With regard to skeletal morphology, the sedc/+ mouse appears phenotypically normal but develops premature OA as hypothesized. We conclude that the sedc/+ mouse is a useful model for the study of OA in individuals with overtly normal skeletal structure and a predisposition for articular cartilage degeneration.

Objective Col2a1 gene mutations cause premature degeneration of knee articular cartilage in disproportionate micromelia (Dmm) and spondyloepiphesial dysplasia congenita (sedc) mice. The present study analyzes the temporomandibular joint (TMJ) in Col2a1 mutant mice in order to provide an animal model of TMJ osteoarthritis (OA) that may offer better understanding of the progression of this disease in humans. Design Dmm/+ mice and controls were compared at two, six, nine and 12 months. Craniums were fixed, processed to paraffin sections, stained with Safranin-O/Fast Green, and analyzed with light microscopy. OA was quantified using a Mankin scoring procedure. Unfolded protein response (UPR) assay was performed and immunohistochemistry (IHC) was used to assay for known OA biomarkers. Results Dmm/+ TMJs showed fissuring of condylar cartilage as early as 6 months of age. Chondrocytes were clustered, leaving acellular regions in the matrix. Significant staining of HtrA1, Ddr2 and Mmp-13 was observed in Dmm/+ mice (p< 0.01). We detected upregulation of the UPR in knee but not TMJ. Conclusions Dmm/+ mice are subject to early-onset OA in the TMJ. We observed upregulation of biomarkers and condylar cartilage degradation concomitant with OA. An upregulated UPR may exacerbate the onset of OA. The Dmm/+ mouse TMJ is a viable model for the study of the progression of OA in humans.

Background Elite controllers (EC), a small subset of the HIV-positive population (< 1%), suppress HIV viremia below the limit of quantification of clinical viral load assays in the absence of antiretroviral therapy (ART). However, there is a paucity of longitudinal data detailing the viral and immune dynamics or HIV reservoir seeding during acute infection in individuals that go on to become Elite Controllers. Case presentation In this report, we describe a case of a 42 year old woman diagnosed during acute infection who rapidly and permanently suppressed her viremia in the absence of antiretroviral therapy (ART). Rapid antibody/antigen testing was either negative or equivocal during acute infection, despite subsequent viral load testing at that time point with 71,550 plasma HIV RNA copies/mL, making initial diagnosis challenging. The patient subsequently developed detectable anti-HIV antibodies and an increase in HIV-specific CD8+ T cell responses to overlapping subtype C HIV gag peptide; very low-level plasma viremia (0.84 RNA copies/mL) was detected by an ultrasensitive assay 2 years following infection. Subsequently, she was started on ART for multifocal furunculosis despite continued suppression of virus and stable CD4+ T cell counts. Following ART initiation, CD8+ T cell responses increased, but no HIV DNA or RNA was able to be isolated from large numbers of peripheral blood CD4+ T cells. Conclusion This case provides important information regarding the establishment of elite HIV control during acute infection and also demonstrates an increase in HIV-specific immune responses following ART despite undetectable peripheral blood cellular measures of HIV persistence. This case also highlights the challenges in diagnosing acute HIV infection without the use of viral load testing in this rare elite controller phenotype.

Hepatitis C Virus (HCV) disproportionately affects people who inject drugs, migrants, prisoners and the homeless. An integrated, peer-led model of care involving primary and secondary care is required to enhance the identification and treatment of HCV in these marginalised groups. HepCare Plus builds on the network and achievements of HepCare Europe (a co-funded Third Health Programme of the European Union/Health Service Executive project). It further identifies those not accessing care and facilitates prompt assessment and treatment of those diagnosed with HCV, with the aid of a peer support worker (PSW) and a community HCV nurse specialist. Of 109 individuals identified and assessed for HCV treatment, 100 commenced HCV treatment. Despite interruptions to treatment (COVID-19 pandemic and national health service cyberattack) there was a high-level of treatment completion with PSW engagement (98%, n = 98). Eighty (73%) individuals were previously aware of a positive HCV status, highlighting the ongoing need to address barriers preventing marginalised groups from engaging with care. HepCare Plus reiterates the defining role of peer-led community interventions in HCV treatment engagement and the need for continuous open-ended HCV care. It provides a sustainable framework to meaningfully combat HCV and achieve the United Nations Sustainable Development Goal of HCV elimination by 2030.

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