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Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease involving multiple organs in which B cells perform important functions such as antibody and cytokine production and antigen presentation. B cells are activated and differentiated by the primary B cell receptor, co-stimulatory molecule signals-such as CD40/CD40L-, the Toll-like receptors 7,9, and various cytokine signals. The importance of immunometabolism in the activation, differentiation, and exerting functions of B cells and other immune cells has been widely reported in recent years. However, the regulatory mechanism of immunometabolism in B cells and its involvement in SLE pathogenesis remain elusive. Similarly, the importance of the PI3K-Akt-mTOR signaling pathway, glycolytic system, and oxidative phosphorylation has been demonstrated in the mechanisms of B cell immunometabolic activation, mainly in mouse studies. However, the activation of the mTOR pathway in B cells in patients with SLE, the induction of plasmablast differentiation through metabolic and transcription factor regulation by mTOR, and the involvement of this phenomenon in SLE pathogenesis are unclear. In our studies using activated B cells derived from healthy donors and from patients with SLE, we observed that methionine, an essential amino acid, is important for mTORC1 activation. Further, we observed that splenic tyrosine kinase and mTORC1 activation synergistically induce EZH2 expression and plasmablasts by suppressing BACH2 expression through epigenomic modification. Additionally, we identified another mechanism by which the glutaminolysis-induced enhancement of mitochondrial function promotes plasmablast differentiation in SLE. In this review, we focused on the SLE exacerbation mechanisms related to the activation of immune cells-especially B cells-and immunometabolism and reported the latest findings in the field., Competing Interests: YT has received speaking fees and/or honoraria from Daiichi-Sankyo, Eli Lilly, Novartis, YL Biologics, Bristol-Myers, Eisai, Chugai, Abbvie, Astellas, Pfizer, Sanofi, Asahi-kasei, GlaxoSmithKline, Mitsubishi-Tanabe, Gilead, Janssen, research grants from Abbvie, Mitsubishi-Tanabe, Chugai, Asahi-Kasei, Eisai, Takeda, and Daiichi-Sankyo and consultant fee from Eli Lilly, Daiichi-Sankyo, Taisho, Ayumi, Sanofi, GlaxoSmithKline, and Abbvie. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Iwata, Hajime Sumikawa and Tanaka.)

Background: Worldwide, different strategies have been chosen to face the COVID-19-patient surge, often affecting access to health care for other patients. This observational study aimed to investigate whether the standard of burn care changed globally during the pandemic, and whether country´s income, geographical location, COVID-19-transmission pattern, and levels of specialization of the burn units affected reallocation of resources and access to burn care., Methods: The Burn Care Survey is a questionnaire developed to collect information on the capacity to provide burn care by burn units around the world, before and during the pandemic. The survey was distributed between September and October 2020. McNemar`s test analyzed differences between services provided before and during the pandemic, χ2 or Fisher's exact test differences between groups. Multivariable logistic regression analyzed the independent effect of different factors on keeping the burn units open during the pandemic., Results: The survey was completed by 234 burn units in 43 countries. During the pandemic, presence of burn surgeons did not change (p = 0.06), while that of anesthetists and dedicated nursing staff was reduced (<0.01), and so did the capacity to manage patients in all age groups (p = 0.04). Use of telemedicine was implemented (p < 0.01), collaboration between burn centers was not. Burn units in LMICs and LICs were more likely to be closed, after adjustment for other factors., Conclusions: During the pandemic, most burn units were open, although availability of standard resources diminished worldwide. The use of telemedicine increased, suggesting the implementation of new strategies to manage burns. Low income was independently associated with reduced access to burn care., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Aim: This study aimed to determine the association between serum 25-hydroxyvitamin D (25(OH)D) levels and vascular endothelial function in patients with type 2 diabetes (T2D)., Methods: This retrospective study included 113 patients with poorly controlled T2D who were admitted for in-hospital diabetes educational program and underwent measurements of serum 25(OH)D levels and reactive hyperemia index (RHI)., Results: Serum 25(OH)D levels significantly correlated with RHI in T2D patients. Receiver operating characteristic (ROC) curve analysis showed that serum 25(OH)D level of 16.5 ng/mL is the optimal cutoff level for predicting vascular endothelial dysfunction (RHI＜1.67), with a sensitivity of 68.5%, specificity of 67.9%, and area under the ROC curve of 0.668 (95% confidence interval [CI]: 0.566-0.770, p=0.002). The mean RHI was significantly lower (1.70±0.54) in patients with low 25(OH)D levels (n=56, 25(OH)D levels ＜16.5 ng/mL) than that (1.99±0.58; p＜0.001) in patients with high 25(OH)D levels (n=57, 25(OH)D level ≥ 16.5 ng/mL). The proportion of patients with RHI＜1.67 was higher in the low 25(OH)D group than in the high 25(OH)D group (38% vs. 18%; p＜0.001). Multivariate logistic regression analysis identified that serum 25(OH)D level ＜16.5 ng/mL was associated with increased odds of RHI ＜1.67 (odds ratio 4.598, 95% CI 1.961-10.783, p＜0.001)., Conclusion: The results demonstrated the association of serum 25(OH)D levels with endothelial function in poorly controlled T2D patients and identified serum 25(OH)D level of ＜16.5 ng/mL as a predictor of RHI ＜1.67. Serum 25(OH)D level is a potentially useful marker of vascular endothelial dysfunction in poorly controlled T2D patients.

Objectives: B cells play an important pathological role in RA. In this study, we investigated the role of metabolic regulator mTOR in B cells and its relevance to the pathology of RA., Methods: Peripheral blood mononuclear cells were isolated from 31 normal subjects and 86 RA patients and the gated B cells were assessed for mTOR phosphorylation and chemokine receptor expression. In vitro studies on peripheral blood B cells isolated from the control and RA patients investigated the molecular mechanisms., Results: Higher concentrations of CXCL10 (CXCR3 ligands) and lower percentages of CXCR3+ memory B cells were present in the peripheral blood of RA patients relative to the control. RA patients with high CXCL10 concentrations had smaller percentage of CXCR3+ memory B cells and high disease activity. One-year treatment with TNF inhibitors increased the percentage of CXCR3+ memory B cells and reduced serum CXCL10 concentrations. mTOR phosphorylation in B cells was further enhanced in RA patients, compared with the control, and was selectively enhanced in CXCR3+ memory B cells. mTOR phosphorylation in CXCR3+ memory B cells correlated with disease activity. In vitro, mTOR phosphorylation in B cells enhanced IL-6 production and increased RANKL expression., Conclusion: mTOR activation in CXCR3+ memory B cells of RA patients is associated with disease activity, mediated through IL-6 production and RANKL expression. The obtained results also suggest that TNF inhibitors mediate an impact on the association between CXCL10 and mTOR activated CXCR3+ memory B cells., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)