Diagnosis and Treatment of Pulmonary Sarcoidosis: A Review

Meta-analysis of [18F]FDG-PET/CT in pulmonary sarcoidosis

BACKGROUND

18F-Fluorodeoxyglucose (FDG) PET/CT is emerging as a tool in the diagnosis and evaluation of pulmonary sarcoidosis, however, there is limited consensus regarding its diagnostic performance and prognostic value.

METHOD

A meta-analysis was conducted with PubMed, Science Direct, MEDLINE, Scopus, and CENTRAL databases searched up to and including September 2023. 1355 studies were screened, with seventeen (n = 708 patients) suitable based on their assessment of the diagnostic performance or prognostic value of FDG-PET/CT. Study quality was assessed using the QUADAS-2 tool. Forest plots of pooled sensitivity and specificity were generated to assess diagnostic performance. Pooled changes in SUVmax were correlated with changes in pulmonary function tests (PFT).

RESULTS

FDG-PET/CT in diagnosing suspected pulmonary sarcoidosis (six studies, n = 400) had a pooled sensitivity of 0.971 (95%CI 0.909-1.000, p = < 0.001) and specificity of 0.873 (95%CI 0.845-0.920)(one study, n = 169). Eleven studies for prognostic analysis (n = 308) indicated a pooled reduction in pulmonary SUVmax of 4.538 (95%CI 5.653-3.453, p = < 0.001) post-treatment. PFTs displayed improvement post-treatment with a percentage increase in predicted forced vital capacity (FVC) and diffusion capacity of the lung for carbon monoxide (DLCO) of 7.346% (95%CI 2.257-12.436, p = 0.005) and 3.464% (95%CI -0.205-7.132, p = 0.064), respectively. Reduction in SUVmax correlated significantly with FVC (r = 0.644, p < 0.001) and DLCO (r = 0.582, p < 0.001) improvement.

CONCLUSION

In cases of suspected pulmonary sarcoidosis, FDG-PET/CT demonstrated good diagnostic performance and correlated with functional health scores. FDG-PET/CT may help to guide immunosuppression in cases of complex sarcoidosis or where treatment rationalisation is needed.

CLINICAL RELEVANCE STATEMENT

FDG-PET/CT has demonstrated a high diagnostic performance in the evaluation of suspected pulmonary sarcoidosis with radiologically assessed disease activity correlating strongly with clinically derived pulmonary function tests.

KEY POINTS

In diagnosing pulmonary sarcoidosis, FDG-PET/CT had a sensitivity and specificity of 0.971 and 0.873, respectively. Disease activity, as determined by SUVmax, reduced following treatment in all the included studies. Reduction in SUVmax correlated with an improvement in functional vital capacity, Diffusion Capacity of the Lungs for Carbon Monoxide, and subjective health scoring systems.

The Use of Steroids to Treat Hypercalcemia Due to Granulomatous Disease From Disseminated Coccidioidomycosis

The clinical course and treatment of hypercalcemia from a granulomatous disease in the setting of an infectious etiology, namely disseminated coccidioidomycosis, remains incompletely understood. The mechanism and treatment of hypercalcemia have been documented in most granulomatous disorders, with sarcoidosis being the most well-understood so far. We discuss a case of a patient with a recent diagnosis of disseminated coccidioidomycosis who presented with hypercalcemia despite adequate infection control. The treatment course involved combinatorial-calcitonin, low-dose bisphosphonates, and corticosteroids, which led to a favorable outcome.

Otud6b induces pulmonary arterial hypertension by mediating the Calpain-1/HIF-1α signaling pathway

Pulmonary hypertension (PAH) is a cardiopulmonary disease in which pulmonary artery pressure continues to rise, leading to right heart failure and death. Otud6b is a member of the ubiquitin family and is involved in cell proliferation, apoptosis and inflammation. The aim of this study was to understand the role and mechanism of Otud6b in PAH. C57BL/6 and Calpain-1 knockout (KO) mice were exposed to a PAH model induced by 10% oxygen. Human pulmonary artery endothelial cells (HPACEs) and human pulmonary artery smooth muscle cells (HPASMCs) were exposed to 3% oxygen to establish an in vitro model. Proteomics was used to determine the role of Otud6b and its relationship to Calpain-1/HIF-1α signaling. The increased expression of Otud6b is associated with the progression of PAH. ROtud6b activates Otud6b, induces HIF-1α activation, increases the production of ET-1 and VEGF, and further aggravates endothelial injury. Reducing Otud6b expression by tracheal infusion of siOtud6b has the opposite effect, improving hemodynamic and cardiac response to PAH, reducing the release of Calpain-1 and HIF-1α, and eliminating the pro-inflammatory and apoptotic effects of Otud6b. At the same time, we also found that blocking Calpain-1 reduced the effect of Otud6b on HIF-1α, and inhibiting HIF-1α reduced the expression of Calpain-1 and Otud6b. Our study shows that increased Otud6b expression during hypoxia promotes the development of PAH models through a positive feedback loop between HIF-1α and Calpain-1. Therefore, we use Otud6b as a biomarker of PAH severity, and regulating Otud6b expression may be an effective target for the treatment of PAH.

Autoimmune Myocarditis, Old Dogs and New Tricks

Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus erythematosus and polymyositis. Even in cases of myocarditis caused by viral infections, dysregulated immune responses contribute to pathogenesis. However, whether triggered by existing autoimmune conditions or viral infections, the precise antigens and immunologic pathways driving myocarditis remain incompletely understood. The emergence of myocarditis associated with immune checkpoint inhibitor therapy, commonly used for treating cancer, has afforded an opportunity to understand autoimmune mechanisms in myocarditis, with autoreactive T cells specific for cardiac myosin playing a pivotal role. Despite their self-antigen recognition, cardiac myosin-specific T cells can be present in healthy individuals due to bypassing the thymic selection stage. In recent studies, novel modalities in suppressing the activity of pathogenic T cells including cardiac myosin-specific T cells have proven effective in treating autoimmune myocarditis. This review offers an overview of the current understanding of heart antigens, autoantibodies, and immune cells as the autoimmune mechanisms underlying various forms of myocarditis, along with the latest updates on clinical management and prospects for future research.

Granulomatous Lung Diseases: A Practical Approach and Review of Common Entities

Granulomas are frequently encountered by pathologists in all types of lung specimens and arise from diverse etiologies. They should always be reported as necrotizing or non-necrotizing, with microorganism stains performed to evaluate for infection. With attention to distribution, quality (poorly vs well-formed), associated features, and correlation with clinical, radiologic, and laboratory data, the differential diagnosis for granulomatous lung disease can usually be narrowed to a clinically helpful "short list." This review describes a practical approach to pulmonary granulomas and reviews the clinicopathological aspects of common entities, including infectious (mycobacteria, fungi) and noninfectious (hypersensitivity pneumonitis, sarcoid, and vasculitis) causes.

Diagnostic delay of sarcoidosis: an integrated systematic review

BACKGROUND

Sarcoidosis is a chronic inflammatory granulomatous disease of unknown cause. Delays in diagnosis can result in disease progression and poorer outcomes for patients. Our aim was to review the current literature to determine the overall diagnostic delay of sarcoidosis, factors associated with diagnostic delay, and the experiences of people with sarcoidosis of diagnostic delay.

METHODS

Three databases (PubMed/Medline, Scopus, and ProQuest) and grey literature sources were searched. Random effects inverse variance meta-analysis was used to pool mean diagnostic delay in all types of sarcoidosis subgroup analysis. Diagnostic delay was defined as the time from reported onset of symptoms to diagnosis of sarcoidosis.

RESULTS

We identified 374 titles, of which 29 studies were included in the review, with an overall sample of 1531 (694 females, 837 males). The overall mean diagnostic delay in all types of sarcoidosis was 7.93 months (95% CI 1.21 to 14.64 months). Meta-aggregation of factors related to diagnostic delay in the included studies identified three categories: (1) the complex and rare features of sarcoidosis, (2) healthcare factors and (3) patient-centred factors. Meta-aggregation of outcomes reported in case studies revealed that the three most frequent outcomes associated with diagnostic delay were: (1) incorrect diagnosis, (2) incorrect treatment and (3) development of complications/disease progression. There was no significant difference in diagnostic delay between countries with gatekeeper health systems (where consumers are referred from a primary care clinician to specialist care) and countries with non-gatekeeper systems. No qualitative studies examining people's experiences of diagnostic delay were identified.

CONCLUSION

The mean diagnostic delay for sarcoidosis is almost 8 months, which has objective consequences for patient management. On the other hand, there is a paucity of evidence about the experience of diagnostic delay in sarcoidosis and factors related to this. Gaining an understanding of people's experiences while seeking a diagnosis of sarcoidosis is vital to gain insight into factors that may contribute to delays, and subsequently inform strategies, tools and training activities aimed at increasing clinician and public awareness about this rare condition.

TRIAL REGISTRATION

PROSPERO Registration number: CRD42022307236.

Phenotypes and Serum Biomarkers in Sarcoidosis

Sarcoidosis is a multisystem disease, which is diagnosed on a compatible clinical presentation, non-necrotizing granulomatous inflammation in one or more tissue samples, and exclusion of alternative causes of granulomatous disease. Considering its heterogeneity, numerous aspects of the disease remain to be elucidated. In this context, the identification and integration of biomarkers may hold significance in clinical practice, aiding in appropriate selection of patients for targeted clinical trials. This work aims to discuss and analyze how validated biomarkers are currently integrated in disease category definitions. Future studies are mandatory to unravel the diverse contributions of genetics, socioeconomic status, environmental exposures, and other sociodemographic variables to disease severity and phenotypic presentation. Furthermore, the implementation of transcriptomics, multidisciplinary approaches, and consideration of patients' perspectives, reporting innovative insights, could be pivotal for a better understanding of disease pathogenesis and the optimization of clinical assistance.

Advance in pathogenesis of sarcoidosis: Triggers and progression

Sarcoidosis, a multisystemic immune disease, significantly impacts patients' quality of life. The complexity and diversity of its pathogenesis, coupled with limited comprehensive research, had hampered both diagnosis and treatment, resulting in an unsatisfactory prognosis for many patients. In recent years, the research had made surprising progress in the triggers of sarcoidosis (genetic inheritance, infection and environmental factors) and the abnormal regulations on immunity during the formation of granuloma. This review consolidated the latest findings on sarcoidosis research, providing a systematic exploration of advanced studies on triggers, immune-related regulatory mechanisms, and clinical applications. By synthesizing previous discoveries, we aimed to offer valuable insights for future research directions and the development of clinical diagnosis and treatment strategies.

Diagnosis of Pulmonary Sarcoidosis

Diagnosis of sarcoidosis depends on a compatible clinical and imaging presentation, histologic finding of non-necrotizing granulomatous inflammation, and exclusion of alternative causes of granulomatous diseases. This study has reviewed the diagnostic algorithms and approaches of sarcoidosis.

Biomarkers and molecular endotypes of sarcoidosis: lessons from omics and non-omics studies

Sarcoidosis is a chronic granulomatous disorder characterized by unknown etiology, undetermined mechanisms, and non-specific therapies except TNF blockade. To improve our understanding of the pathogenicity and to predict the outcomes of the disease, the identification of new biomarkers and molecular endotypes is sorely needed. In this study, we systematically evaluate the biomarkers identified through Omics and non-Omics approaches in sarcoidosis. Most of the currently documented biomarkers for sarcoidosis are mainly identified through conventional "one-for-all" non-Omics targeted studies. Although the application of machine learning algorithms to identify biomarkers and endotypes from unbiased comprehensive Omics studies is still in its infancy, a series of biomarkers, overwhelmingly for diagnosis to differentiate sarcoidosis from healthy controls have been reported. In view of the fact that current biomarker profiles in sarcoidosis are scarce, fragmented and mostly not validated, there is an urgent need to identify novel sarcoidosis biomarkers and molecular endotypes using more advanced Omics approaches to facilitate disease diagnosis and prognosis, resolve disease heterogeneity, and facilitate personalized medicine.

Advances in cellular and tissue-based imaging techniques for sarcoid granulomas

Sarcoidosis embodies a complex inflammatory disorder spanning multiple systems, with its origin remaining elusive. It manifests as the infiltration of inflammatory cells that coalesce into distinctive noncaseous granulomas within afflicted organs. Unraveling this disease necessitates the utilization of cellular or tissue-based imaging methods to both visualize and characterize the biochemistry of these sarcoid granulomas. Although hematoxylin and eosin stain, standard in routine use alongside cytological stains have found utility in diagnosis within clinical contexts, special stains such as Masson's trichrome, reticulin, methenamine silver, and Ziehl-Neelsen provide additional varied perspectives of sarcoid granuloma imaging. Immunohistochemistry aids in pinpointing specific proteins and gene expressions further characterizing these granulomas. Finally, recent advances in spatial transcriptomics promise to divulge profound insights into their spatial orientation and three-dimensional (3-D) molecular mapping. This review focuses on a range of preexisting imaging methods employed for visualizing sarcoid granulomas at the cellular level while also exploring the potential of the latest cutting-edge approaches like spatial transcriptomics and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), with the overarching goal of shedding light on the trajectory of sarcoidosis research.

Clinical manifestations and associated factors of uveitis in patients with pulmonary sarcoidosis: a case control study

Sarcoidosis, an idiopathic and inflammatory disease, affects various organs and can manifest as uveitis. Due to limited evidence, researchers investigated the risk factors associated with uveitis in patients with pulmonary sarcoidosis. A retrospective study was conducted on 71 pulmonary sarcoidosis patients, including 19 with uveitis and 52 without. Data on involved organs, imaging findings, spirometry, and analyses from blood and bronchoalveolar lavage fluid were collected. Logistic regression models were used for multivariate analysis. Among the 71 newly diagnosed pulmonary sarcoidosis patients, uveitis was observed in 19 patients (26.8%). No significant differences were found in clinical characteristics between patients with and without uveitis. Fewer patients with uveitis presented lung parenchymal lesions (P = 0.043). In multivariate analysis, skin lesions (aOR 7.619, 95% CI 1.277-45.472, P = 0.026) and ophthalmic symptoms (aOR 4.065, 95% CI 1.192-13.863, P = 0.025) were associated with uveitis. Absence of uveitis was related to lung parenchymal lesions (aOR 0.233, 95% CI 0.062-0.883, P = 0.032). Approximately one-quarter of patients with an initial diagnosis of pulmonary sarcoidosis were diagnosed with uveitis. Presence of skin lesions, ophthalmic symptoms, and absence of lung parenchymal lesions were related to uveitis. These results need to be clarified by further studies to confirm the clinical role of early ophthalmologic screening for pulmonary sarcoidosis patients with these factors.

The Role of Small Airway Disease in Pulmonary Fibrotic Diseases

Small airway disease (SAD) is a pathological condition that affects the bronchioles and non-cartilaginous airways 2 mm or less in diameter. These airways play a crucial role in respiratory function and are often implicated in various pulmonary disorders. Pulmonary fibrotic diseases are characterized by the thickening and scarring of lung tissue, leading to progressive respiratory failure. We aimed to present the link between SAD and fibrotic lung conditions. The evidence suggests that SAD may act as a precursor or exacerbating factor in the progression of fibrotic diseases. Patients with fibrotic conditions often exhibit signs of small airway dysfunction, which can contribute to worsening respiratory symptoms and decreased lung function. Moreover, individuals with advanced SAD are at a heightened risk of developing fibrotic changes in the lung. The interplay between inflammation, environmental factors, and genetic predisposition further complicates this association. The early detection and management of SAD can potentially mitigate the progression of fibrotic diseases, highlighting the need for comprehensive clinical evaluation and research. This review emphasizes the need to understand the evolving connection between SAD and pulmonary fibrosis, urging further detailed research to clarify the causes and potential treatment between the two entities.

Concurrent features of sarcoidosis and hypersensitivity pneumonitis in two patients exposed to fungal antigens

BACKGROUND

Sarcoidosis and hypersensitivity pneumonitis (HP) are two distinct clinical entities that share granulomatous inflammation, although each of them has specific clinical, radiologic and pathologic profiles. Coexistence of the two diseases have been described, suggesting, at least in some cases, a common biologic background.

CASE PRESENTATION

We describe two patients showing the concurrent diagnosis of sarcoidosis and hypersensitivity pneumonitis. Case 1: a 51-year old never smoker man had a history of occupational exposure, episodes of acute exacerbations and positive serum precipitins to Penicillium spp suggestive of HP, while the positivity of serum angiotensin converting enzyme (ACE) favored sarcoidosis. Case 2: a 42-year old non-smoker woman with occasional finding of enlarged mediastinal lymph nodes had a history of domestic exposure to molds and positive serum precipitins to Aspergillus spp suggestive of HP. In both cases high resolution computed tomography (HRCT) together with broncoscopy findings allowed to maintain both the diagnoses: HRCT showed both enlarged hilar/mediastinal limph nodes and intersitial lung involvement typical of HP; bronchoalveolar lavage presented marked lymphocytosis and granulomatous nodal lesions were observed at transbronchial needle aspiration.

CONCLUSIONS

Sarcoidosis and HP share some clinical findings and the differential diagnosis may be difficult. Our cases suggest that a common trait may be responsible for the concurrent diagnosis of sarcoidosis and hypersensitivity pneumonitis in the same patient.

A case report of sarcoidosis overlapped with Sjogren's syndrome

Introduction and importance

The diagnosis of sarcoidosis and Sjögren's syndrome (SS) in the same patient is a challenge since sarcoidosis is considered an exclusion criterion for SS.

Case presentation

The authors described a 62-year-old woman, who had SS for 8 years and presented with dry mouth, dry eyes, dyspnoea, and erythema nodosum. High resolution computed tomography of the chest showed symmetrical pulmonary micronodules, interstitial changes, and enlarged mediastinal lymph nodes. Anti-nuclear antibodies and anti-SSA antibodies were positive. Schermer's test was also positive. A biopsy of lung nodules revealed non-caseous granuloma. Salivary gland biopsy showed focal lymphocyte infiltration. Diagnosis of sarcoidosis and SS were done according to the classification criteria in this patient.

Clinical discussion

Although the diagnosis of Sjogren requires the exclusion of conditions that cause dry eyes and mouth, such as sarcoidosis, Few studies have reported the coexistence of sarcoidosis and SS such as this case report.

Conclusion

This case extends our understanding of overlapped SS with sarcoidosis and provides a referential value for clinical diagnosis.

The role of the host-microbiome and metabolomics in sarcoidosis

Sarcoidosis is a complex inflammatory fibrotic disease that affects multiple organ systems. It is characterized by the infiltration of lymphocytes and mononuclear phagocytes, which form non-caseating granulomas in affected organs. The lungs and intrathoracic lymph nodes are the most commonly affected organs. The underlying cause of sarcoidosis is unknown, but it is believed to occur in genetically predisposed individuals who are exposed to pathogenic organisms, environmental contaminants, or self and non-self-antigens. Recent research has suggested that the microbiome may play a role in the development of respiratory conditions, including sarcoidosis. Additionally, metabolomic studies have identified potential biomarkers for monitoring sarcoidosis progression. This review will focus on recent microbiome and metabolomic findings in sarcoidosis, with the goal of shedding light on the pathogenesis and possible diagnostic and therapeutic approaches.

A Rare Presentation of Sarcoidosis in a Young Male With Acute Renal Failure: A Case Report and Literature Review

Sarcoidosis presents in a variety of ways, but historically, renal involvement has been considered rare with an incidence of 0.7% and is seldom the presenting feature of the illness. Concomitant involvement of kidney and bone marrow is extremely rare. Atypical forms of presentation, such as in this case, may pose a true diagnostic challenge. A 20-year-old African-American male presented to the emergency department with vague symptoms including fatigue, malaise, anorexia, right-sided lower back pain, and nausea. Acute kidney injury was clearly evident, creatinine was 19.78 mg/dL (normal range 0.60-1.20 mg/dL), and BUN was 124.0 mg/dL (normal range 5.0-25.0 mg/dL). Laboratory results were also remarkable for leukopenia, microcytic anemia, hyperkalemia, anion gap metabolic acidosis, and non-PTH dependent hypercalcemia. Interestingly, urinalysis was equivocal and both chest x-ray (CXR) and abdominopelvic computed tomography (CT) scan were unrevealing. The patient was admitted to the hospital and required renal replacement therapy to stabilize his clinical condition while planning for a renal biopsy that was later performed. While awaiting pathological results, pancytopenia developed, and a bone marrow biopsy was then obtained. On further investigation, angiotensin-converting enzyme (ACE) turned out to be significantly elevated suggesting sarcoidosis. Renal biopsy showed moderate acute tubular injury, tubulitis, extensive interstitial edema, and infiltration by numerous non-caseating granulomas, which confirmed the diagnosis of sarcoidosis. Bone marrow histopathology revealed hypocellularity but no granulomatous infiltration. The patient remained largely asymptomatic throughout his hospital stay, with no signs or symptoms suggesting the involvement of other organs. High-dose corticosteroids were started and continued outpatient after discharge while still on hemodialysis. Pancytopenia resolved while on glucocorticoids and improvement in renal function was such that after roughly two months of steroids, renal replacement therapy was no longer necessary. Overall, kidney injury severe enough to require hemodialysis associated with pancytopenia in a previously healthy 20-year-old constitutes a rather rare sarcoidosis presentation. This highlights the importance of considering sarcoidosis as a possible cause of kidney and bone marrow dysfunction and emphasizes the need for timely biopsy to facilitate accurate diagnosis and early initiation of appropriate therapy to avoid delayed or inadequate care, especially considering that even severe damage is potentially reversible when identified early and treated promptly.

Pulmonary sarcoidosis: A comprehensive review: Past to present

Sarcoidosis is a sterile non-necrotizing granulomatous disease without known causes that can involve multiple organs with a predilection for the lung and thoracic lymph nodes. Worldwide it is estimated to affect 2-160/100,000 people and has a mortality rate over 5 years of approximately 7%. For sarcoidosis patients, the cause of death is due to sarcoid in 60% of the cases, of which up to 80% are from advanced cardiopulmonary failure (pulmonary hypertension and respiratory microbial infections) in all races except in Japan were greater than 70% of the sarcoidosis deaths are due to cardiac sarcoidosis. Scadding stages for pulmonary sarcoidosis associates with clinical outcomes. Stages I and II have radiographic remission in approximately 30%-80% of cases. Stage III only has a 10%-40% chance of resolution, while stage IV has no change of resolution. Up to 40% of pulmonary sarcoidosis patients progress to stage IV disease with lung parenchyma fibroplasia, bronchiectasis with hilar retraction and fibrocystic disease. These patients are at highest risk for the development of precapillary pulmonary hypertension, which may occur in up to 70% of these patients. Sarcoid patients with pre-capillary pulmonary hypertension can respond to targeted pulmonary arterial hypertension medications. Stage IV fibrocytic sarcoidosis with significant pulmonary physiologic impairment, >20% fibrosis on HRCT or pre-capillary pulmonary hypertension have the highest risk of mortality, which can be >40% at 5-years. First line treatment for patients who are symptomatic (cough and dyspnea) with parenchymal infiltrates and abnormal pulmonary function testing (PFT) is oral glucocorticoids, such as prednisone with a typical starting dose of 20-40 mg daily for 2 weeks to 2 months. Prednisone can be tapered over 6-18 months if symptoms, spirometry, PFTs, and radiographs improve. Prolonged prednisone may be required to stabilize disease. Patients requiring prolonged prednisone ≥10 mg/day or those with adverse effects due to glucocorticoids may be prescribed second and third line treatements. Second and third line treatments include immunosuppressive agents (e.g., methotrexate and azathioprine) and anti-tumor necrosis factor (TNF) medication; respectively. Effective treatments for advanced fibrocystic pulmonary disease are being explored. Despite different treatments, relapse rates range from 13% to 75% depending on the stage of sarcoid, number of organs involved, socioeconomic status, and geography. CONCLUSION: The mortality rate for sarcoidosis over a 5 year follow up is approximately 7%. Unfortunately, 10%-40% of patients with sarcoidosis develop progressive pulmonary disease, and >60% of deaths resulting from sarcoidosis are due to advance cardiopulmonary disease. Oral glucocorticoids are the first line treatment, while methotrexate and azathioprine are considered second and anti-TNF agents are third line treatments that are used solely or as glucocorticoid sparing agents for symptomatic extrapulmonary or pulmonary sarcoidosis with infiltrates on chest radiographs and abnormal PFT. Relapse rates have ranged from 13% to 75% depending on the population studied.

Re-evaluating serum angiotensin-converting enzyme in sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology, which mainly affects the lungs and lymph nodes, as well as extrapulmonary organs. Its incidence, and prevalence rate, and disease course largely vary with regions and populations globally. The clinical manifestations of sarcoidosis depend on the affected organs and the degree of severity, and the diagnosis is mainly based on serum biomarkers, radiographic, magnetic resonance, or positron emission tomography imaging, and pathological biopsy. Noncaseating granulomas composing T cells, macrophages, epithelioid cells, and giant cells, were observed in a pathological biopsy, which was the characteristic pathological manifestation of sarcoidosis. Angiotensin-converting enzyme (ACE) was first found in the renin-angiotensin-aldosterone system. Its main function is to convert angiotensin I (Ang I) into Ang II, which plays an important role in regulating blood pressure. Also, an ACE insertion/deletion polymorphism exists in the human genome, which is involved in the occurrence and development of many diseases, including hypertension, heart failure, and sarcoidosis. The serum ACE level, most commonly used as a biomarker in diagnosing sarcoidosis, in patients with sarcoidosis increases. because of epithelioid cells and giant cells of sarcoid granuloma expressing ACE. Thus, it serves as the most commonly used biomarker in the diagnosis of sarcoidosis and also aids in analyzing its therapeutic effect and prognosis in patients with sarcoidosis.

T-cell signature cytokines distinguish pulmonary sarcoidosis from pulmonary tuberculosis

Sarcoidosis is a systemic inflammatory disorder characterized by tissue infiltration due to mononuclear phagocytes and lymphocytes and associated noncaseating granuloma formation. Pulmonary sarcoidosis (PS) shares a number of clinical, radiological, and histopathological characteristics with that of pulmonary tuberculosis (PTB). Due to this, clinicians face issues in differentiating between PS and PTB in a substantial number of cases. There is a lack of any specific biomarker that can diagnose PS distinctively from PTB. We compared T-cell-based signature cytokines in patients with PS and PTB. In this study, we proposed a serum biomarker panel consisting of cytokines from cells: T helper (Th) 1 [interferon-gamma (IFN-γ); tumor necrosis factor-alpha (TNF-α)], Th9 [interleukin (IL)-9], Th17 [IL-17], and T regulatory (Treg) [IL-10; transforming growth factor-beta (TGF-β)]. We performed the principal component analysis that demonstrated that our serum cytokine panel has a significant predictive ability to differentiate PS from PTB. Our results could aid clinicians to improve the diagnostic workflow for patients with PS in TB endemic settings where the diagnosis between PS and PTB is often ambiguous.

An International Survey of Current Clinical Practice in the Treatment of Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a potentially serious form of infiltrative cardiomyopathy. Despite scarce evidence, immunosuppressive treatment is generally recommended, but local routines may vary significantly. We sought to survey the clinical practices in the treatment of CS, with the aim that the results may suggest future research priorities. We conducted a web-based survey focused on treatment-naive patients with CS. We subclassified CS according to the presence/absence of overt cardiac presentation (clinically manifest/silent) and to the presence/absence of active inflammation (metabolically active/inactive by fluorodeoxyglucose positron emission tomography). The survey was developed jointly by the authors and administered to expert clinicians (n = 79) involved in CS treatment. An agreement threshold was set at 70%. A total of 62 of 79 respondents (78.5%) from 12 countries completed the survey. The agreement threshold was reached for: (1) always treating clinically manifest, metabolically active CS, 57 of 62 (91.9%), (2) never treating clinically silent, metabolically inactive CS, 44 of 62 (71.0%), (3) not requiring histopathologic confirmation of sarcoidosis before treatment initiation, (49 of 62, 79.0%), (4) using fluorodeoxyglucose positron emission tomography for assessing treatment indication (44 of 62, 71.0%) and treatment response (44 of 62, 71.0%), and (5) using prednisone as a first-line agent (100%), although respondents were divided on monotherapy (69.4%) or combination with methotrexate 25.8%. The approach to particular scenarios, tapering, and duration of treatment showed the greatest variation in response. In conclusion, in this survey of clinical practice, important aspects of CS treatment reached the agreement threshold, whereas others showed a great degree of clinical equipoise.

SACE and IL-2R as serum biomarkers for evaluation of multi-organ involvement and prognosis of sarcoidosis

BACKGROUND

Serum biomarkers in the evaluation of organ involvement and prognostic monitoring of sarcoidosis have not been determined. The purpose of this study was to identify common biomarkers that could be used to assess organ involvement and monitor outcomes in sarcoidosis patients.

METHODS

From Mar 2013 to Sep 2021, patients with newly diagnosed pulmonary sarcoidosis were enrolled in this study in Shanghai Pulmonary Hospital. The information from medical records was retrospectively collected including diagnosis, organ involvement, laboratory tests and follow up data. Differences of continuous variables between groups were analyzed by unpaired Student's t-test. Multivariate logistic regression model was performed to identify potential independent factors associated with multiple organ involvement.

RESULTS

A total of 832 patients were included in the study. There were 339 (40.7%) patients with single organ pulmonary involvement, while 493 (59.3%) patients had two to seven organs involved. Among the routine serum tests, only the serum angiotensin converting enzyme (SACE) level was an independent factor of multiple organ involvement. Compared to those patients without involvement, SACE levels were higher in patients with extra-thoracic lymph node, skin, or spleen involvement as well as abnormal calcium metabolism. Interleukin-2 receptor (IL-2R) levels were higher in patients with extra-thoracic lymph node, spleen involvement and abnormal calcium metabolism than in those without it. The mean levels of SACE and IL-2R showed upward trends paralleling the increase on number of organs involved. In follow up, SACE and IL-2R levels were both decreased in an improved patient group, while there was no obvious difference was noticed before and after treatment in patients with persistent disease.

CONCLUSION

SACE and IL-2R were useful as serum biomarkers in the initial evaluation of organ involvement as well as monitoring prognosis in sarcoidosis.

High-dose (40 mg) versus low-dose (20 mg) prednisolone for treating sarcoidosis: a randomised trial (SARCORT trial)

BACKGROUND

Current guidelines recommend 20-40 mg·day-1 of oral prednisolone for treating pulmonary sarcoidosis. Whether the higher dose (40 mg·day-1) can improve outcomes remains unknown.

METHODS

We conducted an investigator-initiated, single-centre, open-label, parallel-group, randomised controlled trial (ClinicalTrials.gov identifier NCT03265405). Consecutive subjects with pulmonary sarcoidosis were randomised (1:1) to receive either high-dose (40 mg·day-1 initial dose) or low-dose (20 mg·day-1 initial dose) oral prednisolone, tapered over 6 months. The primary outcome was the frequency of relapse or treatment failure at 18 months from randomisation. Key secondary outcomes included the time to relapse or treatment failure, overall response, change in forced vital capacity (FVC, in litres) at 6 and 18 months, treatment-related adverse effects and health-related quality of life (HRQoL) scores using the Sarcoidosis Health Questionnaire and Fatigue Assessment Scale.

FINDINGS

We included 86 subjects (43 in each group). 42 and 43 subjects completed treatment in the high-dose and low-dose groups, respectively, while 37 (86.0%) and 41 (95.3%), respectively, completed the 18-month follow-up. 20 (46.5%) subjects had relapse or treatment failure in the high-dose group and 19 (44.2%) in the low-dose group (p=0.75). The mean time to relapse/treatment failure was similar between the groups (high-dose 307 days versus low-dose 269 days, p=0.27). The overall response, the changes in FVC at 6 and 18 months and the incidence of adverse effects were also similar. Changes in HRQoL scores did not differ between the study groups.

INTERPRETATION

High-dose prednisolone was not superior to a lower dose in improving outcomes or the HRQoL in sarcoidosis and was associated with similar adverse effects.

Sarcoidosis-Associated Sensory Ganglionopathy and Harlequin Syndrome: A Case Report

Background and Objectives: Sensory ganglionopathy is a rare neurological disorder caused by degeneration of the neurons composing the dorsal root ganglia. It manifests as various sensory disturbances in the trunk, proximal limbs, face, or mouth in a patchy and asymmetrical pattern. Harlequin syndrome is characterized by unilateral flushing and sweating of the face, neck, and upper chest, concurrent with contralateral anhidrosis. Here, we present and discuss a clinical case of sarcoidosis-associated ganglionopathy and Harlequin syndrome. Case presentation: A 31-year-old woman complained of burning pain in the right side of the upper chest and the feet. She also experienced episodes of intense flushing and sweating on the right side of her face, neck, and upper chest. Three years before these symptoms began, the patient was diagnosed with pulmonary sarcoidosis. On neurological examination, sensory disturbances were present. In the trunk, the patient reported pronounced hyperalgesia and allodynia in the upper part of the right chest and some patches on the right side of the upper back. In the extremities, hypoalgesia in the tips of the fingers and hyperalgesia in the feet were noted. An extensive diagnostic workup was performed to eliminate other possible causes of these disorders. A broad range of possible metabolic, immunological, and structural causes were ruled out. Thus, the final clinical diagnosis of sarcoidosis-induced sensory ganglionopathy, small-fiber neuropathy, and Harlequin syndrome was made. Initially, the patient was treated with pregabalin and amitriptyline, but the effect was inadequate for the ganglionopathy-induced pain. Therefore, therapeutic plasma exchange as an immune-modulating treatment was selected, leading to partial pain relief. Conclusions: This case report demonstrates the possible autoimmune origin of both sensory ganglionopathy and Harlequin syndrome. It suggests that an autoimmune etiology for these disorders should be considered and the diagnostic workup should include screening for the most common autoimmune conditions.

Integrative single-cell analysis of cardiac and pulmonary sarcoidosis using publicly available cardiac and bronchoalveolar lavage fluid sequencing datasets

Introduction

Cardiac presentation of autoimmune sarcoidosis, known as cardiac sarcoidosis (CS), is a poorly understood disease with high mortality and low diagnosis rate. While CS is an immunological syndrome, little is known about how cardiac parenchymal and stromal cells mediate its pathogenesis. Moreover, while most current sarcoidosis research is based on research in pulmonary sarcoidosis (PS), it remains unclear how much both presentations of sarcoidosis overlap. To tackle these concerns, we leveraged publicly available sarcoidosis transcriptomic datasets.

Methods

Two publicly available bronchoalveolar lavage single-cell RNA sequencing datasets were integrated to analyze PS relative to control. Additionally, two publicly available cardiac single-nucleus RNA sequencing datasets were integrated to analyze CS relative to control. Following integration, we ran cell-cell communication, transcription factor, and differential expression analyses on parenchymal, stromal, and immune subsets identified in our analysis.

Results

Our analysis revealed that there was an expansion of stromal and immune cells in PS and CS. We also observed upregulation of Th17.1 and attenuated activation transcriptional profiles in the immune cells of CS and PS relative to control. Additionally, we found upregulation of pro-inflammatory and pro-fibrotic transcriptional profiles in the cardiac stromal cells of CS relative to control. We also found that cardiomyocytes exhibited upregulated cardiac stress and proliferation transcriptional profiles in CS relative to control.

Conclusions

Our integrative transcriptomic analysis shows that despite tissue-specific differences, there are shared transcriptional trends between CS and PS. It also shows that stromal and parenchymal populations exhibit transcriptional trends that could explain their pathogenic role in CS.

Symptomatic myopathies in sarcoidosis: disease spectrum and myxovirus resistance protein A expression

OBJECTIVES

Symptomatic myopathy in sarcoidosis patients is not always due to sarcoid myopathy (ScM). We investigated the clinical and pathological spectrum including myxovirus resistance protein A (MxA) expression among sarcoidosis patients.

METHODS

We reviewed the Mayo Clinic database (May 1980-December 2020) to identify sarcoidosis patients with myopathic symptoms and pathological evidence of myopathy.

RESULTS

Among 5885 sarcoidosis patients, 21 had symptomatic myopathy. Eight carried a diagnosis of sarcoidosis 5.5 years (median) prior to myopathy onset. Eleven patients had ScM. The remaining had non-sarcoid myopathies (five IBM, one immune-mediated necrotizing myopathy, one non-specific myositis, two non-specific myopathy and one steroid myopathy). Estimated frequency of IBM is 85 per 100 000 sarcoidosis patients. The following features were associated with non-sarcoid myopathies (P < 0.05): (i) predominant finger flexor and quadriceps weakness, (ii) modified Rankin scale (mRS) >2 at time of diagnosis, (iii) creatine kinase >500 U/l, and (iv) absence of intramuscular granulomas. Sarcoplasmic MxA expression was observed in scattered myofibres in three patients, two of whom were tested for DM-specific autoantibodies and were negative. Immunosuppressive therapy led to improvement in mRS ≥1 in 5/10 ScM, none of the five IBM, and 3/3 remaining patients with non-sarcoid myopathies.

DISCUSSION

Symptomatic myopathy occurred in 0.36% of sarcoidosis. IBM was the second most common cause of myopathies after ScM. Frequency of IBM in sarcoidosis is higher than in the general population. Recognition of features suggestive of alternative aetiologies can guide proper treatment. Our findings of abnormal MxA expression warrant a larger study.

Imaging Plays a Key Role in the Diagnosis and Control of the Treatment of Bone Sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown origin. The most frequent localizations are thoracic lymph nodes and/or parenchymal lung disease, nevertheless any other organ may be involved. Musculoskeletal sarcoidosis, previously considered a rare manifestation of the disease, is presently recognized with increasing frequency, due to the development of modern imaging modalities. The classical X-ray sign of bone sarcoidosis is the image of lace in the phalanges of the hands. Most other locations present with atypical radiological images. Therefore, they may mimic metastatic neoplastic disease, especially when they are the first sign of sarcoidosis not previously recognized. On such occasions, none of the imaging methods will give the correct diagnosis, histopathological verification, monitoring of lesions or clinical data in a patient with confirmed sarcoidosis are indicated. The article summarizes the current status of knowledge concerning the recognition and therapy of bone sarcoidosis. In addition, an illustrative case of patient with bone and bone marrow sarcoidosis is presented.

Is the internet a sufficient source of information on sarcoidosis?

Introduction

Many patients use the internet as a source of health information. Sarcoidosis is a complex disease, and internet resources have not yet been analyzed for reliability and content on sarcoidosis.

Aims

Our study aimed to investigate the content and the quality of information on sarcoidosis provided by internet resources.

Methods

Google, Yahoo, and Bing were searched for the term "sarcoidosis," and the first 200 hits were saved in each case. Those websites that met the inclusion criteria (English language, no registration fees, and relevant to sarcoidosis) were then analyzed by two independent investigators for readability, quality (HON, JAMA, and DISCERN), and content (25 predefined key facts) of the provided information.

Results

The websites were most commonly scientific or governmental (n = 57, 46%), and the median time since the last update was 24 months. Quality was rated with a median JAMA score of 2 (1; 4) and a median overall DISCERN score of 2.4 (1.1; 4.1), both scores represent partially sufficient information. In total, 15% of websites had a HON certificate. Website content measured by the median key fact score was 19 (ranging from 2.5 to 25) with the lowest scores for acute vs. chronic course of the disease, screening for extrapulmonary disease, and diffuse body pain. Poor results were achieved in industry websites and blogs (p = 0.047) with significant differences regarding definition (p = 0.004) and evaluation (p = 0.021).

Discussion

Sarcoidosis-related content of internet resources is partially sufficient; however, several important aspects are frequently not addressed, and the quality of information is moderate. Future directions should focus on providing reliable and comprehensive information on sarcoidosis; physicians from different disciplines and patients including self-support groups should collaborate on achieving this.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

Hypoxemic Respiratory Failure Due to Alveolar Pulmonary Sarcoidosis Following COVID-19 Infection

Pulmonary sarcoidosis is typically recognized as an interstitial lung disease with an infrequent occurrence of alveolar filling or acinar pattern. This rare form of alveolar sarcoidosis is known to have a rapid progression. Several case reports showed the development/worsening of sarcoidosis after COVID-19 infection. We present a case of a 60-year-old male with chronic hypoxic respiratory failure since having COVID-19 disease followed by gradual progression in symptoms, who had atypical sarcoid-like alveolar opacities on radiography, two prior negative bronchoscopies, transbronchial biopsy and BAL, and third bronchoscopic transbronchial biopsy suggestive of findings of poorly formed granulomas with high suspicion of alveolar sarcoidosis after ruling out other comparative possibilities, and later having a drastic improvement with sarcoidosis management. Our patient's worsening symptoms after COVID-19 infection suggest impaired immunoregulation role of the infection in developing the disease process.

Granulomatous myopathy: Sarcoidosis and beyond

Non-necrotizing granulomatous inflammation is a rare but easily recognized histopathological finding in skeletal muscle biopsy. A limited number of diseases are known to be associated with non-necrotizing granulomatous myopathy. Once identified, a careful evaluation for evidence of extramuscular granulomatosis and other signs suggestive of sarcoidosis is warranted as about half of the patients have sarcoid myopathy. In addition, the presence of granulomatous myopathy should trigger a search for clinical and pathological clues of inclusion body myositis (IBM), which accounts for most of the remaining patients and can coexist with sarcoidosis. Recognizing the features of IBM in patients with granulomatous myopathy can potentially spare the patients from unnecessary exposure to immunosuppressive therapies. In patients whose granulomatous myopathy remain unexplained, further investigations should aim at identifying myasthenia gravis and other autoimmune disorders, especially those known to cause granulomatous inflammation in other organs. Laboratory investigations should include acetylcholine receptor, antimitochondrial, antineutrophil cytoplasmic, thyroglobulin, and thyroid peroxidase autoantibodies. In the appropriate clinical context, exposure to immune checkpoint inhibitors and chronic graft-vs-host disease can be causes of granulomatous myopathy. In cases of unexplained granulomatous myopathy, natural killer/T-cell lymphoma should be considered and careful histopathological examination for atypical cells and appropriate immunostaining is crucial. Identifying the etiology of granulomatous myopathy in each patient can guide appropriate treatment.

Diagnosis and Pharmacologic Management of Fibrotic Interstitial Lung Disease

Interstitial lung disease is an umbrella term that encompasses a spectrum of parenchymal lung pathologies affecting the gas exchanging part of the lung. While many of these disease entities are not fibrotic in nature, a number can lead to pulmonary fibrosis which may or may not progress over time. Idiopathic pulmonary fibrosis is the prototypical, progressive fibrotic interstitial lung disease, which can lead to worsening hypoxemic respiratory failure and mortality within a number of years from the time of diagnosis. The importance of an accurate and timely diagnosis of interstitial lung diseases, which is needed to inform prognosis and guide clinical management, cannot be overemphasized. Developing a consensus diagnosis requires the incorporation of a variety of factors by a multidisciplinary team, which then may or may not determine a need for tissue sampling. Clinical management can be challenging given the heterogeneity of disease behavior and the paucity of controlled trials to guide decision making. This review addresses current paradigms and recent updates in the diagnosis and pharmacologic management of these fibrotic interstitial lung diseases.

An expert overview of pulmonary fibrosis in sarcoidosis

INTRODUCTION

Advanced pulmonary sarcoidosis refers to phenotypes of pulmonary sarcoidosis that often lead to significant loss of lung function, respiratory failure, or death. Around 20% of patients with sarcoidosis may progress to this state which is mainly driven by advanced pulmonary fibrosis. Advanced fibrosis often presents with associated complications of sarcoidosis including infections, bronchiectasis, and pulmonary hypertension.

AREAS COVERED

This article will focus on the pathogenesis, natural history of disease, diagnosis, and potential treatment options of pulmonary fibrosis in sarcoidosis. In the expert opinion section, we will discuss the prognosis and management of patients with significant disease.

EXPERT OPINION

While some patients with pulmonary sarcoidosis remain stable or improve with anti-inflammatory therapies, others develop pulmonary fibrosis and further complications. Although advanced pulmonary fibrosis is the leading cause of death in sarcoidosis, there are no evidence-based guidelines for the management of fibrotic sarcoidosis. Current recommendations are based on expert consensus and often include multidisciplinary discussions with experts in sarcoidosis, pulmonary hypertension, and lung transplantation to facilitate care for such complex patients. Current works evaluating treatments include the use of antifibrotic therapies for treatment in advanced pulmonary sarcoidosis.

Treat to target and tight control: Could be a new approach in the treatment of sarcoidosis?

Sarcoidosis is a chronic granulomatous disease with multisystemic involvement. Although it is accepted as a benign disease, it can sometimes cause life-threatening organ (heart, brain) involvement that determines the prognosis of the disease. There are conflicting opinions about the treatment of the disease. In the generally accepted treatment approach the "step-by-step" model has gained weight. According to this approach, corticosteroids (CS) drugs alone are preferred in the first step in patients who require treatment. In the second step, immunosuppressive drugs (IS) are used in patients who do not respond to CS and/or have contraindications to CS use, and biologics (TNF-alpha inhibitors) are used in the third step. This treatment approach may be valid in cases with mild sarcoidosis. However, although sarcoidosis is considered a benign and self-limiting disease in some major organ involvement, the "step-by-step" approach may be a treatment option that puts the patient's life in danger. In such selected patients, much more rigorous, early and combined treatment approaches that definitely include CS, IS or biologic drugs may be required. In selected sarcoidosis patients with high risk, early diagnosis, "treat-to-target" (T2T) and "tight control" follow-up of patients seems to be a rational approach. This article reviews the "step-down" treatment regimens in light of recent literature data and hypothesizes that the T2T model may be a probable new treatment approach in patients with sarcoidosis.

Renal replacement therapy in sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology. Kidney involvement in sarcoidosis may be present in up 25-30% of cases. An early diagnosis and prompt treatment with corticosteroids can improve the prognosis but rarely renal sarcoidosis can lead to kidney failure needing renal replacement therapy (RRT). Acute kidney injury (AKI) in sarcoidosis may be caused by granulomatous interstitial nephritis (GIN) or hypercalcemia. These disorders are usually clinically silent and may lead end stage renal disease (ESKD) if not diagnosed or detected too late. In patients with ESKD, dialysis and renal transplantation can offer results comparable to those observed in patients with other causes of kidney failure. Based on a review of literature, we present an overview of RRT in patients with AKI or chronic kidney disease (CKD) caused by sarcoidosis.

Diagnosis and Treatment of Cardiac Sarcoidosis

About 5% of sarcoidosis patients develop clinically manifest cardiac features. Cardiac sarcoidosis (CS) typically presents with conduction abnormalities, ventricular arrhythmias and heart failure. Its diagnosis is challenging and requires a substantial degree of clinical suspicion as well as expertise in advanced cardiac imaging. Adverse events, particularly malignant arrhythmias and development of heart failure, are common among CS patients. A timely diagnosis is paramount to ameliorating outcomes for these patients. Despite weak evidence, immunosuppression (primarily with corticosteroids) is generally recommended in the presence of active inflammation in the myocardium. The burden of malignant arrhythmias remains important regardless of treatment, thus leading to the recommended use of an implantable cardioverter defibrillator in most patients with clinically manifest CS.

[The role of endoscopy in exploration of the mediastinum, indications and results]

Since 2005, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a standard pulmonological tool. The procedure is safe and well tolerated by patients, with minimal morbidity and almost no mortality. A previous review on the technique was published in 2012. However, over the last ten years, a number of new studies have been published on "benign" (sarcoidosis, tuberculosis…) as well as "malignant" diseases (lung cancer, metastases of extra-thoracic cancers, search for mutations and specific oncogenic markers…). These developments have led to expanded indications for EBUS-TBNA, with which it is indispensable to be familiar, in terms of "staging" as well as "diagnosis". In view of optimizing lymph node sampling, several publications have described and discussed EBUS exploration by means of newly available tools (biopsy forceps, larger needles…), and proposed interpretation of the images thereby produced. Given the ongoing evolution of linear EBUS, it seemed indispensable that information on this marvelous tool be updated. This review is aimed at summarizing the novel elements we have found the most important.

An Atypical Case of Extrapulmonary Sarcoidosis

Sarcoidosis is an idiopathic, inflammatory condition that affects nearly all organs in the body. Lungs are the most frequent and among the earliest sites for detecting it. The most common extrapulmonary manifestations involve the ophthalmic, cardiac, nervous, reticuloendothelial, cutaneous, hepatosplenic, and renal systems. These extrapulmonary manifestations of sarcoid may be misdiagnosed in the absence of the classical pulmonary features, given the high overlap of features with other chronic immunologic diseases. The diagnostic workup to differentiate sarcoid from other similar conditions is extensive, amongst which histology remains a gold standard tool for the diagnosis. Our patient presented with a chronic history of multiple vague complaints including nausea, vomiting, progressive malaise, vision changes, and weight loss. After extensive workup, a diagnosis of sarcoidosis along with multiple rare extrapulmonary involvements was made. The authors highlight essential implications including primary practice goals to avoid misdiagnosis or missed sarcoid diagnoses thus helping improve clinical outcomes in similar populations.

Management of Sarcoidosis: When to Treat, How to Treat and for How Long?

Purpose of Review

This review draws together recent publications, consensus statements on sarcoidosis and our 25-year collective experience in managing this disease. We focus on pulmonary sarcoidosis, highlighting recent and established concepts in disease mechanisms, the diversity of the clinical course, including possible ‘subtypes’ of sarcoidosis, and how to measure disease activity. We discuss the principles guiding therapeutic intervention and summarise the more recent clinical trials in sarcoidosis.

Recent Findings

These include recent progress in understanding the mechanisms of disease using new scientific tools, measurements of disease activity using CT and MRI scans, and the potential role of anti-fibrotic treatment for patients with progressive fibrotic sarcoidosis.

Summary

Sarcoidosis is a heterogeneous disease with variable organ involvement, disease course, and response to treatment. We offer an angle on when and how to treat, and provide an overall roadmap for managing sarcoidosis.

Bone fragility and sarcoidosis: An underestimated relationship

INTRODUCTION

Sarcoidosis is a chronic multisystem inflammatory disease which may affect any organ. Also bone can be involved both directly and indirectly. Data on BMD values and fragility fractures in sarcoidosis patients are few and heterogeneous. This study aimed to characterized the presence of fracture and the relative risk factors in patients with sarcoidosis.

MATERIALS AND METHODS

In this single center cross-sectional study we evaluated 252 sarcoidosis patients (54.7 ± 12.1 years) compared to sex-and age matched healthy controls. We measured BMD at lumbar spine, at femoral neck and at total hip. Moreover, the presence of fragility fractures was collected during osteoporosis visit and all radiological images were examined for the presence of any vertebral fracture according to Genant's method's. Lung function measurements, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, and diffusion capacity for carbon monoxide (DLCO) were assessed.

RESULTS

Bone Mineral Density T-scores were lower in patients affected by sarcoidosis with respect to those obtained in healthy controls, but the difference was statistically significant only for BMD-LS (p < 0.01) and BMD-TH (p < 0.05). Moreover, BMD values at all skeletal sites were significantly associated with DLCO (%) (p < 0.05). The prevalence of fragility fracture was higher in patients with sarcoidosis than in healthy controls (30.6 vs. 12.3%). The patients with ≥3 vertebral fracture had lower values of FVC (%), FEV1 (%), and DLCO (%). Multiple regression analyses showed that BMI was positively associated with fragility fracture, while BMD-TH, DLCO(%) and therapy use was negatively associated.

CONCLUSIONS

Vertebral fractures represent a frequent complication in patients with sarcoidosis. Furthermore, the number of vertebral fractures was linked with a worsening in pulmonary functional tests. Therefore, the degree of severity of the sarcoidosis disease appears to be the main determinant of bone fragility.

Integrative bioinformatics analysis to explore a robust diagnostic signature and landscape of immune cell infiltration in sarcoidosis

Background

The unknown etiology of sarcoidosis with variable clinical features leads to delayed diagnosis and limited therapeutic strategies. Hence, exploring the latent mechanisms and constructing an accessible and reliable diagnostic model of sarcoidosis is vital for innovative therapeutic approaches to improve prognosis.

Methods

This retrospective study analyzed transcriptomes from 11 independent sarcoidosis cohorts, comprising 313 patients and 400 healthy controls. The weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) analysis were performed to identify molecular biomarkers. Machine learning was employed to fit a diagnostic model. The potential pathogenesis and immune landscape were detected by bioinformatics tools.

Results

A 10-gene signature SARDS consisting of GBP1, LEF1, IFIT3, LRRN3, IFI44, LHFPL2, RTP4, CD27, EPHX2, and CXCL10 was further constructed in the training cohorts by the LASSO algorithm, which performed well in the four independent cohorts with the splendid AUCs ranging from 0.938 to 1.000. The findings were validated in seven independent publicly available gene expression datasets retrieved from whole blood, PBMC, alveolar lavage fluid cells, and lung tissue samples from patients with outstanding AUCs ranging from 0.728 to 0.972. Transcriptional signatures associated with sarcoidosis revealed a potential role of immune response in the development of the disease through bioinformatics analysis.

Conclusions

Our study identified and validated molecular biomarkers for the diagnosis of sarcoidosis and constructed the diagnostic model SARDS to improve the accuracy of early diagnosis of the disease.

Hit-hard and early versus step-up treatment in severe sarcoidosis

PURPOSE OF REVIEW

The treatment of sarcoidosis remains uncertain, despite 70 years of study. The conventional approach is to initiate corticosteroids in individuals who require treatment. The position of more aggressive regimes is unknown.

RECENT FINDINGS

Recent recognition that many patients will require prolonged therapy, and the observation that corticosteroids lead to overt and insidious toxicities, have led to suggestions that steroid-sparing medications be used earlier in the management of sarcoidosis. Individuals with poor prognostic features, designated as 'high-risk' sarcoidosis may, especially benefit from a broader palette of therapeutic options in the initial treatment regimen. An even more aggressive approach, known as 'top-down' or 'hit-hard and early' therapy has emerged in the fields of gastroenterology and rheumatology in the past 15 years, on the premise that highly effective early control of inflammation leads to better outcomes. These regimens typically involve early initiation of biologic therapies.

SUMMARY

For certain subpopulations of sarcoidosis patients, 'top-down' therapy could be helpful. Severe pulmonary sarcoidosis, neurosarcoidosis, cardiac sarcoidosis and multiorgan sarcoidosis are phenotypes that may be most relevant for revised therapeutic algorithms. Precision medicine approaches and randomized trials will be necessary to confirm a role for top-down therapy in the routine management of sarcoidosis.

Novel insights in fibrotic pulmonary sarcoidosis

PURPOSE OF REVIEW

In chronic pulmonary sarcoidosis, the transition from the inflammatory to the fibrotic stage of the lungs occurs in about 10-20% of cases, eventually causing end-stage fibrotic disease. To date, pathogenetic mechanisms and clinical management remain challenging; thus, we highlight the recent evidence in pulmonary fibrotic processes, clinical signs for an early detection and the potential role of the current investigated antifibrotic agents and promising targeted therapies.

RECENT FINDINGS

Recent findings of relevant key cellular pathways can be considered as a glimmer of light in the complexity of sarcoidosis. In some patients, granulomas persist and serve as a nidus for fibrosis growth, sustained by several fibrosis-stimulating cytokines. Preclinical studies have detected profibrotic, antifibrotic and pleiotropic T cells as promoters of fibrosis. Epigenetics, genetics and transcriptomics research can lead to new target therapies. Antifibrotic drug nintedanib has shown a positive effect on non-idiopathic pulmonary fibrosis fibrotic lung diseases including fibrotic sarcoidosis; other antifibrotic drugs are under investigation.

SUMMARY

Pulmonary fibrosis strongly impacts the outcome of sarcoidosis, and a better understanding of the underlying pathogenic mechanisms can facilitate the development of novel treatments, improving clinical care and life expectancy of these patients. The greatest challenge is to investigate effective antifibrotic therapies once fibrosis develops. The role of these findings in fibrotic sarcoidosis can be translated into other interstitial lung diseases characterized by the coexistence of inflammatory and fibrotic processes.

Imaging More than Skin-Deep: Radiologic and Dermatologic Presentations of Systemic Disorders

Background: Cutaneous manifestations of systemic diseases are diverse and sometimes precede more serious diseases and symptomatology. Similarly, radiologic imaging plays a key role in early diagnosis and determination of the extent of systemic involvement. Simultaneous awareness of skin and imaging manifestations can help the radiologist to narrow down differential diagnosis even if imaging findings are nonspecific. Aims: To improve diagnostic accuracy and patient care, it is important that clinicians and radiologists be familiar with both cutaneous and radiologic features of various systemic disorders. This article reviews cutaneous manifestations and imaging findings of commonly encountered systemic diseases. Conclusions: Familiarity with the most disease-specific skin lesions help the radiologist pinpoint a specific diagnosis and consequently, in preventing unnecessary invasive workups and contributing to improved patient care.

Pyroptosis in inflammation-related respiratory disease

Pyroptosis is commonly induced by the gasdermin (GSDM) family and is accompanied by the release of inflammatory cytokines such as IL-1β and IL-18. Recently, increasing evidence suggests that pyroptosis plays a role in respiratory diseases. This review aimed to summarize the roles and mechanisms of pyroptosis in inflammation-related respiratory diseases. There are several pathways involved in pyroptosis, such as the canonical inflammasome-induced pathway, non-canonical inflammasome-induced pathway, caspase-1/3/6/7/GSDMB pathway, caspase-8/GSDMC pathway, caspase-8/GSDMD pathway, and caspase-3/GSEME pathway. Pyroptosis may be involved in asthma, chronic obstructive pulmonary disease (COPD), lung cancer, acute lung injury (ALI), silicosis, pulmonary hypertension (PH), and tuberculosis (TB), in which the NLRP3 inflammasome-induced pathway is mostly highlighted. Pyroptosis contributes to the deterioration of asthma, COPD, ALI, silicosis, and PH. In addition, pyroptosis has dual effects on lung cancer and TB. Additionally, whether pyroptosis participates in cystic fibrosis (CF) and sarcoidosis or not is largely unknown, though the activation of NLRP3 inflammasome is found in CF and sarcoidosis. In conclusion, pyroptosis may play a role in inflammation-related respiratory diseases, providing new therapeutic targets.