Patterns of pulmonary function in smoking and nonsmoking patients with progressive systemic sclerosis

Small airways dysfunction in patients with systemic sclerosis and interstitial lung disease

BACKGROUND

A number of studies report small airways involvement in patients with systemic sclerosis (SSc). Furthermore, small airways dysfunction is increasingly recognized in patients with interstitial lung disease (ILD) of idiopathic or autoimmune etiology. The objectives of this study were to evaluate small airways function in SSc patients with ILD and explore the effect of treatment on small airways function by using conventional and contemporary pulmonary function tests (PFTs).

METHODS

This single-center, prospective, observational study included a total of 35 SSc patients, with and without ILD based on HRCT scan, evaluated by a special radiologist blindly. Clinical data were collected from all patients who were also assessed for HRCT findings of small airways disease. Small airways function was assessed by classic spirometry, measurement of diffusing capacity for carbon monoxide, body plethysmography, single breath nitrogen washout (N2SBW) and impulse oscillometry (IOS). The prevalence of small airways dysfunction according to R5-R20, phase III slopeN2SBW and CV/VC methodologies was calculated in the total SSc population. Pulmonary function tests were compared between: (a) SSc-ILD and non-ILD patients and (b) two time points (baseline and follow up visit) in a subset of SSc-ILD patients who received treatment for ILD and were re-evaluated at a follow up visit after 12 months.

RESULTS

Phase III slopeN2SBW and R5-R20 showed the highest diagnostic performance for detecting small airways dysfunction among SSc patients (61 and 37.5%, respectively). Twenty three SSc patients were found with ILD and 14 of them had a 12-month follow up visit. SSc-ILD patients compared to those without ILD exhibited increased phase III slopeN2SBW ≥120% (p = 0.04), R5-R20 ≥0.07 kPa/L/s (p = 0.025), airway resistance (Raw) (p = 0.011), and special airway resistance (sRaw) (p = 0.02), and decreased specific airway conductance (sGaw) (p = 0.022), suggesting impaired small airways function in the SSc-ILD group. Radiographic features of SAD on HRCT were observed in 22% of SSc-ILD patients and in none of SSc-non-ILD patients. Comparison of PFTs between baseline and follow-up visit after 12 months in the 14 SSc-ILD treated patients, showed improvement of phase III slopeN2SBW (p = 0.034), R5-R20 (p = 0.035) and Raw (p = 0.044) but not sRaw and sGaw parameters.

CONCLUSION

Phase III slopeN2SBW and R5-R20 may reveal small airways dysfunction in SSc associated ILD before structural damage and may be partially improved in a subset of patients receiving treatment for ILD.

Increased prevalence of small airways dysfunction in patients with systemic sclerosis as determined by impulse oscillometry

OBJECTIVES

The prevalence and clinical implications of small airways involvement in SSc are still to be fully elucidated. The goal of the present work is to assess the prevalence of small airways dysfunction by impulse oscillometry and to determine whether it correlates with selected disease-related features and respiratory-related quality of life.

METHODS

Ninety-four SSc patients and 93 healthy controls were studied by impulse oscillometry measurements. Small airways dysfunction was defined as the difference between resistance at low frequency, i.e. 5 Hz, and resistance at high frequency, i.e. 20 Hz, termed 'R5-R20', ⩾0.07 kPa/l/s. The St George's Respiratory Questionnaire was used to measure health impairment in SSc patients. Radiological features of small airways disease and parenchymal abnormalities on high resolution CT chest scans were jointly assessed by two thoracic radiologists.

RESULTS

Small airways dysfunction was present in 21.5% of the SSc patient cohort, with a prevalence almost 5-fold higher compared with controls, and it was significantly associated with worse respiratory-related quality of life. Radiological features consistent with small airways abnormalities were detected in 25% of SSc patients, mostly in the absence of interstitial lung changes. Combining functional and radiological evaluations, one-third of the SSc cohort showed at least one feature of small airways involvement, which was associated with the lcSSc phenotype and with longer disease duration.

CONCLUSION

The current study strengthens the hypothesis that small airway dysfunction might be a feature of SSc-related lung involvement, providing the first data on its significant impact on respiratory-related quality of life. A full assessment of lung function in SSc patients should include impulse oscillometry as a complementary technique, due to potential clinical and therapeutic implications.

Autologous Hematopoietic Stem Cell Transplantation for Treatment of Systemic Sclerosis

Systemic Sclerosis (SSc) is a complex autoimmune disease, characterized by high mortality and morbidity. The heterogeneity in terms of extent, severity, and rate of progression of skin and internal organ involvement gives rise to many difficulties in finding the optimal therapeutic interventions for SSc and, to date, no disease-modifying agents are available. In this scenario, it is not surprising that SSc was one of the first autoimmune diseases challenged with high-dose immunosuppressive treatment followed by autologous hematopoietic stem cell transplantation (AHSCT). In the last decades, AHSCT has emerged as a treatment option for refractory SSc through a reduction of the aberrant immune cells, followed by re-constitution of a new, self-tolerant immune system. After several case series and pilot studies, more recently three randomized controlled trials have shown a benefit in skin involvement, organ functions and quality of life measures in AHSCT compared to monthly cyclophosphamide. In addition, although AHSCT presents a certain risk of mortality, it has been shown that the overall survival is better, compared to the cyclophosphamide group. Current evidence suggests that SSc patients who are most likely to benefit from AHSCT are early, active, with rapidly progressing diffuse skin disease, and mild involvement of internal organs. As the studies have progressed, it has become evident the need for a more rigorous patient selection, the optimization of transplant and post-transplant procedures, and the intervention of multidisciplinary teams of specialists to increase the safety and efficacy of AHSCT in SSc.

Pulmonary involvement in systemic sclerosis

Systemic sclerosis (SSc) is a multi-systemic autoimmune disease that mainly affects the skin, lungs, gastrointestinal tract, heart and kidneys. Pulmonary disease in patients with SSc is strongly associated with mortality. The mechanisms involved into its pathophysiology include the activation of autoimmune cells and hyperplasia of fibroblasts with an increased capacity to produce collagen and diminished collagen breakdown. Although pulmonary biopsy is the gold standard for the diagnosis of interstitial lung disease in SSc, the most commonly used method is high-resolution computed tomography due to its high sensitivity and specificity. Herein, a comprehensive review on the pulmonary involvement in SSc is presented highlighting the radiologic-pathologic correlations.

Smoking and pulmonary fibrosis: novel insights

The relationship between smoking and pulmonary fibrosis is under debate and intense investigation. The aim of this paper is to review the existing literature and identify further areas of research interest. Recently the negative influence of cigarette smoking on IPF outcome was highlighted, as non-smokers exhibit a better survival than ex-smokers and combined current- and ex-smokers. In patients with non-specific interstitial pneumonia (NSIP), a high prevalence of emphysema was recently demonstrated, providing an indirect support for a smoking pathogenetic hypothesis in NSIP. The coexistence of pulmonary fibrosis and emphysema has been extensively described in a syndrome termed combined pulmonary fibrosis and emphysema (CPFE). Connective tissue disorders (CTDs) are a group of autoimmune diseases which affect the lung, as one of the most common and severe manifestations. However, the relationship between smoking and autoimmune disorders is still conflicting. Rheumatoid arthritis results from the interaction between genetic and environmental factors, while the best established environmental factor is tobacco smoking. Smoking has also a negative impact on the response of the RA patients to treatment. The aforementioned smoking-related implications give rise to further research questions and certainly provide one more important reason for physicians to advocate smoking cessation and smoke-free environment.

Pulmonary manifestations of scleroderma and mixed connective tissue disease

Pulmonary manifestations are common in connective tissue diseases, and are associated with significant morbidity and mortality in this patient population. Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are clinical entities for which the detection of lung involvement is essential to improve patient care and outcomes. This article discusses the pathogenesis, clinical presentation, and evaluation of the patient with pulmonary disease related to SSc and MCTD, with an emphasis on interstitial lung disease and pulmonary hypertension.

When there's smoke there's…scleroderma: evidence that patients with scleroderma should stop smoking

There is no treatment for the autoimmune disease scleroderma (systemic sclerosis, SSc), a multisystem disorder characterized by vascular damage and fibrosis. In particular, SSc can severely affect the lung, resulting in pulmonary arterial hypertension and fibrosis. Smoking is well-known to affect pulmonary health, and a recent report (Hudson et al., Arthritis Rheum, in press Oct 8) provides convincing evidence that stopping smoking improves disease outcome in SSc patients. This commentary discusses this recent publication which suggests that physicians should encourage SSc patients to stop smoking immediately.

Cigarette smoking in patients with systemic sclerosis

OBJECTIVE

To determine the effects of cigarette smoking on vascular, gastrointestinal, and respiratory outcomes in patients with systemic sclerosis (SSc).

METHODS

Subjects were patients enrolled in the Canadian Scleroderma Research Group cohort. Smoking history was obtained by patient self-report. The effect of smoking was assessed using multiple regression analysis of each SSc clinical outcome of interest (vascular, gastrointestinal, and respiratory). Smoking was modeled both as categorical variables (current, past, and never) and using the Comprehensive Smoking Index (CSI), which integrates smoking intensity, duration of smoking, and time since cessation into a single covariate of smoking effect. All regression models were adjusted for age, sex, disease duration, and limited or diffuse skin involvement.

RESULTS

This study included 606 patients with SSc, of whom 87% were women and 90% were white, and the mean age was 55 years, mean disease duration was 11 years, and 36% had diffuse disease. Of these patients, 16% were current smokers, 42% were past smokers, and 42% were never smokers. The regression analyses showed that smoking had a significant negative effect on almost all vascular, gastrointestinal, and respiratory outcomes. The effects of smoking were in some cases long-lasting (e.g., persistent respiratory abnormalities), and smoking cessation appeared beneficial with respect to some outcomes (e.g., reduced severity of Raynaud's phenomenon).

CONCLUSION

Physicians caring for patients with SSc should prioritize smoking cessation as a recommendation to patients, and resources directed to supporting smoking cessation in patients with SSc should be more readily available.