Clinical Medicine
Abstract
BACKGROUND. Cryptococcal meningitis (CM) causes an estimated 180,000 deaths annually, predominantly in sub-Saharan Africa, where most patients receive fluconazole (FLC) monotherapy. While relapse after FLC monotherapy with resistant strains is frequently observed, the mechanisms and impact of emergence of FLC resistance in human CM are poorly understood. Heteroresistance (HetR) — a resistant subpopulation within a susceptible strain — is a recently described phenomenon in Cryptococcus neoformans (Cn) and Cryptococcus gattii (Cg), the significance of which has not previously been studied in humans. METHODS. A cohort of 20 patients with HIV-associated CM in Tanzania was prospectively observed during therapy with either FLC monotherapy or in combination with flucytosine (5FC). Total and resistant subpopulations of Cryptococcus spp. were quantified directly from patient cerebrospinal fluid (CSF). Stored isolates underwent whole genome sequencing and phenotypic characterization. RESULTS. Heteroresistance was detectable in Cryptococcus spp. in the CSF of all patients at baseline (i.e., prior to initiation of therapy). During FLC monotherapy, the proportion of resistant colonies in the CSF increased during the first 2 weeks of treatment. In contrast, no resistant subpopulation was detectable in CSF by day 14 in those receiving a combination of FLC and 5FC. Genomic analysis revealed high rates of aneuploidy in heteroresistant colonies as well as in relapse isolates, with chromosome 1 (Chr1) disomy predominating. This is apparently due to the presence on Chr1 of ERG11, which is the FLC drug target, and AFR1, which encodes a drug efflux pump. In vitro efflux levels positively correlated with the level of heteroresistance. CONCLUSION. Our findings demonstrate for what we believe is the first time the presence and emergence of aneuploidy-driven FLC heteroresistance in human CM, association of efflux levels with heteroresistance, and the successful suppression of heteroresistance with 5FC/FLC combination therapy. FUNDING. This work was supported by the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377/Z/11/Z and the Daniel Turnberg Travel Fellowship.
Authors
Neil R.H. Stone, Johanna Rhodes, Matthew C. Fisher, Sayoki Mfinanga, Sokoine Kivuyo, Joan Rugemalila, Ella Shtifman Segal, Leor Needleman, Síle F. Molloy, June Kwon-Chung, Thomas S. Harrison, William Hope, Judith Berman, Tihana Bicanic
Abstract
Background/Purpose: Plasmacytoid dendritic cells (pDC) produce large amounts of type I IFN (IFN-I), cytokines convincingly linked to systemic lupus erythematosus (SLE) pathogenesis. BIIB059 is a humanized mAb that binds BDCA2, a pDC-specific receptor that inhibits the production of IFN-I and other inflammatory mediators when ligated. A first-in-human study was conducted to assess safety, tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) effects of single BIIB059 doses in healthy volunteers (HV) and patients with SLE with active cutaneous disease as well as proof of biological activity and preliminary clinical response in the SLE cohort. Methods: A randomized, double-blind, placebo-controlled, clinical trial was conducted in HV (n=54) and patients with SLE (n=12). All subjects were monitored for adverse events. Serum BIIB059 concentrations, BDCA2 levels on pDCs, and IFN-responsive biomarkers in whole blood and skin biopsies were measured. Skin disease activity was determined using the Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A).Results: Single doses of BIIB059 were associated with a favorable safety and PK profile. BIIB059 administration led to BDCA2 internalization on pDCs, which correlated with circulating BIIB059 levels. BIIB059 administration in patients with SLE decreased expression of IFN response genes in blood, normalized MxA expression and reduced immune infiltrates in skin lesions, and decreased CLASI-A score. Conclusion: Single doses of BIIB059 were associated with favorable safety and PK/PD profiles, and robust target engagement and biological activity, supporting further development of BIIB059 in SLE. The data suggest that targeting pDCs may be beneficial for patients with SLE, especially those with cutaneous manifestations.
Authors
Richard Furie, Victoria P. Werth, Joseph F. Merola, Lauren Stevenson, Taylor L. Reynolds, Himanshu Naik, Wenting Wang, Romy Christmann, Agnes Gardet, Alex Pellerin, Stefan Hamann, Pavan Auluck, Catherine Barbey, Parul Gulati, Dania Rabah, Nathalie Franchimont
Abstract
Background. Sphingolipids are important components of cellular membranes and functionally associated with fundamental processes such as cell differentiation, neuronal signaling and myelin sheath formation. Defects in the synthesis or degradation of sphingolipids leads to various neurological pathologies, however, the entire spectrum of sphingolipid metabolism disorders remained elusive. Methods. A combined approach of genomics and lipidomics was applied to identify and characterize a human sphingolipid metabolism disorder.Results. By whole-exome sequencing in a patient with a multisystem neurological disorder of both the central and peripheral nervous system, we identified a homozygous p.(Ala280Val) variant in DEGS1, which catalyzes the last step in the ceramide synthesis pathway. The blood sphingolipid profile in the patient showed a significant increase in dihydro sphingolipid species which was further recapitulated in patient-derived fibroblasts, in CRISPR/Cas9-derived DEGS1 knockout cells, and by pharmacological inhibition of DEGS1. The enzymatic activity in patient fibroblasts was reduced by 80% compared to wild type cells which was in line with a reduced expression of mutant DEGS1 protein. Moreover, an atypical and potentially neurotoxic sphingosine isomer was identified in patient plasma and in cells expressing mutant DEGS1. Conclusion. We report DEGS1 dysfunction as cause for a novel sphingolipid disorder with hypomyelination and degeneration of both the central and peripheral nervous system.Trial registration. Not applicable.Funding. RESOLVE: Project number 305707; SNF: Project 31003A_153390/1; Rare Disease Initiative Zurich.
Authors
Gergely Karsai, Florian Kraft, Natja Haag, G. Christoph Korenke, Benjamin Hänisch, Alaa Othman, Saranya Suriyanarayanan, Regula Steiner, Cordula Knopp, Michael Mull, Markus Bergmann, J. Michael Schröder, Joachim Weis, Miriam Elbracht, Matthias Begemann, Thorsten Hornemann, Ingo Kurth
Abstract
BACKGROUND. Awake neurosurgery requires patients to converse and respond to visual or verbal prompts to identify and protect brain tissue supporting essential functions such as language, primary sensory modalities, and motor function. These procedures can be poorly tolerated due to patient anxiety, yet acute anxiolytic medications typically cause sedation and impair cortical function. METHODS. In this study, direct electrical stimulation of the left dorsal anterior cingulum bundle was discovered to reliably evoke positive affect and anxiolysis without sedation in an epilepsy patient undergoing research testing during standard, in-patient intracranial electrode monitoring. These effects were quantified using subjective and objective behavioral measures, and stimulation was found to evoke robust changes in local and distant neural activity. RESULTS. The index patient ultimately required an awake craniotomy procedure to confirm safe resection margins in the treatment of her epilepsy. During the procedure, cingulum bundle stimulation enhanced positive affect and reduced the patient’s anxiety to the point that intravenous anesthetic/anxiolytic medications were discontinued and cognitive testing was completed. Behavioral responses were subsequently replicated in two patients with anatomically similar electrode placements localized to an approximately 1cm span along the anterior dorsal cingulum bundle above genu of the corpus callosum. CONCLUSIONS. The current study demonstrates a robust anxiolytic response to cingulum bundle stimulation in three epilepsy patients. TRIAL REGISTRATION. The current study was not affiliated with any formal clinical trial. FUNDING. This project was supported by the American Foundation for Suicide Prevention and the National Institutes of Health.
Authors
Kelly R. Bijanki, Joseph R. Manns, Cory S. Inman, Ki Sueng Choi, Sahar Harati, Nigel P. Pedersen, Daniel L. Drane, Allison C. Waters, Rebecca E. Fasano, Helen S. Mayberg, Jon T. Willie
Abstract
BACKGROUND.l-Carnitine, an abundant nutrient in red meat, accelerates atherosclerosis in mice via gut microbiota–dependent formation of trimethylamine (TMA) and trimethylamine N-oxide (TMAO) via a multistep pathway involving an atherogenic intermediate, γ-butyrobetaine (γBB). The contribution of γBB in gut microbiota–dependent l-carnitine metabolism in humans is unknown. METHODS. Omnivores and vegans/vegetarians ingested deuterium-labeled l-carnitine (d3-l-carnitine) or γBB (d9-γBB), and both plasma metabolites and fecal polymicrobial transformations were examined at baseline, following oral antibiotics, or following chronic (≥2 months) l-carnitine supplementation. Human fecal commensals capable of performing each step of the l-carnitine→γBB→TMA transformation were identified. RESULTS. Studies with oral d3-l-carnitine or d9-γBB before versus after antibiotic exposure revealed gut microbiota contribution to the initial 2 steps in a metaorganismal l-carnitine→γBB→TMA→TMAO pathway in subjects. Moreover, a striking increase in d3-TMAO generation was observed in omnivores over vegans/vegetarians (>20-fold; P = 0.001) following oral d3-l-carnitine ingestion, whereas fasting endogenous plasma l-carnitine and γBB levels were similar in vegans/vegetarians (n = 32) versus omnivores (n = 40). Fecal metabolic transformation studies, and oral isotope tracer studies before versus after chronic l-carnitine supplementation, revealed that omnivores and vegans/vegetarians alike rapidly converted carnitine to γBB, whereas the second gut microbial transformation, γBB→TMA, was diet inducible (l-carnitine, omnivorous). Extensive anaerobic subculturing of human feces identified no single commensal capable of l-carnitine→TMA transformation, multiple community members that converted l-carnitine to γBB, and only 1 Clostridiales bacterium, Emergencia timonensis, that converted γBB to TMA. In coculture, E. timonensis promoted the complete l-carnitine→TMA transformation. CONCLUSION. In humans, dietary l-carnitine is converted into the atherosclerosis- and thrombosis-promoting metabolite TMAO via 2 sequential gut microbiota–dependent transformations: (a) initial rapid generation of the atherogenic intermediate γBB, followed by (b) transformation into TMA via low-abundance microbiota in omnivores, and to a markedly lower extent, in vegans/vegetarians. Gut microbiota γBB→TMA/TMAO transformation is induced by omnivorous dietary patterns and chronic l-carnitine exposure. TRIAL REGISTRATION. ClinicalTrials.gov NCT01731236. FUNDING. NIH and Office of Dietary Supplements grants HL103866, HL126827, and DK106000, and the Leducq Foundation.
Authors
Robert A. Koeth, Betzabe Rachel Lam-Galvez, Jennifer Kirsop, Zeneng Wang, Bruce S. Levison, Xiaodong Gu, Matthew F. Copeland, David Bartlett, David B. Cody, Hong J. Dai, Miranda K. Culley, Xinmin S. Li, Xiaoming Fu, Yuping Wu, Lin Li, Joseph A. DiDonato, W.H. Wilson Tang, Jose Carlos Garcia-Garcia, Stanley L. Hazen
Abstract
BACKGROUND. Patients with schizophrenia (SCZ) experience chronic cognitive deficits. Histone deacetylases (HDACs) are enzymes that regulate cognitive circuitry; however, the role of HDACs in cognitive disorders, including SCZ, remains unknown in humans. We previously determined that HDAC2 mRNA levels were lower in dorsolateral prefrontal cortex (DLPFC) tissue from donors with SCZ compared with controls. Here we investigated the relationship between in vivo HDAC expression and cognitive impairment in patients with SCZ and matched healthy controls using [11C]Martinostat positron emission tomography (PET). METHODS. In a case-control study, relative [11C]Martinostat uptake was compared between 14 patients with SCZ or schizoaffective disorder (SCZ/SAD) and 17 controls using hypothesis-driven region-of-interest analysis and unbiased whole brain voxel-wise approaches. Clinical measures, including the MATRICS consensus cognitive battery, were administered. RESULTS. Relative HDAC expression was lower in the DLPFC of patients with SCZ/SAD compared with controls, and HDAC expression positively correlated with cognitive performance scores across groups. Patients with SCZ/SAD also showed lower relative HDAC expression in the dorsomedial prefrontal cortex and orbitofrontal gyrus, and higher relative HDAC expression in the cerebral white matter, pons, and cerebellum compared with controls. CONCLUSIONS. These findings provide in vivo evidence of HDAC dysregulation in patients with SCZ and suggest that altered HDAC expression may impact cognitive function in humans. FUNDING. National Institute of Mental Health (NIMH), Brain and Behavior Foundation, Massachusetts General Hospital (MGH), Athinoula A. Martinos Center for Biomedical Imaging, National Institute of Biomedical Imaging and Bioengineering (NIBIB), NIH Shared Instrumentation Grant Program.
Authors
Tonya M. Gilbert, Nicole R. Zürcher, Christine J. Wu, Anisha Bhanot, Baileigh G. Hightower, Minhae Kim, Daniel S. Albrecht, Hsiao-Ying Wey, Frederick A. Schroeder, Anais Rodriguez-Thompson, Thomas M. Morin, Kamber L. Hart, Amelia M. Pellegrini, Misha M. Riley, Changning Wang, Steven M. Stufflebeam, Stephen J. Haggarty, Daphne J. Holt, Marco L. Loggia, Roy H. Perlis, Hannah E. Brown, Joshua L. Roffman, Jacob M. Hooker
Abstract
BACKGROUND. Varicella-zoster virus (VZV) is under consideration as a promising recombinant viral vector to deliver foreign antigens including HIV. However, new vectors have come under increased scrutiny since vaccination with Ad5-vectored HIV vaccine trials demonstrated increased HIV risk in individuals with pre-immunity to the vector which was thought to be associated with mucosal immune activation (IA). Therefore, defining the impact of VZV vaccination on IA is particularly important with the prospect of developing an HIV/VZV chimeric vaccine. METHODS. VZV-seropositive healthy Kenyan women (n=44) were immunized with high dose live-attenuated VZV vaccine, and the expression of IA markers including CD38 and HLA-DR on CD4 T cells isolated from blood, cervix and rectum, markers of cell migration and tissue retention and the concentration of genital and intestinal cytokines were assessed. A delayed group (n=22) was used to control for natural variations in these parameters. RESULTS. Although immunogenic, VZV vaccination did not result in significant difference in the frequency of cervical activated (HLA-DR+CD38+) CD4 T cells (median 1.61%, IQR 0.93%-2.76%) at 12 weeks post-vaccination when compared to baseline (median 1.58%, IQR 0.75%-3.04%), the primary outcome for this study. VZV vaccination also had no measurable effect on any of the IA parameters at 4, 8 and 12 weeks post-vaccination. CONCLUSION. This study provides the first-ever evidence about the effects of VZV-vaccination on human mucosal IA status and supports further evaluation of VZV as a potential vector in an HIV vaccine. TRIAL REGISTRATION. ClinicalTrials.gov NCT02514018. FUNDING. Primary support from CIHR. For others see below.
Authors
Catia T. Perciani, Bashir Farah, Rupert Kaul, Mario A. Ostrowski, Salaheddin M. Mahmud, Omu Anzala, Walter Jaoko, Kelly S. MacDonald
Abstract
BACKGROUND. Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous smoking-related disease characterized by airway obstruction and inflammation. This inflammation may persist even after smoking cessation and responds variably to corticosteroids. Personalizing treatment to biologically similar “molecular phenotypes” may improve therapeutic efficacy in COPD. IL-17A is involved in neutrophilic inflammation and corticosteroid resistance, and thus may be particularly important in a COPD molecular phenotype. METHODS. We generated a gene expression signature of IL-17A response in bronchial airway epithelial brushings (“BAE”) from smokers with and without COPD (n = 238), and validated it using data from two randomized trials of IL-17 blockade in psoriasis. This IL-17 signature was related to clinical and pathologic characteristics in two additional human studies of COPD: (1) SPIROMICS (n = 47), which included former and current smokers with COPD, and (2) GLUCOLD (n = 79), in which COPD participants were randomized to placebo or corticosteroids. RESULTS. The IL-17 signature was associated with an inflammatory profile characteristic of an IL-17 response, including increased airway neutrophils and macrophages. In SPIROMICS the signature was associated with increased airway obstruction and functional small airway disease on quantitative chest CT. In GLUCOLD the signature was associated with decreased response to corticosteroids, irrespective of airway eosinophilic or Type 2 inflammation. CONCLUSION. These data suggest that a gene signature of IL-17 airway epithelial response distinguishes a biologically, radiographically, and clinically distinct COPD subgroup that may benefit from personalized therapy. TRIAL REGISTRATION. ClinicalTrials.gov NCT01969344. FUNDING. Primary support from NIH/NHLBI. For others see below.
Authors
Stephanie A. Christenson, Maarten van den Berge, Alen Faiz, Kai Imkamp, Nirav Bhakta, Luke R. Bonser, Lorna T. Zlock, Igor Z. Barjaktarevic, R. Graham Barr, Eugene R. Bleecker, Richard C. Boucher, Russell P. Bowler, Alejandro P. Comellas, Jeffrey L. Curtis, MeiLan K. Han, Nadia N. Hansel, Pieter S. Hiemstra, Robert J. Kaner, Jerry A. Krishnan, Fernando J. Martinez, Wanda K. O'Neal, Robert Paine III, Wim Timens, J. Michael Wells, Avrum Spira, David J. Erle, Prescott G. Woodruff
Abstract
BACKGROUND. Liquid biopsies have demonstrated that the constitutively active androgen receptor splice variant-7 (AR-V7) associates with reduced response and overall survival (OS) from endocrine therapies in castration resistant prostate cancer (CRPC). However, these studies provide little information pertaining to AR-V7 expression in prostate cancer (PC) tissue. METHODS. Following generation and validation of a novel AR-V7 antibody for immunohistochemistry, AR-V7 protein expression was determined for 358 primary prostate samples and 293 metastatic biopsies. Associations with disease progression, full length AR (AR-FL) expression, response to therapy, and gene expression was determined. RESULTS. We demonstrated that AR-V7 protein is rarely expressed (<1%) in primary PC but is frequently detected (75% of cases) following androgen deprivation therapy, with further significant (P = 0.020) increase in expression following abiraterone acetate or enzalutamide therapy. In CRPC, AR-V7 expression is predominantly (94% of cases) nuclear and correlates with AR-FL expression (P ≤ 0.001) and AR copy number (P = 0.026). However, dissociation of expression was observed suggesting mRNA splicing remains crucial for AR-V7 generation. AR-V7 expression was heterogeneous between different metastases from a patient although AR-V7 expression was similar within a metastasis. Moreover, AR-V7 expression correlated with a unique 59-gene signature in CRPC, including HOXB13, a critical co-regulator of AR-V7 function. Finally, AR-V7 negative disease associated with better PSA responses (100% vs 54%; P = 0.03) and OS (74.3 vs 25.2mo, HR 0.23 [0.07-0.79], P = 0.02) from endocrine therapies (pre-chemotherapy). CONCLUSION. This study provides impetus to develop therapies that abrogate AR-V7 signaling to improve our understanding of AR-V7 biology, and to confirm its clinical significance.
Authors
Adam Sharp, Ilsa Coleman, Wei Yuan, Cynthia Sprenger, David Dolling, Daniel Nava Rodrigues, Joshua W. Russo, Ines Figueiredo, Claudia Bertan, George Seed, Ruth Riisnaes, Takuma Uo, Antje Neeb, Jonathan Welti, Colm Morrissey, Suzanne Carreira, Jun Luo, Peter S. Nelson, Steven P. Balk, Lawrence D. True, Johann De Bono, Stephen R. Plymate
Abstract
BACKGROUND. Chronic obstructive pulmonary disease (COPD) is characterized by airway remodeling. Characterization of airway changes on computed tomography has been challenging due to the complexity of the recurring branching patterns, and this can be better measured using fractal dimensions. METHODS. We analyzed segmented airway trees of 8135 participants enrolled in the COPDGene cohort. The fractal complexity of the segmented airway tree was measured by the Airway Fractal Dimension (AFD) using the Minkowski-Bouligand box-counting dimension. We examined associations between AFD and lung function and respiratory morbidity using multivariable regression analyses. We further estimated the extent of peribronchial emphysema (%) within 5mm of the airway tree as this is likely to affect AFD. We classified participants into 4 groups based on median AFD and %peribronchial emphysema, and estimated survival. RESULTS. AFD was significantly associated with FEV1 (p<0.001) and FEV1/FVC (p<0.001) after adjusting for age, race, gender, smoking status, pack-years of smoking, body-mass-index, CT emphysema, air trapping, airway thickness, and CT scanner type. On multivariable analysis, AFD was also associated with respiratory-quality of life and six-minute walk distance, as well as exacerbations, lung function decline and mortality on longitudinal follow-up. We identified a subset of participants with AFDmedian who had worse survival compared with participants with high AFD and low peribronchial emphysema (adjusted HR = 2.72, 95%CI 2.20 to 3.35; p<0.001), a substantial number of whom were not identified by traditional spirometry severity grades. CONCLUSIONS. Airway fractal dimension as a measure of airway branching complexity and remodeling in smokers is associated with respiratory morbidity and lung function change, offers prognostic information additional to traditional CT measures of airway wall thickness, and can be used to estimate mortality risk.
Authors
Sandeep Bodduluri, Abhilash S. Kizhakke Puliyakote, Sarah E. Gerard, Joseph M. Reinhardt, Eric A. Hoffman, John D. Newell Jr., Hrudaya P. Nath, MeiLan K. Han, George R. Washko, Raúl San José Estépar, Mark T. Dransfield, Surya P. Bhatt
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Copyright © 2019 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)