13 research outputs found

    Prion infectivity in the spleen of a <em>PRNP</em> heterozygous individual with subclinical variant Creutzfeldt-Jakob disease

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    Blood transfusion has been identified as a source of human-to-human transmission of variant Creutzfeldt–Jakob disease. Three cases of variant Creutzfeldt–Jakob disease have been identified following red cell transfusions from donors who subsequently developed variant Creutzfeldt–Jakob disease and an asymptomatic red cell transfusion recipient, who did not die of variant Creutzfeldt–Jakob disease, has been identified with prion protein deposition in the spleen and a lymph node, but not the brain. This individual was heterozygous (MV) at codon 129 of the prion protein gene (PRNP), whereas all previous definite and probable cases of variant Creutzfeldt–Jakob disease have been methionine homozygotes (MM). A critical question for public health is whether the prion protein deposition reported in peripheral tissues from this MV individual correlates with infectivity. Additionally it is important to establish whether the PRNP codon 129 genotype has influenced the transmission characteristics of the infectious agent. Brain and spleen from the MV blood recipient were inoculated into murine strains that have consistently demonstrated transmission of the variant Creutzfeldt–Jakob disease agent. Mice were assessed for clinical and pathological signs of disease and transmission data were compared with other transmission studies in variant Creutzfeldt–Jakob disease, including those on the spleen and brain of the donor to the index case. Transmission of variant Creutzfeldt–Jakob disease was observed from the MV blood recipient spleen, but not from the brain, whereas there was transmission from both spleen and brain tissues from the red blood cell donor. Longer incubation times were observed for the blood donor spleen inoculum compared with the blood donor brain inoculum, suggesting lower titres of infectivity in the spleen. The distribution of vacuolar pathology and abnormal prion protein in infected mice were similar following inoculation with both donor and recipient spleen homogenates, providing initial evidence of similar transmission properties after propagation in PRNP codon 129 MV and MM individuals. These studies demonstrate that spleen tissue from a PRNP MV genotype individual can propagate the variant Creutzfeldt–Jakob disease agent and that the infectious agent can be present in the spleen without CNS involvement

    Variably protease-sensitive prionopathy, a unique prion variant with inefficient transmission properties

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    Variably protease-sensitive prionopathy (VPSPr) can occur in persons of all codon 129 genotypes in the human prion protein gene (PRNP) and is characterized by a unique biochemical profile when compared with other human prion diseases. We investigated transmission properties of VPSPr by inoculating transgenic mice expressing human PRNP with brain tissue from 2 persons with the valine-homozygous (VV) and 1 with the heterozygous methionine/valine codon 129 genotype. No clinical signs or vacuolar pathology were observed in any inoculated mice. Small deposits of prion protein accumulated in the brains of inoculated mice after challenge with brain material from VV VPSPr patients. Some of these deposits resembled microplaques that occur in the brains of VPSPr patients. Comparison of these transmission properties with those of sporadic Creutzfeldt-Jakob disease in the same lines of mice indicated that VPSPr has distinct biological properties. Moreover, we established that VPSPr has limited potential for human-to-human transmission

    HIV Disclosure Anxiety:A Systematic Review and Theoretical Synthesis

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    HIV disclosure can help people living with HIV to access social support, enhance antiretroviral adherence, facilitate engagement in care and reduce unprotected sex. Given interpersonal risks associated with HIV disclosure, however, anxiety about sharing one’s status is common. To investigate anxiety about HIV disclosure in HIV-positive populations, we conducted a systematic review of qualitative and quantitative studies, with 119 studies included. The review demonstrated that perceived interpersonal risks are associated with HIV disclosure and outlined evidence of associations with anxiety, fear and worry. We present a new cognitive model of HIV disclosure anxiety adapted from clinical theories of health and social anxiety, consistent with evidence from the review. The model attempts to explain the development and maintenance of anxiety in individuals whose functioning is most affected by concerns about sharing their status. Implications for helping people living with HIV struggling with significant levels of anxiety about HIV disclosure are discussed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10461-016-1453-3) contains supplementary material, which is available to authorized users

    Clinical efficacy of COMPASS, a digital cognitive-behavioural therapy programme for treating anxiety and depression in patients with long-term physical health conditions:A protocol for randomised controlled trial

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    INTRODUCTION: Approximately 30% of people with long-term physical health conditions (LTCs) experience mental health problems, with negative consequences and costs for individuals and healthcare services. Access to psychological treatment is scarce and, when available, often focuses on treating primary mental health problems rather than illness-related anxiety/depression. The aim of this study is to evaluate the clinical efficacy of a newly developed, therapist-supported, digital cognitive-behavioural treatment (COMPASS) for reducing LTC-related psychological distress (anxiety/depression), compared with standard charity support (SCS). METHODS AND ANALYSIS: A two-arm, parallel-group randomised controlled trial (1:1 ratio) with nested qualitative study will be conducted. Two-hundred adults with LTC-related anxiety and depression will be recruited through national LTC charities. They will be randomly allocated to receive COMPASS or SCS only. An independent administrator will use Qualtrics randomiser for treatment allocation, to ensure allocation concealment. Participants will access treatment from home over 10 weeks. The COMPASS group will have access to the digital programme and six therapist contacts: one welcome message and five fortnightly phone calls. Data will be collected online at baseline, 6 weeks and 12 weeks post-randomisation for primary outcome (Patient Health Questionnaire Anxiety and Depression Scale) and secondary outcomes (anxiety, depression, daily functioning, COVID-19-related distress, illness-related distress, quality of life, knowledge and confidence for illness self-management, symptom severity and improvement). Analyses will be conducted following the intention-to-treat principle by a data analyst blinded to treatment allocation. A purposively sampled group of COMPASS participants and therapists will be interviewed. Interviews will be thematically analysed. ETHICS AND DISSEMINATION: The study is approved by King’s College London’s Psychiatry, Nursing and Midwifery Research Ethics Subcommittee (reference: LRS-19/20–20347). All participants will provide informed consent to take part if eligible. Findings will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER: NCT04535778
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