Pharmacomicrobiology of Methotrexate in Rheumatoid Arthritis: Gut Microbiome as Predictor of Therapeutic Response

Rheumatoid arthritis (RA) is a disabling autoimmune disease with invasive arthritis as the main manifestation and synovitis as the basic pathological change, which can cause progressive destruction of articular cartilage and bone, ultimately leading to joint deformity and loss of function. Since its introduction in the 1980s and its widespread use in the treatment of RA, low-dose methotrexate (MTX) therapy has dramatically changed the course and outcome of RA treatment. The clinical use of this drug will be more rational with a better understanding of the pharmacology, anti-inflammatory mechanisms of action and adverse reaction about it. At present, the current clinical status of newly diagnosed RA is that MTX is initiated first regardless of the patients’ suitability. But up to 50% of patients could not reach adequate clinical efficacy or have severe adverse events. Prior to drug initiation, a prognostic tool for treatment response is lacking, which is thought to be the most important cause of the situation. A growing body of studies have shown that differences in microbial metagenomes (including bacterial strains, genes, enzymes, proteins and/or metabolites) in the gastrointestinal tract of RA patients may at least partially determine their bioavailability and/or subsequent response to MTX. Based on this, some researchers established a random forest model to predict whether different RA patients (with different gut microbiome) would respond to MTX. Of course, MTX, in turn, alters the gut microbiome in a dose-dependent manner. The interaction between drugs and microorganisms is called pharmacomicrobiology. Then, the concept of precision medicine has been raised. In this view, we summarize the characteristics and anti-inflammatory mechanisms of MTX and highlight the interaction between gut microbiome and MTX aiming to find the optimal treatment for patients according to individual differences and discuss the application and prospect of precision medicine.

Emergence of mTOR mutation as an acquired resistance mechanism to AKT inhibition, and subsequent response to mTORC1/2 inhibition

Acquired resistance to molecular targeted therapy is a significant challenge of the precision medicine era. The ability to understand these mechanisms of resistance may improve patient selection and allow for the development of rationally designed next-line or combination treatment strategies and improved patient outcomes. AKT is a critical effector of the phosphoinositide 3-kinase signaling cascade, one of the most commonly activated pathways in human cancer. Deregulation of signaling pathways, such as RAF/MEK/ERK are previously described mechanisms of resistance to AKT/PI3K inhibitors. Mutations in the mTOR gene, however, are exceedingly rare. We present a case of acquired mTOR resistance, following targeted AKT inhibition, and subsequent response to mTOR1/2 inhibitor in a patient with metastatic endometrial cancer, the first documented response to ATP-competitive mTOR inhibition in this setting. This case supports mTOR mutation as a mechanism of resistance, and underscores the importance of tumor molecular profiling, exemplifying precision medicine in action.

Transcriptomic Remodelling of Fetal Endothelial Cells During Establishment of Inflammatory Memory

Inflammatory memory involves the molecular and cellular ‘reprogramming’ of innate immune cells following exogenous stimuli, leading to non-specific protection against subsequent pathogen exposure. This phenomenon has now also been described in non-hematopoietic cells, such as human fetal and adult endothelial cells. In this study we mapped the cell-specific DNA methylation profile and the transcriptomic remodelling during the establishment of inflammatory memory in two distinct fetal endothelial cell types – a progenitor cell (ECFC) and a differentiated cell (HUVEC) population. We show that both cell types have a core transcriptional response to an initial exposure to a viral-like ligand, Poly(I:C), characterised by interferon responsive genes. There was also an ECFC specific response, marked by the transcription factor ELF1, suggesting a non-canonical viral response pathway in progenitor endothelial cells. Next, we show that both ECFCs and HUVECs establish memory in response to an initial viral exposure, resulting in an altered subsequent response to lipopolysaccharide. While the capacity to train or tolerize the induction of specific sets of genes was similar between the two cell types, the progenitor ECFCs show a higher capacity to establish memory. Among tolerized cellular pathways are those involved in endothelial barrier establishment and leukocyte migration, both important for regulating systemic immune-endothelial cell interactions. These findings suggest that the capacity for inflammatory memory may be a common trait across different endothelial cell types but also indicate that the specific downstream targets may vary by developmental stage.

Antipsychotic-placebo separation on the PANSS-6 subscale as compared to the PANSS-30: a pooled participant-level analysis

In order for measurement-based care to be implemented, there is a need for brief rating instruments that can be administered in a short amount of time, but that are still sufficiently informative. Here, we assessed the drug–placebo sensitivity of the six-item subscale (PANSS-6) of the 30-item Positive and Negative Syndrome Scale (PANSS-30) using a large collection of patient-level data (n = 6685) from randomized controlled trials of risperidone and paliperidone. When analyzing the data by study, we found no material difference in mean effect sizes (ES) between the two measures (PANSS-30 ES = 0.45, PANSS-6 ES = 0.44; p = 0.642). Stratifying the pooled population according to several putative effect moderators (e.g., age, formulation, dose, or diagnosis) generally yielded no meaningful ES differences between the two measures. Similarly, early improvement (≥20% improvement at week 1) on the PANSS-6 predicted subsequent response (≥40% improvement at endpoint) as well as the analog prediction using PANSS-30. Finally, cross-sectional symptom remission assessed via the PANSS-6 showed very good agreement (sensitivity = 100%, specificity = 98%) with cross-sectional symptom remission defined by the Remission in Schizophrenia Working Group.

#3097 Temporal and spectral dynamics of reward and risk processing in the amygdala revealed with stereo-EEG recordings in epilepsy

Objectives/AimsTo examine the temporal and spectral characteristics of local field potentials recorded from the amygdala in epilepsy in the context of the anticipation and receipt of rewards and losses using an incentive learning task and a risky decision-making task.Methods16 Epilepsy patients completed two tasks. In the monetary incentive delay (MID) task, patients saw reward and loss cues which indicated whether money could be won or lost depending on whether a subsequent response was or was not quick/accurate enough, respectively. This was compared with neutral cues where responses were neither rewarded nor punished regardless of response.In the risk task, patients were presented with two face down cards with values ranging from 1 to 10. When the first card is revealed, patients have to choose whether to bet or not bet that the second card is higher. After the card is revealed, patients receive a monetary reward if it is higher and a loss if it is lower. If patients do not bet, they receive nothing.ResultsIn both tasks, patients showed larger left amygdala theta band oscillatory activity to the receipt of monetary rewards compared to no money. In contrast, there were no significant responses to monetary losses. During the decision phase of the risk task, there was increased theta activity when patients chose to bet instead of not betting and when the decision had low risk (card <= 5) compared to high risk (card above 5). There were no effects of uncertainty.ConclusionsThe combined results of these two studies embellish our understanding of the role of the amygdala in motivation and decision-making processes and lend further support for its role in reward related processes rather than its often cited fear-related functions (Baxter & Murray, 2002; Murray, 2007). Theta activation is linked to cognitive processes in frontal cortices and coupled to MTL activity (Helfrich & Knight, 2016). As left amygdala theta activation was only recruited when patients were making their bet and not just anticipating reward, the pattern of results lend support to its role in cognition-emotion interactions specific to risk and reward but not uncertainty. Indeed, the hemispheric asymmetry is highly consistent with EEG studies showing left prefrontal dominance in reward processing (Manssuer et al., 2021).

The Impact of Marijuana on Antidepressant Treatment in Adolescents: Clinical and Pharmacologic Considerations

The neuropharmacology of marijuana, including its effects on selective serotonin reuptake inhibitor (SSRI)/antidepressant metabolism and the subsequent response and tolerability in youth, has received limited attention. We sought to (1) review clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) interactions between cannabinoids and selected SSRIs, (2) use PK models to examine the impact of cannabinoids on SSRI exposure (area under curve (AUC)) and maximum concentration (CMAX) in adolescents, and (3) examine the frequency of adverse events reported when SSRIs and cannabinoids are used concomitantly. Cannabinoid metabolism, interactions with SSRIs, impact on relevant PK/PD pathways and known drug–drug interactions were reviewed. Then, the impact of tetrahydrocannabinol (THC) and cannabidiol (CBD) on exposure (AUC24) and CMAX for escitalopram and sertraline was modeled using pediatric PK data. Using data from the Food and Drug Administration Adverse Events Reporting System (FAERS), the relationship between CBD and CYP2C19-metabolized SSRIs and side effects was examined. Cannabis and CBD inhibit cytochrome activity, alter serotonergic transmission, and modulate SSRI response. In PK models, CBD and/or THC increases sertraline and es/citalopram concentrations in adolescents, and coadministration of CBD and CYP2C19-metabolized SSRIs increases the risk of cough, diarrhea, dizziness, and fatigue. Given the significant SSRI–cannabinoid interactions, clinicians should discuss THC and CBD use in youth prescribed SSRIs and be aware of the impact of initiating, stopping, or decreasing cannabinoid use as this may significantly affect es/citalopram and sertraline exposure.

Deoxycholic Acid Activates and Sensitizes Vagal Nociceptive Afferent C-fibers in Guinea Pig Esophagus

Bile acid reflux in the esophagus plays a role in the pathogenesis of certain esophageal disorders where it can induce esophageal pain and heartburn. The present study aimed to determine whether bile acid, deoxycholic acid (DCA), directly activates and sensitizes esophageal vagal nociceptive afferent C-fiber subtypes. DCA-elicited effects on vagal nodose and jugular neurons were studied by calcium imaging. Its effects on esophageal-labeled nodose and jugular neurons were then determined by patch-clamp recording. At nodose and jugular C-fiber nerve endings in the esophagus, DCA-evoked action potentials (APs) were compared by extra-cellular single-unit recordings in ex vivo esophageal-vagal preparations. DCA application induced calcium influxes in nodose and jugular neurons and elicited inward currents in esophageal-labeled nodose and jugular neurons. In the presence of DCA, the current densities elicited by capsaicin were enhanced in those labeled neurons. Consistently, DCA perfusion at nerve terminals in the esophagus evoked APs in about 50% of esophageal nodose and jugular C-fibers. In DCA-sensitive C-fibers, DCA perfusion also sensitized the fibers such that the subsequent response to capsaicin was amplified. Collectively, these results provide new evidence that DCA directly activates and sensitizes nociceptive nodose and jugular C-fibers in the esophagus. Such activation and sensitization effects may contribute to bile acid-induced esophageal nociceptive symptoms that are refractory to proton-pump inhibitor therapy.

Call and Response? Neighborhood Inequality and Political Voice

Over the past 20 years, many cities across the United States have adopted a range of information and communication technologies (ICTs) to make it easier for residents to get informed, communicate their preferences, and hold public officials accountable. In this paper, we ask two questions. First, are service requests and responses illustrative of existing neighborhood differences across a city? Second, do patterns of request and response differ by the type of complaint made to the city? We leverage data from the city of Milwaukee, Wisconsin, to examine neighborhood variation in service requests and subsequent response times to those complaints. Our analysis makes a number of important contributions to the current literature on ICTs, including providing a more nuanced understanding of how types of requests vary by neighborhood context, and a more comprehensive picture of how requests and response times reveal social and racial disparities across the city.

Pseudoprogression and cancer immunotherapy: A seven year retrospective study of rate, temporal course, and predictive markers in an Irish tertiary referral center.

2651 Background: Immunotherapy is a relatively new treatment strategy which has achieved unprecedented clinical efficacy in many advanced malignancies. However, the pattern of tumour response to immunotherapy is distinct from other therapies and poses major challenges to clinicians. One such challenge is pseudoprogression. The aim of this study was to assess the current management of patients on immunotherapy with radiological evidence of disease progression at first restaging imaging in an Irish cancer centre, and to determine the rate, time course, and predictive markers of pseudoprogression in those patients treated beyond progression (TBP). Methods: Patients treated with immunotherapy for metastatic malignancy in MMUH between March 2013 and September 2020 were retrospectively drawn. Inclusion required follow-up restaging imaging every 4-12 weeks for the duration of treatment. Patterns of response during immunotherapy were established from radiology reports and categorized as stable (SD), response (R), mixed disease (MD), or progressive disease (PD). Pseudoprogression was defined as progression/ mixed disease at first restaging compared to baseline followed by subsequent response/stable disease. Results: The cohort of 228 patients was comprised of 80 NSCLC, 74 melanoma, 25 RCC, 19 gynaecological, 14 gastrointestinal, 6 breast, 1 ESSCLC, and 9 other cancer patients. Median age was 61.16 (IQR 49.47-69.44). Therapeutic agents were anti-PD1 alone (176) or in combination with targeted therapy (6) or CTLA4 (13), CTLA4 alone (15), and anti-PD-L1 alone (13) or in combination with chemotherapy (5). At first restaging, the number (%) classified as SD, R, MD, and PD, respectively, was 29 (12.8), 62 (27.2), 16 (7), and 76 (33.3). Treatment was stopped prior to restaging in 44 (19.3) cases. Of the 92 patients with mixed/ progressive disease, 41 were TBP and 51 were not treated beyond progression (NTBP). Evidence of radiological progression and worsening performance status (PS) were the most common reasons given by clinicians for NTBP. Of those TBP, 20 had subsequent response/stable disease, occurring at a median of 105.50 (range 58.0-420) days after the initial restaging scan and giving an overall pseudoprogression rate of 8.8%. At one year, 100% of the pseudoprogression group was alive. The neutrophil-lymphocyte ratio (NLR) was significantly lower in the pseudoprogression group compared to those with true progression (p = 0.006). There was no significant difference in performance status between the two groups. Conclusions: Pseudoprogression on cancer immunotherapy is real but uncommon, with an overall incidence of 8.8%. It can occur any time up to 420 days after initial progression and indicates a high likelihood of > 1 year survival. A low NLR may be a useful predictor of pseudoprogression but a technological solution is likely needed.

Neuroimaging as a Window Into the Pathophysiological Mechanisms of Schizophrenia

Schizophrenia is a complex neuropsychiatric disorder with a diverse clinical phenotype that has a substantial personal and public health burden. To advance the mechanistic understanding of the illness, neuroimaging can be utilized to capture different aspects of brain pathology in vivo, including brain structural integrity deficits, functional dysconnectivity, and altered neurotransmitter systems. In this review, we consider a number of key scientific questions relevant in the context of neuroimaging studies aimed at unraveling the pathophysiology of schizophrenia and take the opportunity to reflect on our progress toward advancing the mechanistic understanding of the illness. Our data is congruent with the idea that the brain is fundamentally affected in the illness, where widespread structural gray and white matter involvement, functionally abnormal cortical and subcortical information processing, and neurometabolic dysregulation are present in patients. Importantly, certain brain circuits appear preferentially affected and subtle abnormalities are already evident in first episode psychosis patients. We also demonstrated that brain circuitry alterations are clinically relevant by showing that these pathological signatures can be leveraged for predicting subsequent response to antipsychotic treatment. Interestingly, dopamine D2 receptor blockers alleviate neural abnormalities to some extent. Taken together, it is highly unlikely that the pathogenesis of schizophrenia is uniform, it is more plausible that there may be multiple different etiologies that converge to the behavioral phenotype of schizophrenia. Our data underscore that mechanistically oriented neuroimaging studies must take non-specific factors such as antipsychotic drug exposure or illness chronicity into consideration when interpreting disease signatures, as a clear characterization of primary pathophysiological processes is an imperative prerequisite for rational drug development and for alleviating disease burden in our patients.