Single-cell and spatial transcriptomics reveal aberrant lymphoid developmental programs driving granuloma formation.

Granulomas are lumps of immune cells that can form in various organs. Most granulomas appear unstructured, yet they have some resemblance to lymphoid organs. To better understand granuloma formation, we performed single-cell sequencing and spatial transcriptomics on granulomas from patients with sarcoidosis and bioinformatically reconstructed the underlying gene regulatory networks. We discovered an immune stimulatory environment in granulomas that repurposes transcriptional programs associated with lymphoid organ development. Granuloma formation followed characteristic spatial patterns and involved genes linked to immunometabolism, cytokine and chemokine signaling, and extracellular matrix remodeling. Three cell types emerged as key players in granuloma formation: metabolically reprogrammed macrophages, cytokine-producing Th17.1 cells, and fibroblasts with inflammatory and tissue-remodeling phenotypes. Pharmacological inhibition of one of the identified processes attenuated granuloma formation in a sarcoidosis mouse model. We show that human granulomas adopt characteristic aspects of normal lymphoid organ development in aberrant combinations, indicating that granulomas constitute aberrant lymphoid organs.

Chronic signaling via the metabolic checkpoint kinase mTORC1 induces macrophage granuloma formation and marks sarcoidosis progression.

The aggregation of hypertrophic macrophages constitutes the basis of all granulomatous diseases, such as tuberculosis or sarcoidosis, and is decisive for disease pathogenesis. However, macrophage-intrinsic pathways driving granuloma initiation and maintenance remain elusive. We found that activation of the metabolic checkpoint kinase mTORC1 in macrophages by deletion of the gene encoding tuberous sclerosis 2 (Tsc2) was sufficient to induce hypertrophy and proliferation, resulting in excessive granuloma formation in vivo. TSC2-deficient macrophages formed mTORC1-dependent granulomatous structures in vitro and showed constitutive proliferation that was mediated by the neo-expression of cyclin-dependent kinase 4 (CDK4). Moreover, mTORC1 promoted metabolic reprogramming via CDK4 toward increased glycolysis while simultaneously inhibiting NF-κB signaling and apoptosis. Inhibition of mTORC1 induced apoptosis and completely resolved granulomas in myeloid TSC2-deficient mice. In human sarcoidosis patients, mTORC1 activation, macrophage proliferation and glycolysis were identified as hallmarks that correlated with clinical disease progression. Collectively, TSC2 maintains macrophage quiescence and prevents mTORC1-dependent granulomatous disease with clinical implications for sarcoidosis.

Sarcoidosis immunopathogenesis - a new concept of maladaptive trained immunity.

Sarcoidosis is a chronic immune disease of unknown origin for which we still lack an immunological framework unifying causal agents, host factors, and natural history of disease. Here, we discuss the initial triggers of disease, and how myeloid cells drive granuloma formation and contribute to immunopathogenesis. We highlight recent advances in our understanding of innate immune memory and propose the hypothesis that maladaptive innate immune training connects previous environmental exposure to granuloma maintenance and expansion. Lastly, we consider how this hypothesis may open novel therapeutic avenues, while corticosteroids remain the front-line treatment.

Diagnosis and Management of Cardiac Sarcoidosis: A Scientific Statement From the American Heart Association.

Cardiac sarcoidosis is an infiltrative cardiomyopathy that results from granulomatous inflammation of the myocardium and may present with high-grade conduction disease, ventricular arrhythmias, and right or left ventricular dysfunction. Over the past several decades, the prevalence of cardiac sarcoidosis has increased. Definitive histological confirmation is often not possible, so clinicians frequently face uncertainty about the accuracy of diagnosis. Hence, the likelihood of cardiac sarcoidosis should be thought of as a continuum (definite, highly probable, probable, possible, low probability, unlikely) rather than in a binary fashion. Treatment should be initiated in individuals with clinical manifestations and active inflammation in a tiered approach, with corticosteroids as first-line treatment. The lack of randomized clinical trials in cardiac sarcoidosis has led to treatment decisions based on cohort studies and consensus opinions, with substantial variation observed across centers. This scientific statement is intended to guide clinical practice and to facilitate management conformity by providing a framework for the diagnosis and management of cardiac sarcoidosis.

Genome-wide association study identifies multiple HLA loci for sarcoidosis susceptibility.

Sarcoidosis is a complex systemic disease. Our study aimed to (1) identify novel alleles associated with sarcoidosis susceptibility; (2) provide an in-depth evaluation of HLA alleles and sarcoidosis susceptibility and (3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1335 sarcoidosis cases and 1264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1487 cases and 1504 controls). The EA and AA cohort was recruited from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. Forty-nine SNPs in the HLA region in HLA-DRA, -DRB9, -DRB5, -DQA1 and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101 and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage from subjects and lung tissue and whole blood from GTEx. We identified six novel SNPs (out of the seven SNPs representing the 49 significant SNPs) and nine HLA alleles associated with sarcoidosis susceptibility in the largest EA population. We also replicated our findings in an AA population. Our study reiterates the potential role of antigen recognition and/or presentation HLA class II genes in sarcoidosis pathogenesis.

Aberrant monocytopoiesis drives granuloma development in sarcoidosis.

In sarcoidosis, granulomas develop in multiple organs including the liver and lungs. Although mechanistic target of rapamycin complex 1 (mTORC1) activation in macrophages drives granuloma development in sarcoidosis by enhancing macrophage proliferation, little is known about the macrophage subsets that proliferate and mature into granuloma macrophages. Here, we show that aberrantly increased monocytopoiesis gives rise to granulomas in a sarcoidosis model, in which Tsc2, a negative regulator of mTORC1, is conditionally deleted in CSF1R-expressing macrophages (Tsc2csf1rΔ mice). In Tsc2csf1rΔ mice, common myeloid progenitors (CMPs), granulocyte-monocyte progenitors (GMPs), common monocyte progenitors / monocyte progenitors (cMoPs / MPs), inducible monocyte progenitors (iMoPs), and Ly6Cint CX3CR1low CD14- immature monocytes (iMOs), but not monocyte-dendritic cell progenitors (MDPs) and common dendritic cell progenitors (CDPs), accumulated and proliferated in the spleen. Consistent with this, monocytes, neutrophils, and neutrophil-like monocytes increased in the spleens of Tsc2csf1rΔ mice, whereas dendritic cells did not. The adoptive transfer of splenic iMOs into wild-type mice gave rise to granulomas in the liver and lungs. In these target organs, iMOs matured into Ly6Chi classical monocytes/macrophages (cMOs). Giant macrophages (gMAs) also accumulated in the liver and lungs, which were similar to granuloma macrophages in expression of cell surface markers such as MerTK and SLAMF7. Furthermore, the gMA-specific genes were expressed in human macrophages from sarcoidosis skin lesions. These results suggest that mTORC1 drives granuloma development by promoting the proliferation of monocyte/neutrophil progenitors and iMOs predominantly in the spleen, and that proliferating iMOs mature into cMOs and then gMAs to give rise to granuloma after migration into the liver and lungs in sarcoidosis.

Aberrant Lipid Metabolism in Macrophages Is Associated with Granuloma Formation in Sarcoidosis.

Rationale: Chronic sarcoidosis is a complex granulomatous disease with limited treatment options that can progress over time. Understanding the molecular pathways contributing to disease would aid in new therapeutic development. Objectives: To understand whether macrophages from patients with nonresolving chronic sarcoidosis are predisposed to macrophage aggregation and granuloma formation and whether modulation of the underlying molecular pathways influence sarcoidosis granuloma formation. Methods: Macrophages were cultivated in vitro from isolated peripheral blood CD14+ monocytes and evaluated for spontaneous aggregation. Transcriptomics analyses and phenotypic and drug inhibitory experiments were performed on these monocyte-derived macrophages. Human skin biopsies from patients with sarcoidosis and a myeloid Tsc2-specific sarcoidosis mouse model were analyzed for validatory experiments. Measurements and Main Results: Monocyte-derived macrophages from patients with chronic sarcoidosis spontaneously formed extensive granulomas in vitro compared with healthy control participants. Transcriptomic analyses separated healthy and sarcoidosis macrophages and identified an enrichment in lipid metabolic processes. In vitro patient granulomas, sarcoidosis mouse model granulomas, and those directly analyzed from lesional patient skin expressed an aberrant lipid metabolism profile and contained increased neutral lipids. Conversely, a combination of statins and cholesterol-reducing agents reduced granuloma formation both in vitro and in vivo in a sarcoidosis mouse model. Conclusions: Together, our findings show that altered lipid metabolism in sarcoidosis macrophages is associated with its predisposition to granuloma formation and suggest cholesterol-reducing therapies as a treatment option in patients.

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.

Investigating cryopreserved PBMC functionality in an antigen-induced model of sarcoidosis granuloma formation.

Sarcoidosis, a systemic inflammatory disease, poses challenges in understanding its etiology and variable clinical courses. Despite ongoing uncertainty about causative agents and genetic predisposition, granuloma formation remains its hallmark feature. To address this, we developed a validated in vitro human granuloma model using patient-derived peripheral blood mononuclear cells (PBMCs), offering a dynamic platform for studying early granuloma formation and sarcoidosis pathogenesis. However, a current limitation of this model is its dependence on freshly isolated PBMCs obtained from whole blood. While cryopreservation is a common method for long-term sample preservation, the biological effects of freezing and thawing PBMCs on granuloma formation remain unclear. This study aimed to assess the viability and functionality of cryopreserved sarcoidosis PBMCs within the granuloma model, revealing similar granulomatous responses to fresh cells and highlighting the potential of cryopreserved PBMCs as a valuable tool for studying sarcoidosis and related diseases.

Joint involvement in sarcoidosis: systematic review and meta-analysis of prevalence, clinical pattern and outcome.

OBJECTIVES: To characterize joint involvement (JI) in sarcoidosis, a systematic search of MEDLINE, EMBASE and Cochrane Library was conducted from inception to July 2022 for publications reporting its prevalence, pattern, treatment and outcome. METHODS: The pooled prevalence estimates (PPE) with 95% CI were calculated using binomial distribution and random effects. Meta-regression method was used to examine factors affecting heterogeneity between studies. RESULTS: Forty-nine articles were identified comprising a total of 8574 sarcoidosis patients, where 12% presented with JI (95% CI 10, 14; I2 = 0%). The PPE for sarcoid arthritis (SA) was 19% (95% CI 14, 24; I2 = 95%), and 32% (95% CI 13, 51; I2 = 99%) for arthralgia. Heterogeneity was due to higher JI prevalence reported in Western Asia and the Middle East, in rheumatology clinics and via surveys. Sample size of SA varied from 12 to 117 cases. Ankles were most frequently affected (PPE 80%) followed by knees and wrists. Monoarthritis was uncommon (PPE 1%; 95% CI 0, 2; I2 = 55%). Acute SA prevailed (PPE 79%; 95% CI 72, 88; I2 = 69%) with an equal proportion of oligo and polyarthritis and was frequently accompanied by erythema nodosum (PPE 62%; 95% CI 52, 71; I2 = 16%). Chronic SA was predominantly polyarticular with a higher frequency of the upper extremity joints affected. Most common non-articular manifestations with SA included fever (52%), erythema nodosum (41%), hilar adenopathy (86%) and interstitial lung disease (23%) of which one-third required corticosteroids and/or immunosuppressants. CONCLUSION: SA occurred early in the disease with a PPE of 19% and most frequent pattern of acute oligo- or polyarthritis predominantly affecting the lower extremity large joints.

Significant delayed conduction and characteristic ventricular tachycardias in patients with cardiac sarcoidosis and electrical storm.

INTRODUCTION: Electrical storm (ES) of ventricular tachyarrhythmias (VTAs) is an important cause of sudden death in patients with cardiac sarcoidosis (CS). VTAs in CS are associated with myocardial scarring and inflammation. However, little is known about the risk factors of ES in patients with CS and VTAs. The objective of this study is to clarify the characteristics and risk factors for the development of ES in patients with CS. METHODS: The study population included consecutive 52 patients with CS and sustained VTA. Twenty-five out of 52 patients experienced ES. We evaluated clinical characteristics, imaging modalities, and electrocardiogram (ECG) parameters to determine the risk factors associated with ES. RESULTS: Half of the patients experienced VTAs as the initial symptom of sarcoidosis, and eight patients had ES as the initial VTA episode. There were no differences in cardiac imaging abnormalities between patients with and without ES. Among ECG markers, significant QRS fragmentation (odds ratio [OR]: 7.9, p = .01) and epsilon waves (OR: 12.24, p = .02) were associated with ES. Among the ventricular tachycardia (VT) characteristics, multiple morphologies of monomorphic VTs (OR: 10.9, p < .01), short VT cycle lengths (OR: 12.5, p < .01), and polymorphic VT (OR: 13.5, p < .01) were associated with ES. Bidirectional VTs were detected in 10 patients with ES and one patient without ES. Immunosuppressive therapy relieved ES in some patients. CONCLUSIONS: ES was common in patients with CS and VTAs. Significant depolarization abnormalities that appeared as QRS fragmentation, epsilon waves, and specific VT characteristics were associated with ES.

Efficacy of denosumab in the treatment of hypercalcemic renal dysfunction in sarcoidosis: a case report.

A 70-year-old female patient was admitted for close examination and treatment of hypercalcemia (corrected serum calcium levels: 3.04 mmol/L) and renal dysfunction (serum creatinine levels: 254.59 µmol/L). The patient had a history of sarcoidosis, diagnosed based on epithelioid cell granulomas in subcutaneous nodule biopsies, uveitis, and bilateral hilar lymphadenopathy, which had spontaneously remitted 10 years before admission. Because the patient was diagnosed with hypercalcemia associated with recurrent sarcoidosis, prednisone (20 mg/day) was initiated, and its dose was tapered following the decrease in serum calcium and creatinine levels. However, the levels of these parameters increased again when the prednisone dose was reduced to ≤ 4 mg/day. We were concerned about glucocorticoid-induced osteoporosis in the patient but hesitated to use first-line bisphosphonates because of renal dysfunction. Therefore, denosumab was initiated to reduce the risk of hypercalcemia, renal dysfunction, and glucocorticoid-induced osteoporosis. Serum creatinine and corrected serum calcium levels subsequently decreased. The prednisone dose could be reduced following repeated denosumab administration.Thus, denosumab can be a multifaceted, beneficial option for sarcoidosis-induced hypercalcemia, as it alleviates renal dysfunction indirectly by normalizing serum calcium levels, facilitates reduction of the glucocorticoid dose, and ameliorates glucocorticoid-induced osteoporosis.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1.

BACKGROUND: An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs). METHODS: This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment." RESULTS: Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1ß, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome. CONCLUSION: Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Blood glucose and lipids are associated with sarcoidosis: findings from observational and mendelian randomization studies.

BACKGROUND: Several researches have demonstrated that patients with sarcoidosis accompanied with the abnormality in blood glucose and/or lipids, however, the causal relationship between them remains uncertain. To elucidate the potential association and causality of blood glucose and lipids with sarcoidosis, we conducted a propensity score matching (PSM)-based observational study combined with mendelian randomization (MR) analysis. METHODS: All subjects in this study were retrospectively collected from Tongji Hospital during 2010 and 2023. 1:1 PSM was employed to control the potential confounders as appropriate. Univariable and multivariable logistic regression analyses were performed to estimate the associations of sarcoidosis with fasting glucose, high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), total cholesterol (TC), and total triglyceride (TG). The further subtype analysis was also conducted. Afterwards, a bidirectional MR analysis based on public data deeply explored the causality among the 5 candidate traits and sarcoidosis, for which the inverse-variance weighted (IVW) method was utilized as the main inferring approach. RESULTS: In the observational study, a total number of 756 subjects were enrolled, with 162 sarcoidosis patients and 594 non-sarcoidosis participants, while 160 pairs of subjects were matched after PSM. Multivariable logistic regression analysis indicated that HDLC (OR: 0.151; 95% CI: 0.056-0.408; P < 0.001) and TC (OR: 3.942; 95% CI: 2.644-5.877; P < 0.001) were strongly associated with sarcoidosis. Subtype analysis showed that low HDLC was independently correlated to risk of lesions in bronchus and lungs, and mediastinal lymph nodes, while high TC was to cervical lymph nodes. In MR analysis, high fasting glucose, low HDLC, and high TC were identified as the causal factors of sarcoidosis. CONCLUSION: HDLC and TC had the potential to influence the risk of sarcoidosis, which could be regarded as predictors and may provide new diagnostic and therapeutic targets for sarcoidosis.

Efficacy and safety of Infliximab in systemic sarcoidosis according to GenPhenReSa organ-involvement phenotype: a retrospective study of 55 patients.

BACKGROUND: Infliximab is currently recommended as a third-line treatment for refractory sarcoidosis. Data in function of clinical phenotype are currently lacking. We evaluated patients' characteristics and responses to infliximab according to their GenPhenReSa cluster. METHODS: We evaluated clinical and biological characteristics of patients diagnosed with sarcoidosis who received infliximab between September 2008 and April 2019 at our centre. RESULTS: Fifty-five patients (median disease duration, 87 months) received infliximab: 48 (87%) as a second- or third-line treatment, and 7 (13%) as a first-line treatment. After a median duration of 12 months, 24 (45%) and 14 (25%) patients achieved complete and partial responses, respectively, together with a significant decrease in the number of affected organs and tapering of steroid doses. All patients with neurosarcoidosis (OR 17), 90% in group 2 (ocular-cardiac-cutaneous-CNS, OR 7.4), and approximately two-thirds of those in groups 1 (abdominal organs), 4 (pulmonary-lympho-nodal), and 5 (extrapulmonary), achieved a response, whereas patients in group 3 (musculoskeletal-cutaneous) had a treatment-failure OR of 9. Infliximab could be stopped after complete remission was achieved in 7 patients: 4 relapsed after a median of 6 months. Overall, 36% of patients experienced serious adverse events, mainly infections, which led to treatment cessation in 29% of patients and caused two deaths. CONCLUSIONS: Other than patients with musculoskeletal-cutaneous involvement (group 3), infliximab led to a good response for patients with CNS (group 2) and liver (group 1) organ-predominant sarcoidosis. However, it led to serious infections and merely suspended sarcoidosis, so further research on factors predictive of relapse is needed.

Decreased serpin C1 in extracellular vesicles predicts response to methotrexate treatment in patients with pulmonary sarcoidosis.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease of unknown etiology primarily affecting the lungs. Treatment is needed when disease symptoms worsen and organ function deteriorates. In pulmonary sarcoidosis, prednisone and methotrexate (MTX) are the most common anti-inflammatory therapies. However, there is large inter-patient variability in response to treatment, and predictive response markers are currently lacking. OBJECTIVE: In this study, we investigated the predictive potential of biomarkers in extracellular vesicles (EVs) isolated from biobanked serum of patients with pulmonary sarcoidosis stored prior to start of therapy. METHODS: Protein concentrations of a four-protein test panel of inflammatory proteins were measured in a discovery (n = 16) and replication (n = 129) cohort of patients with sarcoidosis and 47 healthy controls. Response to therapy was defined as an improvement of the absolute score of > 5% forced vital capacity (FVC) and/or > 10% diffusion lung of carbon monoxide (DLCO) after 24 weeks compared to baseline (before treatment). RESULTS: Serum protein levels differed between EV fractions and serum, and between sarcoidosis cases and controls. Serpin C1 concentrations in the low density lipid particle EV fraction were lower at baseline in the group of patients with a good response to MTX treatment in both the discovery cohort (p = 0.059) and in the replication cohort (p = 0.032). EV Serpin C1 showed to be a significant predictor for response to treatment with MTX (OR 0.4; p = 0.032). CONCLUSION: This study shows that proteins isolated from EVs harbor a distinct signal and have potential as new predictive therapy response biomarkers in sarcoidosis.

Disease trajectories in interstitial lung diseases - data from the EXCITING-ILD registry.

BACKGROUND: Interstitial lung diseases (ILD) comprise a heterogeneous group of mainly chronic lung diseases with different disease trajectories. Progression (PF-ILD) occurs in up to 50% of patients and is associated with increased mortality. METHODS: The EXCITING-ILD (Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases) registry was analysed for disease trajectories in different ILD. The course of disease was classified as significant (absolute forced vital capacity FVC decline > 10%) or moderate progression (FVC decline 5-10%), stable disease (FVC decline or increase < 5%) or improvement (FVC increase ≥ 5%) during time in registry. A second definition for PF-ILD included absolute decline in FVC % predicted ≥ 10% within 24 months or ≥ 1 respiratory-related hospitalisation. Risk factors for progression were determined by Cox proportional-hazard models and by logistic regression with forward selection. Kaplan-Meier curves were utilised to estimate survival time and time to progression. RESULTS: Within the EXCITING-ILD registry 28.5% of the patients died (n = 171), mainly due to ILD (n = 71, 41.5%). Median survival time from date of diagnosis on was 15.5 years (range 0.1 to 34.4 years). From 601 included patients, progression was detected in 50.6% of the patients (n = 304) with shortest median time to progression in idiopathic NSIP (iNSIP; median 14.6 months) and idiopathic pulmonary fibrosis (IPF; median 18.9 months). Reasons for the determination as PF-ILD were mainly deterioration in lung function (PFT; 57.8%) and respiratory hospitalisations (40.6%). In multivariate analyses reduced baseline FVC together with age were significant predictors for progression (OR = 1.00, p < 0.001). Higher GAP indices were a significant risk factor for a shorter survival time (GAP stage III vs. I HR = 9.06, p < 0.001). A significant shorter survival time was found in IPF compared to sarcoidosis (HR = 0.04, p < 0.001), CTD-ILD (HR = 0.33, p < 0.001), and HP (HR = 0.30, p < 0.001). Patients with at least one reported ILD exacerbation as a reason for hospitalisation had a median survival time of 7.3 years (range 0.1 to 34.4 years) compared to 19.6 years (range 0.3 to 19.6 years) in patients without exacerbations (HR = 0.39, p < 0.001). CONCLUSION: Disease progression is common in all ILD and associated with increased mortality. Most important risk factors for progression are impaired baseline forced vital capacity and higher age, as well as acute exacerbations and respiratory hospitalisations for mortality. Early detection of progression remains challenging, further clinical criteria in addition to PFT might be helpful.

Transcriptional and Immune Landscape of Cardiac Sarcoidosis.

BACKGROUND: Cardiac involvement is an important determinant of mortality among sarcoidosis patients. Although granulomatous inflammation is a hallmark finding in cardiac sarcoidosis, the precise immune cell populations that comprise the granuloma remain unresolved. Furthermore, it is unclear how the cellular and transcriptomic landscape of cardiac sarcoidosis differs from other inflammatory heart diseases. METHODS: We leveraged spatial transcriptomics (GeoMx digital spatial profiler) and single-nucleus RNA sequencing to elucidate the cellular and transcriptional landscape of cardiac sarcoidosis. Using GeoMX digital spatial profiler technology, we compared the transcriptomal profile of CD68+ rich immune cell infiltrates in human cardiac sarcoidosis, giant cell myocarditis, and lymphocytic myocarditis. We performed single-nucleus RNA sequencing of human cardiac sarcoidosis to identify immune cell types and examined their transcriptomic landscape and regulation. Using multichannel immunofluorescence staining, we validated immune cell populations identified by single-nucleus RNA sequencing, determined their spatial relationship, and devised an immunostaining approach to distinguish cardiac sarcoidosis from other inflammatory heart diseases. RESULTS: Despite overlapping histological features, spatial transcriptomics identified transcriptional signatures and associated pathways that robustly differentiated cardiac sarcoidosis from giant cell myocarditis and lymphocytic myocarditis. Single-nucleus RNA sequencing revealed the presence of diverse populations of myeloid cells in cardiac sarcoidosis with distinct molecular features. We identified GPNMB (transmembrane glycoprotein NMB) as a novel marker of multinucleated giant cells and predicted that the MITF (microphthalmia-associated transcription factor) family of transcription factors regulated this cell type. We also detected additional macrophage populations in cardiac sarcoidosis including HLA-DR (human leukocyte antigen-DR)+ macrophages, SYTL3 (synaptotagmin-like protein 3)+ macrophages and CD163+ resident macrophages. HLA-DR+ macrophages were found immediately adjacent to GPMMB+ giant cells, a distinct feature compared with other inflammatory cardiac diseases. SYTL3+ macrophages were located scattered throughout the granuloma and CD163+ macrophages, CD1c+ dendritic cells, nonclassical monocytes, and T cells were located at the periphery and outside of the granuloma. Finally, we demonstrate mTOR (mammalian target of rapamycin) pathway activation is associated with proliferation and is selectively found in HLA-DR+ and SYLT3+ macrophages. CONCLUSIONS: In this study, we identified diverse populations of immune cells with distinct molecular signatures that comprise the sarcoid granuloma. These findings provide new insights into the pathology of cardiac sarcoidosis and highlight opportunities to improve diagnostic testing.

A rare case of cutaneous lupus erythematosus presenting with periorbital erythema and edema.

Cutaneous lupus erythematosus (CLE) is an autoimmune skin disease that can manifest itself with a variety of skin symptoms. Periorbital erythema, a rare variant of CLE, presents challenges in terms of diagnosis and treatment. Here, we report a case of CLE presenting with periorbital erythema and edema. A 42-year-old female patient presented with complaints of erythema, edema, and scaling on the right eyelid that started four months ago. A skin biopsy was performed on the lesioned skin of the eyelid to differentiate dermatomyositis, cutaneous lupus erythematosus, sarcoidosis, lupus vulgaris, and cutaneous lymphoma. Histopathological examination revealed focal hyperkeratosis and parakeratosis on the surface of the epidermis, vacuolar degeneration in the basal layer of the epidermis, lymphocyte exocytosis with necrotic keratinocytes, edema in the dermis, melanophages, and perivascular, periadnexal lymphocytic reaction. Laboratory tests showed negative antinuclear antibody and anti-dsDNA, but positivity for anti-Ro-52. In the absence of any other complaints, the patient was diagnosed with cutaneous lupus erythematosus presenting with periorbital erythema based on clinical, histopathological, and laboratory findings. Hydroxychloroquine 200 mg/day, topical corticosteroid, and topical tacrolimus were administered. Two months later, significant improvement in the lesions was observed. In conclusion, it should be kept in mind that periorbital erythema can develop as a rare variant of CLE and can be misdiagnosed as contact dermatitis, dermatomyositis, sarcoidosis, or cutaneous lymphoma. Additionally, the ANA and anti-dsDNA antibodies are often found to be negative in these cases. In establishing the diagnosis, firstly considering the disease, followed by histopathological examinations and laboratory tests, is crucial.

Deep convolutional neural network for differentiating between sarcoidosis and lymphoma based on [18F]FDG maximum-intensity projection images.

OBJECTIVES: To compare the [18F]FDG PET/CT findings of untreated sarcoidosis and malignant lymphoma (ML) and develop convolutional neural network (CNN) models to differentiate between these diseases using maximum intensity projection (MIP) [18F]FDG PET images. METHODS: We retrospectively collected data on consecutive patients newly diagnosed with sarcoidosis and ML who underwent [18F]FDG PET/CT before treatment. Two nuclear radiologists reviewed the images. CNN models were created using MIP PET images and evaluated with k-fold cross-validation. The points of interest were visualized using gradient-weighted class activation mapping (Grad-CAM). RESULTS: A total of 56 patients with sarcoidosis and 62 patients with ML were included. Patients with sarcoidosis had more prominent FDG accumulation in the mediastinal lymph nodes and lung lesions, while those with ML had more prominent accumulation in the cervical lymph nodes (all p < 0.001). For the mediastinal lymph nodes, sarcoidosis patients had significant FDG accumulation in the level 2, 4, 7, and 10 lymph nodes (all p < 0.01). Otherwise, the accumulation in ML patients tended to be in the level 1 lymph nodes (p = 0.08). The CNN model using frontal and lateral MIP images achieved an average accuracy of 0.890 (95% CI: 0.804-0.977), a sensitivity of 0.898 (95% CI: 0.782-1.000), a specificity of 0.907 (95% CI: 0.799-1.000), and an area under the curve of 0.963 (95% CI: 0.899-1.000). Grad-CAM showed that the model focused on the sites of abnormal FDG accumulation. CONCLUSIONS: CNN models based on differences in FDG accumulation sites archive high performance in differentiating between sarcoidosis and ML. CLINICAL RELEVANCE STATEMENT: We developed a CNN model using MIP images of [18F]FDG PET/CT to distinguish between sarcoidosis and malignant lymphoma. It achieved high performance and could be useful in diagnosing diseases with involvement across organs and lymph nodes. KEY POINTS: • There are differences in FDG distribution when comparing whole-body [18F]FDG PET/CT findings in patients with sarcoidosis and malignant lymphoma before treatment. • Convolutional neural networks, a type of deep learning technique, trained with maximum-intensity projection PET images from two angles showed high performance. • A deep learning model that utilizes differences in FDG distribution may be helpful in differentiating between diseases with lesions that are characteristically widespread among organs and lymph nodes.