-dependent MM. Through its role as a critical cofactor and regulator of MYC and E2F activity, CDK7 is therefore a master regulator of oncogenic cellular programs supporting MM growth and survival, and a valuable therapeutic target providing rationale for development of YKL-5-124 for clinical use.


Subject(s)
Cyclin-Dependent Kinase-Activating Kinase , Multiple Myeloma , Animals , Mice , Cyclin-Dependent Kinases/genetics , Cyclin-Dependent Kinases/metabolism , Multiple Myeloma/genetics
10.
Rapid Commun Mass Spectrom ; 37(7): e9471, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36617505

ABSTRACT

RATIONALE: Noble gases are widely used as physically based climate proxies, notably in dissolved water samples as tracers of past recharge temperature in groundwater and air-sea gas exchange processes in seawater. Recent advances in measuring large-volume samples of dissolved noble gas isotopic ratios at high precision have expanded the range of climate parameters that can be interpreted. METHODS: We build on prior methods for measuring noble gas stable isotopes at high precision with a new large-volume equilibration (LVE) method wherein sample gases are equilibrated in the sample flask between the dissolved phase and the headspace. The original dissolved gas composition is determined by measuring the headspace gases and correcting for the equilibrium dissolved gas content of the discarded water using known solubilities and fractionation factors. We evaluate the accuracy and precision of this method with air-equilibrated water standards of known noble gas composition. RESULTS: Replicate air-equilibrated water standards and field measurements demonstrate that the LVE method achieves comparable precision to prior methods, with major advantages of measuring the Ne content as a constraint on excess air and allowing for long-term sample storage. Isotope ratios measured with the LVE method in replicate samples were consistent between two laboratories, and LVE elemental noble gas abundances agreed closely with replicate samples measured using established copper-tube methods and static noble gas mass spectrometry. CONCLUSIONS: The new LVE method enables reconstruction of past water table depths at ±1 m precision along with excess air, recharge temperature, and age and hydrogeochemical indicators. It has wide application to investigating climate signals and physical gas exchange processes in groundwater and seawater.

11.
Pediatr Dev Pathol ; 26(2): 149-152, 2023.
Article in English | MEDLINE | ID: mdl-36533315

ABSTRACT

Pediatric renal tumors are a rare entity and majority of these tumors are accounted for by Wilms tumor. The second most common renal tumor is clear cell sarcoma of the kidney (CSSK). Most of the CSSK have either BCOR-internal tandem duplication (ITD) or YWHAE-NUTM2B/E fusion. The sarcomas with BCOR-CCNB3 fusion are well documented in soft tissue and bone tumors, but are extremely rare in the pediatric renal setting. We are reporting an extremely rare case of pediatric clear cell sarcoma of the kidney (CSSK) with BCOR-CCNB3 fusion, which was a diagnostic challenge on morphological grounds. A final diagnosis could only be reached after multiple reviews and NGS based RNA fusion testing. We have also performed a brief review of literature which revealed eight (8) other cases of this rare entity.


Subject(s)
Kidney Neoplasms , Sarcoma, Clear Cell , Humans , Child , Sarcoma, Clear Cell/diagnosis , Sarcoma, Clear Cell/genetics , Repressor Proteins/genetics , Transcription Factors , Kidney Neoplasms/diagnosis , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , Biomarkers, Tumor/genetics , Kidney/pathology , Cyclin B , Proto-Oncogene Proteins/genetics
12.
Methods Mol Biol ; 2578: 121-141, 2023.
Article in English | MEDLINE | ID: mdl-36152284

ABSTRACT

This chapter describes an epitope-directed approach to generate antipeptide monoclonal antibodies to multiple nonoverlapping protein sites using a cocktail of fusion peptides as immunogen. It provides a step-by-step protocol on how antigenic peptides on a target protein can be identified by in silico prediction and discusses considerations for final peptide selection. Each antigenic peptide (10-20 amino acids long) is displayed as three-copy inserts on the surface exposed loop of a thioredoxin scaffold protein. The corresponding DNA coding sequence specifying the tripeptide insert flanked by Gly-Ser-Gly-Ser-Gly linkers is cloned in-frame into the Rsr II site of the thioredoxin gene in the pET-32a vector. The presence of a C-terminal polyhistidine tag (His6-tag) allows the soluble fusion proteins to be purified by one-step native immobilized metal affinity chromatography (IMAC) to greater than 95% purity. Multiple thioredoxin fusion proteins are mixed in equimolar concentrations and used as an immunogen cocktail for animal immunization. The use of short antigenic peptides of known sequence facilitates direct epitope mapping requiring only small mutagenesis scan peptide libraries in the multipin peptide format.


Subject(s)
Antibodies, Monoclonal , Peptide Library , Amino Acid Sequence , Animals , Antibodies, Monoclonal/genetics , Antigens , Epitope Mapping/methods , Epitopes , Peptides/genetics , Thioredoxins/genetics
13.
Am J Surg Pathol ; 46(11): 1554-1561, 2022 11 01.
Article in English | MEDLINE | ID: mdl-35941720

ABSTRACT

Over the past decade, several distinct novel renal epithelial neoplasms driven by underlying tuberous sclerosis comples ( TSC)/ mammalian target of rapamycin (MTOR) pathway mutations have been described. We report herein two distinctive TSC2 -mutated renal cell carcinomas which do not fit any previously described entity. The two renal carcinomas occurred in young patients (ages 10 and 31 y), and were characterized by highly permeative growth within the kidney with metastases to perirenal lymph nodes. The neoplastic cells were predominantly large, multinucleated giant cells having variably eosinophilic to xanthomatous cytoplasm with basophilic stippling and frequent vacuolization. While the discohesive nature of the neoplastic cells, xanthomatous cytoplasm, immunoreactivity for histiocytic markers and minimal immunoreactivity for conventional epithelial markers raised the possibility of a histiocytic neoplasm, multifocal immunoreactivity for cytokeratin 20 helped establish their epithelial nature. Despite the aggressive growth pattern of these neoplasms and lymph node metastases, mitotic figures were rare and Ki-67 indices were low (<1%). One patient with follow-up shows no evidence of disease seven years after nephrectomy with no adjuvant therapy. Next-generation sequencing demonstrated TSC2 mutations in each case. By immunohistochemistry, downstream markers of mTOR pathway activation S6K1, 4EBP1, and glycoprotein nonmetastatic melanoma protein B were all highly expressed in these neoplasms, suggesting mTOR pathway activation as the neoplastic driver. While the cytokeratin 20 immunoreactivity and focal basophilic cytoplasmic stippling suggest a relationship to eosinophilic solid and cystic renal cell carcinoma, and cytoplasmic vacuolization suggests a relationship to eosinophilic vacuolated tumor, these neoplasms appear to be distinctive given their permeative growth patterns and predominant xanthomatous giant cell morphology. Addition of cytokeratin 20 to a panel of epithelial markers helps avoid misdiagnosis in such cases.


Subject(s)
Carcinoma, Renal Cell , Kidney Neoplasms , Tuberous Sclerosis , Adolescent , Adult , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Renal Cell/pathology , Child , Female , Giant Cells/pathology , Glycoproteins , Humans , Keratin-20 , Ki-67 Antigen , Kidney Neoplasms/pathology , Male , TOR Serine-Threonine Kinases/genetics , Tuberous Sclerosis Complex 1 Protein , Young Adult
14.
Cureus ; 14(6): e26214, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35891827

ABSTRACT

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare and non-invasive tumors of the appendix, and their unexpected discovery during surgery can pose challenges to management. To date, only two cases pertaining to LAMNs without peritoneal spread in pregnancy exist in the literature. Here, we present a literature review of appendiceal mucinous neoplasms and discuss our management and operative approach to a large, incidental appendiceal mucinous neoplasm discovered during an emergency cesarean section of a 38-year-old female.

15.
ACS Omega ; 7(29): 25510-25520, 2022 Jul 26.
Article in English | MEDLINE | ID: mdl-35903176

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) inactivation is an important step toward enhanced biosafety in testing facilities and affords a reduction in the biocontainment level necessary for handling virus-positive biological specimens. Virus inactivation methods commonly employ heat, detergents, or combinations thereof. In this work, we address the dearth of information on the efficacy of SARS-CoV-2 inactivation procedures in plasma and their downstream impact on immunoassays. We evaluated the effects of heat (56 °C for 30 min), detergent (1-5% Triton X-100), and solvent-detergent (SD) combinations [0.3-1% tri-n-butyl phosphate (TNBP) and 1-2% Triton X-100] on 19 immunoassays across different assay formats. Treatments are deemed immunoassay-compatible when the average and range of percentage recovery (treated concentration relative to untreated concentration) lie between 90-110 and 80-120%, respectively. We show that SD treatment (0.3% TNBP/1% Triton-X100) is compatible with more than half of the downstream immunoassays tested and is effective in reducing SARS-CoV-2 infectivity in plasma to below detectable levels in plaque assays. This facile method offers enhanced safety for laboratory workers handling biological specimens in clinical and research settings.

16.
Ophthalmic Plast Reconstr Surg ; 38(5): e154-e158, 2022.
Article in English | MEDLINE | ID: mdl-35550454

ABSTRACT

The authors describe a rare case of primary extradural ectopic meningioma of the orbit in a 13-year-old female managed with surgical excision, adding to the very limited literature of this diagnosis in children. This is the second case to show a radiological abnormality in the gyrus rectus and olfactory bulb; however, in our case, there was no radiological evidence of connection seen.


Subject(s)
Meningeal Neoplasms , Meningioma , Orbital Neoplasms , Adolescent , Child , Female , Humans , Magnetic Resonance Imaging , Meningeal Neoplasms/diagnosis , Meningeal Neoplasms/surgery , Meningioma/diagnosis , Meningioma/surgery , Orbit , Orbital Neoplasms/diagnosis , Orbital Neoplasms/surgery
17.
Aust N Z J Obstet Gynaecol ; 62(4): 589-595, 2022 08.
Article in English | MEDLINE | ID: mdl-35482668

ABSTRACT

BACKGROUND: Laparoscopy is the gold standard approach for many surgical procedures, but it is a complex skill to learn. Laparoscopic simulation training may help, but it is unclear how to best engage trainees in these programs. Test-enhanced learning (TEL) uses regular, well-defined assessments of performance throughout the training phase of learning. AIM: The aim of this study was to assess the effects of TEL on a laparoscopic simulation program involving a cohort of medical student volunteers. MATERIALS AND METHODS: A prospective cohort study was performed with a convenience sample of 40 medical students. Students were recruited to participate in a ten-week laparoscopic simulation program. Twenty students participated in a laparoscopic surgical program with TEL ('TEL group'), and 20 students participated in a standard laparoscopic simulation program ('control group'). RESULTS: Attendance in the TEL group was significantly higher than in the standard group (71 vs 51.5%, P = 0.03). There was no difference between groups in mean time scores. Four themes were identified in qualitative data drawn from student surveys - personal traits and motivators, training context, clear goals and feedback enabling understanding of one's own performance. CONCLUSION: Testing laparoscopic skills throughout a learning program, in conjunction with individualised feedback and tracking of learning trajectory, increases trainee attendance. Laparoscopic simulation training programs are encouraged to reflect on the pedagogic framework in which their procedural skills training operates.


Subject(s)
Laparoscopy , Simulation Training , Clinical Competence , Computer Simulation , Humans , Laparoscopy/education , Prospective Studies
18.
Clin Biochem ; 104: 51-58, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35331754

ABSTRACT

BACKGROUND: Lack of validation and standardization of research-use-only (RUO) immunoassays brings with it inherent threats to authenticity and functional quality. Poor correlation between different commercial neprilysin RUO immunoassays is concerning and discordant findings need to be resolved. We seek to identify and validate reliable neprilysin immunoassays to strengthen the scientific rigor and reproducibility of neprilysin-related investigation and of biomarker research in general. METHODS: Soluble neprilysin (sNEP) concentrations were determined in cohorts (n = 532) from Spain (Cohort 1), New Zealand (NZ, Cohort 2) and Singapore (Cohort 3), using commercial kits from six vendors. Apparent sNEP concentrations were correlated between different assays and with plasma neprilysin activity. Assay reliability was further validated by performance verification, MS analysis and cross-reactivity tests. RESULTS: sNEP in Cohorts 1 and 2 measured concurrently in Spain and NZ showed significant inter-laboratory correlation only for the Aviscera Bioscience sNEP ELISA SK00724-01. Neprilysin concentrations obtained with the R&D systems and SK00724-01 ELISAs correlated with each other but not with neprilysin activity. In Cohort 3, sNEP concentrations from the Perkin Elmer AlphaLISA and Biotechne ELLA assays agreed (r = 0.89) and both correlated with neprilysin activity (r = 0.87, 0.77 respectively). MS analysis detected authentic neprilysin in the AlphaLISA kit calibrator and in antibody pull-down material from human plasma. The AlphaLISA assay performed within acceptable limits (spike and recovery, dilutional linearity, inter- and intra-assay CV) and showed no cross-reactivity against neprilysin substrates and closely-related analogues. CONCLUSION: AlphaLISA and ELLA assays provide reliable measures of sNEP concentrations. Reliability of other commercial neprilysin assays remains in question.


Subject(s)
Heart Failure , Neprilysin , Biomarkers , Enzyme-Linked Immunosorbent Assay , Humans , Reproducibility of Results , Spain
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