Monocyte-driven atypical cytokine storm and aberrant neutrophil activation as key mediators of COVID-19 disease severity.

Epidemiological and clinical reports indicate that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we perform cytokine and multiplex immune profiling in COVID-19 patients. We show that hypercytokinemia in COVID-19 differs from the interferon-gamma-driven cytokine storm in macrophage activation syndrome, and is more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling shows that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Antigen presenting machinery expression is also reduced in critical disease. Furthermore, we report that neutrophils contribute to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together our findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity

Flemish network on rare connective tissue diseases (CTD): patient pathways in systemic sclerosis. First steps taken.

peer reviewedDespite the low prevalence of each rare disease, the total burden is high. Patients with rare diseases encounter numerous barriers, including delayed diagnosis and limited access to high-quality treatments. In order to tackle these challenges, the European Commission launched the European Reference Networks (ERNs), cross-border networks of healthcare providers and patients representatives. In parallel, the aims and structure of these ERNs were translated at the federal and regional levels, resulting in the creation of the Flemish Network of Rare Diseases. In line with the mission of the ERNs and to ensure equal access to care, we describe as first patient pathways for systemic sclerosis (SSc), as a pilot model for other rare connective and musculoskeletal diseases. Consensus was reached on following key messages: 1. Patients with SSc should have multidisciplinary clinical and investigational evaluations in a tertiary reference expert centre at baseline, and subsequently every three to 5 years. Intermediately, a yearly clinical evaluation should be provided in the reference centre, whilst SSc technical evaluations are permissionably executed in a centre that follows SSc-specific clinical practice guidelines. In between, monitoring can take place in secondary care units, under the condition that qualitative examinations and care including interactive multidisciplinary consultations can be provided. 2. Patients with early diffuse cutaneous SSc, (progressive) interstitial lung disease and/or pulmonary arterial hypertension should undergo regular evaluations in specialised tertiary care reference institutions. 3. Monitoring of patients with progressive interstitial lung disease and/or pulmonary (arterial) hypertension will be done in agreement with experts of ERN LUNG

Clinical characteristics of sarcoidosis patients in Belgium

doi: 10.1080/17843286.2020.1821493status: publishe

Towards the Essence of Progressiveness: Bringing Progressive Fibrosing Interstitial Lung Disease (PF-ILD) to the Next Stage

Although only recently introduced in the ILD community, the concept of progressive fibrosing interstitial lung disease (PF-ILD) has rapidly acquired an important place in the management of non-idiopathic pulmonary fibrosis fibrosing ILD (nonIPF fILD) patients. It confirms a clinical gut feeling that an important subgroup of nonIPF fILD portends a dismal prognosis despite therapeutically addressing the alleged triggering event. Due to several recently published landmark papers showing a treatment benefit with currently available antifibrotic drugs in PF-ILD patients, endorsing a PF-ILD phenotype has vital therapeutic consequences. Importantly, defining progressiveness is based on former progression, which has proven to be a rather moderate predictor of future progression. As fibrosis extent >20% and the presence of honeycombing have superior predictive properties regarding future progression, we advocate immediate initiation of antifibrotic treatment in the presence of these risk factors. In this perspective, we describe the historical context wherein PF-ILD has emerged, determine the currently employed PF-ILD criteria and their inherent limitations and propose new directions to mature its definition. Finally, while ascertaining progression in a nonIPF fILD patient clearly demonstrates the need for (additional) therapy, in the future, therapeutic decisions should be taken after assessing which pathway is ultimately driving the progression. Although not readily available, pathophysiological insight and diagnostic means are emergent to go full steam ahead in this novel direction.status: publishe

Progression in the Management of Non-Idiopathic Pulmonary Fibrosis Interstitial Lung Diseases, Where Are We Now and Where We Would Like to Be

A significant proportion of patients with interstitial lung disease (ILD) may develop a progressive fibrosing phenotype characterized by worsening of symptoms and pulmonary function, progressive fibrosis on chest computed tomography and increased mortality. The clinical course in these patients mimics the relentless progressiveness of idiopathic pulmonary fibrosis (IPF). Common pathophysiological mechanisms such as a shared genetic susceptibility and a common downstream pathway—self-sustaining fibroproliferation—support the concept of a progressive fibrosing phenotype, which is applicable to a broad range of non-IPF ILDs. While antifibrotic drugs became the standard of care in IPF, immunosuppressive agents are still the mainstay of treatment in non-IPF fibrosing ILD (F-ILD). However, recently, randomized placebo-controlled trials have demonstrated the efficacy and safety of antifibrotic treatment in systemic sclerosis-associated F-ILD and a broad range of F-ILDs with a progressive phenotype. This review summarizes the current pharmacological management and highlights the unmet needs in patients with non-IPF ILD

Effects of Corticosteroid Treatment and Antigen Avoidance in a Large Hypersensitivity Pneumonitis Cohort: A Single-Centre Cohort Study

BACKGROUND: Although the third most frequent interstitial lung disease, hypersensitivity pneumonitis (HP) remains an enigmatic disease without clear diagnostic and therapeutic guidelines. We assessed the effect of the commonly used therapeutic interventions (i.e. exposure avoidance and corticosteroid treatment) in an HP cohort. METHODS: We collected clinical data of all HP patients followed at our centre between January 1, 2005, and December 31, 2016. HP patients were stratified according to the presence of fibrosis on chest CT. Survival was analysed using the multivariate Cox proportional hazards model. Forced vital capacity (percent predicted, FVC%) and diffusing capacity of the lung for carbon monoxide (percent predicted, DLCO%) evolution were analysed using linear mixed-effect models. RESULTS: Two hundred and two HP patients were identified: 93 non-fibrotic HP (nfHP) and 109 fibrotic HP (fHP), experiencing a monthly FVC% decline before treatment of 0.93% and 0.56%, respectively. While nfHP had an excellent survival, fHP patients experienced a median survival of 9.2 years. Corticosteroid treatment and exposure avoidance did not result in survival differences. Although nfHP patients showed FVC% and DLCO% increase after corticosteroid initiation, no therapeutic effect was seen in fHP patients. FVC% and DLCO% increased in nfHP patients after exposure avoidance, while a positive numerical trend was seen for FVC% after exposure avoidance in fHP patients (p = 0.15). CONCLUSIONS: nfHP patients experienced an excellent survival with good therapeutic effect on pulmonary function tests with both corticosteroid initiation as well as antigen avoidance. In contrast, fHP patients experienced a dismal prognosis (median survival of 9.2 years) without any therapeutic effect of corticosteroid treatment. Whether antigen avoidance is useful in fHP patients is still unclear.status: publishe