Fibrotic Pulmonary Sarcoidosis.

Fibrotic pulmonary sarcoidosis (fPS) affects about 20% of patients. fPS carries a significant morbidity and mortality. However, its prognosis is highly variable, depending mainly on fibrosis extent, functional impairment severity, and the development of pulmonary hypertension. Moreover, fPS outcomes are also influenced by several other complications, including acute exacerbations, and infections. fPS natural history is unknown, in particular regarding the risk of progressive self-sustaining fibrosis. The management of fPS is challenging, including anti-inflammatory treatment if granulomatous activity persists, rehabilitation, and in highly selected patients antifibrotic treatment and lung transplantation.

Infectious Complications of Pulmonary Sarcoidosis.

In this review, the infectious complications observed in sarcoidosis are considered from a practical point of view to help the clinician not to overlook them in a difficult context, as pulmonary sarcoidosis makes the recognition of superinfections more difficult. An increased incidence of community-acquired pneumonia and of opportunistic pneumonia has been reported, especially in immunosuppressed patients. Pulmonary destructive lesions of advanced sarcoidosis increase the incidence of chronic pulmonary aspergillosis and infection by other agents. Screening and treatment of latent tuberculosis infection are crucial to prevent severe tuberculosis. Severity in COVID-19 appears to be increased by comorbidities rather than by sarcoidosis per se. The diagnosis of infectious complications can be challenging and should be considered as a potential differential diagnosis when the exacerbation of sarcoidosis is suspected. These complications not only increase the need for hospitalizations, but also increase the risk of death. This aspect must be carefully considered when assessing the overall health burden associated with sarcoidosis. The impact of immune dysregulation on infectious risk is unclear except in exceptional cases. In the absence of evidence-based studies on immunosuppressants in the specific context of pulmonary sarcoidosis, it is recommended to apply guidelines used in areas outside sarcoidosis. Preventive measures are essential, beginning with an appropriate use of immunosuppressants and the avoidance of unjustified treatments and doses. This approach should take into account the risk of tuberculosis, especially in highly endemic countries. Additionally, parallel emphasis should be placed on vaccinations, especially against COVID-19.

Prognostic impact of venous thromboembolism on the course of sarcoidosis: A multicenter retrospective case-control study.

Sarcoidosis is an independent risk factor for venous thromboembolism (VTE). However, the characteristics and clinical evolution of sarcoidosis patients presenting a VTE (sarcoidosis/VTE group) in the course of their disease are not known. Consequently, if VTE occurrence is associated with a more severe disease is still pending. We conducted a retrospective case-control study of sarcoidosis/VTE patients compared to matched sarcoidosis controls without VTE in two French tertiary centers, analysed and compared the clinical, biological, functional, imaging and evolutive profiles of the two groups. Sixty-one patients were included with at least one episode of VTE during course of sarcoidosis. At sarcoidosis onset (before/at the time of VTE occurrence) the number of affected organs, radiological stages and pulmonary functional tests were not significantly different between the two groups. In contrast, we found that sarcoidosis/VTE patients required more frequently a systemic immunosuppressive therapy (corticosteroids and/or immunosuppressors, 79% versus 58%; p = 0.008). The functional course was also poorer in sarcoidosis/VTE patients with a more frequent decrease in functional vital capacity (33% versus 18% in sarcoidosis/VTE patients and controls, respectively, p = 0.008). Finally, sarcoidosis/VTE patients presented more frequently with pulmonary hypertension (10% versus 1% in patients and controls, respectively, p = 0.006), and their survival was significantly worse (log-rank p <0.001). The occurrence of VTE during sarcoidosis is associated with a more severe disease and a poorer prognosis. The occurrence of VTE during sarcoidosis might signal a more inflammatory and/or evolutive disease in sarcoidosis/VTE patients and should be taken in consideration when designing therapeutic strategies for them.

High-altitude pulmonary edema: the intercellular network hypothesis.

The pathophysiology of high-altitude pulmonary edema is currently attributed to exacerbated heterogeneous hypoxic pulmonary vasoconstriction. However, although other cellular mechanisms have been hypothesized, they are still poorly understood. In this review, we focused on cells of the pulmonary acinus, the distal unit for gas exchange, known to be responders to acute hypoxia, notably through many humoral or tissue factors that connect this intercellular network constituting the alveolo-capillary barrier. Hypoxia could drive alveolar edema by: 1) damaging the fluid reabsorption capacity of alveolar epithelial cells, 2) increasing the endothelial and epithelial permeability, especially by alteration of occluding junctions, 3) triggering the inflammation mainly led by alveolar macrophages, 4) increasing interstitial water accumulation by disruption of extracellular matrix architecture and tight junctions, 5) inducing pulmonary vasoconstriction through an orchestrated response of pulmonary arterial endothelial and smooth muscle cells. Hypoxia may also alter the function of fibroblasts and pericytes that contribute to the interconnection of the cells of the alveolar-capillary barrier. Due to its complex intercellular network and delicate pressure gradient equilibrium, the alveolar-capillary barrier is simultaneously affected by acute hypoxia in all its components, leading to rapid accumulation of water in the alveoli.

Frontal cutaneous and bone sarcoidosis: an example of the contiguous spread of granulomas.

Sarcoidosis is a multisystemic granulomatous disease of unknown origin. It has been argued that the skin is one of the entry doors of the possible antigen that causes sarcoidosis and after entering the skin, the causal agent may progress to the underlying bone. We report four cases with development of sarcoidosis in old scars located on the forehead, and contiguous bone involvement of the frontal bone. In most cases scar sarcoidosis was the first manifestation of the disease, and in most cases it was asymptomatic. Two patients never required treatment, and in all cases the frontal problem improved or remained stable spontaneously or under sarcoidosis treatment. Scar sarcoidosis in the frontal area may have contiguous bone damage. This bone involvement does not seem to be associated with neurological extension.

Intimal granulomatous angiitis in sarcoid pulmonary vasculitis: worth remembering.

Intimal granulomatous angiitis is a facet of pulmonary sarcoidosis vasculitis that has almost been forgotten. Its observation may offer new understanding of the various patterns of pulmonary hypertension associated with sarcoidosis. https://bit.ly/3g6Ms76.

Differential diagnosis of pulmonary sarcoidosis: a review.

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

Validation of the Sarcoidosis Diagnostic Score in a Multicontinental Study.

Rationale: The Sarcoidosis Diagnostic Score (SDS) has been established to quantitate the clinical features consistent with sarcoidosis in a monocentric study. Objectives: We aimed to confirm the diagnostic value of SDS in a large, multicontinental study and to assess the utility of SDS in differentiating sarcoidosis from alternative diagnoses, including infectious and noninfectious granulomatous diseases. Methods: We included patients with biopsy-confirmed sarcoidosis at nine centers across the world. Patients without sarcoidosis seen at the same sites served as control patients. Using a modified World Association of Sarcoidosis and Other Granulomatous Disorders organ assessment instrument, we scored all patients for the presence of granuloma on biopsy, highly probable symptoms, and least probable symptoms for each area. Two sarcoidosis scores were generated: SDS Biopsy (with biopsy) and SDS Clinical (without biopsy). SDS Clinical and Biopsy were calculated for all patients. We calculated and compared the area under the curve (AUC) for SDS Clinical and Biopsy according to different diagnosis scenarios. Results: A total of 1,041 patients with sarcoidosis and 1,035 without sarcoidosis were included. The results for SDS Clinical (AUC, 0.888; 95% confidence interval [CI], 0.874-0.902) and SDS Biopsy (AUC, 0.979; 95% CI, 0.973-0.985) according to AUC were good to excellent for differentiating sarcoidosis from alternative diagnosis. SDS Clinical was less discriminatory in males (P = 0.01) and in high tuberculosis prevalence centers (P < 0.001). However, SDS Clinical (AUC, 0.684; 95% CI, 0.602-0.766) and SDS Biopsy (AUC, 0.754; 95% CI, 0.673-0.835) were not sufficiently discriminative for noninfectious granulomatous diseases, but both SDSs could differentiate sarcoidosis from infectious granulomatous diseases. Algorithms were proposed for the SDS Clinical and SDS Biopsy to assist the clinician in the diagnostic process, and cutoff values were proposed for the SDS Clinical and SDS Biopsy, allowing the diagnosis of sarcoidosis to be safely confirmed or rejected in most cases except for noninfectious granulomatous disease. Conclusions: This multicontinental study confirms that both SDS Clinical and SDS Biopsy have good to excellent performance in discriminating sarcoidosis from alternative diagnoses. Differences in the AUC were seen for high tuberculosis prevalence versus low tuberculosis prevalence centers and for males versus females. Both SDSs had good discriminatory function for infectious granulomatous disease but failed in cases of noninfectious granulomatous disease such as berylliosis.

Exposure to inorganic particles in paediatric sarcoidosis: the PEDIASARC study.

Inorganic antigens may contribute to paediatric sarcoidosis. Thirty-six patients matched with 36 healthy controls as well as a group of 21 sickle-cell disease (SCD) controls answered an environmental questionnaire. Patients' indirect exposure to inorganic particles, through coresidents' occupations, was higher than in healthy and SCD controls (median score: 2.5 (0.5-7) vs 0.5 (0-2), p=0.003 and 1 (0-2), p=0.012, respectively), especially for construction, exposures to metal dust, talc, abrasive reagents and scouring products. Wood or fossil energies heating were also linked to paediatric sarcoidosis. This study supports a link between mineral environmental exposure due to adult coresident occupations and paediatric sarcoidosis.

Hypoxia Promotes a Mixed Inflammatory-Fibrotic Macrophages Phenotype in Active Sarcoidosis.

Background: Macrophages are pivotal cells in sarcoidosis. Monocytes-derived (MD) macrophages have recently been demonstrated to play a major role especially in pulmonary sarcoidosis. From inflammatory tissues to granulomas, they may be exposed to low oxygen tension environments. As hypoxia impact on sarcoidosis immune cells has never been addressed, we designed the present study to investigate MD-macrophages from sarcoidosis patients in this context. We hypothesized that hypoxia may induce functional changes on MD-macrophages which could have a potential impact on the course of sarcoidosis. Methods: We studied MD-macrophages, from high active sarcoidosis (AS) (n=26), low active or inactive sarcoidosis (IS) (n=24) and healthy controls (n=34) exposed 24 hours to normoxia (21% O2) or hypoxia (1.5% O2). Different macrophage functions were explored: hypoxia-inducible factor-1α (HIF-1α) and nuclear factor-kappa B (NF-κB) activation, cytokines secretion, phagocytosis, CD80/CD86/HLA-DR expression, profibrotic response. Results: We observed that hypoxia, with a significantly more pronounced effect in AS compared with controls and IS, increased the HIF-1α trans-activity, promoted a proinflammatory response (TNFα, IL1ß) without activating NF-κB pathway and a profibrotic response (TGFß1, PDGF-BB) with PAI-1 secretion associated with human lung fibroblast migration inhibition. These results were confirmed by immunodetection of HIF-1α and PAI-1 in granulomas observed in pulmonary biopsies from patients with sarcoidosis. Hypoxia also decreased the expression of CD80/CD86 and HLA-DR on MD-macrophages in the three groups while it did not impair phagocytosis and the expression of CD36 expression on cells in AS and IS at variance with controls. Conclusions: Hypoxia had a significant impact on MD-macrophages from sarcoidosis patients, with the strongest effect seen in patients with high active disease. Therefore, hypoxia could play a significant role in sarcoidosis pathogenesis by increasing the macrophage proinflammatory response, maintaining phagocytosis and reducing antigen presentation, leading to a deficient T cell response. In addition, hypoxia could favor fibrosis by promoting profibrotic cytokines response and by sequestering fibroblasts in the vicinity of granulomas.

The impact of demographic disparities in the presentation of sarcoidosis: A multicenter prospective study.

OBJECTIVE: To study how demographic differences impact disease manifestation of sarcoidosis using the WASOG tool in a large multicentric study. METHODS: Clinical data regarding 1445 patients with sarcoidosis from 14 clinical sites in 10 countries were prospectively reviewed from Feb 1, 2020 to Sep 30, 2020. Organ involvement was evaluated for the whole group and for subgroups differentiated by sex, race, and age. RESULTS: The median age of the patients at diagnosis was 46 years old; 60.8% of the patients were female. The most commonly involved organ was lung (96%), followed by skin (24%) and eye (22%). Black patients had more multiple organ involvement than White patients (OR = 3.227, 95% CI: 2.243-4.643) and females had more multiple organ involvement than males (OR = 1.238, 95% CI: 1.083-1.415). Black patients had more frequent involvement of neurologic, skin, eye, extra thoracic lymph node, liver and spleen than White and Asian patients. Women were more likely to have eye (OR = 1.522, 95%CI: 1.259-1.838) or skin involvement (OR = 1.369, 95%CI: 1.152-1.628). Men were more likely to have cardiac involvement (OR = 1.326, 95%CI: 1.096-1.605). A total of 262 (18.1%) patients did not receive systemic treatment for sarcoidosis. Therapy was more common in Black patients than in other races. CONCLUSION: The initial presentation and treatment of sarcoidosis was related to sex, race, and age. Black and female individuals are found to have multiple organ involvement more frequently. Age at diagnosis<45, Black patients and multiple organ involvement were independent predictors of treatment.

How to Tackle the Diagnosis and Treatment in the Diverse Scenarios of Extrapulmonary Sarcoidosis.

Extrapulmonary sarcoidosis occurs in 30-50% of cases of sarcoidosis, most often in association with pulmonary involvement, and virtually any organ can be involved. Its incidence depends according to the organs considered, clinical phenotype, and history of sarcoidosis, but also on epidemiological factors like age, sex, geographic ancestry, and socio-professional factors. The presentation, symptomatology, organ dysfunction, severity, and lethal risk vary from and to patient even at the level of the same organ. The presentation may be specific or not, and its occurrence is at variable times in the history of sarcoidosis from initial to delayed. There are schematically two types of presentation, one when pulmonary sarcoidosis is first discovered, the problem is then to detect extrapulmonary localizations and to assess their link with sarcoidosis, while the other presentation is when extrapulmonary manifestations are indicative of the disease with the need to promptly make the diagnosis of sarcoidosis. To improve diagnosis accuracy, extrapulmonary manifestations need to be known and a medical strategy is warranted to avoid both under- and over-diagnosis. An accurate estimation of impairment and risk linked to extrapulmonary sarcoidosis is essential to offer the best treatment. Most frequent extrapulmonary localizations are skin lesions, arthritis, uveitis, peripheral lymphadenopathy, and hepatic involvement. Potentially severe involvement may stem from the heart, nervous system, kidney, eye and larynx. There is a lack of randomized trials to support recommendations which are often derived from what is known for lung sarcoidosis and from the natural history of the disease at the level of the respective organ. The treatment needs to be holistic and personalized, taking into account not only extrapulmonary localizations but also lung involvement, parasarcoidosis syndrome if any, symptoms, quality of life, medical history, drugs contra-indications, and potential adverse events and patient preferences. The treatment is based on the use of anti-sarcoidosis drugs, on treatments related to organ dysfunction and supportive treatments. Multidisciplinary discussions and referral to sarcoidosis centers of excellence may be helpful for difficult diagnosis and treatment decisions.

Models Contribution to the Understanding of Sarcoidosis Pathogenesis: "Are There Good Models of Sarcoidosis?"

Sarcoidosis is a systemic, granulomatous, and noninfectious disease of unknown etiology. The clinical heterogeneity of the disease (targeted tissue(s), course of the disease, and therapy response) supports the idea that a multiplicity of trigger antigens may be involved. The pathogenesis of sarcoidosis is not yet completely understood, although in recent years, considerable efforts were put to develop novel experimental research models of sarcoidosis. In particular, sarcoidosis patient cells were used within in vitro 3D models to study their characteristics compared to control patients. Likewise, a series of transgenic mouse models were developed to highlight the role of particular signaling pathways in granuloma formation and persistence. The purpose of this review is to put in perspective the contributions of the most recent models in the understanding of sarcoidosis.

Child-Adult Transition in Sarcoidosis: A Series of 52 Patients.

(1) Background: Pediatric sarcoidosis is a rare and mostly severe disease. Very few pediatric series with a prolonged follow-up are reported. We aimed to evaluate the evolution of pediatric sarcoidosis in adulthood. (2) Material and methods: Patients over 18-years-old with a pediatric-onset sarcoidosis (≤15-year-old) who completed at least a three-year follow-up in French expert centers were included. Clinical information at presentation and outcome in adulthood were studied. (3) Results: A total of 52 patients were included (34 prospectively in childhood and 18 retrospectively in adulthood), with a mean age of 12 (±2.7) at diagnosis. The median duration time of follow-up was 11.5 years (range 3-44.5). Relapses mostly occurred during treatment decrease (84.5%), others within the three years after treatment interruption (9.1%), and rarely when the disease was stable for more than three years (6.4%). Sarcoidosis was severe in 11 (21.2%) in adulthood. Patients received a high corticosteroid cumulative dose (median 17,900 mg) for a median duration of five years (range 0-32), resulting in mostly mild (18; 35.3%) and rarely severe (2; 3.8%) adverse events. (4) Conclusions: Pediatric-onset sarcoidosis needed a long-term treatment in almost half of the patients. Around one fifth of pediatric-onset sarcoidosis patients had severe sarcoidosis consequences in adulthood.

Experimental models of sarcoidosis: where are we now?

PURPOSE OF REVIEW: Sarcoidosis remains a mysterious disease that presents many challenges both in pathogenetic understanding and in the management of patients. This review presents experimental models for sarcoidosis developed since 2016 and discusses their strengths and weaknesses and how they have contributed to the understanding and therapeutic approaches in this disease. In addition, future directions are proposed to overcome the limitations of current models. RECENT FINDINGS: New cellular models using infectious antigen as trigger, and transgenic models in mice have recently been developed to study signaling pathways potentially implicated in the pathogenesis of sarcoidosis. SUMMARY: No model fully reproduces sarcoidosis, but most of them generate data supporting key concepts and some open up therapeutic perspectives, like mTOR inhibition or IL-1ß blocking. However, there are still many limitations to these models, largely related to the complexity of sarcoidosis, which might be overcome with new technologies, such as mathematical modeling.

Predictors of mortality in fibrosing pulmonary sarcoidosis.

INTRODUCTION: Pulmonary fibrosing sarcoidosis is associated with increased mortality. This study was aimed to explore the prognosis value of a panel of parameters for predicting mortality. METHODS: This retrospective study included 216 patients with confirmed stage 4 pulmonary sarcoidosis. Stage 4 diagnosis date served as baseline. The following information was systematically present at baseline: epidemiological characteristics; treatments; pulmonary function; composite physiologic index (CPI); systolic pulmonary artery pressure at echocardiography; pulmonary fibrosis extent, main pulmonary artery/ascending aorta diameters ratio (MPAD/AAD) and MPAD/body surface area (BSA) measured and calculated using computed tomography, Walsh's algorithm based on CPI, lung fibrosis extent and MPAD/AAD ratio, and modified Walsh's algorithm with MPAD/BSA replacing MPAD/AAD allowed to estimate good or bad prognosis profiles. The primary outcome of the study was all cause mortality and lung transplantation. The value of baseline parameters was tested as predictors of mortality using univariate and multivariate analyses. RESULTS: Median follow-up was 105 months. There were 41 deaths and 5 transplantations. At multivariate analysis, survival was independently predicted by several parameters including CPI, lung fibrosis extent, pulmonary hypertension at echography or MPAD/BSA ratio, Walsh's algorithm, and geographic origin. The modified Walsh's algorithm was most highly predictive. CONCLUSION: Survival was best predicted by geographic origin, lung fibrosis extent, PH at echography or MPAD/BSA ratio, as well as by various scores among them the modified Walsh's algorithm had very high predictive value thanks to MPAD/BSA ratio which accurately predicted mortality.