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Janus kinase (JAK) inhibitors (also termed Jakinibs) constitute a family of small drugs that target various isoforms of JAKs (JAK1, JAK2, JAK3 and/or tyrosine kinase 2 (Tyk2)). They ...exert anti-inflammatory properties linked, in part, to the modulation of the activation state of pro-inflammatory M1 macrophages. The exact impact of JAK inhibitors on a wider spectrum of activation states of macrophages is however still to be determined, especially in the context of disorders involving concomitant activation of pro-inflammatory M1 macrophages and profibrotic M2 macrophages. This is especially the case in autoimmune pulmonary fibrosis like scleroderma-associated interstitial lung disease (ILD), in which M1 and M2 macrophages play a key pathogenic role. In this study, we directly compared the anti-inflammatory and anti-fibrotic effects of three JAK inhibitors (ruxolitinib (JAK2/1 inhibitor); tofacitinib (JAK3/2 inhibitor) and itacitinib (JAK1 inhibitor)) on five different activation states of primary human monocyte-derived macrophages (MDM). These three JAK inhibitors exert anti-inflammatory properties towards macrophages, as demonstrated by the down-expression of key polarization markers (CD86, MHCII, TLR4) and the limited secretion of key pro-inflammatory cytokines (CXCL10, IL-6 and TNFα) in M1 macrophages activated by IFNγ and LPS or by IFNγ alone. We also highlighted that these JAK inhibitors can limit M2a activation of macrophages induced by IL-4 and IL-13, as notably demonstrated by the down-regulation of the M2a associated surface marker CD206 and of the secretion of CCL18. Moreover, these JAK inhibitors reduced the expression of markers such as CXCL13, MARCO and SOCS3 in alternatively activated macrophages induced by IL-10 and dexamethasone (M2c + dex) or IL-10 alone (M2c MDM). For all polarization states, Jakinibs with inhibitory properties over JAK2 had the highest effects, at both 1 μM or 0.1 μM. Based on these in vitro results, we also explored the effects of JAK2/1 inhibition by ruxolitinib in vivo, on mouse macrophages in a model of HOCl-induced ILD, that mimics scleroderma-associated ILD. In this model, we showed that ruxolitinib significantly prevented the upregulation of pro-inflammatory M1 markers (TNFα, CXCL10, NOS2) and pro-fibrotic M2 markers (Arg1 and Chi3L3). These results were associated with an improvement of skin and pulmonary involvement. Overall, our results suggest that the combined anti-inflammatory and anti-fibrotic properties of JAK2/1 inhibitors could be relevant to target lung macrophages in autoimmune and inflammatory pulmonary disorders that have no efficient disease modifying drugs to date.
Purpose
The SARS-CoV-2 infection can lead to a severe acute respiratory distress syndrome (ARDS) with prolonged mechanical ventilation and high mortality rate. Interestingly, COVID-19-associated ARDS ...share biological and clinical features with sepsis-associated immunosuppression since lymphopenia and acquired infections associated with late mortality are frequently encountered. Mechanisms responsible for COVID-19-associated lymphopenia need to be explored since they could be responsible for delayed virus clearance and increased mortality rate among intensive care unit (ICU) patients.
Methods
A series of 26 clinically annotated COVID-19 patients were analyzed by thorough phenotypic and functional investigations at days 0, 4, and 7 after ICU admission.
Results
We revealed that, in the absence of any difference in demographic parameters nor medical history between the two groups, ARDS patients presented with an increased number of myeloid-derived suppressor cells (MDSC) and a decreased number of CD8
pos
effector memory cell compared to patients hospitalized for COVID-19 moderate pneumonia. Interestingly, COVID-19-related MDSC expansion was directly correlated to lymphopenia and enhanced arginase activity. Lastly, T cell proliferative capacity in vitro was significantly reduced among COVID-19 patients and could be restored through arginine supplementation.
Conclusions
The present study reports a critical role for MDSC in COVID-19-associated ARDS. Our findings open the possibility of arginine supplementation as an adjuvant therapy for these ICU patients, aiming to reduce immunosuppression and help virus clearance, thereby decreasing the duration of mechanical ventilation, nosocomial infection acquisition, and mortality.
Objective
To compare microvascular damages on nailfold capillaroscopy (NFC) with macrovascular manifestations evaluated by hand power Doppler ultrasonography (PDUS) in systemic sclerosis (SSc) ...patients, and to assess the associations of these damages with the main digital manifestations of the disease: digital ulcers, acroosteolysis, and calcinosis.
Methods
NFC, hand radiographs, and PDUS were systematically performed in 64 unselected SSc patients. PDUS evaluation with assessment of ulnar artery occlusion (UAO) and finger pulp blood flow (FPBF) were performed blinded for the results of radiographs and NFC.
Results
UAO and pathologic FPBF were associated with severe capillary loss (<4 capillaries/mm) on NFC (odds ratio OR 4.04 95% confidence interval (95% CI) 1.23–13.29; P < 0.05, and OR 3.38 95% CI 1.03–11.05; P < 0.05, respectively). Digital ulcer history was associated with UAO (OR 10.71 95% CI 3.36–34.13; P < 0.0001), pathologic FPBF (OR 7.67 95% CI 2.52–23.28; P < 0.0001), late NFC pattern (OR 6.33 95% CI 2.03–19.68; P = 0.001), and severe capillary loss (OR 8.52 95% CI 2.15–33.78; P = 0.001). Acroosteolysis was also associated with UAO (OR 15.83 95% CI 3.95–63.54; P < 0.0001), pathologic FPBF (OR 5.52 95% CI 1.71–17.90; P = 0.003), late NFC pattern (OR 6.86 95% CI 2.18–21.53; P = 0.001), and severe capillary loss (OR 7.20 95% CI 2.16–24.02; P = 0.001). Calcinosis on radiographs was associated with late NFC pattern (OR 5.41 95% CI 1.82–16.12; P = 0.002), severe capillary loss (OR 12.69 95% CI 3.14–51.26; P < 0.0001), and UAO (OR 3.19 95% CI 1.14–8.92; P = 0.025). Combination of UAO and severe capillary loss in the same patient was especially associated with digital ulcer history (OR 18.60 95% CI 2.24–154.34; P = 0.001) and acroosteolysis (OR 10.83 95% CI 2.56–45.88; P = 0.001).
Conclusion
Microvascular damages evaluated by NFC and macrovascular features like UAO assessed by PDUS show concordant associations with the main digital manifestations of the disease.
Inhalation of crystalline silica (SiO
) is a risk factor of systemic autoimmune diseases such as systemic sclerosis (SSc) and fibrotic pulmonary disorders such as silicosis. A defect of apoptotic ...cell clearance (i.e., efferocytosis, a key process in the resolution of inflammation) is reported in macrophages from patients with fibrotic or autoimmune diseases. However, the precise links between SiO
exposure and efferocytosis impairment remain to be determined. Answering to this question may help to better link innate immunity and fibrosis. In this study, we first aim to determine whether SiO
might alter efferocytosis capacities of human and mouse macrophages. We secondly explore possible mechanisms explaining efferocytosis impairment, with a specific focus on macrophage polarization and on the RhoA/ROCK pathway, a key regulator of cytoskeleton remodeling and phagocytosis. Human monocyte-derived macrophages (MDM) and C57BL/6J mice exposed to SiO
and to CFSE-positive apoptotic Jurkat cells were analyzed by flow cytometry to determine their efferocytosis index (EI). The effects of ROCK inhibitors (Y27632 and Fasudil) on EI of SiO
-exposed MDM and MDM from SSc patients were evaluated
. Our results demonstrated that SiO
significantly decreased EI of human MDM
and mouse alveolar macrophages
. In human MDM, this SiO
-associated impairment of efferocytosis, required the expression of the membrane receptor SR-B1 and was associated with a decreased expression of M2 polarization markers (CD206, CD204, and CD163). F-actin staining, RhoA activation and impairment of efferocytosis, all induced by SiO
, were reversed by ROCK inhibitors. Moreover, the EI of MDM from SSc patients was similar to the EI of
- SiO
-exposed MDM and Y27632 significantly increased SSc MDM efferocytosis capacities, suggesting a likewise activation of the RhoA/ROCK pathway in SSc. Altogether, our results demonstrate that SiO
exposure may contribute to the impairment of efferocytosis capacities of mouse and human macrophages but also of MDM in SiO
-associated autoimmune diseases and fibrotic disorders such as SSc; in this context, the silica/RhoA/ROCK pathway may constitute a relevant therapeutic target.
Objective
To evaluate the association of ulnar artery occlusion (UAO) assessed using Doppler ultrasound (DUS) with the severity markers of systemic sclerosis (SSc).
Methods
Two hundred four ...unselected patients fulfilling the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria for SSc were included in this cross‐sectional multicenter study. All patients underwent bilateral hand DUS to evaluate the presence of UAO and clinical/paraclinical visceral evaluation according to current guidelines. Univariable and multivariable ordinal regression models were applied, grading the severity of UAO as “no UAO,” “only one UAO,” and “UAO on both hands,” and assessing its association with clinical features of SSc. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.
Results
UAO was found in 76 patients (37.3%) and was bilateral in 49 patients (24%). UAO as an ordinal event was significantly associated with disease duration, history of fingertip ulcers, telangiectasia, higher modified Rodnan skin thickness score (MRSS), worse diffusing capacity for carbon monoxide (DLco) values, higher tricuspid jet velocity, late capillaroscopic pattern, and positivity for anticentromere antibodies (ACAs) (univariable analysis). In the adjusted multivariable ordinal model, UAO was less frequent in women (OR 0.35 95% CI 0.15–0.83, P = 0.017) and in patients receiving steroids (OR 0.24 95% CI 0.09–0.62, P = 0.0034). In multivariable analyses, significant association with UAO was retained for history of fingertip ulcers (OR 2.55 95% CI 1.24–5.21, P = 0.011), higher MRSS (OR 1.65 95% CI 1.06–2.56, P =0.025), lower DLco values (OR 0.85 95% CI 0.78–0.94, P = 0.0015), and ACA positivity (OR 2.89 95% CI 1.36–6.11, P = 0.0056).
Conclusion
UAO may represent a relevant severity marker of vasculopathy in SSc. Its predictive value for the onset of severe vascular manifestations such as pulmonary arterial hypertension, and its association with mortality, remain to be determined in longitudinal studies.
Macrophages play a central role in the pathogenesis of inflammatory and fibrotic lung diseases. However, alveolar macrophages (AM) are poorly available in humans to perform in vitro studies due to a ...limited access to broncho-alveolar lavage (BAL). In this study, to identify the best alternative in vitro model for human AM, we compared the phenotype of AM obtained from BAL of patients suffering from three lung diseases (lung cancers, sarcoidosis and Systemic Sclerosis (SSc)-associated interstitial lung disease) to human blood monocyte-derived macrophages (MDMs) differentiated with M-CSF or GM-CSF. The expression of eight membrane markers was evaluated by flow cytometry. Globally, AM phenotype was closer to GM-CSF MDMs. However, the expression levels of CD163, CD169, CD204, CD64 and CD36 were significantly higher in SSc-ILD than in lung cancers. Considering the expression of CD204 and CD36, the phenotype of SSc-AM was closer to MDMs, from healthy donors or SSc patients, differentiated by M-CSF rather than GM-CSF. The comparative secretion of IL-6 by SSc-MDMs and SSc-AM is concordant with these phenotypic considerations. Altogether, these results support the M-CSF MDM model as a relevant in vitro alternative to simulate AM in fibrotic disorders such as SSc.
The objective of this study is to assess the association of clinical manifestations of systemic sclerosis (SSc) with the absolute count of circulating blood monocyte subpopulations according to their ...membrane expression of CD16
.
Forty-eight consecutive patients fulfilling the 2013 ACR/EULAR classification criteria for SSc were included in this cross-sectional study. CD16+ monocyte absolute count was defined by flow cytometry and confronted to the clinical characteristics of SSc patients. Twenty-three healthy donors (HD) were randomly selected for comparison. SSc patients had an increased number of total circulating blood monocytes compared to HD (
p
< 0.001). The CD16− subpopulation absolute count was increased in SSc patients compared to HD (
p
< 0.001) but was similar in limited SSc (lSSc) and diffuse SSc (dSSc). On the contrary, the CD16+ population absolute count was increased in dSSc compared to both HD and lSSc patients (dSSc 0.071 Giga/L (±0.034) vs HD 0.039 Giga/L (±0.030),
p
< 0.01, and dSSc 0.071 Giga/L (±0.034) vs lSSc 0.048 Giga/L (±0.024),
p
< 0.05). The CD16+ monocyte subpopulation absolute count was significantly correlated with the severity of skin fibrosis evaluated by the modified Rodnan skin score (
p
< 0.001). The CD16+ monocyte subpopulation was also associated with pulmonary fibrosis (
p
< 0.05), with the severity of the restrictive ventilatory defect evaluated by total lung capacity (
p
< 0.05) and with the pulmonary function impairment reflected by diffusing capacity of the lungs for carbon monoxyde measures (
p
< 0.01). These results suggest that CD16+ monocytes are associated with the main fibrotic manifestations of SSc and their role in the pathogenesis of fibrosis in this autoimmune disorder should therefore be further considered.
A defect in the apoptotic cell clearance (efferocytosis) by phagocytic cells may participate in autoimmunity and chronic inflammation. The mechanisms leading to the emergence of autoimmunity in ...systemic sclerosis (SSc) are still to be determined. In this study, the efferocytosis capacities of blood monocyte‐derived macrophages (MDM) from patients with SSc were evaluated. Blood monocytes obtained from patients with SSc and healthy donors (HD) were differentiated in vitro into macrophages. The capacities of MDM to engulf CFSE+ apoptotic Jurkat human T lymphocytes were compared between SSc MDM and HD using flow cytometry. The expression of classical engulfing receptors in SSc MDM and HD MDM was also evaluated and their involvement in the modulation of efferocytosis was confirmed using a siRNA approach. The mean phagocytic index (PI) reflecting efferocytosis capacities of SSc MDM (PI = 19.3 ± 3.0; n = 21) was significantly decreased in comparison with the PI of HD MDM (PI = 35.9 ± 3.0; n = 31; P < 0.001). In comparison with HD, SSc MDM exhibited a downregulated expression of scavenger receptor (SR)‐B1, SR‐A1 and integrin β5 (ITGβ5). In HD MDM, the extinction of these receptors was followed by a reduction of efferocytosis only for the repression of ITGβ5, suggesting a possible selective role of this integrin in the impaired efferocytosis observed in SSc. As efferocytosis may be at the crossroads of inflammation, autoimmunity and fibrosis, in showing impaired efferocytosis capacities of blood MDM in SSc, our study offers new pathogenesis considerations for the involvement of macrophages in the autoimmune processes driving this disorder.
Efferocytosis capacities are strongly decreased in monocyte‐derived macrophages from systemic sclerosis (SSc) patients. A downexpression of integrin β5 in proinflammatory and in SSc macrophages may explain a deficient efferocytosis. Impaired efferocytosis of macrophages may play a key role in autoimmune processes in SSc.
Apixaban and rivaroxaban have first-line use for many patients needing anticoagulation for venous thromboembolism (VTE). The pharmacokinetics of these drugs in non-obese subjects have been ...extensively studied, and, while changes in pharmacokinetics have been documented in obese patients, data remain scarce for these anticoagulants. The aim of this study was to perform an external validation of published population pharmacokinetic (PPK) models of apixaban and rivaroxaban in a cohort of obese patients with VTE. A literature search was conducted in the PubMed/MEDLINE, Scopus, and Embase databases following the PRISMA statement. External validation was performed using MonolixSuite software, using prediction-based and simulation-based diagnostics. An external validation dataset from the university hospitals of Brest and Rennes, France, included 116 apixaban pharmacokinetic samples from 69 patients and 121 rivaroxaban samples from 81 patients. Five PPK models of apixaban and 16 models of rivaroxaban were included, according to the inclusion criteria of the study. Two of the apixaban PPK models presented acceptable performances, whereas no rivaroxaban PPK model did. This study identified two published models of apixaban applicable to apixaban in obese patients with VTE. However, none of the rivaroxaban models evaluated were applicable. Dedicated studies appear necessary to elucidate rivaroxaban pharmacokinetics in this population.
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