Mass cytometry reveals atypical immune profile notably impaired maturation of memory CD4 T with Gb3-related CD27 expression in CD4 T cells in Fabry disease.

Fabry disease (FD) is an X-linked disease characterized by an accumulation of glycosphingolipids, notably of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lysoGb3) leading to renal failure, cardiomyopathy, and cerebral strokes. Inflammatory processes are involved in the pathophysiology. We investigated the immunological phenotype of peripheral blood mononuclear cells in Fabry patients depending on the clinical phenotype, treatment, Gb3, and lysoGb3 levels and the presence of anti-drug antibodies (ADA). Leucocytes from 41 male patients and 20 controls were analyzed with mass cytometry using both unsupervised and supervised algorithms. FD patients had an increased expression of CD27 and CD28 in memory CD45- and CD45 + CCR7-CD4 T cells (respectively p < 0.014 and p < 0.02). Percentage of CD45RA-CCR7-CD27 + CD28+ cells in CD4 T cells was correlated with plasma lysoGb3 (r = 0.60; p = 0.0036) and phenotype (p < 0.003). The correlation between Gb3 and CD27 in CD4 T cells almost reached significance (r = 0.33; p = 0.058). There was no immune profile associated with the presence of ADA. Treatment with agalsidase beta was associated with an increased proportion of Natural Killer cells. These findings provide valuable insights for understanding FD, linking Gb3 accumulation to inflammation, and proposing new prognostic biomarkers.

Upper respiratory tract and orofacial manifestations of new-onset giant cell arteritis: results from a large, prospective inception cohort study.

OBJECTIVES: Giant cell arteritis (GCA) often features upper respiratory tract (URT) and orofacial manifestations, which signal the involvement of external carotid artery branches. In this study, we aimed to describe the frequency of various URT/orofacial symptoms at GCA onset, as well as the main characteristics of patients presenting these symptoms. METHODS: We included all patients who were newly diagnosed with GCA between 1976 and April 2022 at the Internal Medicine Department of a tertiary-care hospital. Ten URT or orofacial symptoms were prospectively examined systematically in each patient. We used multivariate analyses to identify the GCA characteristics, including URT/orofacial symptoms, associated with temporal artery biopsy (TAB) positivity. RESULTS: At least 1 URT/orofacial symptom was present in 68.6% of the 599 patients (3 or more symptoms in 30% of cases). Jaw claudication, maxillary pain, and pain during mouth opening were the most prevalent symptoms. Dry cough was recorded in 17% of cases. GCA patients with URT/orofacial symptoms had more clinical abnormalities of the temporal artery bed and ischaemic ophthalmological complications, but less large-vessel vasculitis according to imaging. The likelihood of a positive TAB was increased in patients with an abnormal temporal artery upon clinical examination (OR 4.16; CI 2.75-6.37, p < 0.001) or jaw claudication (OR 2.18; CI 1.35-3.65, p = 0.002), and decreased in those with hoarseness (OR 0.47; CI 0.26-0.87, p = 0.02) or earache (OR 0.54; CI 0.31-0.95, p = 0.03). Isolated URT/orofacial presentation (i.e., without headache or visual signs) accounted for 5.2% of the entire cohort. CONCLUSIONS: Oral-facial symptoms were present in two-thirds of GCS cases. Thus, they could serve as leading clinical clues for a GCA diagnosis, and are a risk factor for permanent visual loss. Several URT/orofacial symptoms such as jaw claudication, hoarseness, and earache influenced the likelihood of a positive TAB. Isolated URT/orofacial presentation of GCA is a rare but potentially challenging occurrence.

The functional disabilities of the dominant and opposite hands in patients with systemic sclerosis.

OBJECTIVES: Hand involvement in patients with systemic sclerosis (SSc) is responsible for 75% of the overall disability but varies greatly among individuals. No study has yet compared the functionalities between the two hands of SSc patients. We thus evaluated the joint limitations and extent of skin involvement in the dominant and contralateral hands. METHODS: This prospective, descriptive, comparative single-centre study enrolled SSc patients diagnosed using the ACR/EULAR criteria. We assessed limitations in the joint range of motion during active and passive mobilisation; the first commissure opening angles; the Kapandji scale and Rodnan hand scores; the digital pressures; the finger brachial pressure indices; and the number of telangiectasias, calcinosis, digital ulcerations, and painful joints on each hand. RESULTS: Thirty patients were included. Spontaneous flexion joint limitations were significantly greater in the dominant hand (p<0.0001). The Kapandji score was lower (p<0.001) and the Rodnan hand score significantly higher, for the dominant hand (p<0.001). The digital pressure was similar between the hands. CONCLUSIONS: The dominant hand exhibited significantly more skin sclerosis and mean flexion deterioration, a lower Kapandji score, and a tendency toward reduced mean extension, compared with the other hand. No vascular pathology was noted in either hand. Larger studies are needed to confirm these results and to draw therapeutic conclusions.

Relationship between histopathological features of non-infectious aortitis and the results of pre-operative 18F-FDG-PET/CT: a retrospective study of 16 patients.

OBJECTIVES: To describe the characteristics of 18F-fluorodeoxyglucose positron-emission tomography/computed-tomography (18FDG-PET/CT) findings before surgery in patients with active, histologically confirmed aortitis, and to correlate the degree of arterial wall inflammation with PETVAS score. METHODS: This was a multiple-centre retrospective study including cases with histologically proven active, non-infectious aortitis who had a 18FDG-PET/CT performed within one year before surgery for aneurysm repair. PETVAS score was determined by radiologists blinded to the pathology findings. Cardiovascular pathologists reviewed aortic tissue samples and graded the degree of inflammation in the vessel wall. RESULTS: Sixteen patients were included (8 giant cell arteritis, 4 clinically isolated aortitis, 2 Takayasu's arteritis, 1 relapsing polychondritis, and 1 rheumatoid arthritis). In 5/16 (31%) patients, 18FDG-PET/CT did not detect the presence of aortic inflammation; two of whom were being treated with glucocorticoids at the time of procedure. Ascending thoracic and abdominal aorta had the highest FDG uptake among the affected territories. Patients without active aortitis on 18FDG-PET/CT were significantly older (p=0.027), had a lower PETVAS score (p=0.007), and had a lower degree of adventitial inflammation (p=0.035). In contrast, there was no difference between 18FDG-PET/CT active and inactive aortitis patients as regards the timing between PET/CT and surgery, serum CRP level (during 18FDG-PET/CT) and, FDG uptake per study site. CONCLUSIONS: In histologically proved aortitis, 18FDG-PET/CT before surgery did not detect vascular inflammation in 31% patients, and PETVAS score correlated with the degree of adventitial histopathologic inflammation.

New-onset giant cell arteritis with lower ESR and CRP level carries a similar ischemic risk to other forms of the disease but has an excellent late prognosis: a case-control study.

INTRODUCTION: Biopsy-proven giant cell arteritis (GCA) occasionally presents without acute-phase reaction. In this setting, GCA may be initially overlooked and glucocorticoid treatment unduly delayed, potentially increasing ischemic risk. PATIENTS AND METHODS: From an inception cohort of patients with newly diagnosed, biopsy-verified GCA, we retrieved all cases without elevation of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level before starting glucocorticoid treatment. We compared the baseline features and outcomes of these patients and two additional patients recruited after GCA diagnosis with those of 42 randomly selected patients with high baseline ESR and CRP. RESULTS: Of 396 patients, 14 (3.5%) had lower baseline values of both ESR and CRP. Lower baseline ESR and CRP were associated with fewer American College of Rheumatology criteria met (p < 0.001, 95% CI - 1.1; - 0.9), and less jaw claudication (p = 0.06, 95% CI 0.8; 44.9), but similar rates of permanent blindness (p = 1.0). Patients with lower ESR and CRP also showed obvious differences regarding mean blood cell counts and mean hemoglobin level, but also less anti-cardiolipin antibody positivity (p = 0.04, 95% CI 0.8; ∞) and hepatic cholestasis (p = 0.03, 95% CI 1.0; 422). Patients with lower ESR and CRP had fewer GCA relapses (p = 0.03, 95% CI - 1.1; - 0.1), fewer glucocorticoid-induced complications (p = 0.01, 95% CI - 2.0; - 0.1), and successfully stopped glucocorticoids sooner than the other patients (18.3 months vs 34 months in average, p = 0.02, 95% CI - 27;- 0.9). CONCLUSION: Biopsy-proven GCA presenting with lower ESR and CRP is not an exceptional occurrence. It is clinically less typical but carries similar ischemic risk to other forms of the disease. Conversely, the late GCA prognosis of these patients is excellent.

Features and risk factors for new (secondary) permanent visual involvement in giant cell arteritis.

OBJECTIVES: New permanent visual loss (PVL) in treated patients with giant cell arteritis (GCA) is a rare but worrisome occurrence. In this study, we aimed to describe the frequency and main features of new PVL occurring after the beginning of glucocorticoid therapy in patients with newly diagnosed GCA. METHODS: We included in an inception cohort all consecutive patients newly diagnosed with GCA in the internal medicine department of a tertiary-care hospital between 1976 and May 2020. The study population comprised all the patients without bilateral PVL before treatment who were followed for at least one year. Only well-documented visual events that set after the initiation of glucocorticoid treatment were regarded as new PVL. RESULTS: Eleven out of 502 patients (2.2%) experienced a new PVL including 6 occurrences during the initial therapeutic phase and 5 during the tapering phase. Patients with new PVL during treatment had higher mean age, more often displayed temporal artery abnormalities on physical examination, and had higher mean platelet counts at GCA onset. There was a strong excess risk of contralateral recurrence during treatment in patients with unilateral loss at GCA onset compared with patients with uncomplicated GCA (10.5% vs 1.1%, OR=10.26, p<0.001). CONCLUSIONS: New PVL in treated GCA is a rare, but significant occurrence. Older patients and patients who already had unilateral PVL at diagnosis have higher risk of new ischaemic visual loss during treatment compared to the other patients. Close clinical, laboratory, and eye monitoring of these high-risk patients is of paramount importance.

Steroid-sparing effect of anakinra in giant-cell arteritis: a case series with clinical, biological and iconographic long-term assessments.

OBJECTIVES: The treatment of GCA relies on corticosteroids but is burdened by a high rate of relapses and adverse effects. Anti-IL-6 treatments show a clear benefit with a significant steroid-sparing effect, but late relapses occur after treatment discontinuation. In addition to IL-6, IL-1 also appears to play a significant role in GCA pathophysiology. We report herein the efficacy of anakinra, an IL-1 receptor antagonist, in six GCA patients exhibiting corticosteroid dependence or resistance, specifically analysing the outcome of aortitis in four of them. METHODS: This retrospective study analysed the cases of all GCA patients treated with anakinra from the French Study Group for Large Vessel Vasculitis. RESULTS: After a median duration of anakinra therapy of 19 (18-32) months, all six patients exhibited complete clinical and biological remission. Among the four patients with large-vessel involvement, one had a disappearance of aortitis under anakinra and three showed a decrease in vascular uptake. After a median follow-up of 56 (48-63) months, corticosteroids were discontinued in four patients, and corticosteroid dosage could be decreased to 5 mg/day in two patients. One patient relapsed 13 months after anakinra introduction in the context of increasing the daily anakinra injection interval to every 48 h. Three patients experienced transient injection-site reactions, and one patient had pneumonia. CONCLUSION: In this short series, anakinra appears to be an efficient and safe steroid-sparing agent in refractory GCA, with a possible beneficial effect on large-vessel involvement.

An immunohistochemical analysis of fibroblasts in giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) is a systemic vasculitis of large and medium vessels characterized by an inflammatory arterial infiltrate. GCA begins in the adventitia and leads to vascular remodeling by promoting proliferation of myofibroblasts in the intima. The morphology of the fibroblasts in the adventitia in GCA is unclear. Access to temporal artery biopsies allows morphological studies and evaluation of the microenvironment of the arterial wall. We evaluated the distribution of vascular fibroblasts and of markers of their activation in GCA. METHODS: Formalin-fixed paraffin-embedded tissue sections from 29 patients with GCA and 36 controls were examined. Immunohistochemistry was performed for CD90, vimentin, desmin, alpha-smooth muscle actin (ASMA), prolyl-4-hydroxylase (P4H), and myosin to evaluate the distribution of fibroblasts within the intima, media, and adventitia. RESULTS: Temporal arteries from patients with GCA showed increased levels of CD90, vimentin, and ASMA in the adventitia and intima compared to the controls. Desmin was expressed only in the media in both groups. P4H was expressed similarly in the adventitia and intima in the two groups. Adventitial and intimal CD90+ cells co-expressed P4H, ASMA, and myosin at a high level in GCA. CONCLUSION: The results suggest a role for adventitial fibroblasts in GCA. Inhibiting the differentiation of adventitial fibroblasts to myofibroblasts has therapeutic potential for GCA.

A COVID-19 forecasting system using adaptive neuro-fuzzy inference.

This article proposes an Adaptive Neuro-Fuzzy Inference System (ANFIS) to forecast the number of COVID-19 cases in the United Kingdom. With the combination of artificial neural network and fuzzy logic structure, the model is trained based on collected data. The study examines various factors of ANFIS to come up with an effective time series prediction model. The result indicates that Spain and Italy data can strengthen the predictive power of COVID-19 cases in the UK. It is suggested that the policymakers should adopt Adaptive Neuro-Fuzzy Inference System (ANFIS) to predict contagion effect during the COVID-19 pandemic.

Vascular Presentation and Outcomes of Patients With Giant Cell Arteritis and Isolated Symptomatic Limb Involvement.

OBJECTIVE: The aims of this study were to describe and assess the vascular outcomes of patients with giant cell arteritis (GCA) presenting with only symptomatic isolated limb involvement (LI-GCA). METHODS: We recruited patients from 5 tertiary centers who were diagnosed with GCA based on histology or vasculitis demonstration on imaging and who presented with isolated symptomatic limb involvement at diagnosis. For each included patient, we randomly selected 3 control patients who satisfied the 5 criteria from the American College of Rheumatology at diagnosis. RESULTS: We included 27 LI-GCA patients and 81 control patients. Compared with the controls, the patients with LI-GCA were younger (p = 0.005), exhibited a more delayed diagnosis (p = 0.006), and had lower C-reactive protein levels (p = 0.001), but they did not show more cardiovascular risk factors. Glucocorticoid use (starting and tapering doses) and relapse rates did not differ in the 2 groups, but the patients with LI-GCA received longer treatment (p = 0.02). Cardiovascular complications occurred in 67% of the patients with LI-GCA versus 21% of the control patients (p < 0.0001), especially ischemic events (p < 0.0001) including stroke (p = 0.03) and myocardial infarction (p = 0.01). Vascular surgery was required in 44% of the patients with LI-GCA versus 2% of the controls (p < 0.0001). Excluding vascular surgery, the cumulative incidence of cardiovascular complications was higher in the patients with LI-GCA (log-rank test: p < 0.0001) than in the controls (hazard ratio, 5.73; 95% confidence interval, 2.94-11.28; p < 0.0001). CONCLUSIONS: Compared with the typical cranial form of GCA, LI-GCA has a worse cardiovascular-related prognosis. Further studies are required to determine the best management of these patients.

Different patterns and specific outcomes of large-vessel involvements in giant cell arteritis.

Large-vessel involvement (LVI) in giant cell arteritis (GCA) includes different clinical and imaging patterns that are rarely described separately at diagnosis and whose specific cardiovascular outcomes are unknown. We conducted a nationwide retrospective study and included GCA patients with LVI demonstrated on imaging at diagnosis between 2007 and 2017. We analyzed the prognosis of three different imaging patterns of LVI present at diagnosis, with some of them overlapping but with the first one present in all patients: 1) inflammation of the aorta and/or its branches; 2) dilation of the aorta; and 3) stenosis of the aortic branches. A control group of GCA patients without LVI was constituted. We included 183 patients with LVI and 105 controls without LVI. Altogether, among the 183 patients who all showed inflammation of the aorta and/or its main branches, concomitant aortic dilation and large-vessel stenosis were observed in 27 (15%) and 55 (30%) patients, respectively. During the follow-up period, new cardiovascular events occurred in 49% and 11% of LVI patients and controls, respectively (p < 0.0001). Inflammation of the aorta and/or its branches (HR: 3.42 [2.09-5.83], p < 0.0001) and large-artery stenosis (HR: 2.75 [1.80-4.15], p < 0.0001) were independent predictive factors of new cardiovascular events. Conversely, the use of an immunosuppressant besides corticosteroids was a protective factor against new cardiovascular events (HR: 0.44 [0.29-0.66], p < 0.0001) and the development of aortic dilation (HR: 0.43 [0.23-0.77], p = 0.005). This study suggests different forms of cardiovascular events according to the initial imaging pattern of LVI.

The different clinical patterns of giant cell arteritis.

OBJECTIVES: To estimate the frequency of different clinical patterns in giant-cell arteritis (GCA) at onset. METHODS: All GCA patients consecutively followed-up in two referral centers for GCA with a biopsy-proven diagnosis and/or large-vessel vasculitis (LVV) demonstrated on imaging were analysed. RESULTS: We analysed the initial clinical presentation of 693 patients with a median age of 75 [48-94] years and including 486 (70%) women. We identified four different clinical patterns: isolated cranial GCA (in 80%), symptomatic LVV with or without associated cranial signs (9%), isolated fever or inflammatory response (9%), and isolated polymyalgia rheumatica with vasculitis (2%). A silent LVV was found in 110 (45%) out of the 247 patients without large-vessel symptoms who underwent imaging at GCA diagnosis. Symptomatic LVV patients were more frequently GC-dependent compared to other patterns (p=0.03) and showed the longest treatment duration (median: 37 [15-212] months versus <30 months for other clinical phenotypes; p=0.001). CONCLUSIONS: This study suggests that 80% of GCA patients display a typical presentation, whereas the other 20% showed rarer presentations. Patients with symptomatic LVV required longer treatment duration.

Giant-cell arteritis: concordance study between aortic CT angiography and FDG-PET/CT in detection of large-vessel involvement.

PURPOSE: The purpose of our study was to assess the concordance of aortic CT angiography (CTA) and FDG-PET/CT in the detection of large-vessel involvement at diagnosis in patients with giant-cell arteritis (GCA). METHODS: We created a multicenter cohort of patients with GCA diagnosed between 2010 and 2015, and who underwent both FDG-PET/CT and aortic CTA before or in the first ten days following treatment introduction. Eight vascular segments were studied on each procedure. We calculated concordance between both imaging techniques in a per-patient and a per-segment analysis, using Cohen's kappa concordance index. RESULTS: We included 28 patients (21/7 women/men, median age 67 [56-82]). Nineteen patients had large-vessel involvement on PET/CT and 18 of these patients also presented positive findings on CTA. In a per-segment analysis, a median of 5 [1-7] and 3 [1-6] vascular territories were involved on positive PET/CT and CTA, respectively (p = 0.03). In qualitative analysis, i.e., positivity of the procedure suggesting a large-vessel involvement, the concordance rate between both procedures was 0.85 [0.64-1]. In quantitative analysis, i.e., per-segment analysis in both procedures, the global concordance rate was 0.64 [0.54-0.75]. Using FDG-PET/CT as a reference, CTA showed excellent sensitivity (95%) and specificity (100%) in a per-patient analysis. In a per-segment analysis, sensitivity and specificity were 61% and 97.9%, respectively. CONCLUSIONS: CTA and FDG-PET/CT were both able to detect large-vessel involvement in GCA with comparable results in a per-patient analysis. However, PET/CT showed higher performance in a per-segment analysis, especially in the detection of inflammation of the aorta's branches.

Microscopic polyangiitis and non-HBV polyarteritis nodosa with poor-prognosis factors: 10-year results of the prospective CHUSPAN trial.

OBJECTIVES: To analyse the 10-year outcomes of 64 patients with non-HBV polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA) and Five-Factor Score-defined poor-prognosis factors enrolled (1994-2000) in the prospective, randomised, open-label CHUSPAN trial. METHODS: The 64 patients were randomised to receive 12 (33: 23 MPA, 10 PAN) or 6 (31: 17 MPA, 14 PAN) cyclophosphamide (CYC) pulses combined with glucocorticoids. Ten-year follow-up of these patients included times to relapse(s), failure(s) and/or deaths calculated from treatment onset. Data were censored after 120 months of follow-up. RESULTS: Eleven patients were lost to-follow-up (mean±SD follow-up: 61.9±35.2 months), with no between-group difference. As previously reported, baseline clinical characteristics and laboratory values were comparable for the 2 groups. After induction, 53/64 (83%) entered remission, with comparable percentages for both groups. The regimen was intensified for 11 initial non-responders: 4 achieved remission and 8 died before doing so. During extended follow-up, 26 patients experienced ≥1 relapse(s): 12 in the 12-pulse group and 14 in the 6-pulse group (p=0.47). At 10 years, overall and disease-free survival rates were 57.4% and 29.9%, with no between-group differences (p=0.185 and p=0.367, respectively). Factors associated with shorter disease-free survival were age ≥65 years and alveolar haemorrhage at diagnosis. CONCLUSIONS: Although the 3-year CHUSPAN trial results indicated the superiority of 12 vs. 6 CYC pulses, that early advantage progressively declined and became non-significant by 10 years.

Proteomic analysis of vascular smooth muscle cells in physiological condition and in pulmonary arterial hypertension: Toward contractile versus synthetic phenotypes.

Vascular smooth muscle cells (VSMCs) are highly specialized cells that regulate vascular tone and participate in vessel remodeling in physiological and pathological conditions. It is unclear why certain vascular pathologies involve one type of vessel and spare others. Our objective was to compare the proteomes of normal human VSMC from aorta (human aortic smooth muscle cells, HAoSMC), umbilical artery (human umbilical artery smooth muscle cells, HUASMC), pulmonary artery (HPASMC), or pulmonary artery VSMC from patients with pulmonary arterial hypertension (PAH-SMC). Proteomes of VSMC were compared by 2D DIGE and MS. Only 19 proteins were differentially expressed between HAoSMC and HPASMC while 132 and 124 were differentially expressed between HUASMC and HAoSMC or HPASMC, respectively (fold change 1.5≤ or -1.5≥, p < 0.05). As much as 336 proteins were differentially expressed between HPASMC and PAH-SMC (fold change 1.5≤ or -1.5≥, p < 0.05). HUASMC expressed increased amount of α-smooth muscle actin compared to either HPASMC or HAoSMC (although not statistically significant). In addition, PAH-SMC expressed decreased amount of smooth muscle myosin heavy chain and proliferation rate was increased compared to HPASMC thus supporting that PAH-SMC have a more synthetic phenotype. Analysis with Ingenuity identified paxillin and (embryonic lethal, abnormal vision, drosophila) like 1 (ELAVL1) as molecules linked with a lot of proteins differentially expressed between HPASMC and PAH-SMC. There was a trend toward reduced proliferation of PAH-SMC with paxillin-si-RNA and increased proliferation with ELAVL1-siRNA. Thus, VSMCs have very diverse protein content depending on their origin and this is in link with phenotypic differentiation. Paxillin targeting may be a promising treatment of PAH. ELAVL1 also participate in the regulation of PAH-SMC proliferation.

Involvement and prognosis value of CD8(+) T cells in giant cell arteritis.

CD8(+) T cells participate in the pathogenesis of some vasculitides. However, little is known about their role in Giant Cell Arteritis (GCA). This study was conducted to investigate CD8(+) T cell involvement in the pathogenesis of GCA. Analyses were performed at diagnosis and after 3 months of glucocorticoid treatment in 34 GCA patients and 26 age-matched healthy volunteers. Percentages of CD8(+) T-cell subsets, spectratype analysis of the TCR Vß families of CD8(+) T cells, levels of cytokines and chemokines and immunohistochemistry of temporal artery biopsies (TAB) were assessed. Among total CD8(+) T cells, percentages of circulating cytotoxic CD8 T lymphocytes (CTL, CD3(+)CD8(+)perforin(+)granzymeB(+)), Tc17 (CD3(+)CD8(+)IL-17(+)), CD63(+)CD8(+) T cells and levels of soluble granzymes A and B were higher in patients than in controls, whereas the percentage of Tc1 cells (CD3(+)CD8(+)IFN-γ(+)) was similar. Moreover, CD8(+) T cells displayed a restricted TCR repertoire in GCA patients. Percentages of circulating CTL, Tc17 and soluble levels of granzymes A and B decreased after treatment. CXCR3 expression on CD8(+) T cells and its serum ligands (CXCL9, -10, -11) were higher in patients. Analyses of TAB revealed high expression of CXCL9 and -10 associated with infiltration by CXCR3(+)CD8(+) T cells expressing granzyme B and TiA1. The intensity of the CD8 T-cell infiltrate in TAB was predictive of the severity of the disease. This study demonstrates the implication and the prognostic value of CD8(+) T-cells in GCA and suggests that CD8(+) T-cells are recruited within the vascular wall through an interaction between CXCR3 and its ligands.

Contribution of dot-blot assay to the diagnosis and management of myositis: a three-year practice at a university hospital centre.

OBJECTIVES: Idiopathic inflammatory myopathies (IIM) are heterogeneous autoimmune diseases with wide clinical spectrum that may lead to delayed diagnosis. The aim of this study was to examine the impact of IIM-specific dot-blot assay on diagnostic process of patients presenting with muscular or systemic symptoms evocating of IIM. METHODS: We collected all the prescriptions of an IIM specific dot-blot assay (8 autoantigens including Jo-1, PL-7, PL-12, SRP, Mi-2, Ku, PM/Scl and Scl-70) over a 38-month period. RESULTS: 316 myositis dot-blot assays (MSD) were performed in 274 patients (156 women, mean age 53±10.6 years) referring for muscular and/or systemic symptoms suggesting IIM. The timing of dot prescription through the diagnostic process was highly variable: without (35%), concomitantly (16%) or after electromyographic studies (35%). Fifty-nine patients (22%) had IIM according to Bohan and Peter's criteria. Among them, 29 (49%) had positive dot (8 Jo-1, 6 PM-Scl, 5 PL-12, 5 SRP, 2 Mi-2, 2 PL-7 and 1 Ku). Various other diagnoses were performed including 35 autoimmune disease or granulomatosis (12%), 19 inflammatory rheumatic disease (7%), 16 non inflammatory muscular disorders (6%), 10 drug-induced myalgia (4%), 11 infectious myositis (4%). Except 11 borderline SRP results and one transient PM-Scl, MSD was positive only in one case of IIM. Dot allowed clinicians to correct diagnosis in 4 cases and improved the diagnosis of IIM subtypes in 4 cases. CONCLUSIONS: This study reflects the interest of myositis dot in the rapid diagnosis process of patients with non-specific muscular symptoms leading to various diagnoses including IIM.

The atypical Rho GTPase, RhoU, regulates cell-adhesion molecules during cardiac morphogenesis.

The vertebrate heart undergoes early complex morphologic events in order to develop key cardiac structures that regulate its overall function (Fahed et al., 2013). Although many genetic factors that participate in patterning the heart have been elucidated (Tu and Chi, 2012), the cellular events that drive cardiac morphogenesis have been less clear. From a chemical genetic screen to identify cellular pathways that control cardiac morphogenesis in zebrafish, we observed that inhibition of the Rho signaling pathways resulted in failure to form the atrioventricular canal and loop the linear heart tube. To identify specific Rho proteins that may regulate this process, we analyzed cardiac expression profiling data and discovered that RhoU was expressed at the atrioventricular canal during the time when it forms. Loss of RhoU function recapitulated the atrioventricular canal and cardiac looping defects observed in the ROCK inhibitor treated zebrafish. Similar to its family member RhoV/Chp (Tay et al., 2010), we discovered that RhoU regulates the cell junctions between cardiomyocytes through the Arhgef7b/Pak kinase pathway in order to guide atrioventricular canal development and cardiac looping. Inhibition of this pathway resulted in similar underlying cardiac defects and conversely, overexpression of a PAK kinase was able to rescue the loss of RhoU cardiac defect. Finally, we found that Wnt signaling, which has been implicated in atrioventricular canal development (Verhoeven et al., 2011), may regulate the expression of RhoU at the atrioventricular canal. Overall, these findings reveal a cardiac developmental pathway involving RhoU/Arhgef7b/Pak signaling, which helps coordinate cell junction formation between atrioventricular cardiomyocytes to promote cell adhesiveness and cell shapes during cardiac morphogenesis. Failure to properly form these cell adhesions during cardiac development may lead to structural heart defects and mechanistically account for the cellular events that occur in certain human congenital heart diseases.

Brain angiogenesis inhibitor 1 (BAI1) is a pattern recognition receptor that mediates macrophage binding and engulfment of Gram-negative bacteria.

Bacterial recognition by host cells is essential for initiation of infection and the host response. Bacteria interact with host cells via multiple pattern recognition receptors that recognize microbial products or pathogen-associated molecular patterns. In response to this interaction, host cell signaling cascades are activated that lead to inflammatory responses and/or phagocytic clearance of attached bacteria. Brain angiogenesis inhibitor 1 (BAI1) is a receptor that recognizes apoptotic cells through its conserved type I thrombospondin repeats and triggers their engulfment through an ELMO1/Dock/Rac1 signaling module. Because thrombospondin repeats in other proteins have been shown to bind bacterial surface components, we hypothesized that BAI1 may also mediate the recognition and clearance of pathogenic bacteria. We found that preincubation of bacteria with recombinant soluble BAI1 ectodomain or knockdown of endogenous BAI1 in primary macrophages significantly reduced binding and internalization of the Gram-negative pathogen Salmonella typhimurium. Conversely, overexpression of BAI1 enhanced attachment and engulfment of Salmonella in macrophages and in heterologous nonphagocytic cells. Bacterial uptake is triggered by the BAI1-mediated activation of Rac through an ELMO/Dock-dependent mechanism, and inhibition of the BAI1/ELMO1 interaction prevents both Rac activation and bacterial uptake. Moreover, inhibition of ELMO1 or Rac function significantly impairs the proinflammatory response to infection. Finally, we show that BAI1 interacts with a variety of Gram-negative, but not Gram-positive, bacteria through recognition of their surface lipopolysaccharide. Together these findings identify BAI1 as a pattern recognition receptor that mediates nonopsonic phagocytosis of Gram-negative bacteria by macrophages and directly affects the host response to infection.