Potent anti-inflammatory effects of an H2 S-releasing naproxen (ATB-346) in a human model of inflammation.

ATB-346 is a hydrogen sulfide-releasing non-steroidal anti-inflammatory drug (H2 S-NSAID) derived from naproxen, which in preclinical studies has been shown to have markedly reduced gastrointestinal adverse effects. However, its anti-inflammatory properties in humans compared to naproxen are yet to be confirmed. To test this, we used a dermal model of acute inflammation in healthy, human volunteers, triggered by ultraviolet-killed Escherichia coli. This robust model allows quantification of the cardinal signs of inflammation along with cellular and humoral factors accumulating within the inflamed skin. ATB-346 was non-inferior to naproxen in terms of its inhibition of cyclooxygenase activity as well as pain and tenderness. ATB-346 significantly inhibited neutrophil infiltration at the site of inflammation at 4 h, compared to untreated controls. Subjects treated with ATB-346 also experienced significantly reduced pain and tenderness compared to healthy controls. Furthermore, both classical and intermediate monocyte subsets infiltrating the site of inflammation at 48 h expressed significantly lower levels of CD14 compared to untreated controls, demonstrating a shift toward an anti-inflammatory phenotype. Collectively, we have shown for the first time in humans that ATB-346 is potently anti-inflammatory and propose that ATB-346 represents the next generation of H2 S-NSAIDs, as a viable alternative to conventional NSAIDs, with reduced adverse effects profile.

4-methyl-5-(4-methylphenyl)-4,5-dihydrooxazol-2-amine (4,4'-DMAR, 4,4'-dimethylaminorex): availability, prevalence of use, desired effects and acute toxicity.

OBJECTIVE: 4-Methyl-5-(4-methylphenyl)-4,5-dihydrooxazol-2-amine (4,4'-dimethylaminorex (4,4'-DMAR)) is a derivative of the controlled substances aminorex and 4-methylaminorex marketed as a potential novel psychoactive substance. This paper brings together the published scientific and 'grey' literature to understand 4,4'-DMAR as a novel psychoactive substance. METHODS: Searches of the published scientific and 'grey' literature, using the keywords '4-methyl-euphoria', '4-methyl-U4Euh', '4-M-4-MAR', '4,4-dimethylaminorex', '4,4'-DMAR', 'para-methyl-4-aminorex' and 'Serotoni', were undertaken to identify information on the availability, prevalence of use and desired/unwanted effects of 4,4'-DMAR. RESULTS: No studies have reported the prevalence of use of 4,4'-DMAR. Internet snapshot studies in April and May 2014 showed availability of 4,4'-DMAR from one and two Internet suppliers respectively. Price decreased with increasing purchase amounts from €12/g for a 1-g purchase to €2.20/g for a 100-g purchase in April 2014. Internet discussion fora suggest that the desired and unwanted effects of 4,4'-DMAR are similar to those seen with other sympathomimetic drugs such as 3,4-methylenedioxy-methamphetamine and mephedrone, although the duration of unwanted effects and 'comedown' appear to be longer. Unwanted effects were reported at doses of 5-200 mg, which overlaps with the reported doses (10-200 mg) associated with desired effects. 4,4'-DMAR has been detected, along with other drugs, in 27 deaths in Europe; the contribution of the 4,4'-DMAR in these deaths has not been established. CONCLUSIONS: Currently, there appears to limited availability of 4,4'-DMAR; therefore, use is likely to be low. Its desired and unwanted effects appear similar to other sympathomimetic recreational drugs such as methylenedioxy-methamphetamine or mephedrone.

Post-resolution macrophages shape long-term tissue immunity and integrity in a mouse model of pneumococcal pneumonia.

Resolving inflammation is thought to return the affected tissue back to homoeostasis but recent evidence supports a non-linear model of resolution involving a phase of prolonged immune activity. Here we show that within days following resolution of Streptococcus pneumoniae-triggered lung inflammation, there is an influx of antigen specific lymphocytes with a memory and tissue-resident phenotype as well as macrophages bearing alveolar or interstitial phenotype. The transcriptome of these macrophages shows enrichment of genes associated with prostaglandin biosynthesis and genes that drive T cell chemotaxis and differentiation. Therapeutic depletion of post-resolution macrophages, inhibition of prostaglandin E2 (PGE2) synthesis or treatment with an EP4 antagonist, MF498, reduce numbers of lung CD4+/CD44+/CD62L+ and CD4+/CD44+/CD62L-/CD27+ T cells as well as their expression of the α-integrin, CD103. The T cells fail to reappear and reactivate upon secondary challenge for up to six weeks following primary infection. Concomitantly, EP4 antagonism through MF498 causes accumulation of lung macrophages and marked tissue fibrosis. Our study thus shows that PGE2 signalling, predominantly via EP4, plays an important role during the second wave of immune activity following resolution of inflammation. This secondary immune activation drives local tissue-resident T cell development while limiting tissue injury.

Relationship between ethnicity and multidisciplinary intervention for young people with rheumatic and musculoskeletal diseases.

Introduction: There is growing recognition of the impact of societal factors on health throughout a patient's lifespan. The COVID-19 pandemic has exposed the impact of racial disparity on health outcomes. Aims: We aimed to investigate the association between ethnicity and the multidisciplinary team (MDT) interventions for young people (YP) with complex care needs. Method: This retrospective, single-centre, cross-sectional study was conducted within the department of adolescent and young adult rheumatology at University College Hospital, London, between August 2019 and August 2021. We extracted demographic, clinical and laboratory data. The index of multiple deprivation was extracted from the Office for National Statistics database. R software was used for analysis. Results: We identified 310 YP referred to the MDT with a median age of 18 years (interquartile range 17-19). The female patient to male patient ratio was 2.4. Over a third of our cohort were from deprived areas. Comparison between Black, Asian and minority ethnic (BAME) and White ethnic groups revealed significant differences in terms of referral for pain optimisation (p=0.006), social support (p<0.00001), and adherence and non-clinic attendance (p=0.0004). Conclusion: Our findings reveal the importance of quality data for early identification and support of vulnerable YP, particularly those from BAME communities.

Recruitment of inflammatory monocytes by senescent fibroblasts inhibits antigen-specific tissue immunity during human aging.

We have previously shown that healthy older adults exhibit reduced cutaneous immune responses during a varicella zoster virus (VZV) antigen challenge that correlated with a nonspecific inflammatory response to the injection itself. Here we found that needle damage during intradermal injections in older adults led to an increase in the number of cutaneous senescent fibroblasts expressing CCL2, resulting in the local recruitment of inflammatory monocytes. These infiltrating monocytes secreted prostaglandin E2, which inhibited resident memory T cell activation and proliferation. Pretreatment of older participants with a p38 mitogen-activated protein kinase inhibitor in vivo decreased CCL2 expression and inhibited monocyte recruitment and secretion of prostaglandin E2. This coincided with an increased response to VZV antigen challenge in the skin. Our results point to a series of molecular and cellular mechanisms that link cellular senescence, tissue damage, excessive inflammation and reduced immune responsiveness in human skin and demonstrate that tissue-specific immunity can be restored in older adults by short-term inhibition of inflammatory responses.

Unusual cause of flare in antineutrophil cytoplasmic antibody-associated vasculitis.

A 53-year-old woman attended for a routine outpatient appointment for follow-up of antineutrophil cytoplasmic antibody-positive vasculitis. Her disease had relapsed despite appropriate medical management with mycophenolate mofetil (MMF), as evidenced by rising acute phase response and antimyeloperoxidase titre with ongoing symptoms. On further questioning, she had been taking oral charcoal as part of a detoxification diet, which we postulate was causing significantly impaired MMF absorption. This case report summarises the presentation and highlights the importance of a thorough drug history, and should prompt the reader to keep an open mind with regard to drug interactions and treatment regimen adherence when treatment is, unexpectedly, seemingly failing.