Pulmonary Manifestations of Systemic Lupus Erythematosus

Quantitative proteomic analysis and replacement therapy identifies haptoglobin as a therapeutic target in a murine model of SLE-associated diffuse alveolar hemorrhage

Background

Diffuse alveolar hemorrhage (DAH) is a catastrophic clinical syndrome and one of the manifestations of pulmonary involvement in systemic lupus erythematosus (SLE), which is characterized by hemoptysis, diffuse pulmonary infiltrates, and respiratory failure. However, the treatment options for DAH remain limited, and DAH-related studies are needed to explore more effective therapeutic directions for better disease management and improved prognosis.

Methods

This study utilized the pristane-induced DAH murine model to mimic the pathological process of DAH in patients with SLE. Proteomic analysis was conducted to detect differentially expressed proteins (DEPs) in the plasma of surviving and non-surviving mice, followed by an analysis of biological functions and pathways. The most significant DEP was then confirmed in the plasma of SLE patients with or without DAH and DAH murine model with or without fatal outcomes. Finally, the therapeutic value of haptoglobin (Hp) replacement was validated in a DAH murine model through lung histopathology, RT-qPCR, and survival analysis.

Results

This study identified 178 DEPs, with 118 upregulated and 60 downregulated DEPs in the non-survival group. Within a set of notable Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, complement and coagulation cascades emerged as the most prominent pathway associated with the process of DAH. Later, the most significant DEP, haptoglobin (Hp), was confirmed to exhibit a significant decrease in the plasma of individuals with SLE-DAH and DAH murine model with poor outcomes by the ELISA test. Finally, compared with the control group, the severity of DAH in the Hp treatment group was alleviated significantly, as manifested by the decreased levels of pro-inflammatory cytokines (IL-6 and TNF-α), increased levels of anti-inflammatory cytokines (IL-10 and TGF-β), and decreased mortality.

Conclusion

A reduction in plasma Hp levels was observed in SLE-DAH, and the replacement therapy with Hp could alleviate pulmonary hemorrhage and reduce mortality in DAH mice. This study identified Hp as a potential biomarker for its clinical diagnosis and a direction for treatment.

Prevalence, patient characteristics and treatment patterns among systemic lupus erythematosus-pulmonary arterial hypertension patients in real-world clinical practice: A retrospective analysis of Medical Data Vision Database in Japan

OBJECTIVES

Real-world evidence regarding prevalence, patient characteristics, and treatment patterns for pulmonary arterial hypertension (PAH) related to systemic lupus erythematosus (SLE) in Japan is limited.

METHODS

We conducted a retrospective study analysing Japan's Medical Data Vision database from April 2008 to September 2020. Prevalence, incidence, patient characteristics, treatment patterns, and use of vasodilators by treatment line were evaluated.

RESULTS

The prevalence of PAH was 0.392% in SLE patients (n = 114/29,077). Cumulative incidence was 0.53% (3 years) and 0.77% (5 years). Of 114 SLE-PAH patients, 49% developed PAH <1 year from SLE diagnosis. SLE-PAH patients were predominantly females (88% vs. 72%), had a lower mean age at SLE diagnosis (53 vs. 56 years), and had more severe SLE (61% vs. 25%) than non-PAH-SLE patients. Glucocorticoids (58%) and vasodilators (27%) were preferred first-line monotherapy for SLE-PAH. A combination of glucocorticoids and immunosuppressants (19%) was the predominant first-line combination therapy. Endothelin receptor antagonists (40% and 44%) and nitric oxide analogues (31% and 40%) were dominant first- and second-line vasodilators.

CONCLUSIONS

SLE-PAH patients were predominantly females, were younger at diagnosis, and had more severe SLE than non-PAH-SLE patients. Most were diagnosed <1 year of SLE diagnosis. In Japan's real-world practice, the initial treatment goal is SLE management, while vasodilators are preferred in advanced diseases, as per the Medical Data Vision database.

Systemic Lupus Erythematosus-related Lung Disease

Systemic Lupus Erythematosus (SLE) is a multifaceted, multisystem autoimmune disorder with diverse clinical expressions. While prevalence reports vary widely, pulmonary involvement accounts for significant morbidity and mortality in SLE. This comprehensive review explores the spectrum of pulmonary disease in SLE, including upper airway manifestations (e.g., laryngeal affection), lower airway conditions (e.g., bronchitis, bronchiolitis, bronchiectasis), parenchymal diseases (e.g., interstitial lung disease, acute lupus pneumonitis, diffuse alveolar hemorrhage), pleural diseases (e.g., serositis, shrinking lung syndrome), and vascular diseases (e.g., pulmonary arterial hypertension, pulmonary embolism, acute reversible hypoxemia syndrome). We discuss diagnostic modalities, treatment strategies, and prognosis for each pulmonary manifestation. With diagnostics remaining a challenge and with the absence of standardized treatment guidelines, we emphasize the need for evidence-based guidelines to optimize patient care and improve outcomes in this complex disease.

[Shrinking lung syndrome in systemic lupus erythematosus: A study of 9 patients]

INTRODUCTION

Shrinking lung syndrome (SLS) is a rare manifestation of systemic lupus erythematosus. Our aim was to describe the clinical, radiological, and functional characteristics of a cohort with SLS and its evolution over time.

METHODS

A retrospective study was conducted between 2009 and 2018. Demographic, clinical, functional, radiological, and treatment data were collected.

RESULTS

Out of a total of 225 patients, 11 presented with SLS (prevalence of 4.8%). Two patients were excluded. The mean age was 39.33±16 years, and 6 were female. The main symptoms were dyspnea and pleuritic pain. The mean forced vital capacity was 49%, total lung capacity was 60%, carbon monoxide diffusing capacity was 66%, carbon monoxide transference factor was 128%, maximal inspiratory pressure was 66%, and maximal expiratory pressure was 82%. All patients received corticosteroids. After a median follow-up of 19 months, 4 cases showed improvement, and 4 cases remained stable.

CONCLUSIONS

SLS should be considered in every lupus patient with unexplained dyspnea. Although it often shows improvement, many cases experience persistent deterioration despite treatment.

Pulmonary Manifestations of Systemic Lupus Erythematosus Among Adults in Aseer Region, Saudi Arabia

Background

Nearly half of the Systemic lupus erythematosus (SLE) patients develop lung involvement. The study assessed the extent of pulmonary involvement among SLE patients and to identify the associated factors in the population.

Methodology

This retrospective cohort study was conducted at Aseer Hospital and Khamis Myshat Hospital in the Southern region of Saudi Arabia. The study spanned from January 1, 2016, to June 3, 2023. Patient inclusion criteria encompassed individuals who received a definitive diagnosis and classification as per American College of Rheumatology criteria, while patients under 18 years of age and those with mixed connective tissue diseases were exclude.

Results

A total of 247 participants were included. 41.7% (n=103) aged 41 years and older, 95.1% (n = 235) were females. Around 10.10% had diabetes mellitus and 17.00% had hypertension and hypothyroidism. Lupus Nephritis was in 15.40%. Chest involvement was reported in 21.9%, in the form of pleuritis (6.10%), pleural effusion (4.00%), and lupus pneumonitis (4.00%), interstitial lung disease (4.00%), pulmonary embolism (3.60%) of individuals, and pulmonary hemorrhage (2.80%). The respiratory symptoms reported by SLE were; dyspnea, cough, and chest pain each having a prevalence of around 18.0%. Palpitations have a relatively high occurrence at 13.80%. Meanwhile, hemoptysis (blood coughing) has a lower prevalence of 1.20%, and fever is reported at 2.80%. Having chronic kidney disease and hypertension were significantly associated with having pulmonary involvement; (χ2=3.308, p=0.027) and (χ2=7.782, Fisher's p=0.002) respectively. The seropositivity for antiphospholipid Abs, anti-CCP, and antids-DNA were significantly associated with pulmonary involvement (χ2=3.239, =p=0.049), (χ2=4.621, Fisher's p=0.023), and (χ2=8.248, p=0.010) respectively.

Conclusion

The study found that 21.9% of SLE patients experience chest involvement, with varying degrees of pulmonary symptoms. Factors such as chronic kidney disease, hypertension, antiphospholipid antibodies, Anti-CCP positivity, and seropositivity for Anti-dsDNA were found to be significant associations with lung involvement, contributing to our understanding of SLE.

Interstitial Lung Disease in Systemic Lupus Erythematosus and Systemic Sclerosis: How Can We Manage the Challenge?

Interstitial lung disease (ILD) is a severe and frequent manifestation of connective tissue diseases (CTD). Due to its debilitating potential, it requires serious evaluation and treatment. The prevalence of ILD in systemic lupus erythematosus (SLE) is still controversial. Therefore, in order to establish the diagnosis of ILD, an overlap syndrome must be excluded. Increasing the identification of SLE-associated ILD cases should become a target. To treat this complication, various therapies are now being proposed. To date, no placebo-controlled studies were conducted. Regarding another CTD, systemic sclerosis (SSc), SSc-associated ILD is considered one of the leading causes of mortality. The incidence of ILD varies among disease subtypes, being influenced by diagnostic method, but also by disease duration. Due to the high prevalence of this complication, all SSc patients should be investigated for ILD at the time of SSc diagnosis and during the course of the disease. Fortunately, progress was made in terms of treatment. Nintedanib, a tyrosine kinases inhibitor, showed promising results. It appeared to decrease the rate of progression of ILD compared to placebo. This review aimed to provide up-to-date findings related to SLE-associated ILD and SSc-associated ILD, in order to raise awareness of their diagnosis and management.

Mivebresib alleviates systemic lupus erythematosus-associated diffuse alveolar hemorrhage via inhibiting infiltration of monocytes and M1 polarization of macrophages

BACKGROUND

Diffuse alveolar hemorrhage (DAH) is a serious complication that can arise from systemic lupus erythematosus (SLE) and other autoimmune diseases. While current treatments for DAH have limitations and adverse side effects, recent evidence suggests that inflammatory macrophages play a crucial role in the development of DAH. In this study, we investigated Mivebresib, a BET protein-bromodomain-containing protein 4 (BRD4) inhibitor, as a potential treatment for DAH.

RESULTS

Our findings show that Mivebresib effectively protected C57BL/6J mice against pristane-induced DAH by inhibiting the migration and polarization of monocytes and macrophages, as well as pathogenic B and T cells. Specifically, Mivebresib modified the distribution of leukocytes, impeded the polarization of inflammatory macrophages, and reduced the frequency of CD19 + CD5 + B cells in the lungs of pristane-treated mice. Furthermore, in vitro experiments demonstrated that Mivebresib inhibited LPS-induced M1 polarization of macrophages and the expression of pro-inflammatory cytokines, M1 marker genes, and chemokines-chemokine receptors while thwarting the secretion of IL-6 and TNF-α. Transcriptomic analysis suggested and experiments comfimed that Mivebresib inhibits M1 polarization via interrupting the p300/BRD4/HIF1A axis.

CONCLUSIONS

Our study demonstrates that Mivebresib has therapeutic potential for the life-threatening complication of DAH caused by SLE. By inhibiting macrophage polarization and the infiltration of inflammatory cells, Mivebresib may offer a promising treatment option for patients suffering from this disease.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

Identification of the shared genes and immune signatures between systemic lupus erythematosus and idiopathic pulmonary fibrosis

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disorder which could lead to inflammation and fibrosis in various organs. Pulmonary fibrosis is a severe complication in patients with SLE. Nonetheless, SLE-derived pulmonary fibrosis has unknown pathogenesis. Of pulmonary fibrosis, Idiopathic pulmonary fibrosis (IPF) is a typicality and deadly form. Aiming to investigate the gene signatures and possible immune mechanisms in SLE-derived pulmonary fibrosis, we explored common characters between SLE and IPF from Gene Expression Omnibus (GEO) database.

RESULTS

We employed the weighted gene co-expression network analysis (WGCNA) to identify the shared genes. Two modules were significantly identified in both SLE and IPF, respectively. The overlapped 40 genes were selected out for further analysis. The GO enrichment analysis of shared genes between SLE and IPF was performed with ClueGO and indicated that p38MAPK cascade, a key inflammation response pathway, may be a common feature in both SLE and IPF. The validation datasets also illustrated this point. The enrichment analysis of common miRNAs was obtained from the Human microRNA Disease Database (HMDD) and the enrichment analysis with the DIANA tools also indicated that MAPK pathways' role in the pathogenesis of SLE and IPF. The target genes of these common miRNAs were identified by the TargetScan7.2 and a common miRNAs-mRNAs network was constructed with the overlapped genes in target and shared genes to show the regulated target of SLE-derived pulmonary fibrosis. The result of CIBERSORT showed decreased regulatory T cells (Tregs), naïve CD4+ T cells and rest mast cells but increased activated NK cells and activated mast cells in both SLE and IPF. The target genes of cyclophosphamide were also obtained from the Drug Repurposing Hub and had an interaction with the common gene PTGS2 predicted with protein-protein interaction (PPI) and molecular docking, indicating its potential treatment effect.

CONCLUSIONS

This study originally uncovered the MAPK pathway, and the infiltration of some immune-cell subsets might be pivotal factors for pulmonary fibrosis complication in SLE, which could be used as potentially therapeutic targets. The cyclophosphamide may treat SLE-derived pulmonary fibrosis through interaction with PTGS2, which could be activated by p38MAPK.

eNAMPT/TLR4 inflammatory cascade activation is a key contributor to SLE Lung vasculitis and alveolar hemorrhage

Rationale

Effective therapies to reduce the severity and high mortality of pulmonary vasculitis and diffuse alveolar hemorrhage (DAH) in patients with systemic lupus erythematosus (SLE) is a serious unmet need. We explored whether biologic neutralization of eNAMPT (extracellular nicotinamide phosphoribosyl-transferase), a novel DAMP and Toll-like receptor 4 ligand, represents a viable therapeutic strategy in lupus vasculitis.

Methods

Serum was collected from SLE subjects (n = 37) for eNAMPT protein measurements. In the preclinical pristane-induced murine model of lung vasculitis/hemorrhage, C57BL/6 J mice (n = 5-10/group) were treated with PBS, IgG (1 mg/kg), or the eNAMPT-neutralizing ALT-100 mAb (1 mg/kg, IP or subcutaneously (SQ). Lung injury evaluation (Day 10) included histology/immuno-histochemistry, BAL protein/cellularity, tissue biochemistry, RNA sequencing, and plasma biomarker assessment.

Results

SLE subjects showed highly significant increases in blood NAMPT mRNA expression and eNAMPT protein levels compared to healthy controls. Preclinical pristane-exposed mice studies showed significantly increased NAMPT lung tissue expression and increased plasma eNAMPT levels accompanied by marked increases in alveolar hemorrhage and lung inflammation (BAL protein, PMNs, activated monocytes). In contrast, ALT-100 mAb-treated mice showed significant attenuation of inflammatory lung injury, alveolar hemorrhage, BAL protein, tissue leukocytes, and plasma inflammatory cytokines (eNAMPT, IL-6, IL-8). Lung RNA sequencing showed pristane-induced activation of inflammatory genes/pathways including NFkB, cytokine/chemokine, IL-1β, and MMP signaling pathways, each rectified in ALT-100 mAb-treated mice.

Conclusions

These findings highlight the role of eNAMPT/TLR4-mediated inflammatory signaling in the pathobiology of SLE pulmonary vasculitis and alveolar hemorrhage. Biologic neutralization of this novel DAMP appears to serve as a viable strategy to reduce the severity of SLE lung vasculitis.

Microvascular lung injury and endoplasmic reticulum stress in systemic lupus erythematosus-associated alveolar hemorrhage and pulmonary vasculitis

Human COPA mutations affecting retrograde Golgi-to-endoplasmic reticulum (ER) protein transport cause diffuse alveolar hemorrhage (DAH) and ER stress ("COPA syndrome"). Patients with SLE also can develop DAH. C57BL/6 (B6) mice with pristane-induced lupus develop monocyte-dependent DAH indistinguishable from human DAH, whereas BALB/c mice are resistant. We examined Copa and ER stress in pristane-induced lupus. Copa expression, ER stress, vascular injury, and apoptosis were assessed in mice and COPA was quantified in blood from patients with SLE. Copa mRNA and protein expression were impaired in B6 mice with pristane-induced DAH, but not in pristane-treated BALB/c mice. An ER stress response (increased Hsp5a/BiP, Ddit3/CHOP, Eif2a, and spliced Xbp1) was seen in lungs from pristane-treated B6, but not BALB/c, mice. Resistance of BALB/c mice to DAH was overcome by treating them with low-dose thapsigargin plus pristane. CB6F1 mice did not develop DAH or ER stress, suggesting that susceptibility was recessive. Increased pulmonary expression of von Willebrand factor (Vwf), a marker of endothelial injury, and the chemokine Ccl2 in DAH suggested that pristane promotes lung microvascular injury and monocyte recruitment. Consistent with that possibility, lung endothelial cells and infiltrating bone marrow-derived cells from pristane-treated B6 mice expressed BiP and showed evidence of apoptosis (annexin-V and activated caspase-3 staining). COPA expression also was low in patients with SLE with lung involvement. Pristane-induced DAH may be initiated by endothelial injury, resulting in ER stress, apoptosis of lung endothelial cells, and recruitment of myeloid cells that propagate lung injury. The pathogenesis of DAH in SLE and COPA syndrome may overlap.

Systemic Lupus Erythematosus and Lung Involvement: A Comprehensive Review

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multiorgan manifestations, including pleuropulmonary involvement (20-90%). The precise mechanism of pleuropulmonary involvement in SLE is not well-understood; however, systemic type 1 interferons, circulating immune complexes, and neutrophils seem to play essential roles. There are eight types of pleuropulmonary involvement: lupus pleuritis, pleural effusion, acute lupus pneumonitis, shrinking lung syndrome, interstitial lung disease, diffuse alveolar hemorrhage (DAH), pulmonary arterial hypertension, and pulmonary embolism. DAH has a high mortality rate (68-75%). The diagnostic tools for pleuropulmonary involvement in SLE include chest X-ray (CXR), computed tomography (CT), pulmonary function tests (PFT), bronchoalveolar lavage, biopsy, technetium-99m hexamethylprophylene amine oxime perfusion scan, and (18)F-fluorodeoxyglucose positron emission tomography. An approach for detecting pleuropulmonary involvement in SLE includes high-resolution CT, CXR, and PFT. Little is known about specific therapies for pleuropulmonary involvement in SLE. However, immunosuppressive therapies such as corticosteroids and cyclophosphamide are generally used. Rituximab has also been successfully used in three of the eight pleuropulmonary involvement forms: lupus pleuritis, acute lupus pneumonitis, and shrinking lung syndrome. Pleuropulmonary manifestations are part of the clinical criteria for SLE diagnosis. However, no review article has focused on the involvement of pleuropulmonary disease in SLE. Therefore, this article summarizes the literature on the epidemiology, pathogenesis, diagnosis, and management of pleuropulmonary involvement in SLE.

The role of PET/CT in connective tissue disorders: systemic sclerosis, Sjögren's syndrome and systemic lupus erythematosus

Advanced imaging techniques are needed to help clinicians in the diagnosis, in the choice of the right time for therapeutic interventions or for modifications and monitoring of treatment response in patients with autoimmune connective tissue diseases. Nuclear medicine imaging, especially PET/CT and PET/MRI, may play an important role in detecting disease activity, assessing early treatment response as well as in clarifying the complex mechanisms underlying systemic sclerosis, Sjögren's syndrome or systemic lupus erythematosus. In addition, [¹⁸F]FDG PET/CT may help in excluding or detecting coexisting malignancies. Other more specific radiopharmaceuticals are being developed and investigated, targeting specific cells and molecules involved in connective tissue diseases. Further larger studies with standardized imaging protocol and image interpretation are strongly required before including PET/CT in the diagnostic work-up of subsets of patients with autoimmune connective tissue diseases.

Neutrophils Contribute to ER Stress in Lung Epithelial Cells in the Pristane-Induced Diffuse Alveolar Hemorrhage Mouse Model

Diffuse alveolar hemorrhage (DAH), although rare, is a life-threatening complication of systemic lupus erythematosus (SLE). Little is known about the pathophysiology of DAH in humans, although increasingly neutrophils, NETosis and inflammatory monocytes have been shown to play an important role in the pristane-induced model of SLE which develops lung hemorrhage and recapitulates many of the pathologic features of human DAH. Using this experimental model, we asked whether endoplasmic reticulum (ER) stress played a role in driving the pathology of pulmonary hemorrhage and what role infiltrating neutrophils had in this process. Analysis of lung tissue from pristane-treated mice showed genes associated with ER stress and NETosis were increased in a time-dependent manner and reflected the timing of CD11b⁺Ly6G⁺ neutrophil accumulation in the lung. Using precision cut lung slices from untreated mice we observed that neutrophils isolated from the peritoneal cavity of pristane-treated mice could directly induce the expression of genes associated with ER stress, namely Chop and Bip. Mice which had myeloid-specific deletion of PAD4 were generated and treated with pristane to assess the involvement of PAD4 and PAD4-dependent NET formation in pristane-induced lung inflammation. Specific deletion of PAD4 in myeloid cells resulted in decreased expression of ER stress genes in the pristane model, with accompanying reduction in IFN-driven genes and pathology. Lastly, coculture experiments of human neutrophils and human lung epithelial cell line (BEAS-2b) showed neutrophils from SLE patients induced significantly more ER stress and interferon-stimulated genes in epithelial cells compared to healthy control neutrophils. These results support a pathogenic role of neutrophils and NETs in lung injury during pristane-induced DAH through the induction of ER stress response and suggest that overactivation of neutrophils in SLE and NETosis may underlie development of DAH.

Systemic lupus erythematosus/ANCA-associated vasculitis overlap: An explanation for atypical lupus manifestation

The coexistence of systemic lupus erythematosus (SLE) and ANCA-associated vasculitis (AAV) as an overlapping syndrome is not common. Here, we report a case of a 33-year-old woman, with recent SLE diagnosis due to skin, kidney, articular, and immunologic compromise, in whom a chest CT scan showed bilateral nodules, consolidations, and tree-in-bud pattern; thoracoscopic lung biopsy revealed diffuse non-caseating granulomas, without other features of sarcoid, organizing pneumonia, or hypersensitivity pneumonitis with high positive p-ANCA titers. Overlap between SLE and AAV was a possible explanation for lupus granulomatous pneumonitis, and for this reason, a multidisciplinary meeting was held to evaluate complex patients with interstitial lung diseases patients.

Pulmonary thromboembolism and alveolar hemorrhage as initial manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs. SLE can affect the lung, the pulmonary vasculature, and the pleura. A 38-year-old female with limb pain and ecchymosis who later developed pulmonary thromboembolism and alveolar hemorrhage is presented here. Clinical, imaging, laboratory, and histopathological evidence is presented. The patient met the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) criteria for SLE. Furthermore, the patient had a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of 35; thus, indicating severe disease. This case is an example of concomitant venous and arterial lung complications in an SLE patient.

2020 guide for the diagnosis and treatment of interstitial lung disease associated with connective tissue disease

The prognosis of patients with connective tissue disease (CTD) has improved significantly in recent years, but interstitial lung disease (ILD) associated with connective tissue disease (CTD-ILD) remains a refractory condition, which is a leading cause of mortality. Because it is an important prognostic factor, many observational and interventional studies have been conducted to date. However, CTD is a heterogeneous group of conditions, which makes the clinical course, treatment responses, and prognosis of CTD-ILD extremely diverse. To summarize the current understanding and unsolved questions, the Japanese Respiratory Society and the Japan College of Rheumatology collaborated to publish the world's first guide focusing on CTD-ILD, based on the evidence and expert consensus of pulmonologists and rheumatologists, along with radiologists, pathologists, and dermatologists. The task force members proposed a total of 27 items, including 7 for general topics, 9 for disease-specific topics, 3 for complications, 4 for pharmacologic treatments, and 4 for non-pharmacologic therapies, with teams of 2-4 authors and reviewers for each item to prepare a consensus statement based on a systematic literature review. Subsequently, public opinions were collected from members of both societies, and a critical review was conducted by external reviewers. Finally, the task force finalized the guide upon discussion and consensus generation. This guide is expected to contribute to the standardization of CTD-ILD medical care and is also useful as a tool for promoting future research by clarifying unresolved issues.

ISHLT consensus document on lung transplantation in patients with connective tissue disease: Part I: Epidemiology, assessment of extrapulmonary conditions, candidate evaluation, selection criteria, and pathology statements

Patients with connective tissue disease (CTD) and advanced lung disease are often considered suboptimal candidates for lung transplantation (LTx) due to their underlying medical complexity and potential surgical risk. There is substantial variability across LTx centers regarding the evaluation and listing of these patients. The International Society for Heart and Lung Transplantation-supported consensus document on lung transplantation in patients with CTD standardization aims to clarify definitions of each disease state included under the term CTD, to describe the extrapulmonary manifestations of each disease requiring consideration before transplantation, and to outline the absolute contraindications to transplantation allowing risk stratification during the evaluation and selection of candidates for LTx.

Monogenic lupus with homozygous C4A deficiency presenting as bronchiectasis and immune-mediated thrombocytopenia

Monogenic lupus is a subset of lupus caused by single-gene disorders, integrating the paradoxical combination of autoimmunity and immunodeficiency. Pulmonary manifestations with recurrent pneumonia and bronchiectasis have rarely been described as the predominant presentation of juvenile lupus and may suggest an alternate differential like primary immunodeficiency, especially in early childhood. We describe a case of 10-year girl who presented with a history of recurrent pneumonia, arthritis, alopecia, and poor weight gain for the past 2 years. On examination, she had respiratory distress, bilateral diffuse crackles and arthritis of the small joints of hands. Lab investigations showed pancytopenia, low complement levels and high titers of ANA and anti-dsDNA antibodies. The patient was diagnosed with juvenile lupus. Imaging studies revealed evidence of multiple lobar collapse and consolidation with bronchiectasis. She was started on steroids, HCQ and supportive measures for bronchiectasis. The child reported relief in initial symptoms of lupus on follow-up but developed recurrent thrombocytopenia requiring IVIG and escalating the doses of oral steroids. The young age and atypical presentation prompted a screening for monogenic lupus, and clinical exome sequencing revealed a novel homozygous missense variation in exon 20 of the C4Agene with clinically reduced C4 levels, consistent with the diagnosis of C4A deficiency.

A Fatal Case of Diffuse Alveolar Hemorrhage in the Setting of Systemic Lupus Erythematosus: A Case Report and Review of Noninfectious Causes of Acute Pulmonary Hemorrhage in Adults

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease, characterized by autoantibody production and immune complex formation, that has the potential to affect virtually any organ. Pleuropulmonary involvement occurs in 50–70% and commonly manifests as pleuritis and pleural effusion. Diffuse alveolar hemorrhage (DAH) is a rare manifestation of SLE. Most cases of DAH occur in young adults with an underlying autoimmune disease such as systemic vasculitis or Goodpasture syndrome. SLE is typically lower on the list of initial differential diagnoses of DAH due to its rarity compared to other etiologies. We present a case of a patient with dyspnea on exertion, dry coughs, lower extremity edema, and intermittent periorbital edema who ultimately succumbed to respiratory failure secondary to DAH in the setting of SLE. The diagnosis of SLE was suspected clinically and confirmed at autopsy due to her rapid clinical deterioration. DAH requires prompt intervention, and management is guided by the underlying disease process. SLE is a potentially treatable disease; therefore, timely diagnosis is important in order to exclude other noninfectious causes of DAH (reviewed in this report) and to initiate appropriate therapy.

Lupus and the Lungs: The Assessment and Management of Pulmonary Manifestations of Systemic Lupus Erythematosus

Pulmonary manifestations of systemic lupus erythematosus (SLE) are wide-ranging and debilitating in nature. Previous studies suggest that anywhere between 20 and 90% of patients with SLE will be troubled by some form of respiratory involvement throughout the course of their disease. This can include disorders of the lung parenchyma (such as interstitial lung disease and acute pneumonitis), pleura (resulting in pleurisy and pleural effusion), and pulmonary vasculature [including pulmonary arterial hypertension (PAH), pulmonary embolic disease, and pulmonary vasculitis], whilst shrinking lung syndrome is a rare complication of the disease. Furthermore, the risks of respiratory infection (which often mimic acute pulmonary manifestations of SLE) are increased by the immunosuppressive treatment that is routinely used in the management of lupus. Although these conditions commonly present with a combination of dyspnea, cough and chest pain, it is important to consider that some patients may be asymptomatic with the only suggestion of the respiratory disorder being found incidentally on thoracic imaging or pulmonary function tests. Treatment decisions are often based upon evidence from case reports or small cases series given the paucity of clinical trial data specifically focused on pulmonary manifestations of SLE. Many therapeutic options are often initiated based on studies in severe manifestations of SLE affecting other organ systems or from experience drawn from the use of these therapeutics in the pulmonary manifestations of other systemic autoimmune rheumatic diseases. In this review, we describe the key features of the pulmonary manifestations of SLE and approaches to investigation and management in clinical practice.

Management of Severe Refractory Systemic Lupus Erythematosus: Real-World Experience and Literature Review

Systemic lupus erythematosus (SLE) is a highly heterogeneous disease affecting multiple organs and is characterized by an aberrant immune response. Although the mortality of SLE has decreased significantly since the application of glucocorticoids, severe or refractory SLE can potentially cause irreversible organ damage and contribute to the disease morbidity and mortality. Early recognition of severe SLE or life-threatening conditions is of great challenge to clinicians since the onset symptoms can be rapid and aggressive, involving the visceral organs of the neuropsychiatric, gastrointestinal, hematologic, renal, pulmonary, and cardiovascular systems, etc. Additionally, SLE patients with specific comorbidities and detrimental complications could lead to a clinical dilemma and contribute to poor prognosis. Prompt and adequate treatment for severe refractory SLE is crucial for a better prognosis. However, as evidence from well-designed randomized controlled trials is limited, this review aims to provide real-world evidence based on cohort studies from Peking Union Medical College Hospital, the national tertiary referral center in China, together with the literature, on clinical characteristics, risks and prognostic factors, and treatment strategies for severe and/or refractory SLE.

Coronavirus disease 2019 (COVID-19) in patients with systemic autoimmune diseases or vasculitis: radiologic presentation

Coronavirus disease 2019 (COVID-19) has transformed into a worldwide challenge, since its outbreak in December 2019. Generally, patients with underlying medical conditions are at a higher risk of complications and fatality of pneumonias. Whether patients with systemic autoimmune diseases or vasculitides, are at increased risk for serious complications associated with COVID-19, is not established yet. Computed tomography (CT) has been employed as a diagnostic tool in the evaluation of patients with clinical suspicion of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection with a reported sensitivity of higher than reverse transcription polymerase chain reaction (RT-PCR) test. Multifocal bilateral ground-glass opacities (GGOs) with peripheral and posterior distribution and subsequent superimposition of consolidations are considered the main imaging features of the disease in chest CT. However, chest CT images of underlying rheumatologic or autoimmune diseases or vasculitides, such as systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Behçet disease, and granulomatosis with polyangiitis, especially those with extensive lung involvement can overshadow or obliterate features of COVID-19. In addition, CT findings of such diseases may resemble manifestations of COVID-19 (such as ground glass opacities with or without superimposed consolidation), making the diagnosis of viral infections, more challenging on imaging. Comparing the imaging findings with prior studies (if available) for any interval change is the most helpful approach. Otherwise, the diagnosis of COVID-19 in such patients must be cautiously made according to the clinical context and laboratory results, considering a very high clinical index of suspicion on imaging.

Severe pulmonary arterial hypertension and interstitial pneumonia related to systemic lupus erythematosus successfully treated with mycophenolate mofetil: A novel case report

BACKGROUND

Pulmonary arterial hypertension (PAH) and interstitial pneumonia (IP) are relatively rare complications of systemic lupus erythematosus (SLE) and are associated with a poor prognosis. Overcoming these complications is a challenge for improving the prognosis.

CASE REPORT

A 41-year-old woman was diagnosed with SLE complicated by IP at the age of 21 years and with antiphospholipid syndrome at the age of 32 years at another hospital. She had been administered prednisolone (PSL) at a dose ≥15 mg daily, as well as various immunosuppressants and antiplatelet/anticoagulation therapy. On day I of hospitalization, She presented to our emergency outpatient department with fever, marked dyspnea, and skin ulcer on the left lower leg and was admitted the same day. Chest radiography revealed marked cardiomegaly and interstitial shadow, and right heart catheterization showed elevation in the mean pulmonary arterial pressure to 47 mmHg, indicating PAH. While oxygen therapy was started, high-dose steroid therapy and mycophenolate mofetil (MMF) were administered for treatment of SLE complicated by PAH/IP, and prostacyclin (_{prostaglandin I2}), endothelin receptor antagonist, and PDE5 inhibitor were administered for PAH. Both SLE disease activity and PAH/IP improved and were maintained with no exacerbation for 2 years. The PSL dose could eventually be reduced to 5 mg/day.

CONCLUSION

In SLE complicated by PAH/IP, reports on the efficacy of MMF are scarce, and our findings suggested that MMF may be a treatment option in such cases.

Systemic Lupus Erythematosus

Systemic lupus erythematosus (lupus) is characterized by aberrant activity of the immune system, leading to variable clinical symptoms. Lupus is more prevalent in African American women and women in other ethnic minority groups. Diagnosing, treating, and identifying novel therapies for lupus is challenging because of its genetic and phenotypic heterogeneity. Lupus nephritis is the most common target-organ manifestation and requires individualized care to minimize toxicity. A multidisciplinary approach to caring for pregnant patients with lupus is essential to optimize outcomes.

Assessment of lung glucose uptake in patients with systemic lupus erythematosus pulmonary arterial hypertension: a quantitative FDG-PET imaging study

PURPOSE

Pulmonary arterial hypertension (PAH) is a recognized complication of systemic lupus erythematosus (SLE-PAH) patients and its lung pathology shares similarity to idiopathic PAH (IPAH) with distinctive inflammatory feature. FDG-PET reports glucose metabolism from both hyperproliferative and inflammatory cellular elements of vascular pathology in PAH. We explored the application of FDG-PET in reporting SLE-PAH pulmonary vascular pathology.

METHODS

Sixty-minute dynamic FDG-PET imaging was applied in 14 SLE-PAH patients, 20 IPAH patients and 10 healthy volunteers. Patlak analysis was used to quantify lung FDG uptake (influx rate Ki).

RESULTS

Mean lung FDG uptake in SLE-PAH (Ki 0.00714 ± 0.000602 mL/g/min) was significantly higher than that of the healthy volunteers (Ki 0.000262 ± 0.000168 mL/g/min) (p < 0.05). SLE-PAH patients with SLE disease activity score SLEDAI ≥ 5 demonstrated significantly increased lung FDG uptake (Ki 0.001075 ± 0.00055 mL/g/min) than those with SLEDAI < 5 (Ki 0.000233 ± 0.00017 mL/g/min) (p = 0.0038) and IPAH (Ki 0.000524 ± 0.000314 mL/g/min) (p = 0.0025). Lung FDG uptake in SLE-PAH correlated with SLEDAI score and plasma complement C3 and C4 levels (Ki vs SLEDAI, r = 0.607, p = 0.021; Ki vs C3, r = - 0.568, p = 0.034; Ki vs C4, r = - 0.661, p = 0.010). There were no significantly correlations between lung FDG uptake and pulmonary vascular haemodynamics and 6 min walking distance in both IPAH and SLE-PAH patients.

CONCLUSIONS

Our data indicated that increased lung FDG uptake in SLE-PAH patients correlates with SLE disease activity (SLEDAI) and immune/inflammatory status (C3 and C4). FDG-PET imaging may be developed as a potential intrapulmonary disease activity marker in SLE-PAH patients.

Acute respiratory involvement in Colombian patients with systemic lupus erythematosus undergoing chest computed tomography

INTRODUCTION

Systemic lupus erythematosus (SLE) is an inflammatory disease which affects multiple organs. The respiratory system is compromised in 1.6% to 36% of the patients with SLE. The objective of this study was to know the prevalence of these alterations, their associated variables, and outcomes in patients with SLE between 2012 and 2017.

METHODS

A cross-sectional study of 200 patients with SLE underwent chest computed tomography (CT). The primary outcome was acute respiratory involvement (ARI). A descriptive, bivariate and multivariate analysis were performed using Stata 12.0 software.

RESULTS

ARI was present in 40% of the SLE patients undergoing chest CT. The most frequent ARI was pleural effusion in 33%, followed by pneumonia (16.5%), lupus pneumonitis (9%), pulmonary embolism (3%) and pulmonary hemorrhage (2.5%). In bivariate and multivariate analysis a statistically significant association between ARI and nephropathy, hematological impairment, active disease, dead, readmission and prolonged hospital stay was found.

CONCLUSION

This is the first Colombian study that evaluates ARI in patients with SLE. ARI is an important and frequent condition in patients with SLE, pleural effusion being the most prevalent cause of ARI. There are some variables (nephropathy, hematological impairment and activity disease) that are associated with ARI and could be the basis of intervention.

Alpha-1-Antitrypsin Ameliorates Pristane Induced Diffuse Alveolar Hemorrhage in Mice

Diffuse alveolar hemorrhage (DAH) is a fatal complication in patients with lupus. DAH can be induced in B6 mice by an intraperitoneal injection of pristane. Since human alpha-1-antitrypsin (hAAT) is an anti-inflammatory and immuno-regulatory protein, we investigated the protective effect of hAAT against pristane-induced DAH in B6 mice and hAAT transgenic (hAAT-Tg) mice. We first showed that hAAT Tg expression lowers TNF-α production in B cells, as well as CD4+ T cells in untreated mice. Conversely, the frequency of regulatory CD4+CD25+ and CD4+CD25-IL-10+ cells was significantly higher in hAAT-Tg than in B6 mice. This confirmed the anti-inflammatory effect of hAAT that was observed even at steady state. One week after a pristane injection, the frequency of peritoneal Ly6C^hi inflammatory monocytes and neutrophils in hAAT-Tg mice was significantly lower than that in B6 mice. Importantly, pristane-induced DAH was completely prevented in hAAT-Tg mice and this was associated with a modulation of anti- to pro-inflammatory myeloid cell ratio/balance. We also showed that treatment with hAAT decreased the severity of DAH in B6 mice. These results showed for the first time that hAAT has a therapeutic potential for the treatment of DAH.

Pulmonary manifestations in systemic lupus erythematosus: pleural involvement, acute pneumonitis, chronic interstitial lung disease and diffuse alveolar hemorrhage

Systemic lupus erythematosus is the diffuse autoimmune connective tissue disease that most frequently involves pulmonary involvement, affecting 20% of 90% of the patients. The percentage varies depending on the defining criteria (symptoms, pulmonary tests or histopathological studies). At least once during the disease course, 50% of those affected have pleural and/or pulmonary manifestations, which are associated with higher morbidity and mortality. Pulmonary involvement has no correlation with lupus activity biomarkers, and it is necessary to rule out infectious processes in the initial approach. Bacterial infection is most frequently the cause of lung involvement in lupus and is one of the most important causes of death. Pulmonary involvement is considered to be primary when it is associated with disease activity, and secondary when other causes participate. Drugs have been reported to be associated with pulmonary damage, including interstitial disease. The incidence of malignant lung diseases is increased in systemic lupus erythematosus. Treatment depends on the type and severity of pulmonary involvement.

Primary respiratory disease in patients with systemic lupus erythematosus: data from the Spanish rheumatology society lupus registry (RELESSER) cohort

Background

The purpose of this study was to assess the prevalence, associated factors, and impact on mortality of primary respiratory disease in a large systemic lupus erythematosus (SLE) retrospective cohort.

Methods

All adult patients in the RELESSER-TRANS (Registry of Systemic Lupus Erythematosus Patients of the Spanish Society of Rheumatology [SER], cross-sectional phase) registry were retrospectively investigated for the presence of primary pleuropulmonary manifestations.

Results

In total 3215 patients were included. At least one pleuropulmonary manifestation was present in 31% of patients. The most common manifestation was pleural disease (21%), followed by lupus pneumonitis (3.6%), pulmonary thromboembolism (2.9%), primary pulmonary hypertension (2.4%), diffuse interstitial lung disease (2%), alveolar hemorrhage (0.8%), and shrinking lung syndrome (0.8%).

In the multivariable analysis, the variables associated with the development of pleuropulmonary manifestation were older age at disease onset (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.02–1.04), higher SLEDAI (Systemic Lupus Erythematosus Disease Activity Index) scores (OR 1.03, 95% CI 1.00–1.07), the presence of Raynaud’s phenomenon (OR 1.41, 95% CI 1.09–1.84), secondary antiphospholipid syndrome (OR 2.20, 95% CI 1.63–2.97), and the previous or concomitant occurrence of severe lupus nephritis, (OR 1.48, 95% CI 1.12–1.95) neuropsychiatric manifestations (OR 1.49, 95% CI 1.11–2.02), non-ischemic cardiac disease (OR 2.91, 95% CI 1.90–4.15), vasculitis (OR 1.81, 95% CI 1.25–2.62), hematological manifestations (OR 1.31, 95% CI 1.00–1.71), and gastrointestinal manifestations, excluding hepatitis (OR 2.05, 95% CI 1.14–3.66). Anti-RNP positivity had a clear tendency to significance (OR 1.32, 95% CI 1.00–1.75; P = 0.054).

The development of pleuropulmonary manifestations independently contributes to a diminished survival (hazard ratio of 3.13). However, not all complications will influence the prognosis in the same way. Whereas the occurrence of pleural disease or pulmonary thromboembolism has a minimal impact on the survival of these patients, the remaining manifestations have a major impact on mortality.

Conclusion

Except for pleural disease, the remaining respiratory manifestations are very uncommon in SLE (<4%). Pleuropulmonary manifestations independently contributed to a decreased survival in these patients.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1776-8) contains supplementary material, which is available to authorized users.

IL-16/miR-125a axis controls neutrophil recruitment in pristane-induced lung inflammation

Severe lung inflammation and alveolar hemorrhage can be life-threatening in systemic lupus erythematosus (SLE) patients if not treated early and aggressively. Neutrophil influx is the driver key of this pathology, but little is known regarding the molecular events regulating this recruitment. Here, we uncover a role for IL-16/mir-125a in this pathology and show not only that IL-16 is a target for miR-125a but that reduced miR-125a expression in SLE patients associates with lung involvement. Furthermore, in the pristane model of acute "SLE-like" lung inflammation and alveolar hemorrhage, we observed reduced pulmonary miR-125a and enhanced IL-16 expression. Neutrophil infiltration was markedly reduced in the peritoneal lavage of pristane-treated IL-16-deficient mice and elevated following i.n. delivery of IL-16. Moreover, a miR-125a mimic reduced pristane-induced IL-16 expression and neutrophil recruitment and rescued lung pathology. Mechanistically, IL-16 acts directly on the pulmonary epithelium and markedly enhances neutrophil chemoattractant expression both in vitro and in vivo, while the miR-125a mimic can prevent this. Our results reveal a role for miR-125a/IL-16 in regulating lung inflammation and suggest this axis may be a therapeutic target for management of acute lung injury in SLE.

Case of severe acute lupus myocarditis and multiple-organ failure

We report a case of severe lupus myocarditis with rapid, acute deterioration to cardiogenic shock and multiorgan failure, highlighting the importance of early identification and treatment of acute presentations in patients with systemic lupus erythematosus. A 31-year-old woman with previously diagnosed subacute cutaneous lupus erythematosus initially presented with abdominal pain and frank per-rectal bleeding. She deteriorated rapidly with type 1 respiratory failure and acute kidney injury requiring dialysis secondary to acute cardiac failure with a prolonged intensive care unit admission, over a month. A significantly elevated troponin, global hypokinesia on echocardiogram and normal coronary artery angiogram and cardiac MRI lead to the diagnosis of acute lupus myocarditis as the cause for the cardiogenic shock. She was treated with high-dose corticosteroids and eventually made a full recovery, with cardiac function returning to normal.

Comparison of short-term outcomes for connective tissue disease-related interstitial lung disease and idiopathic pulmonary fibrosis after lung transplantation

Background

Pulmonary involvement is common in connective tissue disease (CTD), and respiratory failure is a major cause of morbidity and mortality in CTD-related interstitial lung disease (CTD-ILD). Lung transplantation is thus important for these patients. However, survival, outcomes, and management of these patients after transplantation have been debated. The aim of this study was to evaluate the outcomes for CTD-ILD compared to those for idiopathic pulmonary fibrosis (IPF) after lung transplantation.

Methods

We performed a single-centre retrospective study of 62 patients with CTD-ILD or IPF who underwent lung transplantation at a tertiary hospital in South Korea between October 2012 and October 2016.

Results

Patients with CTD-ILD (n=15) were younger (46 vs. 60 years, P=0.001) and were less likely to be male (33.3% vs. 76.6%, P=0.004) than were patients with IPF (n=47). The 1-year cumulative survival rate was 80.0% for CTD-ILD and 59.6% for IPF (log-rank P=0.394). There was no difference in the cumulative survival rate (log-rank P=0.613) of age- and sex-matched patients with CTD-ILD (n=15) and IPF (n=15). The incidence of primary graft dysfunction was similar (P=0.154), and 2 (18.2%) patients developed possible CTD flare.

Conclusions

Patients with CTD-ILD and those with IPF who underwent lung transplantation had similar survival rates.

Pulmonary manifestations in late versus early systemic lupus erythematosus: A systematic review and meta-analysis

OBJECTIVES

Phenotypes differ between late- and early-onset systemic lupus erythematosus (SLE). Prior studies suggested that there may be more pulmonary disease among late-onset patients. Our objective was to perform a systematic review and meta-analysis to evaluate the differences in pulmonary manifestations in late- versus early-onset SLE.

METHODS

We searched the literature using PubMed, CINAHL, Web of Science, Cochrane Library, and EMBASE. We excluded studies that did not include American College of Rheumatology SLE classification criteria, an early-onset SLE comparison group, or those that defined late-onset SLE as <50 years of age. We rated study quality using the Newcastle-Ottawa Quality Scale. We used Forest plots to compare odds ratios (95% confidence intervals) of pulmonary manifestations by age. Study heterogeneity was assessed using I².

RESULTS

Thirty-nine studies, representing 10,963 early-onset and 1656 late-onset patients with SLE, met eligibility criteria. The odds of developing several pulmonary manifestations were higher in the late-onset group. Interstitial lung disease (ILD) was nearly three times more common (OR = 2.56 (1.27, 5.16)). Pleuritis (OR = 1.53 (1.19, 1.96)) and serositis (OR = 1.31 (1.05, 1.65)) were also more common in the late-onset group. The mean Newcastle-Ottawa Quality Scale score for study quality was moderate (6.3 ± 0.7, scale 0-9).

CONCLUSIONS

Pulmonary manifestations of SLE were more common in late-onset SLE patients compared to their younger peers, in particular ILD and serositis. Age-related changes of the immune system, tobacco exposure, race, and possible overlap with Sjögren's syndrome should be examined in future studies.

A fatal case of diffuse alveolar hemorrhage as the initial presentation of systemic lupus erythematosus: A case report and literature review

Diffuse alveolar hemorrhage (DAH) is a rare fatal pulmonary complication of systemic lupus erythematosus (SLE). The clinical syndrome is characterized by hemoptysis, acute fall in hematocrit, hypoxemic respiratory failure, and diffuses pulmonary infiltrates. We describe a case of 23-year-old female who presented with Ludwig's angina that was complicated by diffuse alveolar hemorrhage as the initial presentation of undiagnosed systemic lupus erythematosus. A high index of suspicion is need for prompt diagnosis and treatment in order to avoid the high mortality associated with such cases.

Rare complicated parapneumonic effusion, Mycoplasma pneumoniae with new-onset lupus flare: Case report and literature review

Mycoplasma pneumoniae has been associated with respiratory tract infections. Mycoplasma pneumoniae pneumonia–related pleural effusion is rarely reported. Extra-pulmonary abnormalities such as encephalitis, myocarditis, glomerulonephritis, and myringitis have been reported. However pulmonary manifestations in systemic lupus erythematosus include pneumonitis, pleurisy, interstitial lung disease, and thromboembolic disease. We present the case of a 26-year-old male who came for evaluation of fever, cough, and shortness of breath with right-sided chest pain. He was found to have right-side loculated complicated parapneumonic effusion and underwent drainage with a pleural catheter followed by fibrinolytic therapy. He was then found to have new-onset systemic lupus erythematosus concomitant with Mycoplasma pneumonia, leading to lupus flare and lupus nephritis. He responded well to levofloxacin, steroids, hydroxychloroquine, and mycophenolate, with complete resolution of loculated pleural effusion and symptom improvement. Our case describes the rare combination of Mycoplasma pneumoniae pneumonia, parapneumonic pleural effusion, and lupus flare with lupus nephritis. Early identification and treatment can lead to better out come in young patients.

Pristane-induced lupus: considerations on this experimental model

Systemic lupus erythematosus (SLE) is a multifactorial, autoimmune inflammatory disease with pleomorphic clinical manifestations involving different organs and tissues. The etiology of this disease has been associated with a dysfunctional response of B and T lymphocytes against environmental stimuli in individuals genetically susceptible to SLE, which determines an immune response against different autoantigens and, consequently, tissue damage. The study of different murine models has provided a better understanding of these autoimmune phenomena. This review primarily focuses on that has been learned from the pristane-induced lupus (PIL) model and how this model can be used to supplement recent advances in understanding the pathogenesis of SLE. We also consider both current and future therapies for this disease. The PubMed, SciELO, and Embase databases were searched for relevant articles published from 1950 to 2016. PIL has been shown to be a useful tool for understanding the multiple mechanisms involved in systemic autoimmunity. In addition, it can be considered an efficient model to evaluate the environmental contributions and interferon signatures present in patients with SLE.

Experimental lupus is aggravated in mouse strains with impaired induction of neutrophil extracellular traps

Many effector mechanisms of neutrophils have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Neutrophil extracellular traps (NETs) have been assigned a particularly detrimental role. Here we investigated the functional impact of neutrophils and NETs on a mouse model of lupus triggered by intraperitoneal injection of the cell death-inducing alkane pristane. Pristane-induced lupus (PIL) was aggravated in 2 mouse strains with impaired induction of NET formation, i.e., NOX2-deficient (Ncf1-mutated) and peptidyl arginine deiminase 4-deficient (PAD4-deficient) mice, as seen from elevated levels of antinuclear autoantibodies (ANAs) and exacerbated glomerulonephritis. We observed a dramatically reduced ability to form pristane-induced NETs in vivo in both Ncf1-mutated and PAD4-deficient mice, accompanied by higher levels of inflammatory mediators in the peritoneum. Similarly, neutropenic Mcl-1ΔMyelo mice exhibited higher levels of ANAs, which indicates a regulatory function in lupus of NETs and neutrophils. Blood neutrophils from Ncf1-mutated and human individuals with SLE exhibited exuberant spontaneous NET formation. Treatment with specific chemical NOX2 activators induced NET formation and ameliorated PIL. Our findings suggest that aberrant NET is one of the factors promoting experimental lupus-like autoimmunity by uncontrolled release of inflammatory mediators.

Pathogenesis of Diffuse Alveolar Hemorrhage in Murine Lupus

OBJECTIVE

Diffuse alveolar hemorrhage (DAH) in lupus patients confers >50% mortality, and the cause is unknown. We undertook this study to examine the pathogenesis of DAH in C57BL/6 mice with pristane-induced lupus, a model of human lupus-associated DAH.

METHODS

Clinical/pathologic and immunologic manifestations of DAH in pristane-induced lupus were compared with those of DAH in humans. Tissue distribution of pristane was examined by mass spectrometry. Cell types responsible for disease were determined by in vivo depletion using clodronate liposomes and antineutrophil monoclonal antibodies (anti-Ly-6G). The effect of complement depletion with cobra venom factor (CVF) was examined.

RESULTS

After intraperitoneal injection, pristane migrated to the lung, causing cell death, small vessel vasculitis, and alveolar hemorrhage similar to that seen in DAH in humans. B cell-deficient mice were resistant to induction of DAH, but susceptibility was restored by infusing IgM. C3^-/- and CD18^-/- mice were also resistant, and DAH was prevented in wild-type mice by CVF. Induction of DAH was independent of Toll-like receptors, inflammasomes, and inducible nitric oxide. Mortality was increased in interleukin-10 (IL-10)-deficient mice, and pristane treatment decreased IL-10 receptor expression in monocytes and STAT-3 phosphorylation in lung macrophages. In vivo neutrophil depletion was not protective, while treatment with clodronate liposomes prevented DAH, which suggests that macrophage activation is central to DAH pathogenesis.

CONCLUSION

The pathogenesis of DAH involves opsonization of dead cells by natural IgM and complement followed by complement receptor-mediated lung inflammation. The disease is macrophage dependent, and IL-10 is protective. Complement inhibition and/or macrophage-targeted therapies may reduce mortality in lupus-associated DAH.

Serum interleukin-17 in Egyptian children with systemic lupus erythematosus: is it related to pulmonary affection?

Objective Pulmonary involvement in paediatric systemic lupus erythematosus (pSLE) is not an uncommon finding; however, subclinical affection occurs more frequently. Many studies have reported that cytokine dysregulation as interleukin-17 (IL-17) over-expression plays a key role in the pathogenesis of systemic lupus erythematosus (SLE). We aim to assess serum levels of IL-17 A and their association with pulmonary involvement in children with SLE. Methods Serum IL-17A levels - determined by solid phase sandwich ELISA - were assessed in forty-two pSLE patients and compared to 45 age-matched healthy controls. All patients were subjected to pulmonary function tests to detect subclinical pulmonary affection. High-resolution CT (HRCT) chest scan was carried out in patients with abnormal pulmonary function tests (PFTs) and those with chronic respiratory symptoms. Results Abnormal PFTs were found in 73% of patients; of them, only 25% had abnormal findings in HRCT chest. Serum levels of IL-17 A were significantly elevated in pSLE patients as compared to healthy controls ( p < 0.001). The serum levels of IL-17 A had a highly significant positive correlation with SLEDAI ( r = 0.811 and p < 0.001) Strong negative correlation was found between serum levels of IL-17A with both FEV1 and FVC ( p < 0.05). Conclusions Serum IL-17A is elevated in pSLE patients, which correlates with disease activity. IL-17 seems to have a possible role in the pathogenesis of subclinical lung affection. Abnormal PFTS may be found in pSLE patients even with normal radiology.

In Vivo Therapeutic Success of MicroRNA-155 Antagomir in a Mouse Model of Lupus Alveolar Hemorrhage

OBJECTIVE

Diffuse alveolar hemorrhage (DAH) is a rare but life-threatening complication of systemic lupus erythematosus (SLE). Pristane-treated B6 mice develop severe DAH within 2 weeks of treatment. MicroRNA-155 (miR-155) is a pleiotropic microRNA that plays a crucial role in the regulation of immune responses. Recent studies have revealed a pathogenic role of miR-155 in various autoimmune disorders. The purpose of this study was to examine the role of miR-155 in the development of DAH in pristane-induced lupus using miR-155-knockout (miR-155(-/-)) mice and miR-155 antagomir to silence miR-155.

METHODS

DAH was induced by an intraperitoneal injection of 0.5 ml of pristane. MicroRNA-155 antagomir was administered intravenously to silence miR-155 expression. Lung tissues were collected for RNA extraction and were embedded in paraffin for sectioning. Gene expression profiling data were analyzed using Ingenuity Pathway Analysis. Real-time quantitative polymerase chain reaction analysis was used for single-gene validation. Luciferase reporter assay and argonaute 2 immunoprecipitation were performed for target validation.

RESULTS

MicroRNA-155 expression was significantly increased during the development of DAH. Disease progression was reduced in miR-155(-/-) mice as well as by in vivo silencing of miR-155 using a miR-155 antagomir. MicroRNA-155 silencing dampened pristane-induced ectopic activation of multiple inflammatory pathways and reduced the expression of proinflammatory cytokines. Several negative regulators of NF-κB signaling were inhibited by pristane and were reactivated in miR-155(-/-) mice. In particular, the antiinflammatory factor peroxisome proliferator-activated receptor α was identified as a direct target of miR-155.

CONCLUSION

MicroRNA-155 promotes pristane-induced lung inflammation. It contributes to ectopic activation of NF-κB signaling pathways by targeting multiple negative regulators. MicroRNA-155 antagomir may be a promising therapeutic strategy for treating acute lung inflammation in lupus.

Systemic lupus erythematosus presenting as acute lupus pneumonitis in a young female

Acute lupus pneumonitis is a rare initial presentation of systemic lupus erythematosus (SLE). We report a 19-year-old female presenting with fever and recurrent hemoptysis with radiological evidence of parenchymal lung involvement with mild pleural effusion. Subsequent development of malar and discoid rash with anti-nuclear antibodies (ANA) and anti-dsDNA positivity clinched the diagnosis. Her clinical signs and symptoms resolved with a course of intravenous pulse methyl-prednisolone along with radiological resolution.

Organ involvement other than lupus nephritis in childhood-onset systemic lupus erythematosus

In this review we critically analyze pulmonary, gastrointestinal and cardiac manifestations of childhood-onset systemic lupus erythematosus (cSLE). Clinical manifestations of these organ systems may be the initial manifestation of cSLE; frequently occur with very active cSLE; and are potential life-threatening manifestations often presenting to the emergency department and requiring admission to the intensive care unit. Early recognition and treatment of the pulmonary, gastrointestinal and cardiac manifestations of cSLE will result in improved prognosis and better outcomes.

Connective tissue diseases, multimorbidity and the ageing lung

Connective tissue diseases encompass a wide range of heterogeneous disorders characterised by immune-mediated chronic inflammation often leading to tissue damage, collagen deposition and possible loss of function of the target organ. Lung involvement is a common complication of connective tissue diseases. Depending on the underlying disease, various thoracic compartments can be involved but interstitial lung disease is a major contributor to morbidity and mortality. Interstitial lung disease, pulmonary hypertension or both are found most commonly in systemic sclerosis. In the elderly, the prevalence of connective tissue diseases continues to rise due to both longer life expectancy and more effective and better-tolerated treatments. In the geriatric population, connective tissue diseases are almost invariably accompanied by age-related comorbidities, and disease- and treatment-related complications, which contribute to the significant morbidity and mortality associated with these conditions, and complicate treatment decision-making. Connective tissue diseases in the elderly represent a growing concern for healthcare providers and an increasing burden of global health resources worldwide. A better understanding of the mechanisms involved in the regulation of the immune functions in the elderly and evidence-based guidelines specifically designed for this patient population are instrumental to improving the management of connective tissue diseases in elderly patients.

Systemic lupus erythematosus: An update for ophthalmologists

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.