Complex Autoantibody Responses Occur following Moderate to Severe Traumatic Brain Injury.

Most of the variation in outcome following severe traumatic brain injury (TBI) remains unexplained by currently recognized prognostic factors. Neuroinflammation may account for some of this difference. We hypothesized that TBI generated variable autoantibody responses between individuals that would contribute to outcome. We developed a custom protein microarray to detect autoantibodies to both CNS and systemic Ags in serum from the acute-phase (the first 7 d), late (6-12 mo), and long-term (6-13 y) intervals after TBI in human patients. We identified two distinct patterns of immune response to TBI. The first was a broad response to the majority of Ags tested, predominantly IgM mediated in the acute phase, then IgG dominant at late and long-term time points. The second was responses to specific Ags, most frequently myelin-associated glycopeptide (MAG), which persisted for several months post-TBI but then subsequently resolved. Exploratory analyses suggested that patients with a greater acute IgM response experienced worse outcomes than predicted from current known risk factors, suggesting a direct or indirect role in worsening outcome. Furthermore, late persistence of anti-MAG IgM autoantibodies correlated with raised serum neurofilament light concentrations at these time points, suggesting an association with ongoing neurodegeneration over the first year postinjury. Our results show that autoantibody production occurs in some individuals following TBI, can persist for many years, and is associated with worse patient outcome. The complexity of responses means that conventional approaches based on measuring responses to single antigenic targets may be misleading.

Case reports in the Lancet: From neurophobia to global pandemics.

While neurology remains the best-represented specialty, it was Hematology and Rheumatology cases that were more often reported by non-specialists. The overall distribution by country has also changed, reflecting recent outbreaks of infectious agents.

The MS Remyelinating Drug Bexarotene (an RXR Agonist) Promotes Induction of Human Tregs and Suppresses Th17 Differentiation In Vitro.

The retinoid X receptor agonist bexarotene promotes remyelination in patients with multiple sclerosis. Murine studies have also demonstrated that RXR agonists have anti-inflammatory effects by enhancing the ability of all-trans-retinoic acid (atRA) to promote T-regulatory cell (Treg) induction and reduce Th17 differentiation in vitro. By stimulating human naïve CD4 T-cells in the presence of Treg or Th17 skewing cytokines, we show that bexarotene also tips the human Treg/Th17 axis in favor of Treg induction, but unlike murine cells this occurs independently of atRA and retinoic acid receptor signaling. Tregs induced in the presence of bexarotene express canonical markers of T-regulation and are functionally suppressive in vitro. Circulating Treg numbers did not increase in the blood of trial patients receiving bexarotene; we believe this is because Treg induction is likely to occur within tissues. These findings lend support to developing RXR agonists as treatments of autoimmune diseases, in particular multiple sclerosis.

Therapeutically expanded human regulatory T-cells are super-suppressive due to HIF1A induced expression of CD73.

The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression. In conjunction with CD39, CD73 expression enables expanded Tregs to convert ATP to immunosuppressive adenosine. We conclude that for maximum therapeutic benefit, Treg expansion protocols should be optimised for CD39/CD73 co-expression.

From pathogenesis to novel therapies in the treatment of primary biliary cholangitis.

INTRODUCTION: Primary biliary cholangitis (PBC) is an immune-mediated liver disease characterized by chronic inflammation of the intrahepatic bile ducts, causing progressive ductopenia, cholestasis and fibrosis, and leading to liver failure. Ursodeoxycholic acid (UDCA) is the first-line therapy for the treatment of PBC patients. This is effective in majority of patients; however, up to 20 percent of patients have an incomplete response to UDCA therapy and have a reduced prognosis as compared to healthy individuals. Obeticholic acid (OCA) has been recently registered as second-line therapy for patients with incomplete response to UDCA, with plans to demonstrate the long-term clinical efficacy. Areas covered: Recent evolution in our understanding of disease mechanisms is leading to the advent of new and re-purposed therapeutic agents targeting key processes in the etiopathogenesis. Several therapeutic targets have been proposed which can be categorized into three compartments: immune, biliary and fibrosis. In this review we describe the main biological mechanisms underpinning disease development and progression in PBC and the new targeted therapies on the horizon. Expert commentary: Testing new drugs towards hard clinical endpoints is challenging in PBC due to its low prevalence and the slow progression of the disease. Novel promising biomarkers are under study and should be evaluated as surrogate endpoints in clinical trials.

Novel therapeutics for primary biliary cholangitis: Toward a disease-stage-based approach.

Primary biliary cholangitis (PBC; previously "primary biliary cirrhosis") is a cholestatic, putatively autoimmune-mediated liver disease with a clear female preponderance affecting the intrahepatic small and medium-size bile ducts and resulting in bile duct destruction, ductopenia and portal fibrosis that progresses slowly to biliary cirrhosis. Despite suboptimal response in one third of patients treated with ursodeoxycholic acid (UDCA), this remains the only FDA-approved agent for this disease. In this review, we cover recent advances in research that have yielded numerous agents currently at different stages of the drug pipeline, some of which are expected to be approved in the near future. We also discuss accumulating evidence supporting the use of older agents (fibrates and glucocorticoids) as an adjunctive therapy to UDCA in non-responsive patients. We suggest that with the imminent expansion of the therapeutic armamentarium for PBC, a more comprehensive approach - ideally taking into account not only biochemical markers of disease stage - is needed to better select patients in whom these strategies might be most useful. Studies are also needed to compare the relative efficacy of different proposed second-line treatments not only against UDCA monotherapy.

Advances in pharmacotherapy for primary biliary cirrhosis.

INTRODUCTION: Primary biliary cirrhosis (PBC) is a chronic autoimmune liver disease mostly seen in middle-aged women characterized by progressive nonsuppurative destruction of small bile ducts resulting in intrahepatic cholestasis, parenchymal injury and ultimately end-stage liver disease. Despite major breakthroughs in our understanding of PBC, there remains only one FDA-approved agent for treatment: ursodeoxycholic acid (UDCA) to which one-third of patients are unresponsive. AREAS COVERED: Biochemical response to treatment with UDCA is associated with excellent survival rates in PBC patients. However, there is a need for alternative treatments for nonresponders. Results from human epidemiological and genetic studies as well as preclinical studies in PBC animal models have provided a strong impetus for the development of new therapeutic agents. In this review, we discuss the recent advances in translational research in PBC focusing on promising therapeutic approaches, namely immune-based targeted therapies and agents targeting the synthesis and circulation of bile acids. EXPERT OPINION: We are in a new era for the development of novel therapies for PBC. Data on fibrates, budesonide and obeticholic acid offer encouragement for nonresponders to UDCA.