Publications by authors named "Patrick Haslett"

Background & Aims: Current therapy for chronic hepatitis B virus (cHBV) infection involves lifelong treatment. New treatments that enable HBV functional cure would represent a clinically meaningful advance. ALN-HBV and VIR-2218 are investigational RNA interference therapeutics that target all major HBV transcripts.

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Article Synopsis
  • - Preclinical studies indicate that off-target effects from RNA interference contribute significantly to hepatotoxicity in GalNAc-siRNA conjugates.
  • - Researchers developed a new strategy called enhanced stabilization chemistry plus (ESC+) which effectively reduces off-target binding while preserving the intended on-target effects in RNA therapies.
  • - This approach was successfully applied to ALN-HBV, leading to a redesigned version (ALN-HBV02) with better specificity and safety, allowing it to resume clinical development.
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Understanding mechanisms of hepatocellular damage may lead to new treatments for liver disease, and genome-wide association studies (GWAS) of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) serum activities have proven useful for investigating liver biology. Here we report 100 loci associating with both enzymes, using GWAS across 411,048 subjects in the UK Biobank. The rare missense variant SLC30A10 Thr95Ile (rs188273166) associates with the largest elevation of both enzymes, and this association replicates in the DiscovEHR study.

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Background And Objectives: In the rare disease primary hyperoxaluria type 1, overproduction of oxalate by the liver causes kidney stones, nephrocalcinosis, kidney failure, and systemic oxalosis. Lumasiran, an RNA interference therapeutic, suppresses glycolate oxidase, reducing hepatic oxalate production. The objective of this first-in-human, randomized, placebo-controlled trial was to evaluate the safety, pharmacokinetic, and pharmacodynamic profiles of lumasiran in healthy participants and patients with primary hyperoxaluria type 1.

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Nephrotic syndrome (NS) is associated with metabolic perturbances including profound dyslipidemia characterized by hypercholesterolemia and hypertriglyceridemia. A major underlying mechanism of hypertriglyceridemia in NS is lipoprotein lipase (LPL) deficiency and dysfunction. There is emerging evidence that elevated angiopoietin-like protein 3 (ANGPTL3), an LPL inhibitor that is primarily expressed and secreted by hepatocytes, may be in part responsible for these findings.

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There is a significant unmet need for a safe and effective therapy for the treatment of children with congenital hyperinsulinism. We hypothesized that amplification of the glucagon signaling pathway could ameliorate hyperinsulinism associated hypoglycemia. In order to test this we evaluated the effects of loss of Prkar1a, a negative regulator of Protein Kinase A in the context of hyperinsulinemic conditions.

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The chemokine (C-C motif) chemokine ligand 18 (CCL18) is a structural homolog of CCL3 primarily produced by monocyte-derived cells with an M2 phenotype. Elevated levels of CCL18 have been observed in several diseases associated with malignancies and chronic inflammation. The role of CCL18 in Human Immunodeficiency Virus (HIV-1) infection remains unknown.

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The liver plays a central role in metabolism; however, xenobiotic metabolism variations between human hepatocytes and those in model organisms create challenges in establishing functional test beds to detect the potential drug toxicity and efficacy of candidate small molecules. In the emerging areas of RNA interference, viral gene therapy, and genome editing, more robust, long-lasting, and predictive human liver models may accelerate progress. Here, we apply a new modality to a previously established, functionally stable, multi-well bioengineered microliver-fabricated from primary human hepatocytes and supportive stromal cells-in order to advance both small molecule and nucleic acid therapeutic pipelines.

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Objective: To evaluate the natural course of disease progression in patients with Sanfilippo syndrome type B (mucopolysaccharidosis type IIIB), identify potential end points for future therapy trials, and characterize biomarkers related to the disease.

Study Design: A prospective, multicenter study was conducted. Baseline, 6-month, and 12-month assessments included neurodevelopmental status (Bayley Scales of Infant Development, Third edition), adaptive status (Vineland Adaptive Behavior Scales, Second Edition), volumetric brain magnetic resonance imaging, cerebrospinal fluid heparan sulfate, and urine glycosaminoglycan (GAG) measurements.

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Primary hyperoxaluria type 1 (PH1), an inherited rare disease of glyoxylate metabolism, arises from mutations in the enzyme alanine-glyoxylate aminotransferase. The resulting deficiency in this enzyme leads to abnormally high oxalate production resulting in calcium oxalate crystal formation and deposition in the kidney and many other tissues, with systemic oxalosis and ESRD being a common outcome. Although a small subset of patients manages the disease with vitamin B6 treatments, the only effective treatment for most is a combined liver-kidney transplant, which requires life-long immune suppression and carries significant mortality risk.

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Objective: This was an open-label, phase 1/2 dose-escalation, safety trial of intrathecal recombinant human heparan-N-sulfatase (rhHNS) administered via intrathecal drug delivery device (IDDD) for treating mucopolysaccharidosis IIIA (NCT01155778).

Study Design: Twelve patients received 10, 45, or 90mg of rhHNS via IDDD once monthly for a total of 6 doses. Primary endpoints included adverse events (AEs) and anti-rhHNS antibodies.

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Aims: Heparan sulfate (HS) accumulates in the central nervous system in mucopolysaccharidosis III type A (MPS IIIA). A validated LC-MS/MS assay was developed to measure HS in human cerebrospinal fluid (CSF).

Methods & Results: HS was extracted and digested and the resultant disaccharides were derivatized with a novel label, 4-butylaniline, enabling isoform separation and isotope-tagged analog introduction as an internal standard for LC-MS/MS.

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Objectives: To characterize the clinical course of mucopolysaccharidosis type IIIA (MPS IIIA), and identify potential endpoints for future treatment trials.

Study Design: Children with a confirmed diagnosis of MPS IIIA, functioning above a developmental age of 1 year, were followed for up to 2 years. Cognitive status and brain atrophy were assessed by standardized tests and volumetric magnetic resonance imaging, respectively.

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The Sanfilippo Behavior Rating Scale (SBRS), a 68 item questionnaire, has been developed to assess the behavioral phenotype of children with Sanfilippo syndrome and its progression over time. Fifteen scales rate orality, movement/activity, attention/self-control, emotional function including anger and fear, and social interaction. Items within scales intercorrelate; measures of internal consistency are adequate.

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Objectives: (1) Develop a methodology for obtaining reliable cognitive and developmental data in children with neurodegenerative disease and cognitive impairment and in turn monitor disease state and treatment outcomes. (2) Demonstrate validity of age-equivalent scores.

Methods: We present guidelines for obtaining accurate test scores in low-functioning and behaviorally disruptive pediatric patients, followed by a method validation study: (1) using disease-specific protocols to assess salient aspects of the known phenotype, (2) selecting appropriate tests, (3) managing behavior, and (4) using age-equivalent scores on standardized tools.

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Background: In subjects with psoriasis, inflammation and epidermal hyperplasia are thought to be controlled by T cell-derived cytokines. Evidence suggests that the T(H)17 cell cytokine IL-17A (IL-17) might play a role in disease pathogenesis.

Objective: We sought to understand the effect that neutralization of IL-17 has on the clinical features of psoriasis and to understand the role that IL-17 has in inflammatory pathways underlying psoriasis in human subjects.

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Background: Leprosy was the first disease classified according to the thymus derived T-cell in the 1960s and the first disease classified by the cytokine profile as intact interferon-γ (IFN-γ) and interleukin-2 (IL2) or TH1 (tuberculoid) and deficient IFN-γ and IL2 or TH2 (lepromatous), in the 1980s.

Objective: In the present study, we set out to explore the T helper 17 (TH17) lymphocyte subset, the hallmark of T-cell plasticity, in skin biopsies from patients with erythema nodosum leprosum (ENL) who were treated with thalidomide.

Method: RNA was extracted from paraffin embedded tissue before and after thalidomide treatment of ENL and RT-PCR was performed.

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Natural killer T (NKT) cells are a heterogeneous population of lymphocytes that recognize antigens presented by CD1d and have attracted attention because of their potential role linking innate and adaptive immune responses. Peripheral NKT cells display a memory-activated phenotype and can rapidly secrete large amounts of pro-inflammatory cytokines upon antigenic activation. In this study, we evaluated NKT cells in the context of patients co-infected with HIV-1 and Mycobacterium leprae.

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Lepromatous leprosy is a model of immune evasion wherein pathogen-specific IL-10-secreting T cells and concomitant failure of Th-1 immunity permit uncontrolled proliferation of the intracellular pathogen, Mycobacterium leprae (M. leprae). The mechanism of this immune escape is unknown.

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Leprosy and human immunodeficiency virus-1 (HIV-1) are examples of human infections where interactions between the pathogen and the host cellular immunity determine the clinical manifestations of disease. Hence, a significant immunopathological interaction between HIV-1 and leprosy might be expected. In the present study we explored several aspects of cellular immunity in patients co-infected with HIV-1 and Mycobacterium leprae.

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Background: Defects of plasmacytoid (p) and myeloid (m) dendritic cells (DCs) occur in HIV infection. The aim of this study was to evaluate the maturation and function of DCs in children with perinatal HIV infection who were on antiretroviral therapy.

Materials And Methods: Twenty HIV-infected children (median age = 12.

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We report a case of acquired immunodeficiency syndrome (AIDS)-associated, acyclovir-refractory genital herpes infection treated with topical imidazoquinoline therapy. The patient's plasmacytoid dendritic cells made a robust interferon- alpha response following in vitro stimulation with imidazoquinoline but not with herpes simplex virus. We hypothesize that disease resulting from defective herpes simplex virus-stimulated interferon- alpha may be overcome by stimulating intact alternative pathways.

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In humans, innate immune recognition of mycobacteria, including Mycobacterium tuberculosis and Mycobacterium leprae, involves toll-like receptor-2 (TLR-2), expressed on immature dendritic cells (DCs), and the T-cell gammadelta receptor expressed by a subpopulation of T cells that utilize Vdelta2 (Vdelta2 T cells). To investigate modulatory relationships between these host-cell populations in a microbial context, in vitro experiments were performed with human DCs and Vdelta2 T cells stimulated with model TLR-2 ligands and phosphoantigens, respectively. We observed that TLR-2-stimulated DCs enhanced interferon-gamma (IFN-gamma) production by Vdelta2 T cells; conversely, activated Vdelta2 T cells enhanced TLR-2-induced DC maturation via soluble factors including IFN-gamma, which costimulated interleukin-12 (IL-12) p70 secretion by DCs.

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We report a practical technique to assess peripheral blood dendritic cell (DC) maturation and function in whole blood (WB), which requires minimal blood volumes and minimizes ex vivo manipulations of clinical specimens. We determined optimal conditions for flow cytometric analysis of markers of DC maturation, including CCR7, CD25, CD80 and CD83, and of the intracellular cytokines, tumor necrosis factor-alpha (TNF-alpha) and interferon-alpha (IFN-alpha), in both myeloid (mDC) and plasmacytoid (pDC) lineages. We demonstrate concentration-dependent production of these cytokines by DC following short-term stimulation with ligands to Toll-like receptors (TLRs) 2/1, 3, 4, 7, 8 and 9.

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The immunomodulatory drug thalidomide is the treatment of choice for erythema nodosum leprosum (ENL), an inflammatory cutaneous and systemic complication of multibacillary leprosy. To elucidate the mechanism of action of thalidomide in this syndrome, we prospectively investigated 20 patients with ENL who were treated with thalidomide for 21 days. All patients responded to treatment, with the majority of them having complete resolution of cutaneous lesions within 7 days.

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