Scleroderma lung disease: evolving understanding in light of newer studies

The Role of Endogenous Eicosapentaenoic Acid and Docosahexaenoic Acid-Derived Resolvins in Systemic Sclerosis

Resolvins, the member of specialized pro-resolving mediators, are produced from omega-3 polyunsaturated fatty acids as a response to an acute inflammatory process in that termination and resolution of inflammation. In the acute inflammation, these lipid mediators limit polymorphonuclear cells infiltration, proinflammatory cytokine production; promote efferocytosis, and regulate several cell types being important roles in innate and adaptive immunity. Any dysregulation or defect of the resolution phase result in prolonged, persistent inflammation and eventually fibrosis. Resolvins are implicated in the development of various chronic autoimmune diseases. Systemic sclerosis (SSc) is a very complicated, chronic autoimmune disorder proceeding with vasculopathy, inflammation, and fibrosis. Dysregulation of innate and adaptive immunity is another important contributing factor in the pathogenesis of SSc. In this review, we will focus on the different roles of this new family of lipid mediators, characterized by the ability to prevent the spread of inflammation and its chronicity in various ways and how they can control the development of fibrotic diseases like SSc.

Characteristics of patients with systemic sclerosis living in Qatar

Objective: The aim of this study was to determine the demographic, clinical, and immunological characteristics of patients with systemic sclerosis living in Qatar. Method: This retrospective study included 42 patients with systemic sclerosis who attended Rheumatology Clinics at Hamad General Hospital in Doha, Qatar, between January 2000 and December 2014. All patients fulfilled the 1980 American College of Rheumatology (ACR) classification criteria for systemic sclerosis. Results: The 42 consecutively recruited patients of mixed ethnicities consisted of 37 (88.1%) females and 5 (11.9%) males. Of the total 42 patients, 22 (52.4%) had diffuse cutaneous systemic sclerosis (dcSSc) and 20 (47.6%) had limited cutaneous systemic sclerosis (lcSSc). Mean age at onset of first symptoms was 34.5 ± 12 years, and mean age at diagnosis was 36.1 ± 11.5 years. During follow-up, Raynaud's phenomenon occurred in 36 (85.7%) patients, sclerodactyly in 39 (92.9%) patients, digital ulcers in 16 (38.1%) patients, calcinosis in 6 (14.3%) patients, telangiectasia in 16 (38.1%) patients, and arthritis in 13 (31%) patients. The gastrointestinal and respiratory systems were the most frequently affected internal organs. Gastrointestinal involvement was present in 36 (85.7%) patients, and respiratory involvement was found in 30 (71.4%) patients. The majority of patients had positive antinuclear antibodies (ANA; 97.6%). Anti-Scl-70 antibody was found in 66.7% and anti-centromere antibody (ACA) was detected in 14.3% of the patients. Conclusion: To our knowledge, this is the first study that describes the clinical and immunological profile of patients with systemic sclerosis living in Qatar. This study cohort showed an earlier age of disease onset and diagnosis than that reported in other international studies. Furthermore, in contrast to several other studies, the diffuse type of scleroderma was more commonly observed than the limited type, which resulted in a high frequency of anti-Scl-70 antibody and interstitial lung disease.

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.

Cyclophosphamide versus mycophenolate mofetil in scleroderma interstitial lung disease (SSc-ILD) as induction therapy: a single-centre, retrospective analysis

BACKGROUND

Scleroderma is a systemic autoimmune disease characterized mainly by skin manifestations and involvement of various visceral organs, especially the lungs. Lung involvement is the leading cause of mortality in patients with scleroderma. There are data to suggest that cyclophosphamide (CYC) and mycophenolate mofetil (MMF) are effective in the management of scleroderma interstitial lung disease (SSc-ILD) but no head to head comparative data are available to date.

METHODS

For the last 3 years, patients with SSc-ILD have been treated at our centre by protocol-based administration of intravenous CYC and MMF. Results of lung function tests (spirometry) were recorded at baseline, 3 months and 6 months in every patient. The clinical records of patients with systemic sclerosis and significant ILD, who were not previously exposed to any immunosuppressant and were treated with MMF OR CYC, were reviewed. The efficacy of treatment was assessed by the change in forced vital capacity on spirometry.

RESULTS

Of the total 57 patients included in the analysis, 34 were treated with MMF and 23 were treated with CYC. Mean duration of illness was 4.19 ± 2.82 years in the MMF and 6.04 ± 5.96 years in the CYC group. After 6 months of therapy, FVC increased by 10.84 ± 13.81 % in the CYC group and by 6.07 ± 11.92 % in the MMF group. This improvement from baseline was statistically significant in both groups (P < 0.01). The improvement was comparable with no statistically significant differences between groups (P = 0.373). There were no major adverse events reported in either arm.

CONCLUSION

Both MMF and CYC were equally effective in stabilizing lung function in patients with scleroderma and ILD.

Recent Treatments of Interstitial Lung Disease with Systemic Sclerosis

Systemic sclerosis (SSc) is a disorder characterized by immune dysfunction, microvascular injury, and fibrosis. Organ involvement in patients with SSc is variable; however, pulmonary involvement occurs in up to 90% of patients with SSc. Interstitial lung disease (ILD) is a major cause of mortality and, thus, a major determinant in the prognosis of patients with SSc. This review summarizes current findings about the characteristics of ILD in patients with SSc, selection of patients with SSc-ILD who are candidates for the treatment, and current treatment options.

Clinical course of lung physiology in patients with scleroderma and interstitial lung disease: analysis of the Scleroderma Lung Study Placebo Group

OBJECTIVE

Patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) are thought to have the greatest decline in lung function (forced vital capacity [FVC]% predicted) in the early years after disease onset. The aim of this study was to assess the natural history of the decline in FVC% predicted in patients receiving placebo in the Scleroderma Lung Study and to evaluate possible factors for cohort enrichment in future therapeutic trials.

METHODS

Patients randomized to receive placebo (n=79) were divided into 3 groups based on the duration of SSc (0-2 years, 2-4 years, and >4 years). Descriptive statistics and a mixed-effects model were used to analyze the rate of decline in the FVC% predicted over a 1-year period. Additional analyses stratified according to the severity of fibrosis on high-resolution computed tomography (HRCT) were performed, and interactions between disease severity and disease duration were explored.

RESULTS

The mean±SD decline in the unadjusted FVC% predicted during the 1-year period was 4.2±12.8%. At baseline, 28.5%, 43.0%, and 28.5% of patients were in the groups with disease durations of 0-2 years, 2-4 years, and >4 years, respectively. The rate of decline in the FVC% predicted was not significantly different across the 3 disease groups (P=0.85). When stratified by baseline fibrosis on HRCT, the rate of decline in the FVC% predicted was statistically significantly greater in the group with severe fibrosis (mean annualized decline in the FVC% predicted 7.2% versus 2.7% in the groups with no or moderate fibrosis; P=0.008). The decline observed in the group with severe fibrosis was most pronounced in those with a relatively short disease duration (0-2 years; annualized decline 7.0%).

CONCLUSION

Among patients with SSc-ILD in the Scleroderma Lung Study, the rates of progression of lung disease were similar irrespective of disease duration. The baseline HRCT fibrosis score is a predictor of a future decline in the FVC% predicted in the absence of effective treatment.

Enteric-coated mycophenolate sodium for progressive systemic sclerosis--a prospective open-label study with CT histography for monitoring of pulmonary fibrosis

The purpose of this study was to assess the impact of enteric-coated mycophenolate sodium (EC-MPS) on skin and pulmonary manifestations of patients with progressive systemic sclerosis (Ssc). A prospective, open-label single-centre trial with EC-MPS 2 × 720 mg/day over 12 months and a long-term follow-up of 50 months were conducted. Modified Rodnan skin score (mRSS) was used to assess the skin and pulmonary function tests to assess the pulmonary involvement. In order to quantify the extent of alveolitis/fibrosis via densitometry, the high attenuation value, median lung density and percentiles of lung tissue densities were obtained by high-resolution computed tomography. Eleven patients were included. Three patients had to stop medication before month 6 (2× side effects, 1× progression). For the remaining eight patients, the median mRSS was non-significantly reduced from 13.5 at baseline to 11 at month 12. According to the CT histography, median lung density and high attenuation values remained stable. However, the course of percentiles -200 to -300 and particularly -300 to -400 Hounsfield units slightly increased in seven of eight patients after 12 months, suggesting worsening of pulmonary involvement. Accordingly, median diffusing capacity for carbon monoxide showed a tendency to decline (75.1 % vs. 70.2) while forced vital capacity non-significantly improved (78.0 vs. 85.5 %) during the study. Four patients are still on EC-MPS without clinical signs of progression after 50 months follow-up. EC-MPS showed non-significant improvement of the skin. Pulmonary fibrosis remained stable with only a slight tendency towards progression which might be ascribed to the medication as well as the natural course of the disease. CT histography appears to be a sensitive method for the detection of progression of pulmonary fibrosis and therefore should be considered for further studies in Ssc.

Predicting treatment outcomes and responder subsets in scleroderma-related interstitial lung disease

OBJECTIVE

To identify baseline characteristics of patients with scleroderma-related interstitial lung disease (SSc-ILD) that could serve as predictors of the most favorable response to 12-month treatment with oral cyclophosphamide (CYC).

METHODS

Regression analyses were retrospectively applied to the Scleroderma Lung Study data in order to identify baseline characteristics that correlated with the absolute change in forced vital capacity (FVC) (% predicted values) and the placebo-adjusted change in % predicted FVC over time (the CYC treatment effect).

RESULTS

Completion of the CYC arm of the Scleroderma Lung Study was associated with a placebo-adjusted improvement in the % predicted FVC of 2.11% at 12 months, which increased to 4.16% when patients were followed up for another 6 months (P=0.014). Multivariate regression analyses identified the maximal severity of reticular infiltrates (assessed as maximum fibrosis scores) on high-resolution computed tomography (HRCT) at baseline, the modified Rodnan skin thickness score (MRSS) at baseline, and the Mahler baseline dyspnea index as independent correlates of treatment response. When patients were stratified on the basis of whether 50% or more of any lung zone was involved by reticular infiltrates on HRCT and/or whether patients exhibited an MRSS of at least 23, a subgroup of patients emerged in whom there was an average CYC treatment effect of 9.81% at 18 months (P<0.001). Conversely, there was no treatment effect (a -0.58% difference) in patients with less severe HRCT findings and a lower MRSS at baseline.

CONCLUSION

A retrospective analysis of the Scleroderma Lung Study data identified the severity of reticular infiltrates on baseline HRCT and the baseline MRSS as patient features that might be predictive of responsiveness to CYC therapy.

Effect of mycophenolate sodium in scleroderma-related interstitial lung disease

This study aims to determine the effectiveness of mycophenolate sodium (MS) in patients with scleroderma (SSc)-related interstitial lung disease (ILD). In a prospective observational study, we evaluated 14 consecutive SSc-ILD patients who were treated with MS for 12 months. The effect of MS on lung function was examined by using longitudinal data analytic methods. Wilcoxon rank-sum tests were used to examine the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) by pulmonary function testing. As a group, the median values for FVC, FEV1 and DLCO did not change significantly after 12 months of MS therapy and fulfilled the definition of stable disease by the American Thoracic Society. Individually, after 12 months of treatment, 6 out of 14 patients showed a pulmonary improvement defined as an increase of more than 10% in FVC, and 5 out of 14 patients remained stable. By contrast, the median FVC had declined a non-significant 7.2% from the previous 12 months before MS initiation. No significant drug adverse effects were registered. These prospective data suggest that MS is a safe and well-tolerated therapy for SSc-ILD patients, and it is capable of preventing functional pulmonary deterioration.

Static and dynamic mechanics of the murine lung after intratracheal bleomycin

Background

Despite its widespread use in pulmonary fibrosis research, the bleomycin mouse model has not been thoroughly validated from a pulmonary functional standpoint using new technologies. Purpose of this study was to systematically assess the functional alterations induced in murine lungs by fibrogenic agent bleomycin and to compare the forced oscillation technique with quasi-static pressure-volume curves in mice following bleomycin exposure.

Methods

Single intratracheal injections of saline (50 μL) or bleomycin (2 mg/Kg in 50 μL saline) were administered to C57BL/6 (n = 40) and Balb/c (n = 32) mice. Injury/fibrosis score, tissue volume density (TVD), collagen content, airway resistance (R_N), tissue damping (G) and elastance coefficient (H), hysteresivity (η), and area of pressure-volume curve (PV-A) were determined after 7 and 21 days (inflammation and fibrosis stage, respectively). Statistical hypothesis testing was performed using one-way ANOVA with LSD post hoc tests.

Results

Both C57BL/6 and Balb/c mice developed weight loss and lung inflammation after bleomycin. However, only C57BL/6 mice displayed cachexia and fibrosis, evidenced by increased fibrosis score, TVD, and collagen. At day 7, PV-A increased significantly and G and H non-significantly in bleomycin-exposed C57BL/6 mice compared to saline controls and further increase in all parameters was documented at day 21. G and H, but not PV-A, correlated well with the presence of fibrosis based on histology, TVD and collagen. In Balb/c mice, no change in collagen content, histology score, TVD, H and G was noted following bleomycin exposure, yet PV-A increased significantly compared to saline controls.

Conclusions

Lung dysfunction in the bleomycin model is more pronounced during the fibrosis stage rather than the inflammation stage. Forced oscillation mechanics are accurate indicators of experimental bleomycin-induced lung fibrosis. Quasi-static PV-curves may be more sensitive than forced oscillations at detecting inflammation and fibrosis.

Induced sputum as a method for detection of systemic sclerosis-related interstitial lung disease

Inducted sputum (IS) is a non-invasive procedure that can be used for collection of airway secretions. The aim of our study is to evaluate the clinical usefulness of IS for detection of airway inflammation in systemic sclerosis (SSc). Bronchoalveolar lavage and IS were performed to 20 patients with SSc. Eighteen patients who were referred to pulmonary medicine for bronchoalveolar lavage due to other reasons were also recruited for cell counts comparisons. Spirometry, echocardiography and thorax CT (HRCT) imaging were also performed to all patients. Mean macrophage and lymphocyte counts were found to be increased in IS of SSc patients compared with that of control (58.4 ± 14.5% vs. 31.3 ± 16.3%, 30.2 ± 15.4% vs. 15.0 ± 11.5% P < 0.001), whereas mean neutrophil count was lower in the SSc patients (4.1 ± 4.5% vs. 17.2 ± 13.1%, P < 0.05). Significant correlations were noted between BAL and IS findings for macrophage (r = 0.55, P = 0.02) lymphocyte (r = 0.65, P < 0.01) and total cell counts (r = 0.45, P = 0.06). IS is an easy and reliable method for the detection of alveolitis and can be used for early detection of lung involvement in scleroderma.

New pharmacological strategies for the treatment of pulmonary fibrosis

The treatment of pulmonary fibrosis continues to pose major difficulties. Idiopathic pulmonary fibrosis (IPF), the most prevalent chronic fibrosing lung disease, is a devastating condition that carries a prognosis worse than that of many cancers. Abnormalities in multiple pathways involved in wound healing and inflammation lead to the development of this condition. High doses of corticosteroids are now contraindicated in IPF, although they have a role in other fibrosing lung diseases. More effective treatments are urgently required and a number of novel candidate therapies have been put forward, based on animal and in vitro work. As in other complex disorders, it is likely that combinations of agents, rather than single treatments, will be needed. The principle of combination therapy was recently endorsed by the guidelines of the British Thoracic Society, which make a weak recommendation for a combination of prednisolone, azathioprine and N-acetylcysteine. However, enrolment of patients into trials of new therapies is considered to be ‘best current practice’ as this offers sufferers with IPF the chance to receive new agents that may be more effective than current treatments. In pulmonary fibrotic disorders other than IPF, anti-inflammatory therapy is broadly appropriate and benefits most patients, but a clear treatment strategy is essential. The art of management is to distinguish accurately between inherently stable fibrotic disease (with treatment not required), progressive predominantly fibrotic disease (with low-dose long-term treatment warranted to retard progression) and the presence of major associated inflammation (justifying initial high-dose treatment).

Mobilization of endothelial progenitor cells by intravenous cyclophosphamide in patients with systemic sclerosis

OBJECTIVE

To evaluate the effects of i.v. CYC on the number of circulating endothelial progenitor cells (EPCs) in patients with SSc, and the potential association of the EPC response with CYC's effect for treating interstitial lung disease (ILD).

METHODS

This open-label, prospective study involved 12 patients with SSc and alveolitis (CYC group). All patients received six courses of i.v. CYC (0.5 g/m2) at 4-week intervals in combination with low-dose prednisolone. Ten patients were followed for 24 months. Seven SSc patients treated with low-dose prednisolone alone were used as a control for the EPC measurement (control group). Five patients with non-SSc CTD who received i.v. CYC and prednisolone also served as disease controls. EPCs were quantified by the partial enrichment of CD34+ cells followed by three-colour flow cytometry. The circulating levels of vascular injury markers were measured by immunoassay.

RESULTS

The EPC count was significantly increased at 2 weeks after treatment in the CYC group (P=0.02), but not in the control group, while CYC increased EPC count in all disease controls. The SSc patients in the CYC group were divided into five EPC responders and seven EPC non-responders. Circulating vascular injury markers were reduced in the responders, but not in the non-responders. During the 24-month follow-up, 3 of 10 patients developed end-stage lung disease, and all of them were EPC non-responders.

CONCLUSION

A low-dose i.v. CYC induces EPC mobilization, which may contribute to the efficacy for treating SSc-associated ILD.

A long-term prospective randomized controlled study of non-specific interstitial pneumonia (NSIP) treatment in scleroderma

The association of cyclophosphamide (CYC) and prednisone (PRED) for the treatment of lung fibrosis in systemic sclerosis (SSc) was only evaluated in uncontrolled studies, although in idiopathic interstitial lung disease (ILD) this association seems to be beneficial in patients with non-specific interstitial pneumonia (NSIP).

OBJECTIVES

To treat SSc-ILD in a prospective open-label controlled study based on lung pattern during 12 months of treatment.

METHODS

A 3-year analysis was also performed. Twenty-four consecutive patients with SSc and ILD were submitted to an open lung biopsy. Eighteen patients (NSIP) were randomized in two groups: CYC versus CYC + PRED during 12 months. Lung function tests (diffusion lung capacity of monoxide carbone corrected for hemoglobin concentration (DLCO-Hb), forced vital capacity (FVC), total lung capacity) and Modified Rodnan Skin Score (MRSS) were performed before, after one of treatment and after 3 years from the end of the treatment.

RESULTS

Pulmonary function tests were similar in both groups on baseline. After 1 year of treatment, FVC% was comparable between CYC groups (p = 0.72) and in CYC + PRED (p = 0.40). Three years after the end of treatment, FVC% values (p = 0.39 in group CYC and p = 0.61 in CYC + PRED and p = 0.22 in CYC + PRED) and DLCO-Hb (p = 0.54 in CYC and p = 0.28 in CYC + PRED) were similar compared to 1 year of treatment. We observed a reduction of the MRSS in the CYC + PRED group after 1 year of treatment (p = 0.02); although after 3 years, MRSS values remained stable in both groups.

CONCLUSIONS

CYC was effective to stabilize lung function parameters in NSIP lung pattern of SSc disease for 3 years after the end of a 1-year therapy.

Gastroesophageal reflux incites interstitial lung disease in systemic sclerosis: clinical, radiologic, histopathologic, and treatment evidence

OBJECTIVES

Interstitial lung disease (ILD) is currently the main cause of death in systemic sclerosis (SSc) and has an unknown pathogenesis. Gastroesophageal reflux (GER) has been strongly implicated as a cause of ILD in several lung diseases, including SSc-ILD. This review summarizes clinical, radiologic, histopathologic, and treatment aspects of GER in SSc-ILD.

METHODS

The PubMed database was searched using the following keywords: "systemic sclerosis, scleroderma, interstitial lung disease, and gastroesophageal reflux." The research was limited to English-language studies that included SSc patients with ILD.

RESULTS

Pulmonary function tests were related with the presence of GER in several esophageal functional tests (esophageal endoscopy, pH monitoring, and manometric analysis). Regarding the histopathologic data, a pattern called centrilobular fibrosis was described in 21% of 28 lung biopsies, with a bronchocentric distribution and with an intraluminal content resembling gastric fluid. Radiologic evidence of esophageal dilation is very frequent in SSc patients, and consolidation with a patchy distribution was almost exclusively found in SSc patients with centrilobular fibrosis lung pattern. Furthermore, high levels of serum KL-6, a marker of epithelial injury, are indicative of active ILD in SSc disease.

CONCLUSIONS

The association of GER with SSc-ILD is strongly supported by several studies. An aggressive treatment for reflux is recommended in all SSc patients with ILD; however, future studies need to be performed to prove a long-term benefit.