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

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.

The interplay between rheumatic diseases and pulmonary health

Patients with rheumatic diseases (RDs) are prone to a number of comorbidities, particularly those affecting the respiratory system due to inflammatory and autoimmune mechanisms. Rheumatoid arthritis (RA), systemic sclerosis (SSc), and inflammatory idiopathic myopathies (IIMs) often present with progressive interstitial lung disease (ILD). The prevalence of ILD varies among patients with RDs, with 11% in RA, 47% in SSc, and 41% in IIMs. Some diagnostic markers, including KL-6, cytokines TNF-α and IL-6, and autoantibodies (anti-CCP), play a crucial role in assessing and predicting the course of pulmonary involvement in RDs. Lung fibrosis is a progressive disorder in SSc and RA, limiting the effiency of therapeutic interventions. Re-evaluating treatment approaches with disease-modifying anti-rheumatic drugs (DMARDs) is crucial for understanding their impact on the risk of lung affections. Despite initial concerns surrounding methotrexate, recent evidence points to its benefits in RA-associated interstitial lung disease (RA-ILD). Recognizing the intricate relationship between autoimmune RDs and lung affections is crucial for formulating effective treatment strategies. Emphasis is placed on collaborative efforts of rheumatologists and pulmonologists for early diagnosis, comprehensive care, and optimal patient outcomes in RA-ILD.

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.

Case Report: In situ pulmonary artery thrombosis in a 12-year-old girl classified as systemic lupus erythematosus

In situ pulmonary artery thrombosis (ISPAT) is a relatively rare but potentially life-threatening complication of systemic lupus erythematosus (SLE) in children. We report the case of a 12-year-old girl who presented with fever, chest pain, and dyspnea. Immune thrombocytopenia was identified due to purpura and menorrhagia 3 months before presentation with a lowest platelet count of 12 × 109/L. The sudden onset of fever, chest pain, and dyspnea were misdiagnosed as hyperinflammatory responses caused by pneumonia; these symptoms ameliorated with glucocorticoid and antibiotic treatment. The reappearance of symptoms after dose reduction of glucocorticoids and the observation of bloody bronchoalveolar lavage fluid necessitated further evaluation. Pulmonary artery thrombosis/embolism was identified using computed tomography pulmonary angiography and high D-dimer quantitative level of 4,118 μg/L (normal <252 μg/L). Ultrasonography of the deep and superficial veins of both lower limbs and renal veins revealed no thrombosis, suggesting the diagnosis of ISPAT. Further etiological evaluation revealed positive antinuclear antibodies, lupus anticoagulant, and anti-SSA antibodies, confirming SLE. Repeated normal urine analysis indicated that lupus nephritis was unlikely. Further, the negative anticardiolipin and anti-β2 glycoprotein antibodies and temporary positive lupus anticoagulant suggested that antiphospholipid syndrome was unlikely. The patient received anticoagulants, glucocorticoids, hydroxychloroquine, and mycophenolate therapy. Her symptoms gradually improved, and she was discharged. At the 1-month follow-up, the thrombosis had resolved. During the 1-year follow-up, her condition remained well without SLE relapse. Our experience with this case emphasizes searching for SLE in the case of ISPAT and pulmonary hemorrhages. ISPAT can occur in children with SLE and may be caused by hyperinflammatory response during SLE flare.

Lymphoid interstitial pneumonia in a patient with systemic lupus erythematosus: Case report and literature review

Lymphoid interstitial pneumonia (LIP) is a rare form of interstitial pulmonary disease, which has been described in association with a wide range of autoimmune disorders. Although the association of this entity with Sjogren's syndrome is well known, only a few cases are reported in relation to systemic lupus erythematosus (SLE). The aim of this paper is to review the cases reported in literature to date, as well as to describe the characteristics of these patients including the new case presented herein. We will be focusing on the case of a 36-year-old female patient diagnosed with SLE on hydroxychloroquine treatment who develops pleuritic chest pain and progressive dyspnea after 3 years of follow-up. The chest CT scan showed pleural thickening and both multiple and bilateral micronodules. A lung biopsy was also performed, revealing an infiltration of lymphocytes, plasma cells, and histiocytes in the alveolar septa suggestive of LIP. After conducting a review of the literature, we identified seven other cases describing SLE in association with LIP. The majority of them were young women, and LIP tends to appear early in the course of the disease, even as a form of initial presentation in some cases. Symptoms included cough, dyspnea, and pleuritic pain, with the exception of one case which was asymptomatic. It is noteworthy that half of the patients were positive for anti-SSA/anti-SSB autoantibodies, and some of them also met criteria for Sjogren's syndrome. Treatment with steroids and other immunosuppressive agents improved symptoms in all of them.

Acute lupus pneumonitis resembling miliary tuberculosis: A case-based review

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple systems and organs, with pulmonary involvement known to be associated with disease prognosis and mortality. Acute lupus pneumonitis (ALP) resembling miliary tuberculosis (TB) is rare. Here, we present a case of ALP mimicking miliary TB and review the literature. A 19-year-old male student was referred to our hospital with fever. Although the patient met the diagnostic criteria for SLE, diffuse miliary nodules in both lungs were observed on a chest computed tomography scan. A series of tests, including pathological testing of bronchoscopy brushes, T-lymphocyte culture + interferon assay (A + B), tuberculin test, detection of mycobacterium TB DNA, and acid-fast bacilli smear in bronchoalveolar lavage fluid, were unable to confirm the presence of TB infection. We considered the patient to have ALP. After beginning ALP therapy, his symptoms disappeared, and the imaging and hematological results returned to normal. Miliary TB and ALP have similar clinical manifestations and imaging changes, which make diagnosis difficult. This case highlights the need to ensure accurate diagnosis and treatment to improve prognosis.

Pleural clinic: where thoracic ultrasound meets respiratory medicine

Thoracic ultrasound (TUS) has become an essential procedure in respiratory medicine. Due to its intrinsic safety and versatility, it has been applied in patients affected by several respiratory diseases both in intensive care and outpatient settings. TUS can complement and often exceed stethoscope and radiological findings, especially in managing pleural diseases. We hereby aimed to describe the establishment, development, and optimization in a large, tertiary care hospital of a pleural clinic, which is dedicated to the evaluation and monitoring of patients with pleural diseases, including, among others, pleural effusion and/or thickening, pneumothorax and subpleural consolidation. The clinic was initially meant to follow outpatients undergoing medical thoracoscopy. In this scenario, TUS allowed rapid and regular assessment of these patients, promptly diagnosing recurrence of pleural effusion and other complications that could be appropriately managed. Over time, our clinic has rapidly expanded its initial indications thus becoming the place to handle more complex respiratory patients in collaboration with, among others, thoracic surgeons and oncologists. In this article, we critically describe the strengths and pitfalls of our "pleural clinic" and propose an organizational model that results from a synergy between respiratory physicians and other professionals. This model can inspire other healthcare professionals to develop a similar organization based on their local setting.

Shrinking lung syndrome in primary Sjögren's syndrome: a case-based review

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that affects exocrine glands, mainly the salivary and lacrimal glands, leading to the development of sicca symptoms. Patients with pSS may also present with extraglandular manifestations, including lung involvement, estimated to occur in 9-24% of cases. Shrinking lung syndrome (SLS) is an uncommon respiratory complication primarily associated with systemic lupus erythematosus, with a prevalence of approximately 1% in these patients. It typically manifests as dyspnea, pleuritic chest pain, lung volume reduction, and a restrictive pattern on respiratory function tests. Cases reporting SLS with other connective tissue diseases, including pSS, are even rarer. Herein, we describe a case of a 57-year-old woman with a 10-year history of pSS who presented with dyspnea and pleuritic chest pain. After evaluation, the patient was diagnosed with SLS based on clinical, radiologic, laboratorial, and electrophysiologic characteristics. In addition, we identified and analyzed previously published cases of SLS in pSS. Treatment includes corticosteroids, immunosuppressants, and respiratory muscle training. This study highlights the importance of considering SLS in the differential diagnosis of patients with pSS and respiratory symptoms.

Learnings from clinical trials in patients with connective tissue disease-associated interstitial lung disease

Many clinical trial results are available to inform best practices in the treatment of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD).Herein, we summarize the results of clinical trials, including patient-reported outcome instruments, for the treatment of patients with ILD associated with systemic sclerosis (SSc/scleroderma), rheumatoid arthritis, and idiopathic inflammatory myositis, the diseases with the most available data. For SSc-ILD, the US Food and Drug Administration approved nintedanib (a tyrosine kinase inhibitor) in 2020 and subcutaneous tocilizumab (an IL-6 receptor monoclonal antibody) in 2021. Rituximab was recently shown to have similar efficacy but better tolerability than intravenous cyclophosphamide (CYC) for CTD-ILD therapy. Scleroderma Lung Study II, conducted in patients with SSc-ILD, showed that oral CYC and mycophenolate mofetil (MMF) were comparable in their effects on lung function, but MMF was better tolerated. The increasing treatment armamentarium for patients with CTD-ILD offers physicians new opportunities to improve patient outcomes.

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.

Systemic Lupus Erythematosus and Pulmonary Hypertension

Pulmonary Hypertension (PH) is a common manifestation in patients with Systemic Lupus Erythematosus (SLE) and varies from asymptomatic to life-threatening disease. PH can result not only from immune system dysregulation, but also from various conditions, including cardiorespiratory disorders and thromboembolic diseases. Most commonly, SLE-related PH presents with non-specific symptoms, such as progressive dyspnea on exertion, generalized fatigue and weakness and eventually dyspnea at rest. Prompt diagnosis of SLE-related PH and early identification of the underlying pathogenetic mechanisms is demanded in order to introduce targeted therapy to prevent irreversible pulmonary vascular damage. In most cases the management of PH in SLE patients is similar to idiopathic pulmonary arterial hypertension (PAH). Furthermore, specific diagnostic tools like biomarkers or screening protocols, to establish early diagnosis seem to be not available yet. Although, the survival rates for patients with SLE-related PH vary between studies, it is evident that PH presence negatively affects the survival of SLE patients.

Unusual presentation of systemic lupus erythematosus as hemophagocytic lymphohistiocytosis in a female patient: A case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disorder, often resulting in the immune-mediated injury of multiple organ systems, including primary HLH and secondary HLH (sHLH). Among them, sHLH results from infections, malignant, or autoimmune conditions, which have quite poor outcomes even with aggressive management and are more common in adults.

CASE SUMMARY

We report a rare case of a 36-year-old female manifested with sHLH on background with systemic lupus erythematosus (SLE). During hospitalization, the patient was characterized by recurrent high-grade fever, petechiae and ecchymoses of abdominal skin, and pulmonary infection. Whole exon gene sequencing revealed decreased activity of natural killer cells. She received systematic treatment with Methylprednisolone, Etoposide, and anti-infective drugs. Intravenous immunoglobulin and plasmapheresis were applied when the condition was extremely acute and progressive. The patient recovered and did not present any relapse of the HLH for one year of follow-up.

CONCLUSION

The case showed sHLH, thrombotic microvascular, and infection in the whole course of the disease, which was rarely reported by now. The treatment of the patient emphasizes that early recognition and treatment of sHLH in SLE patients was of utmost importance to improve the prognosis and survival rate of patients.

Post-partum Fever of Unknown Origin: An Inaugural Flare of Severe Lupus With Multisystemic Involvement and Hemophagocytic Syndrome

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect almost every organ. Lupus protein-losing enteropathy (PLE) is one of the rarest manifestations of gastrointestinal involvement. Lupus flare as initial presentation is rare and the disease can act as a trigger to other pathologic immune syndromes like Hemophagocytic Lymphohistiocytosis (HLH), although this association is rare. We report the case of a previously healthy African 39-year-old female patient, with a recent history of cesarean section. Admitted to the Emergency Department (ED) with diffuse abdominal pain and fever, having completed a cycle of antibiotic therapy for initially suspected endometritis. The clinical picture progressed with sustained high fever, new-onset lymphadenopathies, systemic rash, acute pulmonary edema and seizures. Laboratory findings included hyperferritinemia, hypertriglyceridemia, proteinuria and hypoalbuminemia. The auto-immune panel was positive for antinuclear antibodies (ANA), anti-dsDNA, anti-SSA and anti-SSB, anti-PL7, anti-RNP, anti-U1-SnRNP, and anti-Pm-Scl75. She also presented hypocomplementemia. An inaugural flare of SLE with multisystemic involvement and concomitant secondary Hemophagocytic Syndrome was considered and therapy with methylprednisolone pulses, Anakinra and Cyclophosphamide was started. By the end of the first cycle of cyclophosphamide, the patient presented clinical worsening with abdominal pain recrudescence and profuse diarrhea. After the exclusion of an infectious process, a Lupus PLE was assumed and Cyclophosphamide protocol was resumed, with sustained clinical improvement after the induction protocol. Despite initially suspected gynecological infection, the clinical progression with multisystemic involvement together with the auto-immune panel made the diagnosis of SLE possible, with other laboratory findings raising the suspicion of HLH. This case represents a rare report of severe SLE with multiple organ involvement accompanied by HLH. Gastrointestinal involvement with PLE added rarity and morbidity to the clinical picture. The case reinforces the idea that when organ dysfunction is due to a severe autoimmune response, supportive treatment can be lifesaving until immunosuppressive drugs reach their full effect.

Delphi-Based Consensus on Interstitial Lung Disease Screening in Patients with Connective Tissue Diseases (Croatian National-Based Study)

The aim of this study was to develop a Croatian Delphi-based expert consensus for screening interstitial lung disease (ILD) associated with connective tissue disease (CTD). A systematic literature review was conducted on risk factors for the development of ILD, prevalence and incidence of ILD, diagnostic and screening methods for ILD, and prognosis of ILD in idiopathic inflammatory myopathy (IIM), mixed connective tissue disease (MCTD), primary Sjögren's syndrome (pSS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and systemic sclerosis (SSc) were performed. Based on the evidence found, experts developed questionnaires for screening and monitoring ILD in each CTD, which were provided via an online survey. Following the electronic survey, two screening algorithms were developed based on the consensus opinions. The detection strategy for ILD included high-resolution computed tomography (HRCT) in addition to pulmonary function testing for IIM, MCTD, and SSc. and pulmonary function testing for newly diagnosed pSS, RA and SLE. However, in patients with identified risk factors for ILD HRCT, these tests should also be performed. A screening strategy for early identification of patients with various CTD-ILD was first developed by a multidisciplinary team of rheumatologists, pulmonologists, and radiologists to identify early CTD patients at risk of ILD, a severe extra-articular manifestation of CTD.

Sexual Dimorphism in Interstitial Lung Disease

Interstitial lung diseases (ILD) are a group of heterogeneous progressive pulmonary disorders, characterised by tissue remodelling and/or fibrotic scarring of the lung parenchyma. ILD patients experience lung function decline with progressive symptoms, poor response to treatment, reduced quality of life and high mortality. ILD can be idiopathic or associated with systemic or connective tissue diseases (CTD) but idiopathic pulmonary fibrosis (IPF) is the most common form. While IPF has a male predominance, women are affected more greatly by CTD and therefore associated ILDs. The mechanisms behind biological sex differences in these progressive lung diseases remain unclear. However, differences in environmental exposures, variable expression of X-chromosome related inflammatory genes and sex hormones play a role. Here, we will outline sex-related differences in the incidence, progression and mechanisms of action of these diseases and discuss existing and novel cellular and pre-clinical studies. Furthermore, we will highlight how sex-differences are not adequately considered in pre-clinical disease models, how gender bias exists in clinical diagnosis and how women are underrepresented in clinical trials. Future action on these observations will hopefully shed light on the role of biological sex in disease development, identify potential targets for intervention and increase female participant numbers in clinical trials.

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.

Diagnosis of systemic lupus erythematosus with early manifestation of an eosinophilic pleural effusion

A woman in her 70s with a history of Crohn's disease presented to the emergency department with dyspnoea, cough and intermittent fevers. Evaluation revealed a pleural effusion with neutrophil predominance, and initial suspicion of infection prompted a short course of antibiotic therapy. However, the patient subsequently developed recurrent pleural effusion with eosinophilic predominance. Serological data confirmed a diagnosis of systemic lupus erythematosus (SLE) and the patient was started on appropriate treatment.This case presents an initial manifestation of eosinophilic-dominant pleural effusion in SLE. Current guidelines in treating pleural effusions do not explore rheumatological causes. However, we believe that our case demonstrates the value of a prompt investigation for rheumatological aetiologies in an otherwise unclassified eosinophilic-predominant pleural effusion. Such an investigation should include serological data as an important confirmatory marker for the diagnosis of SLE.

Cathepsin S Inhibition Suppresses Experimental Systemic Lupus Erythematosus-Associated Pulmonary Arterial Remodeling

Patients with systemic lupus erythematosus (SLE) associated with pulmonary arterial hypnertension (PAH) receive targeted therapy for PAH to decrease pulmonary arterial systolic pressure and significantly prolong their survival. Cysteine cathepsin proteases play critical roles in the progression of cardiovascular disease. Inhibition of cathepsin S (Cat S) has been shown to improve SLE and lupus nephritis. However, the effect of Cat S inhibitors on SLE-associated PAH (SLE-PAH) remains unclear, and there is no animal model for translational research on SLE-PAH. We hypothesized that the inhibition of Cat S may affect PAH development and arterial remodeling associated with SLE. A female animal model of SLE-PAH, female MRL/lpr (Lupus), was used to evaluate the role of pulmonary arterial remodeling in SLE. The key finding of the research work is the establishment of an animal model of SLE associated with PAH in female MRL/lpr mice that is able to evaluate pulmonary arterial remodeling starting from the age of 11 weeks to 15 weeks. Cat S protein level was identified as a marker of experimental SLE. Pulmonary hypertension in female MRL/lpr (Lupus) mice was treated by administering the selective Cat S inhibitor Millipore-219393, which stimulated peroxisome proliferator-activated receptor-gamma (PPARγ) in the lungs to inhibit Cat S expression and pulmonary arterial remodeling. Studies provide an animal model of female MRL/lpr (Lupus) associated with PAH and a deeper understanding of the pathogenesis of SLE-PAH. The results may define the role of cathepsin S in preventing progressive and fatal SLE-PAH and provide approaches for therapeutic interventions in SLE-PAH.

Treating Autoimmune-Related Interstitial Lung Disease With B Cell Depletion

Autoimmune rheumatic diseases may affect vital organs with lung involvement being severe and difficult to treat manifestation. Systemic sclerosis (SSc) commonly affects the lung in the form of interstitial lung disease (ILD). ILD may be also seen in patients with rheumatoid arthritis (RA), Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), inflammatory myositis (IM), antisynthetase syndrome (AS), and the ANCA-associated vasculitides (AAV). Rituximab (RTX) is an anti-CD20 B lymphocyte depleting mAb, often administered in the treatment of autoimmune rheumatic diseases. Although RTX is an off-label treatment for CTD–ILD, there are numerous reports providing data that is effective in improving both pulmonary function tests (PFTs) and chest computed tomography findings consistent with ILD. There are retrospective uncontrolled studies that assess RTX as a treatment of ILD in autoimmune diseases. These studies, apart from one, do not include patients with AAV-ILD. In SSc-ILD, in particular, there are both controlled and uncontrolled studies displaying encouraging results following B cell depletion. In addition, a number of retrospective uncontrolled studies and fewer prospective studies evaluate RTX in connective tissue diseases CTD–ILD. Although RTX is an approved treatment for AAV there are scarce only data focusing on patients with AAV-ILD specifically. The results of a handful of studies comparing treatment of CTD-ILD with RTX to treatment with other agents are in favor of RTX. Results from large, still ongoing controlled trials are awaited to ascertain RTX effects in ILD encountered in autoimmune rheumatic diseases. We review herein the results of the different RTX trials in patients with autoimmune disease–associated with ILD. Despite the heterogeneity of these studies, RTX may be considered an alternative and safe but still off-label treatment for patients with refractory CTD–ILD.

Clinical and radiological features of lung disorders related to connective-tissue diseases: a pictorial essay

Connective tissue diseases (CTDs) include a spectrum of disorders that affect the connective tissue of the human body; they include autoimmune disorders characterized by immune-mediated chronic inflammation and the development of fibrosis. Lung involvement can be misdiagnosed, since pulmonary alterations preceded osteo-articular manifestations only in 20% of cases and they have no clear clinical findings in the early phases. All pulmonary structures may be interested: pulmonary interstitium, airways, pleura and respiratory muscles. Among these autoimmune disorders, rheumatoid arthritis (RA) is characterized by usual interstitial pneumonia (UIP), pulmonary nodules and airway disease with air-trapping, whereas non-specific interstitial pneumonia (NSIP), pulmonary hypertension and esophageal dilatation are frequently revealed in systemic sclerosis (SSc). NSIP and organizing pneumonia (OP) may be found in patients having polymyositis (PM) and dermatomyositis (DM); in some cases, perilobular consolidations and reverse halo-sign areas may be observed. Systemic lupus erythematosus (SLE) is characterized by serositis, acute lupus pneumonitis and alveolar hemorrhage. In the Sjögren syndrome (SS), the most frequent pattern encountered on HRCT images is represented by NSIP; UIP and lymphocytic interstitial pneumonia (LIP) are reported with a lower frequency. Finally, fibrotic NSIP may be the interstitial disease observed in patients having mixed connective tissue diseases (MCTD). This pictorial review therefore aims to provide clinical features and imaging findings associated with autoimmune CTDs, in order to help radiologists, pneumologists and rheumatologists in their diagnoses and management.

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.

Choosing pharmacotherapy for ILD in patients with connective tissue disease

Interstitial lung disease (ILD) is a well-recognised complication of several connective tissue diseases (CTD). This article outlines the various treatment options for the most common CTD-ILDs and discuss the ongoing research in this field. https://bit.ly/39NHwx6.

Role of autoantibodies in the diagnosis and prognosis of interstitial lung disease in autoimmune rheumatic disorders

Interstitial lung disease (ILD) has been recognized as a frequent manifestation associated with a substantial morbidity and mortality burden in patients with autoimmune rheumatic disorders. Serum autoantibodies are considered good biomarkers for identifying several subsets or specific phenotypes of ILD involvement in these patients. This review features the role of several autoantibodies as a diagnostic and prognostic biomarker linked to the presence ILD and specific ILD phenotypes in autoimmune rheumatic disorders. The case of the diverse antisynthetase antibodies in the antisynthease syndrome or the anti-melanoma differentiation-associated 5 protein (MDA5) antibodies as a marker of a severe condition such as rapidly progressive ILD in patients with clinically amyopathic dermatomyositis are some of the associations herein reported in the group of myositis spectrum disorders. Specific autoantibodies such as the well-known anti-topoisomerase I (anti-Scl70) or the anti-Th/To, anti-U11/U12 ribonucleoprotein, and anti-eukaryotic initiation factor 2B (eIF2B) antibodies seems to be specifically linked to ILD in patients with systemic sclerosis. Overlap syndromes between systemic sclerosis and myositis, also have good ILD biomarkers, which are the anti-PM/Scl and anti-Ku autoantibodies. Lastly, other not so often reported disorders as being associated with ILD but recently most recognized as is the case of rheumatoid arthritis associated ILD or entities herein included in the miscellaneous disorders section, which include anti-neutrophil cytoplasmic antibody-associated interstitial lung disease, Sjögren's syndrome or the mixed connective tissue disease, are also discussed.