EBV-Positive Inflammatory Follicular Dendritic Cell Sarcoma of the Spleen: Report of an Aggressive Form With Molecular Characterization

EBV-positive inflammatory follicular dendritic cell sarcoma (EBV+ inflammatory FDCS) is a rare neoplasm almost exclusively located in the spleen or liver. It is characterized by a proliferation of EBV-positive spindle-shaped cells bearing follicular dendritic cell markers, associated with an abundant lymphoplasmacytic infiltrate. EBV+ inflammatory FDCS is often asymptomatic or responsible for mild symptoms. It usually displays an indolent course and its prognosis is excellent after tumor removal, although relapsing and metastatic forms exist. Herein, we describe an aggressive form of splenic EBV+ inflammatory FDCS in a 79-year-old woman presenting with abdominal pain, deterioration of general health status, major inflammatory syndrome, and symptomatic hypercalcemia. A splenectomy was performed leading to a rapid improvement in her clinical condition and normalization of laboratory abnormalities. Unfortunately, her symptoms and laboratory abnormalities reappeared 4 months later. Computed tomography showed a mass in the splenectomy site and multiple liver and peritoneal nodules. Further analyses were performed on tumor tissue and showed positive phospho-ERK staining of tumoral cells indicating activation of MAPK pathway. Inactivating mutations were found on CDKN2A and NF1 genes. Subsequently, the patient's condition deteriorated rapidly. Since interleukin-6 levels were dramatically increased, tocilizumab was used but only had a transient effect on the patient's symptoms and inflammatory syndrome. Antitumor agent gemcitabine was initiated but her clinical condition continued to deteriorate and the patient died 2 weeks later. The management of aggressive forms of EBV+ inflammatory FDCS remains challenging. However, since these tumors seem to display genetic alterations, better characterization could lead to molecular targeted therapies.

Induction failure in granulomatosis with polyangiitis: a nationwide case-control study of risk factors and outcomes

OBJECTIVE

To identify characteristics of granulomatosis with polyangiitis (GPA) associated with induction failure, describe salvage therapies and their efficacy.

METHODS

We conducted a nationwide retrospective case-control study of GPA with induction failure between 2006 and 2021. Each patient with induction failure was randomly paired to three controls matched for age, sex and induction treatment.

RESULTS

We included 51 patients with GPA and induction failure (29 men and 22 women). At induction therapy, median age was 49 years. Twenty-seven patients received intravenous cyclophosphamide (ivCYC) and 24 rituximab (RTX) as induction therapy. Patients with ivCYC induction failure more frequently had PR3-ANCA (93% vs 70%, P = 0.02), relapsing disease (41% vs 7%, P < 0.001) and orbital mass (15% vs 0%, P < 0.01) compared with controls. Patients with disease progression despite RTX induction therapy more frequently had renal involvement (67% vs 25%, P = 0.02) with renal failure (serum creatinine >100 µmol/l in 42% vs 8%, P = 0.02) compared with controls. After salvage therapy, remission was achieved at 6 months in 35 (69%) patients. The most frequent salvage therapy was switching from ivCYC to RTX (or vice versa), showing an efficacy in 21/29 (72%). Remission was achieved in nine (50%) patients with inappropriate response to ivCYC, while in patients with progression after RTX induction, remission was achieved in four (100%) who received ivCYC (with or without immunomodulatory therapy), but only in three (50%) after adding immunomodulatory therapy alone.

CONCLUSION

In patients with induction failure, characteristics of GPA, salvage therapies and their efficacy vary according to induction therapy and failure modality.

Anti-PM-Scl antibodies positive patients encompass three different groups with distinct prognosis

OBJECTIVE

To help identify homogeneous subgroups among patients with anti-polymyositis-scleroderma-antibodies (PM-Scl-Abs) positive auto-immune diseases regardless of diagnostic classifications.

METHODS

This multicentric (four hospitals) retrospective study collected all consecutive patients (from 2011 to 2021) with positive testing for anti-PM-Scl-Abs in a context of connective tissue disease. Subgroups of patients with similar clinico-biological phenotypes were defined using unsupervised multiple correspondence analysis and hierarchical clustering analysis of the features recorded in the first year of follow-up.

RESULTS

One hundred and forty-two patients with anti-PM-Scl-Abs were evaluated and 129 patients were included in the clustering analysis and divided into 3 clusters. Cluster n°1 (n = 47) included patients with frequent skin thickening, digestive involvement and interstitial lung disease (ILD) with Non Specific Interstitial Pneumonia (NSIP). They were more likely to develop progressive fibrosing ILD. Cluster n°2 (n = 36) included patients who all featured NSIP with frequent Organizing pneumonia associated pattern and mechanic's hands. This subgroup had increased risk of relapse and ILD was characterized by a good functional outcome. Cluster n°3 (n = 46) was characterized by predominant or isolated musculoskeletal involvement and frequently matched undifferentiated connective tissue disease (UCTD) criteria. Although very frequent among Anti PM-Scl-Abs positive patients, muscle involvement was less discriminating compared with skin thickening and ILD pattern to classify patients into subgroups.

CONCLUSION

Anti-PM-Scl-Abs associated auto-immune diseases are segregated into 3 subgroups with distinct clinical phenotype and outcomes. Skin thickening and NSIP are determinant predictors in segregation of theses populations.

Hypervirulent Klebsiella Pneumoniae, an Emerging Cause of Endogenous Endophthalmitis in A French Center: A Comparative Cohort Study

INTRODUCTION

Klebsiella pneumoniae (KP) is the most common cause of endogenous endophthalmitis (EE) in Asia, but data in Europe are scarce. We describe eight cases of KP EE compared to a cohort of EE in a French center.

METHODS

EE cases were retrospectively studied between January 2014 and January 2021. KP EE cases were analyzed to assess clinical, microbiological features, and outcome.

RESULTS

Among the 33 EE cases identified, the first causative agent (24%, n = 8) was KP, mainly (7/8) with hypervirulent phenotype (hvKP). All but one of these cases occurred from December 2019 to January 2021. Contrary to non-KP patients, KP patients had multiple extraocular infective foci (p = .006), all presented with liver abscesses (p < .001), 50% had cerebral involvement (p = .13). Visual outcome was poor in both groups.

CONCLUSION

KP is an emerging cause of EE in a French center, consistently associated with liver abscesses, frequent cerebral involvement, and predominance of hvKP strains.

Rituximab plus methotrexate combination as a salvage therapy in persistently active granulomatosis with polyangiitis

OBJECTIVE

To describe the efficacy and safety of rituximab and methotrexate (RTX/MTX) combination therapy in ANCA-associated vasculitides (AAV).

METHODS

A retrospective French nationwide study was conducted in patients with AAV who received RTX/MTX combination therapy for persistently active disease.

RESULTS

Seventeen patients were included. All patients had granulomatosis with polyangiitis (GPA), with positive ANCA in 76% mainly with PR3-ANCA specificity. Sixteen (94%) were still active after rituximab and 11 (65%) after cyclophosphamide (oral and/or intravenous). Patients had experienced a median of 3 (2-4) flares. Manifestations requiring RTX/MTX combination therapy were subglottic or bronchial stenosis in 6 patients (35%), orbital mass in 6 (35%), disabling ENT involvement in 2 (12%), and epiduritis and pachymeningitis in 1 case each (6%). Median follow-up with combination was 11 months (11-26 months). At 6 months, global response was achieved in 15 patients (88%), including partial response in 11 (65%) and complete response in 4 (24%). At last evaluation, global response was achieved in 16 patients (94%). Seven patients (41%) experienced severe adverse events (grade 3 or 4), including infections in 4 (24%) and hepatitis in 2 (12%). Combination therapy was withdrawn in 4 patients (24%) but never for safety concerns. In contrast, MTX dose was decreased in 2 patients (12%) because of adverse events. One patient died of an unknown cause.

CONCLUSION

RTX/MTX combination therapy could be an effective salvage therapy to treat persistently active GPA with granulomatous manifestations, with an acceptable safety profile.

Presentation, Diagnosis, and Management of Subglottic and Tracheal Stenosis During Systemic Inflammatory Diseases

BACKGROUND

Subglottic stenosis (SGS) and tracheal stenosis (TS) are characterized by a narrowing of the airways. The goal of this study was to describe the characteristics and prognosis of nontraumatic and nontumoral SGS or TS.

RESEARCH QUESTION

What are the inflammatory etiologies of SGS and TS, and what are their characteristics and prognosis?

STUDY DESIGN AND METHODS

This multicenter, observational retrospective study was performed in patients with SGS or TS that was neither traumatic nor tumoral.

RESULTS

Eighty-one patients were included, 33 (41%) with granulomatosis with polyangiitis (GPA) and 21 (26%) with relapsing polychondritis (RP). GPA-related stenoses exhibited circumferential subglottic narrowing in 85% of cases, without calcifications. In contrast, RP-related stenoses displayed anterior involvement in 76%, in a longer distance from vocal cords (4 cm), with calcifications in 62%, and extension to bronchi in 86%. Other diagnoses included bullous dermatoses (n = 3), amyloidosis (n = 3), sarcoidosis (n = 2), and Crohn's disease (n = 2); the remaining stenoses (n = 15) were idiopathic. SGS/TS was the initial manifestation of the disease in 66% of cases, with a median interval from stenosis to disease diagnosis of 12 months (interquartile range, 0-48 months). Despite the use of glucocorticoids in 80%, combined with methotrexate in 49%, endoscopic procedures were required in 68% of patients. Relapses of stenoses occurred in 76% without any difference between causes (82% in GPA, 67% in RP, and 75% in idiopathic SGS/TS). Three patients died due to the stenosis, two of RP and one of GPA.

INTERPRETATION

These data show that GPA and RP are the two main inflammatory diseases presenting with SGS/TS. GPA-related stenoses are mostly subglottic and circumferential, whereas RP-related stenoses are mostly tracheal, anterior, and calcified with a frequent extension to bronchi. Relapses of stenoses are common, and relapse rates do not differ between causes. Diagnosis and management of SGS/TS require a multidisciplinary approach.

POS0323 ANTI PM-SCL ASSOCIATED AUTO IMMUNE DISEASES: MULTICENTRIC COHORT OF 128 PATIENTS

Background:

Autoantibodies permit to classify and subgroup connective tissue diseases (CTD) in homogeneous groups of patients in terms of phenotype and prognosis. Anti PM-Scl antibodies have been associated with different CTD categories such as: idiopathic inflammatory myositis (IIM), systemic sclerosis (SSc), Sjögren’s syndrome (SjS), systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD) or undifferentiated connective tissue disease (UCTD).

Objectives:

To determine clinical spectrum of anti-PM-Scl associated disease and if it an homogenous condition.

Methods:

This multicentric (four hospitals) observational and retrospective study included all consecutive patients with positive testing for anti PM-Scl antibodies on immunoblot assay and connective tissue disease (2011 -2020). Epidemiological, biological, clinical and radiological data were collected in standard form as well as patient’s outcome.

Results:

One hundred twenty height patients (female n=96;75%) were included. Median [quartiles] age at diagnosis was 50 [18;84] (IQR) and follow-up duration of 7 [3.75-12] years. Seventy-six (59.3%) patients were simple anti-Pm-Scl positive, and 40.7% were associated with other antibodies: anti-SSA/Ro52 (n=13; 10.92%), SSc associated antibodies (n=21; 16.4%), anti-dsDNA for (n=9; 7%), anti-RNP (n=6; 4.7%) and anti-CCP antibodies (n=6; 4.7%). Most patients had cutaneous involvement (n=106; 83%) with skin thickening (n=47; 36%), mechanics hands (n= 28; 22%), calcinosis (n=26; 20.3%) and subcutaneous edema (n=20; 15.62%). Vascular involvement was frequent with Raynaud phenomenon (n= 89; 69%), telangiectasia (n=36; 28%), skin ulcers (n=27; 21%), pulmonary hypertension (n=8/120; 6.7%) and scleroderma renal crisis (n=2; 1.5%). A majority of patients also displayed an interstitial lung disease (ILD) (n=83; 65.8%); nonspecific interstitial pneumonia (92.7%) and/or organizing pneumonia (25.3%). ILD was characterized by a subacute onset in 37/81 (45.7%); median [quartiles] forced vital capacity (FVC) and total lung capacity (TLC) at diagnosis of 88% [73-105] and 79.5% [68.5-101] respectively. Sixty patients (47%) had muscular sign including myalgia (47%), elevated CPK (n=51; 40%) and muscular weakness (Medical Research Council score <4) (n=19/124;15%). Finally, fifty-three (41.7%) had gastroesophageal reflux. Thirty-nine patients (30.4%) experienced at least one muscular or ILD relapse and 6 (4.84%) died during follow-up (2 breast cancer, 1 pneumonia, 3 unknown etiology). Concerning patients’ prognosis, relapses were associated with skeletal (n=29, 74.4% vs n=32, 35.96%, p < 0.001) or cardiac muscle involvement (n=7, 18.4% vs n=2, 2.5%, p=0.007), and subacute ILD (n=19, 65.5% vs n=18, 34.62%, p= 0.05) with organized pneumonia pattern (n=11, 32.3% vs n=10, 13.9%, p=0.05). Strikingly, ILD occurred mainly in men (90.6% vs 57.2%, p < 0.001) and was associated with anti-Scl-70 positivity (n=14, 16.67% vs 0%, p= 0.01). Muscle involvement was associated arthralgia (n=46, 76.67% vs n=34, 50.75%, p=0.005), respiratory signs at diagnosis: dyspnea NYHA ≥3 (n=46, 75.41% vs n=30, 44.78%, p < 0.001), sub-acute ILD (n=24, 61.54% vs n=13, 30.95%, p=0.0111) with lower FVC (73% [64;88] vs 98 [76;105], p < 0.001). Ulcers were associated with Anti-Scl70 positivity (n=9, 33.33% vs n=5, 4.95%, p < 0.001), Raynaud phenomenon (n=27, 100% vs n=62, 61.39%, p < 0.001), digestive involvement (n=20, 74.07% vs n=34, 33.66%, p < 0.001), ILD with chronic onset (n=15, 78.95% vs n=29, 46.77%, p=0.027) and increased incidence of deaths (n=4, 16% vs n=2, 2.02%, p= 0.01).

Conclusion:

Conducted on the largest cohort of Anti-PM-Scl patients, this study highlights two main phenotypes that determine different outcome and prognosis. One was associated with muscular disease and subacute onset ILD with more frequent relapses. The second with a vascular phenotype associated with chronic ILD, digestive involvement, chronic evolution and increased incidence of death. This could lead to a reclassification of PM-Scl associated auto immune diseases.

Disclosure of Interests:

None declared

High D-dimer plasma concentration in systemic sclerosis patients: Prevalence and association with vascular complications

Objective

To determine the frequency of elevated D-dimer plasma concentration (>500 ng/mL) in patients with systemic sclerosis and evaluate its association with systemic sclerosis-specific microvascular and macrovascular complications.

Methods

Retrospective observational study of patients with systemic sclerosis followed in a tertiary referral center with at least one measurement of D-dimer between 2010 and 2018.

Results

A total of 214 patients were analyzed. Mean age at inclusion was 55.1 ± 14.7 years; 180 (84.1%) were female; 74 (34.6%) had diffuse cutaneous systemic sclerosis. Anti-Scl70 and anti-centromere antibodies were positive in 74 (34.6%) and 75 (35.0%) patients, respectively. D-dimer level was elevated in 93 (43.5%) patients, independently of cutaneous subtype (44.6% in diffuse cutaneous systemic sclerosis vs 42.9% in limited cutaneous systemic sclerosis, p = 0.81). At least one microvascular complication was found in 108 (50.5%) patients: 105 (49.1%) with previous or current digital ulcers, 6 (2.8%) with renal crisis, and 4 (1.9%) with pulmonary arterial hypertension. Microvascular complications were more frequent in patients with elevated D-dimer (57.0% vs 45.5%, p = 0.09), significantly so after exclusion of patients with a history of cancer and/or venous thromboembolism (60.5% vs 44.8%, p = 0.04). Macrovascular complications were detected in 15 (7.0%) patients and were associated with a high D-dimer level (11.8% vs 3.3%, p = 0.03). Over a median follow-up of 2.3 years [1.1-3.3] after D-dimer measurement, new macrovascular complications occurred only in patients with high D-dimer (n = 8).

Conclusion

High D-dimer levels are frequently found in systemic sclerosis patients and seem to be associated with the occurrence of macrovascular and microvascular complications after adjustment for confounding factors.

Plasma Concentrations and Safety of Lopinavir/Ritonavir in COVID-19 Patients

BACKGROUND

Although the efficacy of lopinavir/ritonavir has not been proven, it has been proposed as an off-label treatment for COVID-19. Previously, it has been reported that the plasma concentrations of lopinavir significantly increase in inflammatory settings. As COVID-19 may be associated with major inflammation, assessing the plasma concentrations and safety of lopinavir in COVID-19 patients is essential.

METHODS

Real-world COVID-19 data based on a retrospective study.

RESULTS

Among the 31 COVID-19 patients treated with lopinavir/ritonavir between March 18, 2020 and April 1, 2020, higher lopinavir plasma concentrations were observed, which increased by 4.6-fold (interquartile range: 3.6-6.2), compared with the average plasma concentrations in HIV. Lopinavir concentrations in all except one patient were above the upper limit of the concentration range of HIV treatment. Approximately one to 5 patients prematurely stopped treatment mainly because of an ADR related to hepatic or gastrointestinal disorders.

CONCLUSIONS

Lopinavir plasma concentrations in patients with moderate-to-severe COVID-19 were higher than expected, and they were associated with the occurrence of hepatic or gastrointestinal adverse drug reactions. However, a high plasma concentration may be required for in vivo antiviral activity against SARS-CoV-2, as suggested by previous studies. Therefore, in the absence of adverse drug reaction, lopinavir dosage should not be reduced. Caution is essential because off-label use can be associated with a new drug safety profile.

Mycophenolic acid drug monitoring in patients with systemic sclerosis associated with diffuse skin and/or pulmonary involvement: A monocentric and retrospective French study

OBJECTIVE

To explore pharmacokinetic/pharmacodynamic relationship between mycophenolic acid area under the curve and clinical response at 1 year on skin involvement or interstitial lung disease in patients with systemic sclerosis.

METHOD

Retrospective, monocentric study based on French Scleroderma Database in patients receiving mycophenolate mofetil who experienced a limited sampling strategy to estimate individual mycophenolic acid area under the curve plus two pulmonary function tests and skin evaluation after 1 month and 1 year. Efficacy criterions were variations of modified Rodnan skin score, forced vital capacity, and diffusing lung capacity for carbon monoxide at 1 year.

RESULTS

We included 52 patients; mean age was 49 years (range 17-79), and 36 (69%) were females. Fifty patients (96%) had skin sclerosis, 39 (75%) had diffuse skin involvement with a median modified Rodnan skin score of 14 (0-38). Thirty-eight (76%) had interstitial lung disease, with median forced vital capacity and diffusing lung capacity for carbon monoxide of 81% (37-127) and 56% (28-103) from predicted values, respectively. Twenty-five (51%) patients had pulmonary fibrosis. Mycophenolate mofetil was given for 10 months (0-173) at a median dose of 2000 mg/day (500-3000). In the entire population, no relationship was found between area under the curve and modified Rodnan skin score (p = 0.085), forced vital capacity (p = 0.80), or diffusing lung capacity for carbon monoxide (p = 0.72) variations at 1 year.

CONCLUSION

In this retrospective study, we failed to document any relationship between mycophenolic acid area under the curve and skin involvement or interstitial lung disease evolution. Routine monitoring of mycophenolic acid in systemic sclerosis patients treated with mycophenolate mofetil cannot be recommended based on our results.

Diversity and dynamics of bacterial and fungal communities in cider for distillation

Bacterial and fungal population dynamics in cider for distillation have so far been explored by culture-dependant methods. Cider for distillation can be produced by the spontaneous fermentation of apples that do not undergo any intervention during the process. In this study, cider microbiomes extracted from six tanks containing ciders for distillation from four producers in Normandy were characterized at three main stages of the fermentation process: fermentation Initiation (I), end of the alcoholic Fermentation (F) and end of the Maturation period (M). Cider samples were subjected to Illumina MiSeq sequencing (rRNA 16S V1-V3 and ITS1 region targeting) to determine bacterial and fungal communities. Yeasts (YGC), Zymomonas (mZPP) and lactic acid bacteria selective media (mMRS, mMLO, mPSM) were also used to collect 807 isolates. Alcoholic levels, glycerol, sugar content (glucose, fructose and sucrose), pH, total and volatile acidity, nitrogen, malic and lactic acid contents were determined at all sampling points. Alpha diversity indexes show significant differences (p < 0.05) in microbial populations between I, F and M. Fungal communities were characterized by microorganisms from the environment and phytopathogens at I followed by the association of yearsts with alcoholic fermentation like Saccharomyces and non-Saccharomyces yeasts (Hanseniaspora, Candida). A maturation period for cider leads to an increase of the Dekkera/Brettanomyces population, which is responsible for off-flavors in cider for all producers. Among bacterial communities, the genera community associated to malolactic fermentation (Lactobacillus sp., Leuconostoc sp., Oenococcus sp.) was the most abundant at F and M. Acetic acid bacteria such as Acetobacter sp., Komagataeibacter sp. and Gluconobacter sp. were also detected during the process. Significant differences (p < 0.05) were found in fungal and bacterial populations between the four producers and during the fermentation process. The development of microorganisms associated with cider spoilage such as Zymomonas mobilis, Lactobacillus collinoides or Brettanomyces/Dekkera sp. was anticipated by a metagenomic approach. The monitoring of microbial diversity via high throughput sequencing combined with physical-chemical analysis is an interesting approach to improve the fermentation performance of cider for distillation and therefore, the quality of Calvados.

Clinical efficacy of hydroxychloroquine in patients with covid-19 pneumonia who require oxygen: observational comparative study using routine care data

OBJECTIVE

To assess the effectiveness of hydroxychloroquine in patients admitted to hospital with coronavirus disease 2019 (covid-19) pneumonia who require oxygen.

DESIGN

Comparative observational study using data collected from routine care.

SETTING

Four French tertiary care centres providing care to patients with covid-19 pneumonia between 12 March and 31 March 2020.

PARTICIPANTS

181 patients aged 18-80 years with documented severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia who required oxygen but not intensive care.

INTERVENTIONS

Hydroxychloroquine at a dose of 600 mg/day within 48 hours of admission to hospital (treatment group) versus standard care without hydroxychloroquine (control group).

MAIN OUTCOME MEASURES

The primary outcome was survival without transfer to the intensive care unit at day 21. Secondary outcomes were overall survival, survival without acute respiratory distress syndrome, weaning from oxygen, and discharge from hospital to home or rehabilitation (all at day 21). Analyses were adjusted for confounding factors by inverse probability of treatment weighting.

RESULTS

In the main analysis, 84 patients who received hydroxychloroquine within 48 hours of admission to hospital (treatment group) were compared with 89 patients who did not receive hydroxychloroquine (control group). Eight additional patients received hydroxychloroquine more than 48 hours after admission. In the weighted analyses, the survival rate without transfer to the intensive care unit at day 21 was 76% in the treatment group and 75% in the control group (weighted hazard ratio 0.9, 95% confidence interval 0.4 to 2.1). Overall survival at day 21 was 89% in the treatment group and 91% in the control group (1.2, 0.4 to 3.3). Survival without acute respiratory distress syndrome at day 21 was 69% in the treatment group compared with 74% in the control group (1.3, 0.7 to 2.6). At day 21, 82% of patients in the treatment group had been weaned from oxygen compared with 76% in the control group (weighted risk ratio 1.1, 95% confidence interval 0.9 to 1.3). Eight patients in the treatment group (10%) experienced electrocardiographic modifications that required discontinuation of treatment.

CONCLUSIONS

Hydroxychloroquine has received worldwide attention as a potential treatment for covid-19 because of positive results from small studies. However, the results of this study do not support its use in patients admitted to hospital with covid-19 who require oxygen.

Catastrophic antiphospholipid syndrome following the introduction of rivaroxaban

Summary

Catastrophic antiphospholipid syndrome is the most severe complication of antiphospholipid syndrome. Vitamin K antagonists are the reference treatment for preventing relapsing thrombotic complications in patients with antiphospholipid syndrome. Direct oral anticoagulants are nonetheless sometimes used in this setting. We report two cases of women who were triple-positive for antiphospholipid antibodies and developed catastrophic antiphospholipid syndrome in the week after the introduction of rivaroxaban. The first patient, who had had a previous thrombotic event, had multiorgan failure 3 days after vitamin K antagonists was replaced by rivaroxaban, and the second developed a similar clinical presentation 7 days after introduction of the same treatment. Both catastrophic antiphospholipid syndrome episodes were successfully treated with heparin followed by vitamin K antagonists, corticosteroids, and plasmapheresis. These two cases highlight for the inefficacy of rivaroxaban preventing severe thrombotic events such as catastrophic antiphospholipid syndrome and thus provide further support for recommendations that vitamin K antagonists must remain the reference anticoagulant in patients with triple-positive antiphospholipid antibodies.

The cerebrospinal fluid CD4/CD8 ratio and interleukin-6 and -10 levels in neurosarcoidosis: a multicenter, pragmatic, comparative study

BACKGROUND AND PURPOSE

Neurosarcoidosis is a rare inflammatory disorder of unknown cause. The aim of this study was to evaluate the value of T/B lymphocyte population counts and the concentrations of the cytokines interleukin (IL) 6 and IL-10 in the cerebrospinal fluid (CSF) of neurosarcoidosis patients.

METHODS

A retrospective study CSF biomarkers was conducted in patients with neurosarcoidosis who underwent CSF analysis between 2012 and 2017 as well as various control populations.

RESULTS

Forty-three patients with neurosarcoidosis, 14 with multiple sclerosis (MS) and 48 with other inflammatory disorders were analyzed. The CSF IL-6 levels were higher in sarcoidosis patients than in MS patients (median 8 vs. 3 pg/ml, P = 0.006). The CSF CD4/CD8 ratio was higher in sarcoidosis patients than in MS patients and in patients with other inflammatory disorders (median 3.18 vs. 2.36 and 2.10, respectively, P = 0.008). The CSF IL-6 level was higher in patients with active neurosarcoidosis than in non-active neurosarcoidosis patients (median 13 vs. 3 pg/ml, P = 0.0005). In patients with neurosarcoidosis, a CSF IL-6 concentration >50 pg/ml was associated with a higher risk of relapse or progression-free survival (hazard ratio 3.60; 95% confidence interval 1.78-23.14). A refractory neurosarcoidosis patient was treated with an anti-IL-6 monoclonal antibody that produced a complete neurological response.

CONCLUSIONS

The CSF CD4/CD8 ratio and IL-6 concentration are increased in neurosarcoidosis compared to MS and other inflammatory disorders. A CSF IL-6 concentration >50 pg/ml is associated with relapse or progression of neurosarcoidosis. IL-10 levels may be elevated in neurosarcoidosis.

[Systemic sclerosis]

Systemic sclerosis. Systemic sclerosis is more frequent among women (sex ratio from 3/1 to 8/1) and its prevalence varies from 30 to 240 per millions. Two types of SSc are described depending on the extent of skin involvement : limited and diffuse SSc. Clinical manifestations include fibrosing lesions (skin and pulmonary fibrosis) and vascular abnormalities (Raynaud's phenomenon and pulmonary arterial hypertension (PAH)). Auto-antibodies have been identified in SSc patients, directed at centromere proteins, topoisomerase 1 or RNA polymerase III. SSc is associated with a poor outcome particularly in diffuse forms associated with pulmonary involvement (pulmonary fibrosis and/or PAH). SSc treatment associate symptomatic treatments as well as treatment of visceral complications (PAH, renal crisis) and immunosuppressive therapy in patients with recent onset diffuse SSc and/or rapidely progressing interstitial lung disease.

Shear stress-independent binding of von Willebrand factor-type 2B mutants p.R1306Q & p.V1316M to LRP1 explains their increased clearance

BACKGROUND

von Willebrand factor (VWF) is cleared in a shear stress- and macrophage-dependent manner by LRP1. von Willebrand disease (VWD)-type 2B mutants are endocytosed more efficiently than wild-type (wt)-VWF by macrophages.

OBJECTIVE

To investigate if VWD-type 2B mutations in the VWF A1-domain affect LRP1 binding and LRP1-dependent clearance.

METHODS

Recombinant Fc-tagged A1 domain (A1-Fc, A2-Fc, A3-Fc) and full-length VWF (wt or mutants thereof) were tested for binding to LRP1 or a recombinant fragment thereof in a static immunosorbent assay. Mutant and wt-VWF were also compared for clearance in mice lacking macrophage LRP1 (macLRP1(-) ) and control mice (macLRP1(+) ).

RESULTS

We found that A1-Fc but not A2-Fc or A3-Fc binds dose-dependently to LRP1. Binding of A1-Fc to LRP1 was markedly enhanced by the VWD-type 2B mutation p.V1316M. As expected, full-length wt-VWF was unable to bind LRP1 under static conditions unless ristocetin was added. In contrast, the presence of the p.V1316M or p.R1306Q mutation induced spontaneous binding to LRP1 without the need for ristocetin or shear stress. Both mutants were cleared more rapidly than wt-VWF in control macLRP1(+) mice. Surprisingly, deletion of macrophage LRP1 abrogated the increased clearance of the VWF/p.R1306Q and VWF/p.V1316M mutant.

CONCLUSION

The VWF A1-domain contains a binding site for LRP1. Certain VWD-type 2B mutations relieve the need for shear stress to induce LRP1 binding. Enhanced LRP1 binding coincides with a reduced survival of VWF/p.R1306Q and VWF/p.V1316M. Our data provide a rationale for reduced VWF levels in at least some VWD-type 2B patients.

Pattern of invasion of the embryonic mouse spinal cord by microglial cells at the time of the onset of functional neuronal networks

Microglial cells invade the central nervous system during embryonic development, but their developmental functional roles in vivo remain largely unknown. Accordingly, their invasion pattern during early embryonic development is still poorly understood. To address this issue, we analyzed the initial developmental pattern of microglial cell invasion in the spinal cord of CX3CR1-eGFP mouse embryos using immunohistochemistry. Microglial cells began to invade the mouse embryonic spinal cord at a developmental period corresponding to the onset of spontaneous electrical activity and of synaptogenesis. Microglial cells reached the spinal cord through the peripheral vasculature and began to invade the parenchyma at 11.5 days of embryonic age (E11.5). Remarkably, at E12.5, activated microglial cells aggregated in the dorsolateral region close to terminals of dying dorsal root ganglia neurons. At E13.5, microglial cells in the ventral marginal zone interacted with radial glial cells, whereas ramified microglial cells within the parenchyma interacted with growing capillaries. At this age, activated microglial cells (Mac-2 staining) also accumulated within the lateral motor columns at the onset of the developmental cell death of motoneurons. This cell aggregation was still observed at E14.5, but microglial cells no longer expressed Mac-2. At E15.5, microglial cells were randomly distributed within the parenchyma. Our results provide the essential basis for further studies on the role of microglial cells in the early development of spinal cord neuronal networks in vivo.

Spider, bee, and bird communities in cities are shaped by environmental control and high stochasticity

Spatially organized distribution patterns of species and communities are shaped by both autogenic processes (neutral mechanism theory) and exogenous processes (niche theory). In the latter, environmental variables that are themselves spatially organized induce spatial structure in the response variables. The relative importance of these processes has not yet been investigated in urban habitats. We compared the variance explained by purely spatial, spatially structured environmental, and purely environmental components for the community composition of spiders (Araneae), bees (Apidae), and birds (Aves) at 96 locations in three Swiss cities. Environmental variables (topography, climate, land cover, urban green management) were measured on four different radii around sampling points (< 10 m, 50 m, 250 m, 1000 m), while Moran's eigenvector maps (MEMs) acted as spatial variables. All three taxonomic groups showed weak spatial structure. Spider communities reacted to very fine-scaled environmental changes of lawn and meadow management and climate. Bird community composition was determined by woody plants as well as solar radiation at all radii, the scale of the influence varying among species. Bee communities were weakly explained by isolated variables only. Our results suggest that the anthropogenic structuring of urban areas has disrupted the spatial organization of environmental variables and inhibited the development of biotic spatial processes. The near absence of spatial structure may therefore be a feature typical of urban species assemblages, resulting in urban community composition mainly influenced by local environmental variables. Urban environments represent a close-knit mosaic of habitats that are regularly disturbed. Species communities in urban areas are far from equilibrium. Our analysis also suggests that urban communities need to be considered as being in constant change to adapt to disturbances and changes imposed by human activities.

Water table response to an experimental alley farming trial: dissecting the spatial and temporal structure of the data

Clearing vegetation for traditional agriculture diminishes native habitat and reduces plant transpiration, leading to increased groundwater recharge and onset of dryland salinization due to rising groundwater and mobilization of salt stores in the soil profile. This change in hydrology and salinity can also negatively affect biodiversity in many semiarid regions. Alternating native perennial tree belts with mono-species agriculture within the tree belt alleys is one possible system that can provide recharge control and recover some of the ecosystem services of degraded agricultural landscapes. To assess the effect of this agroforestry technique on groundwater levels, an alley farming trial was established in 1995, incorporating different combinations of belt width, alley width, and revegetation density. Transects of piezometers within each design have been monitored from October 1995 to January 2008. The data set consisted of 70 piezometers monitored on 39 dates. Two trends were observed within the raw data: An increase in water table depth with time and an increase in the range of depths monitored at the site were clearly discernible. However, simple hydrograph analysis of the data has proved unsuccessful at distinguishing the effect of the tree belts on the water table morphology. The statistical techniques employed in this paper to show the effect of the experiment on the water table were variation partitioning, principal coordinates of neighbor matrices (PCNM), and canonical redundancy analysis (RDA). The environmental variables (alley farming design, distance of piezometer from the tree belt, and percentage vegetation cover including edge effect) explained 20-30% of the variation of the transformed and detrended data for the entire site. The spatial PCNM variables explained a further 20-30% of the variation. Partitioning of the site into a northern and southern block increased the proportion of explained variation for the plots in the northern block. The spatial PCNM variables and vegetation cover remained the most significant variables. The PCNM analysis revealed no spatial pattern that could be attributed to the trial. The high proportion of unexplained variation may be due to site variables that have not been considered in this study.

Common factors drive adaptive genetic variation at different spatial scales in Arabis alpina

A major challenges facing landscape geneticists studying adaptive variation is to include all the environmental variables that might be correlated with allele frequencies across the genome. One way of identifying loci that are possibly under selection is to see which ones are associated with environmental gradient or heterogeneity. Since it is difficult to measure all environmental variables, one may take advantage of the spatial nature of environmental filters to incorporate the effect of unaccounted environmental variables in the analysis. Assuming that the spatial signature of these variables is broad-scaled, broad-scale Moran's eigenvector maps (MEM) can be included as explanatory variables in the analysis as proxies for unmeasured environmental variables. We applied this approach to two data sets of the alpine plant Arabis alpina. The first consisted of 140 AFLP loci sampled at 130 sites across the European Alps (large scale). The second one consisted of 712 AFLP loci sampled at 93 sites (regional scale) in three mountain massifs (local scale) of the French Alps. For each scale, we regressed the frequencies of each AFLP allele on a set of eco-climatic and MEM variables as predictors. Twelve (large scale) and 11% (regional scale) of all loci were detected as significantly correlated to at least one of the predictors ( > 0.5), and, except for one massif, 17% at the local scale. After accounting for spatial effects, temperature and precipitation were the two major determinants of allele distributions. Our study shows how MEM models can account for unmeasured environmental variation in landscape genetics models.

Compensatory dynamics are rare in natural ecological communities

In population ecology, there has been a fundamental controversy about the relative importance of competition-driven (density-dependent) population regulation vs. abiotic influences such as temperature and precipitation. The same issue arises at the community level; are population sizes driven primarily by changes in the abundances of cooccurring competitors (i.e., compensatory dynamics), or do most species have a common response to environmental factors? Competitive interactions have had a central place in ecological theory, dating back to Gleason, Volterra, Hutchison and MacArthur, and, more recently, Hubbell's influential unified neutral theory of biodiversity and biogeography. If competitive interactions are important in driving year-to-year fluctuations in abundance, then changes in the abundance of one species should generally be accompanied by compensatory changes in the abundances of others. Thus, one necessary consequence of strong compensatory forces is that, on average, species within communities will covary negatively. Here we use measures of community covariance to assess the prevalence of negative covariance in 41 natural communities comprising different taxa at a range of spatial scales. We found that species in natural communities tended to covary positively rather than negatively, the opposite of what would be expected if compensatory dynamics were important. These findings suggest that abiotic factors such as temperature and precipitation are more important than competitive interactions in driving year-to-year fluctuations in species abundance within communities.

Effect of von Willebrand disease type 2B and type 2M mutations on the susceptibility of von Willebrand factor to ADAMTS-13

BACKGROUND

von Willebrand disease (VWD) type 2 is associated with mutations in von Willebrand factor (VWF) that affect its secretion, multimeric pattern, affinity for platelet receptors and clearance of the protein. While increased proteolysis by a disintegrin-like and metalloprotease with thrombospondin type 1 motifs-13 (ADAMTS-13) has been clearly established for VWF type 2A, only little is known about VWF types 2B and 2M in this regard.

OBJECTIVES

Sensitivity of wild-type (WT) and mutated recombinant (r) VWF to proteolysis by ADAMTS-13 was investigated to better understand the role of this process in the pathophysiology of VWD.

METHODS

We used human rADAMTS-13-WT to digest 11 full-length recombinant forms of VWF carrying molecular abnormalities identified in patients with VWD type 2A (E1638K and P1648S), type 2B (InsM1303, R1306W, R1308P and V1314F) and type 2M (G1324A, E1359K, K1362T, R1374H and I1425F).

RESULTS

Using low ionic strength conditions, all mutations induced increased proteolysis of rVWF by rADAMTS-13 as compared with rVWF-WT. The susceptibility of mutants decreased in the following order: type 2A > type 2B > type 2M > rVWF-WT. At physiological salt concentration (150 mm NaCl) the sensitivity of all rVWF to rADAMTS-13 was significantly decreased. However, type 2A and type 2B mutants still exhibited a significantly higher susceptibility to rADAMTS-13 than rVWF-WT, whereas type 2M mutants normalized.

CONCLUSIONS

Type 2M mutants and rVWF-WT exhibit a similar sensitivity to rADAMTS-13-mediated proteolysis, in agreement with the normal multimeric pattern in vivo. In VWD type 2B, the spontaneous binding to platelets and excessive degradation by ADAMTS-13 of VWF high-molecular-weight multimers may account for their clearance from plasma.

Transforming growth factor α promotes sequential conversion of mature astrocytes into neural progenitors and stem cells

An instability of the mature cell phenotype is thought to participate to the formation of gliomas, primary brain tumors deriving from astrocytes and/or neural stem cells. Transforming growth factor alpha (TGFalpha) is an erbB1 ligand overexpressed in the earliest stages of gliomas, and exerts trophic effects on gliomal cells and astrocytes. Here, we questioned whether prolonged TGFalpha exposure affects the stability of the normal mature astrocyte phenotype. We first developed astrocyte cultures devoid of residual neural stem cells or progenitors. We demonstrate that days of TGFalpha treatment result in the functional conversion of a population of mature astrocytes into radial glial cells, a population of neural progenitors. TGFalpha-generated radial glial cells support embryonic neurons migration, and give birth to cells of the neuronal lineage, expressing neuronal markers and the electrophysiological properties of neuroblasts. Lengthening TGFalpha treatment to months results in the delayed appearance of cells with neural stem cells properties: they form floating cellular spheres that are self-renewing, can be clonally derived from a single cell and differentiated into cells of the neuronal lineage. This study uncovers a novel population of mature astrocytes capable, in response to a single epigenetic factor, to regress progressively into a neural stem-like cell stage via an intermediate progenitor stage.

Frequency-dependent modulation of glycine receptor activation recorded from the zebrafish larvae hindbrain

In vertebrates, most glycinergic inhibitory neurons discharge phasically at a relatively low frequency. Such a pattern of glycine liberation from presynaptic terminals may affect the kinetics of post-synaptic glycine receptors. To examine this influence, we have analyzed the behavior of glycine receptors in response to repetitive stimulation at frequencies at which consecutive outside-out currents did not superimpose (0.5-4 Hz). Neurotransmitter release was mimicked on outside-out patches from zebrafish hindbrain Mauthner cells using fast flow application techniques. The amplitude of outside-out currents evoked by short (1 ms) repetitive applications of a saturating concentration (3 mM) of glycine remained unchanged for application frequencies<or=1 Hz. When the application frequency was increased from 1 to 4 Hz, the amplitude of the outside-out currents decreased with time to reach a steady state level. This decrease in current amplitude was larger and occurred faster with increasing application frequencies. Recovery occurred when the stimulation frequency was decreased back to 1 Hz. The recovery time constant was independent on the application frequency. This frequency-dependent inhibition was also observed for non-saturating glycine concentrations. Our results indicate that glycine receptor activity is down-regulated when the stimulation frequency increases to values>1 Hz. Glycine-evoked current simulations using a simple Markov model describing zebrafish glycine receptor kinetic behavior, indicates that this down-regulation of glycine receptor efficacy is due to a progressive accumulation of the receptors in a long lasting desensitization state. Our simulations suggest that this down-regulation can occur even when spontaneous inhibitory currents were generated randomly at a frequency>1 Hz.

CHO cells expressing the high affinity alpha(IIb)beta3 T562N integrin demonstrate enhanced adhesion under shear

BACKGROUND

Alpha(IIb)beta3-mediated platelet adhesive interactions in the vasculature, which are dependent on the functional state of this receptor, may be sensitive to shear forces.

OBJECTIVES

To evaluate the influence of the alpha(IIb)beta3 affinity state on cell attachment under flow, we compared Chinese hamster ovary cells expressing the low affinity alpha(IIb)beta3 wild-type (wt) receptor to those expressing the high affinity alpha(IIb)beta3 T562N receptor.

MATERIALS AND METHODS

We designed a real-time videomicroscopy adhesion assay for von Willebrand factor (VWF) or fibrinogen under flow conditions.

RESULTS

At 50 s(-1), alpha(IIb)beta3 T562N supported higher cell adhesion to fibrinogen (63.3 +/- 2.9 cells/field) than alpha(IIb)beta3 wt (38.7 +/- 2.4 cells/field, P < 0.0001). At 100 s(-1), alpha(IIb)beta3 T562N mediated cell adhesion (40.5 +/- 3.8 cells/field), while alpha(IIb)beta3 wt did not (5.3 +/- 1.4 cells/field, P < 0.001), allowing to discriminate the efficiency of each receptor. Similar findings were observed for adhesion to VWF. Complete inhibition of cell adhesion to fibrinogen was achieved with 800 microM fibrinogen gamma-chain dodecapeptide [HHLGGAKQAGDV (H12)], while Arg-Gly-Asp-Ser (RGDS) peptide (10-1000 microM) induced a dose-dependent cell detachment. These results suggest that the H12 motif allows initial attachment, in contrast to the RGDS site, which strengthens the stability of adhesion. Interestingly, compared with wt, a 10-fold lower concentration of RGDS was required to reach a similar reduction of cell adhesion mediated by alpha(IIb)beta3 T562N.

CONCLUSIONS

Our data show that alpha(IIb)beta3 activation is associated with a stabilization of integrin binding to fibrinogen or VWF under shear.

Kinetic properties of the alpha2 homo-oligomeric glycine receptor impairs a proper synaptic functioning

Ionotropic glycine receptors (GlyRs) are present in the central nervous system well before the establishment of synaptic contacts. Immature nerve cells are known, at least in the spinal cord, to express alpha2 homomeric GlyRs, the properties of which are relatively unknown compared to those of the adult synaptic form of the GlyR (mainly alpha1/beta heteromeres). Here, the kinetics properties of GlyRs at the single-channel level have been recorded in real-time by means of the patch-clamp technique in the outside-out configuration coupled with an ultra-fast flow application system (< 100 micros). Recordings were performed on chinese hamster ovary (CHO) cells stably transfected with the alpha2 GlyR subunit. We show that the onset, the relaxation and the desensitisation of alpha2 homomeric GlyR-mediated currents are slower by one or two orders of magnitude compared to synaptic mature GlyRs and to other ligand-gated ionotropic channels involved in fast synaptic transmission. First latency analysis performed on single GlyR channels revealed that their slow activation time course was due to delayed openings. When synaptic release of glycine was mimicked (1 mM glycine; 1 ms pulse duration), the opening probability of alpha2 homomeric GlyRs was low (P(o) approximately = 0.1) when compared to mature synaptic GlyRs (Po = 0.9). This low Po is likely to be a direct consequence of the relatively slow activation kinetics of alpha2 homomeric GlyRs when compared to the activation kinetics of mature alpha1/beta GlyRs. Such slow kinetics suggest that embryonic alpha2 homomeric GlyRs cannot be activated by fast neurotransmitter release at mature synapses but rather could be suited for a non-synaptic paracrine-like release of agonist, which is known to occur in the embryo.

Functional glycine receptor maturation in the absence of glycinergic input in dopaminergic neurones of the rat substantia nigra

The postnatal maturation pattern of glycine receptor channels (GlyRs) expressed by dopaminergic (DA) neurones of the rat substantia nigra pars compacta (SNc) was investigated using single-channel and whole-cell patch-clamp recordings in brain slices from rats aged 7-21 postnatal days (P). In neonatal rats (P7-P10), GlyRs exhibited a main conductance state of 100-110 pS with a mean open time of 16 ms. In juvenile rats (P19-P22), both the GlyR main conductance state (46-55 pS) and the mean open time (6.8 ms) were decreased. In neonatal rats, application of 30 microM picrotoxin, which is known to block homomeric GlyRs, strongly reduced glycine-evoked responses, while it was much less effective in juvenile rats. These results suggest that these GlyRs correspond functionally to alpha(2) homomeric GlyRs in neonatal rats and alpha(1)/beta heteromeric GlyRs in juvenile rats. A drastic but transient decrease in the glycine responsiveness of DA neurones occurred around P17 concomitant to the functional switch from the homomeric state to the heteromeric state. This age corresponds to a maturation phase for DA neurones. The application of 1 microM gabazine blocked spontaneous or evoked inhibitory synaptic current, while the addition of 1 microM strychnine had no effect, suggesting a lack of functional glycinergic synapses on DA neurones. Although it has been proposed that taurine is co-released with GABA at GABAergic synapses on DA neurones, in the present study the stimulation of GABAergic fibres failed to activate GlyRs. Blockade of taurine transporters and applications of high K(+) and hyposmotic solutions were also unable to induce any strychnine-sensitive current. We conclude that functional maturation of GlyRs can occur in the absence of any detectable GlyR activation in DA neurones of the SNc.