Histopathology and bronchoalveolar lavage

Mediators of systemic sclerosis-associated interstitial lung disease (SSc-ILD): systematic review and meta-analyses

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is rare, poorly understood, with heterogeneous characteristics resulting in difficult diagnosis. We aimed to systematically review evidence of soluble markers in peripheral blood or bronchoalveolar lavage fluid (BALF) as biomarkers in SSc-ILD.

METHOD

Five databases were screened for observational or interventional, peer-reviewed studies in adults published between January 2000 and September 2021 that assessed levels of biomarkers in peripheral blood or BALF of SSc-ILD patients compared with healthy controls. Qualitative assessment was performed using Critical Appraisal Skills Programme (CASP) checklists. Standardised mean difference (SMD) in biomarkers were combined in random-effects meta-analyses where multiple independent studies reported quantitative data.

RESULTS

768 published studies were identified; 38 articles were included in the qualitative synthesis. Thirteen studies were included in the meta-analyses representing three biomarkers: KL6, SP-D and IL-8. Greater IL-8 levels were associated with SSc-ILD in both peripheral blood and BALF, overall SMD 0.88 (95% CI 0.61 to 1.15; I2=1%). Greater levels of SP-D and KL-6 were both estimated in SSc-ILD peripheral blood compared with healthy controls, at an SMD of 1.78 (95% CI 1.50 to 2.17; I2=8%) and 1.66 (95% CI 1.17 to 2.14; I2=76%), respectively.

CONCLUSION

We provide robust evidence that KL-6, SP-D and IL-8 have the potential to serve as reliable biomarkers in blood/BALF for supporting the diagnosis of SSc-ILD. However, while several other biomarkers have been proposed, the evidence of their independent value in diagnosis and prognosis is currently lacking and needs further investigation.

PROSPERO REGISTRATION NUMBER

CRD42021282452.

Everolimus targeted nanotherapy reduces inflammation and fibrosis in scleroderma-related interstitial lung disease (SSc-ILD) developed by PSGL-1 deficient mice

BACKGROUND AND PURPOSE

Interstitial lung disease (ILD) is the main cause of mortality in systemic sclerosis (SSc) and current therapies available are of low efficacy or high toxicity. Thus, the identification of innovative less toxic and high efficacy therapeutic approaches to ILD treatment is a crucial point. P-selectin Glycoprotein Ligand-1 (PSGL-1) interaction with P-selectin initiates leukocyte extravasation and the lack of its expression brings to SSc-like syndrome with high incidence of ILD in aged mice.

EXPERIMENTAL APPROACH

Aged PSGL-1^-/- mice were used to assay the therapeutic efficacy of an innovative nanotherapy with everolimus (Ev), included in liposomes decorated with high MW hyaluronic acid (LipHA+Ev) and administrated intratracheally to specifically target CD44-expressing lung cells.

KEY RESULTS

PSGL-1^-/- mice had increased number of CD45+ and CD45- cells, including alveolar and interstitial macrophages, eosinophils, granulocytes and NK cells, and elevated number of myofibroblasts in broncoalveolar lavage (BAL). CD45+ and CD45- cells expressing proinflammatory and profibrotic cytokines were also increased. PSGL-1^-/- mice lung histopathology showed increased immune cell infiltration and apoptosis and exacerbated interstitial and peribronchial fibrosis. Targeted nanotherapy with LipHA+Ev reduced BAL number of myofibroblast, cells producing proinflammatory and profibrotic cytokines, and the degree of lung inflammation at histology. LipHA+Ev treatment also provided an important decrease in severity of peribronchial and interstitial lung fibrosis from moderate to mild injury score.

CONCLUSIONS AND IMPLICATIONS

Our preclinical study in PSGL-1^-/- mice indicates that targeted nanotherapy with LipHA+Ev represents an effective treatment for SSc-ILD, reducing the number of inflammatory and fibrotic cells in BAL and reducing inflammation and fibrosis in lungs.

The Role of the Multidisciplinary Health Care Team in the Management of Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterised by immune dysfunction, vascular damage and fibrosis affecting the skin and multiple internal organs. The clinical spectrum of SSc is wide and its manifestations may lead to severe morbidity and mortality, in addition to a great impact on patients' quality of life. Due to the multifaceted clinical manifestations of SSc, its management requires a combined expertise of different medical specialists to guarantee an adequate disease control and prevent organ complications. Multi-disciplinary teams (MDT), which are composed by physicians and other specialized health professionals, represent therefore a key element for the comprehensive management of SSc patients. Moreover, MTD can improve communication and patients' empowerment while the presence of dedicated nurses can help patients to ask questions about their condition. The scope of this narrative review is to analyse the available evidences regarding the role of MDT in the management of SSc patients, and how this holistic approach may improve different disease domains and the overall prognosis. MDT regarding the cardiovascular and lung complication are the more represented in literature, given the great impact in prognosis. Nonetheless, MDT have been shown to be fundamental also in other disease domains as they can intercept early manifestations, thus stratifying patients based on the individual risks in order to personalize patients' follow-up. MDTs may also minimize the treatment delay, enabling fast-track specialist referral. On the other hand, there are few trials specifically studying MDT in SSc and several authors have highlight the lack of standardization.

Caveolin-1 as a critical component in the pathogenesis of lung fibrosis of different etiology: Evidences and mechanisms

Caveolin is a structural protein of flask-shaped invaginations of the plasma membrane termed as caveolae and is widely expressed on the endothelial cells, smooth muscle cells and fibroblasts in the different parts of the body including the lung tissues. The expression of caveolin-1 in the lung tissues is important to prevent the fibrogenic actions of TGF-β1 in lung fibrosis of different etiology including idiopathic pulmonary fibrosis, systemic sclerosis-associated interstitial lung disease and allergen-induced airway remodeling. Caveolin-1-mediated internalization and degradation of TGF-β1 receptors may possibly account for the decreased actions of TGF-β1. Studies have shown that the deficiency of caveolin-1 is very important in inducing lung fibrosis and its upregulation is reported to prevent lung fibrosis. The biological actions of caveolin-1 involve signaling pathways including JNK signaling, IL-4, STAT-3, miR199a-5p, CXCR4⁺ and CXCL12. The present review discusses the key role of caveolin and associated signaling pathways in the pathogenesis of lung fibrosis of different etiology.

Prognostic Role of Exhaled Breath Condensate pH and Fraction Exhaled Nitric Oxide in Systemic Sclerosis Related Interstitial Lung Disease

INTRODUCTION

Interstitial lung disease (ILD) is one of the major causes of death in systemic sclerosis (SSc). This study investigated exhaled breath (EB) and exhaled breath condensate (EBC) biomarkers in patients with SSc and analyzed their role as a prognostic tool in SSc-related ILD.

METHODS

Fraction exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) measured in EB, together with pH, nitrite, nitrate and interleukin-6 levels measured in EBC were prospectively analyzed in 35 patients with SSc. Twelve patients had established ILD by chest high-resolution computed tomography (HRCT), and 23 patients showed no evidence of ILD. EB and EBC biomarkers were determined at inclusion, and pulmonary function tests were annually performed during 4 years of follow-up.

RESULTS

No differences at baseline biomarkers levels were found between groups. In all patients studied, low EBC pH levels were associated with a decreased diffusing capacity for carbon monoxide (DLCO) during follow-up. Low FeNO levels were correlated with lower forced vital capacity (FVC) at baseline, 4years of follow-up and with a decrease in FVC and DLCO during monitoring. Among ILD patients, high eCO levels were correlated with lower baseline FVC. In the global cohort, a worse progression-free survival was identified in patients with EBC pH values lower than 7.88 and FeNO levels lower than 10.75ppb (Log Rank P=.03 and P<.01, respectively).

CONCLUSIONS

EB and EBC could help to detect patients likely to present a deterioration on lung function during follow up.

Recent advances in understanding the pathogenesis of scleroderma-interstitial lung disease

Systemic sclerosis (scleroderma, SSc) is a heterogeneous autoimmune connective tissue disease of unknown etiology. Interstitial lung disease (ILD) is a frequent complication, and a significant contributor to morbidity and mortality among SSc patients. SSc-ILD most commonly occurs within 10 years of diagnosis, and may be seen in patients with either the limited or diffuse cutaneous subset of SSc. SSc-ILD is a multifaceted disease process in which different factors and pathways are involved. Aberrant function of a variety of lung cells, cytokines, growth factors, peptides, and bioactive proteins, in combination with genetic and epigenetic regulators, have crucial functions in the pathogenesis of this disease. Here we present our view on recent advances regarding the pathogenesis of SSc-ILD.

Paraquat-induced pulmonary fibrosis starts at an early stage of inflammation in rats

AIM

To investigate the starting point of paraquat-induced pulmonary fibrosis in rats.

MATERIALS & METHODS

A total of 96 healthy Sprague-Dawley rats were randomly divided into eight groups (n = 12 in each group) including a control and paraquat-poisoning group. Control rats received treatment with saline. Samples were collected at 2, 6, 12, 24, 48, 72 and 120 h after paraquat administered by lavage. All lung tissues were stained with hematoxylin-eosin and Masson's trichrome. Collagen III expressed in bronchoalveolar lavage fluid was detected by ELISA. The α-smooth muscle actin in lung tissue was detected by western blotting.

RESULTS

A rat model of paraquat poisoning was established. Histological examination results indicated that lung fibrosis started in rats 2 h after paraquat poisoning. Compared with the control group, the collagen III protein in bronchoalveolar lavage fluid was significantly upregulated in the 2-h group (α = 0.05) and the same level was maintained in the other poisoning groups. The expression of α-smooth muscle actin in the lung tissue was significantly increased in the 12-h group (α = 0.05) and remained at the same level after 12 h.

CONCLUSION

The paraquat-induced pulmonary fibrosis in rats began at an early stage of inflammation. The therapy of antifibrosis should be applied at an early time of paraquat poisoning.

NO-releasing xanthine KMUP-1 bonded by simvastatin attenuates bleomycin-induced lung inflammation and delayed fibrosis

BACKGROUND AND PURPOSE

Pulmonary fibrosis (PF) is a progressing lung injury initiated by pulmonary inflammation (PI). Bleomycin (BLM) is the most common pathogenesis of PF through early PI and extensive extracellular matrix deposition. This study is aimed to determine whether NO-releasing KMUP-1 inhibits PI and PF, and if so, the benefits of KMUP-1S resulted from simvastatin (SIM)-bonding to KMUP-1.

EXPERIMENT APPROACH

C57BL/6 male mice were intra-tracheally administered BLM (4 U/kg) at day 0. KMUP-1 (1-5 mg/kg), KMUP-1S (2.5 mg/kg), SIM (5 mg/kg), Plus (KMUP-1 2.5 mg/kg + SIM 2.5 mg/kg), and clarithromycin (CAM, 10 mg/kg) were orally and daily administered for 7 and 28 days, respectively, to mice, sacrificed at day-7 and day-28 to isolate the lung tissues, for examining the inflammatory and fibrotic signaling and measuring the cell population and MMP-2/MMP-9 activity in broncholaveolar lavage fluid (BAL).

KEY RESULTS

KMUP-1 and KUP-1S significantly decreased neutrophil counts in BAL fluid. Fibroblastic foci were histologically assessed by H&E and Masson's trichrome stain and treated with KMUP-1 and references. Lung tissues were determined the contents of collagen and the expressions of TGF-β, α-SMA, HMGB1, CTGF, eNOS, p-eNOS, RhoA, Smad3, p-Smad3, MMP-2 and MMP-9 by Western blotting analyses, respectively. These changes areregulated by NO/cGMP and inhibited by various treatments. KMUP-1 and KMUP-1S predominantly prevented HMGB1/MMP-2 expression at day-7 and reduced TGF-β/phosphorylated Smad3 and CTGF at day-28.

CONCLUSIONS AND IMPLICATIONS

KMUP-1 and KMUP-S restore eNOS, inhibit iNOS/ROCKII/MMP-2/MMP-9, attenuate histologic collagen disposition and reduce BALF inflammatory cells, potentially useful for the treatment of BLM-lung PF.

Pathogenesis of pulmonary fibrosis in systemic sclerosis: lessons from interstitial lung disease

Interstitial lung disease is a frequent complication of systemic sclerosis and currently is the leading cause of death. Our ability to predict which individuals are at greatest risk of developing clinically significant, progressive interstitial lung disease remains inadequate. Identification of circulating autoantibodies and other biomarkers, as well as genetic polymorphisms and aberrant gene expression, all hold promise as diagnostic and prognostic tools, as well as therapeutic targets. Many practice patterns for the diagnosis and monitoring of connective tissue disease-associated interstitial lung disease are based upon published experience with idiopathic interstitial lung diseases. Although there are likely commonalities in the pathophysiologic mechanisms and clinical progression among all fibrosing lung diseases, a better understanding of features unique to systemic sclerosis-associated interstitial lung disease is essential to the development of more effective monitoring and treatment strategies.

Present status of bronchoalveolar lavage in interstitial lung disease

PURPOSE OF REVIEW

Sampling the detachable cells and acellular lining secretions of the human respiratory tract by bronchoalveolar lavage (BAL) is a means of obtaining relevant components from the airways and alveolar areas for research use and clinical analysis in normals (controls) and patients with a wide spectrum of interstitial lung diseases (ILDs). This review attempts to discuss recent findings from BAL studies that provide insight into pathogenic mechanisms of ILDs and/or assist in diagnosing disease activity.

RECENT FINDINGS

BAL analysis and usefulness are reviewed for the major forms of ILDs. In addition, some perspective about this sampling method is given and the context for BAL is provided for the respective disease, either for diagnosis or research use.

SUMMARY

Whereas BAL findings continue to impact on understanding disease pathogenesis and this may be its major use now, BAL fluid components, cells in particular, are not correlated well with activity of disease nor for monitoring disease progress or response to treatment. For a few rarer ILDs, BAL fluid characteristics may strongly support a diagnosis.

[Interstitial lung disease in collagen vascular diseases. Diagnostic and therapeutic implications of non-specific interstitial pneumonia]

Interstitial lung disease (ILD) is among the most common organ manifestations in collagen vascular diseases and can be a major determinant of the long-term prognosis. Early diagnosis rests mainly on spirometry, including measurement of the CO diffusion capacity, and high-resolution computed tomography (HRCT). The most common histopathology of ILD in collagen vascular diseases is the non-specific interstitial pneumonia (NSIP) pattern. It is distinguished from the usual interstitial pneumonia (UIP) pattern, which is most common in idiopathic lung fibrosis, by a significant inflammatory component, a distinct HRCT pattern, with often prominent ground-glass opacities, and a distinct cell pattern on bronchoalveolar lavage (BAL) with an often prominent lymphocyte component. Therapeutic experience is heterogeneous but evidence is accumulating suggesting that NSIP in the collagen vascular diseases is amenable to immunosuppression. Rapid clinical and/or radiological deterioration, reflecting inflammatory activity, appears to mark those patients who are most likely to benefit from cyclophosphamide therapy.