Isolated diffusing capacity reduction in systemic sclerosis

Autoantibodies in systemic sclerosis

OBJECTIVES

To describe the clinical, laboratory, and prognostic features associated with the scleroderma-specific autoantibodies.

METHODS

Using the Pittsburgh Scleroderma Databank, all consecutive patients seen between 1980 and 1995 who had autoantibody studies performed were studied. Anticentromere antibodies (ACA), antitopoisomerase (TOPO), anti-U1-RNP (U1-RNP), anti-RNA Polymerase III (Pol 3), anti-U3-RNP (U3-RNP), anti-Th/To (Th/To), and anti-Pm/Scl (Pm/Scl) were determined according to previously described methods. The frequency of clinical features, organ system outcomes, and survival within the patients with a specific antibody were cumulative over the course of the disease. The frequency of a specific feature was compared across groups to identify significant manifestations and outcomes in patients with a specific antibody.

RESULTS

Some demographic, clinical, and organ system findings were associated with the specific antibody, and other features with the scleroderma subtype (limited cutaneous or diffuse cutaneous scleroderma). U3-RNP, U1-RNP, and TOPO were seen more commonly in African-American patients, and ACA was seen in older, female Caucasians. Muscle inflammation was seen in patients with U1-RNP and U3-RNP. Digital tip ulcers and digital tuft resorption were seen more frequently in those with ACA and TOPO. A vasculopathy causing pulmonary hypertension typically occurs with ACA and pulmonary fibrosis with TOPO; however, both types of lung disease were seen in patients with nucleolar antibodies, Th/To and U3-RNP. Importantly, severe interstitial fibrosis was rarely seen in cases with Pol 3. Renal crisis was strongly associated with Pol 3. Survival within limited scleroderma was decreased in the Th/To patients compared with ACA patients. Within the diffuse scleroderma group, patients with Pol 3 had the best survival.

CONCLUSIONS

Scleroderma autoantibodies are associated with very specific demographic, clinical, organ system, and survival features.

RELEVANCE

The determination of scleroderma autoantibodies may be helpful in assessing the prognosis, monitoring, and treatment of scleroderma patients.

Pulmonary arterial hypertension is a major mortality factor in diffuse systemic sclerosis, independent of interstitial lung disease

OBJECTIVE

To determine whether pulmonary arterial hypertension (PAH) is a prognostic factor for mortality in diffuse cutaneous systemic sclerosis (dcSSc), independent of interstitial lung disease (ILD).

METHODS

ILD was diagnosed by high-resolution computed tomography and PAH (pulmonary arterial systolic pressure [PASP] > or =45 mm Hg) by echocardiography. All patients with ILD underwent testing for total lung capacity (TLC), forced vital capacity (FVC), and diffusing capacity for carbon monoxide.

RESULTS

Eighty-six patients with dcSSc (mean age at diagnosis 44.5 years) were followed up for a median of 72.5 months. ILD was found in 52 patients (60%) and PAH in 18 (21%). ILD was associated with PAH in 15 patients. Seventeen patients died (19.8%), 9 of whom had PAH (P = 0.001) and 10 of whom had ILD (P = 0.99). By multivariate analysis, age at SSc diagnosis and PAH were the only independent predictors of death (hazard ratio [HR] 1.057, 95% confidence interval [95% CI] 1.009-1.109, P = 0.020 and HR 4.09, 95% CI 1.47-11.5, P = 0.007, respectively). Mean TLC and mean FVC were similar in ILD patients with and those without PAH (P = 0.71 and P = 0.40, respectively). Among ILD patients, age at SSc diagnosis and PAH were again the sole predictors of death (HR 1.073, 95% CI 1.003-1.149, P = 0.042 and HR 5.07, 95% CI 1.09-23.8, P = 0.038, respectively). Twenty ILD patients received at least 6 monthly pulses of intravenous cyclophosphamide (CYC). In CYC-treated patients with PAH (n = 8), PASP increased significantly during the CYC regimen (mean +/- SD 55 +/- 14.5 mm Hg; P = 0.015 versus baseline), while TLC remained stable during the same period.

CONCLUSION

These results indicate that, independent of ILD, PAH is a major prognostic factor for survival in dcSSc.

Fibrosing alveolitis in systemic sclerosis: the need for early screening and treatment

Abnormalities in lung function occur in 70% of patients with systemic sclerosis (SSc). Fibrosing alveolitis in SSc (FASSc) is more commonly seen in the diffuse cutaneous form of SSc, particularly in the presence of antitopoisomerase antibodies (Scl70), and with the decreasing incidence of scleroderma renal crisis it is now the major cause of mortality in this patient population. Screening of patients recently diagnosed with SSc by pulmonary function tests and the performance of high resolution computed tomography when physiological abnormalities are identified has resulted in the identification of significant numbers of patients with early, asymptomatic FASSc. Whether these patients should be further investigated with a surgical lung biopsy or receive immunosuppression is unclear, because it cannot yet be reliably predicted who will develop progressive disease and the evidence to support the efficacy of treatment is not strong. The objective of the present article was to review the evidence to support the use of immunosuppressive therapy in FASSc and, based on these data, to propose an algorithm for the investigation and management of this difficult clinical problem.

Resting and exercise physiology in interstitial lung diseases

Interstitial lung diseases (ILDs) are a heterogeneous group of parenchymal pulmonary disorders with varying histologic appearances. Pulmonary function tests have gained a prominent role in the diagnosis and management of patients with these disorders. Although their role in the differential diagnosis of the various ILDs is limited, physiologic measurements are pivotal studies providing clues regarding disease severity, prognosis,and response to therapy.

Screening, early detection, and diagnosis of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines

Pulmonary arterial hypertension (PAH) occurs as an idiopathic process or as a component of a variety of disease processes, including chronic thromboembolic disease, connective tissue diseases, congenital heart disease, and exposure to exogenous factors including appetite suppressants or infectious agents such as HIV. This article reviews evidence for screening in susceptible patient groups and the approach to diagnosing PAH when it is suspected, and provides specific recommendations for applying this evidence to clinical practice.

Classification and epidemiology of pulmonary hypertension

Pulmonary hypertension is a complex disease that can be idiopathic, familial, or associated with a wide range of disease processes. This article outlines the classification of primary pulmonary hypertension and discusses the various types of the disease.

Chronic thromboembolic pulmonary hypertension

During the past 2 decades, there has been a steady rise in the number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing surgery and in the number of programs worldwide dedicated to the diagnosis and management of this patient population. This article discusses the natural history and clinical presentation of CTEPH, the evaluation of patients for pulmonary thromboendarterectomy, and the outcomes following surgery, along with a brief review of the procedure as performed at the University of California, San Diego.

Circulating endothelial cells as a marker of ongoing vascular disease in systemic sclerosis

OBJECTIVE

Circulating endothelial cells (CECs) have been described in different conditions involving vascular injury. Vascular abnormalities play a key role in the pathogenesis of systemic sclerosis (SSc). The aim of this study was to search for the presence of CECs in patients with SSc and to evaluate their clinical associations and possible pathogenic role.

METHODS

The study cohort included 46 patients with SSc and 40 healthy controls. Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD34 positive, and P1H12 positive, and activated CECs were defined as CD45 negative and P1H12 positive, CD62 positive, or CD106 positive. Progenitors were identified as CD34 positive and CD133 positive.

RESULTS

Total and activated CEC counts were significantly higher in SSc patients compared with healthy controls and were positively correlated with the disease activity score. With respect to visceral involvement, significant correlation was observed between the CEC number and the severity of pulmonary hypertension. High levels of endothelial progenitors were observed in patients with SSc, and the counts were higher in the early stages of disease.

CONCLUSION

The presence of CECs in patients with SSc may represent direct evidence of endothelial disease and may be a promising new clinical marker for active SSc. Notably, the association between CECs and pulmonary hypertension and impaired carbon monoxide diffusing capacity was evident in patients with limited cutaneous SSc only, suggesting an important role for CECs in this disease subset with prominent vascular changes. Detection of circulating endothelial progenitors may represent a response to vascular ischemia in early SSc, as an attempt at revascularization.

Long-term evaluation of lung function in patients affected by scleroderma treated with cyclic iloprost infusions

OBJECTIVE

The aim of this study was to evaluate pulmonary function in patients suffering from scleroderma treated for 3 years with cyclic iloprost infusions.

METHODS

Thirty patients affected by scleroderma (five men and 25 women, mean age 49.3 years, mean disease duration 8 years, 19 with limited and 11 with diffuse disease patterns) were treated for 5 consecutive days every 4 months for 3 years with iloprost. Pulmonary function was evaluated at baseline and after 3 years. At the end of the trial, color Doppler echocardiography was performed in 26 of the patients.

RESULTS

Spirometric parameters did not significantly change after 3 years of therapy when expressed as percentage of the predicted normal value. Diffusing lung capacity for carbon monoxide decreased at the limit of statistical significance. No patients developed clinical pictures suggestive of severe pulmonary arterial hypertension, which was confirmed in 26 subjects by evaluation of estimated pulmonary artery systolic pressure.

CONCLUSIONS

This long-term study showed that lung function remained substantially stable after 3 years of treatment with cyclic iloprost infusions. No cases of severe pulmonary hypertension were observed.

Visualization and functional consequence of pulmonary vascular impairment in patients with rheumatic diseases

STUDY OBJECTIVES

Systemic rheumatic diseases impair the vasculature in lungs. The aim of this study was to visualize vascular impairment and determine its consequence on lung function.

PATIENTS AND MEASUREMENTS

Seventy-two patients with rheumatic diseases were evaluated by pulmonary function tests, ventilation-perfusion scintigraphy, and thermography of the hands. The ventilation-perfusion mismatch of the lungs was visualized and quantified by calculating the ventilation-perfusion ratio (/) at each pixel. The microvascular impairment in fingers was assessed by the temperature difference between the nail fold and the dorsal hand.

RESULTS

Patients with rheumatic diseases exhibited an increased / that distributed at the periphery of the lungs. The diffusing capacity of the lung for carbon monoxide (DLCO) decreased (mean [+/- SD], 76.4 +/- 27.4% of predicted) relative to the vital capacity (VC) [mean, 88.4 +/- 21.8% of predicted; p < 0.01] regardless of the presence or absence of interstitial lung disease (ILD). The distal-dorsal temperature difference showed colder fingers in patients with Raynaud phenomenon (mean temperature, - 0.6 +/- 2.1 degrees C) than in those without it (mean temperature, 0.3 +/- 1.5 degrees C) and significantly correlated with the ventilation-perfusion mismatch of the lungs both in patients with ILD (p = 0.04) and in those without ILD (p = 0.02). The ventilation-perfusion mismatch of the lungs significantly correlated with the relative reduction in DLCO evaluated by the percent DLCO/percent VC ratio both in patients with ILD (p < 0.01) and in those without ILD (p = 0.02).

CONCLUSIONS

These results suggest that the periphery-distributed microvascular impairment in the lungs leads to ventilation-perfusion mismatch that functionally causes a relative reduction in DLCO in patients with rheumatic diseases. The reduction in DLCO relative to VC represents the vascular impairment in the lungs both in patients with ILD and in those without.

Interstitial lung disease in scleroderma

Pulmonary fibrosis occurs most patients who have scleroderma. It progresses to severe restrictive lung disease in about 15% of patients and remains a major cause of death in this disease. Risks for developing pulmonary fibrosis include diffuse cutaneous scleroderma and anti-Scl-70 antibodies, and risks for developing progressive pulmonary fibrosis and death include low pulmonary function test results at presentation and lung inflammation. Early evaluation of the extent and severity of pulmonary fibrosis and the presence of lung inflammation is key, so that therapy can be given to patients who are at higher risk of progressive pulmonary fibrosis before they develop severe functional impairment occurs. Evaluation often includes pulmonary function tests, HRCT of the lungs, Doppler echocardiogram, and bronchoalveolar lavage. For patients who are unwilling or unable to participate in therapeutic trials that target pulmonary fibrosis in scleroderma, therapy with oral or intravenous cyclophosphamide is often given.

Predictors of end stage lung disease in a cohort of patients with scleroderma

OBJECTIVES

To estimate the incidence of severe lung disease in patients with scleroderma and identify the combination(s) of features present at first assessment which would be useful to predict future risk of severe lung disease.

METHODS

Data were analysed on 561 patients with disease onset occurring on or after 1 January 1982 and disease duration of less than five years before the first assessment. Detailed clinical and laboratory assessments were undertaken at the initial visit. End stage lung disease was defined as pulmonary hypertension requiring continuous ambulatory iloprost, or pulmonary fibrosis requiring continuous oxygen, or death from a scleroderma related lung disease. Patient status was determined at 31 December 1997. The best subset of predictors was identified by Cox regression analysis.

RESULTS

In all, 24 patients reached end stage lung disease. The cumulative incidences were 4%, 6%, and 12% at five, seven, and 14 years respectively. As expected, the lung function tests at baseline, including being in the lowest third of either diffusing lung capacity (hazard ratio (HR) = 18.2, 95% confidence interval (CI) 3.5 to 93.8) or of forced vital capacity (HR=4.1, 95% CI 1.1 to 15.2), were highly significant predictors of end stage lung disease. Interestingly, apart from the presence of proteinuria, none of the other baseline variables, including the extent of skin disease and serological markers, were predictive of severe lung disease.

CONCLUSION

End stage lung disease was infrequent in this large cohort, but the cumulative incidence increased importantly with time. The risk can be predicted from baseline assessment of pulmonary function. In particular, those with normal pulmonary function at baseline are at very low risk.

Life-threatening complications of systemic sclerosis

Pulmonary arterial hypertension is common in patients with SSc. Fig. 1 shows the diagnostic and therapeutic approach to PAH in SSc. Doppler echocardiography may suggest the diagnosis, but RHC is necessary to confirm PAH and to measure vasoreactivity. Therapy is directed at the underlying connective tissue disease. Vasoreactive patients often benefit from therapy with high-dose calcium-channel [figure: see text] blockers, but most patients are not vasoreactive. Intravenous epoprostenol and oral endothelin-1 receptor antagonists improve hemodynamic measurements and symptoms in SSc-associated PAH. The therapy of right ventricular failure is focused on vasodilators, inotropes, and diuretics with careful attention to avoiding systemic hypotension. The scleroderma pulmonary-renal syndrome and the scleroderma renal crisis are distinct syndromes with different clinical presentations, histopathologic manifestations, treatments, and outcomes. The scleroderma pulmonary renal syndrome is an autoimmune vasculitis of kidney and lung associated with normal blood pressure. Treatment is supportive, and prognosis is dismal. In contrast, scleroderma renal crisis is associated with systemic hypertension, onion skinning of afferent arterioles, and response to ACE inhibition and renal replacement therapy. Pericardial effusions are common but only occasionally lead to tamponade. Esophageal dysmotility is often associated with aspiration, leading to pulmonary fibrosis, pneumonia, or ARDS. Diffuse bowel involvement may result in pseudo-obstruction, bacterial overgrowth, or malabsorption. Prokinetic agents, antibiotics, and parenteral nutrition may be required.

Cardiopulmonary Exercise Testing With Pulmonary Artery Catheterization Detects Early Pulmonary Vasculature Changes in Patients With Connective Tissue Diseases

Pulmonary hypertension is a well-recognized complication of connective tissue diseases (CTD), with clinical symptoms typically limited to those with relatively advanced disease. The objective of this study was to identify patients with early pulmonary vasculature changes using cardiopulmonary exercise testing with pulmonary artery catheterization. Four patients with CTD and normal Doppler echocardiogram results identified as high risk for pulmonary hypertension on the basis of disease process underwent cardiopulmonary exercise testing with pulmonary artery catheterization. All patients had normal mean pulmonary artery pressures at rest (<25 mmHg), but exhibited an abnormal rise in mean pulmonary artery pressure with exercise. Cardiopulmonary exercise testing should be considered in patients at high risk for pulmonary hypertension to identify those individuals who may benefit from early therapeutic intervention.

Post-menopause is the main risk factor for developing isolated pulmonary hypertension in systemic sclerosis

In scleroderma patients, isolated pulmonary hypertension (PHT) has been associated with selected HLA haplotypes, severe impairment of the diffusing capacity for carbon monoxide and the diagnosis of CREST. Most patients with CREST have a late-age onset of the disease, corresponding to the perimenopausal or postmenopausal period. We conducted a retrospective cohort study to determine the role of post-menopause and of the other known clinical and biological markers in the development of isolated pulmonary hypertension in Italian patients with systemic sclerosis. 189 female patients with scleroderma who had no ecographic signs of pulmonary hypertension (PHT) and radiographic signs of lung fibrosis at the first visit and did not develop significant pulmonary fibrosis during the observation time were included. Sixty-three out of 189 patients (33.3%) presented isolated pulmonary hypertension. A severe impairment of diffusing capacity for carbon monoxide at admission was found to be an early predictive element for its development. An increased risk was associated with postmenopausal condition (RR = 5.2, p = 0.000), CREST syndrome (RR = 2.8, p = 0.001) and haplotype HLA-B35 (RR = 2.8; p = 0.002). A significant positive interaction between postmenopausal condition and either HLA-B35 (RR = 15.2; p = 0.000) or the diagnosis of CREST (RR = 14.1; p = 0.000) was found. Postmenopausal condition alone or in combination with HLA-B35 and CREST syndrome is the main risk-factor for developing primary pulmonary hypertension in scleroderma patients. This suggests that hormonal replacement therapy could play a role in preventing isolated PHT in patients with systemic sclerosis.

Treatment of systemic sclerosis

Systemic sclerosis is an extremely variable disease in its manifestations and consequently, treatment needs to be individualized depending on the specific problems that each patient has. Limited scleroderma patients have a prolonged duration of Raynaud's phenomenon and puffy fingers before they develop any skin thickening, digital ulcers or gastrointestinal symptoms. They are likely to present with all the classic manifestations of scleroderma. Diffuse scleroderma patients have a much more acute systemic onset with marked whole hand swelling and may initially have only subtle skin thickening. A good understanding of the differences between the natural history of limited and diffuse scleroderma will enable the physician to treat present problems and anticipate future ones more effectively. One should determine which major subset and organ systems are involved before deciding on the appropriate therapy. Advances in organ-specific therapy, particularly calcium channel antagonists in Raynaud's phenomenon, proton pump inhibitors in esophageal reflux, intravenous iloprost and endothelin receptor antagonists in pulmonary hypertension, and ACE inhibitors in renal crisis, have decreased morbidity and mortality in patients with scleroderma. Studies of aggressive therapies to prevent or improve pulmonary fibrosis are in progress. Further clinical experience in wound healing, gastrointestinal malabsorption and physical therapy for loss of motion has helped patients to have a more comfortable life. In recent years, a significant number of controlled clinical trials have been performed and there has been improved understanding of the best way to perform studies and of which patients are most likely to respond to therapy. Penicillamine, methotrexate, photopheresis, relaxin, interferons, and cyclosporine have all been studied in controlled trials with variable outcomes. Although an overall remittive therapy has not yet been determined, new, potentially useful agents are being investigated.

Pulmonary function tests in interstitial lung disease: what role do they have?

Pulmonary function tests have been widely accepted and utilized in the management of interstitial lung diseases. Although the tests performed have changed little over the past several decades, extensive literature has been published highlighting their clinical role in the diagnosis, staging, prognostication, and follow-up of patients with a wide variety of interstitial lung diseases.

The assessment of pulmonary hypertension

The goals of evaluating pulmonary hypertension are detection, definition of severity and the nature of the hemodynamic lesion and its consequences, diagnosis of causal or associated conditions, and determination of optimal therapy. These objectives are reliably achieved by a disciplined approach employing multiple diagnostic tools. This chapter outlines the fundamental background and guidelines for assessing pulmonary hypertension, including consideration of several new and less frequently used methods to elucidate the physiologic mechanism. Since early detection and treatment may improve outcome, screening higher risk populations and a diagnostic approach to the milder spectrum of pulmonary hypertension is also addressed.

Chronic thromboembolic pulmonary hypertension

Remarkable advances have occurred over the past 2 decades in the diagnostic approach, surgical management, and postoperative care of patients afflicted with chronic thromboembolic pulmonary hypertension. Despite these advances, a great deal needs to be achieved if the morbidity and mortality of the disease process are to be reduced further. First, the preliminary insights that have been achieved into the natural history of the disease must be defined further. The level of pulmonary hypertension encountered in most patients with chronic thromboembolic pulmonary hypertension at the time of initial clinical recognition cannot be reached on an acute basis. Gradual hemodynamic progression, therefore, must occur over time. The basis for this progression, why it occurs in certain patients and not others, following an acute thromboembolic event and why it seems to occur over months in certain patients and over decades in others, remain entirely speculative. It is possible that the overall extent of central pulmonary vascular obstruction represents the primary pathophysiologic determinant of disease progression. Given the lack of correlation between the degree of central thromboembolic obstruction and hemodynamic impairment in certain patients, however, it is also possible that other factors, such as the circulating vasoconstrictors, the development of a hypertensive pulmonary arteriopathy, an individual genetic predisposition to pulmonary hypertension, or the compensatory adaptations of the right ventricle, contribute to the extent and rate of disease progression. By identifying and sequentially evaluating patients with persistent pulmonary vascular obstruction or pulmonary hypertension following an acute thromboembolic event, valuable insights into the natural history of thromboembolic pulmonary hypertension and other variants of pulmonary hypertension might be achieved. It is also important to recognize that the development of chronic thromboembolic pulmonary hypertension represents a failure in the long-term management or follow-up surveillance of those with documented acute thromboembolic disease. Recent insights into the recurrent nature of acute thromboembolic disease and its potential for only partial resolution in a number of afflicted individuals suggest that a repeat perfusion scan and, if abnormal, an echocardiogram be performed at the time of anticipated discontinuation of anticoagulation in patients with documented pulmonary embolic disease. Although the cost-effectiveness of this approach has been questioned in the past, recent data suggest that doing so would help identify that subset of patients with unresolved embolism, provide additional information regarding the optimal duration of anticoagulation, and provide a new baseline study for patients in whom anticoagulation is discontinued and who subsequently present with suspected embolic recurrence. Improved diagnostic techniques are also necessary if the mortal risk of thromboendarterectomy is to be reduced. Even in the setting of a broad experiential base, prognostic uncertainty exists in approximately 10% of patients before operative intervention. Because many of these patients will benefit from the procedure, and because many are ineligible for transplantation for reason of age or other restriction, it has been the authors' practice to offer surgery to these patients, although at an assumed higher risk. To not do so would be to deny a potentially lifesaving procedure to many who would benefit and who might be left without an effective therapeutic alternative. The ability to better define the group of patients who will not benefit from surgery, however, would spare those patients the morbid and mortal risks of the procedure and provide a basis for the investigation of other therapeutic alternatives such as pulmonary vasodilating agents. Finally, this patient population offers a unique opportunity to enhance understanding of the pathophysiologic mechanisms involved in acute lung injury. The population involved is uniform, the predisposing event is consistent, the time of onset is predictable, and, compared with other populations at risk for acute lung injury, the presence of confounding variables is negligible. It also provides a unique opportunity to evaluate pharmacologic interventions designed to prevent or diminish the occurrence of acute lung injury and postoperative management strategies designed to minimize its impact.

[Pulmonary hypertension screening in systemic scleroderma: a cohort study of 67 patients]

PURPOSE

Pulmonary hypertension is a severe complication of systemic sclerosis and has emerged as a major cause of morbidity and mortality in this condition. Treatment is all the more efficient as pulmonary hypertension is early diagnosed. A good knowledge of the clinical, biological and functional features of pulmonary hypertension in systemic sclerosis is therefore necessary to suspect and to diagnose pulmonary hypertension as early as possible.

METHODS

Sixty seven patients with systemic sclerosis were retrospectively studied. We compared clinical, immunological, functional (spirometry) and morphological (pulmonary fibrosis) features according to the presence (n = 25) and the characteristic of pulmonary hypertension (isolated or secondary) or the absence (n = 42) of pulmonary hypertension, assessed by Doppler echocardiography.

RESULTS

CREST syndrome (calcinosis, Raynaud's phenomenon, oesophageal involvement, sclerodactyly and telangiectasia) was more frequent in patients with isolated pulmonary hypertension than in patients without PH (72.7% vs 28.5%, P < 0.05; odds-ratio [OR] = 6.6) and dyspnea was more severe (P < 0.001; OR = 11.4). The age at time of pulmonary hypertension diagnosis was higher in patients with secondary pulmonary hypertension than in patients with isolated from (median: 62.5 years (range: 32-35) vs 53 years (range: 37-85), P < 0.05). Patients with isolated pulmonary hypertension had anticardiolipin antibodies more frequently than patients without pulmonary hypertension (72.7% vs 35.7%, P < 0.05). Isolated reduction of diffusing capacity was preferentially observed among patients with isolated pulmonary hypertension than among those without pulmonary hypertension. A linear relation between systolic pulmonary artery pressure values and diffusing capacity values (r = 0.72, P < 0.01) was found. Isolated reduction of diffusing capacity was more frequent in patients with isolated pulmonary hypertension than in patients without pulmonary hypertension (63.6% vs 14.3%, P < 0.001; OR = 10.5).

CONCLUSION

The severity of pulmonary hypertension in systemic sclerosis justifies a systematic screening by Doppler echocardiography and diffusing capacity measurement. Our results allow us to better define the characteristics of sclerodermic patients with isolated or secondary pulmonary hypertension. The search for pulmonary hypertension should be repeated with time and clinicians should be particularly vigilant in the case of a patient presenting these characteristics.

Esophageal involvement and pulmonary manifestations in systemic sclerosis

OBJECTIVE

To assess whether esophageal manometric motor disturbances are associated with abnormalities consistent with interstitial lung disease (ILD) on both pulmonary function tests (PFT) and high resolution computerized tomography (HRCT) scans in patients with systemic sclerosis (SSc), during initial evaluation and at 2 years followup.

METHODS

Esophageal manometry, PFT, and HRCT scans were performed in 43 consecutive SSc patients. PFT and HRCT scan parameters were compared between patients with severe esophageal motor dysfunction (i.e., aperistalsis and decreased low esophageal sphincter pressure), patients with moderate esophageal motor dysfunction (hypoperistalsis), and patients without esophageal motor dysfunction on manometry.

RESULTS

During initial evaluation of SSc, patients with severe esophageal motor impairment, compared with those with moderate and without esophageal dysmotility, exhibited significantly decreased median values of diffusing capacity for carbon monoxide (DLco) (68% vs. 94% vs. 104%) and exhibited higher prevalence of evidence for ILD on HRCT scan (57% vs. 27% vs. 18%). At 2 years followup of SSc, patients with severe esophageal motor disturbances, compared with those without, had faster deterioration of DLco median values (-16% vs. +1%) and higher frequency of ILD on HRCT scan (70% vs. 25%).

CONCLUSION

Our series underscores a correlation between the degree of esophageal manometric motor disturbances and evidence for ILD on PFT and HRCT scan in SSc patients, suggesting that gastroesophageal reflux (GER) may be one of the contributing factors of ILD in SSc. Our findings further indicate that patients with severe esophageal impairment may require closer followup of lung parameters. In turn, it suggests that aggressive therapy of GER should be initiated in these SSc patients, as it may result in decreased deterioration of pulmonary function.

[Pulmonary involvement in systemic scleroderma. Part I. Chronic fibrosing interstitial lung disease]

INTRODUCTION

Chronic pulmonary interstitial fibrosis is the most frequent respiratory manifestation in systemic sclerosis, occurring in 80% of cases. It remains a severe complication of the disease and is the primary cause of mortality related to respiratory insufficiency in 20 to 60% of cases.

CURRENT KNOWLEDGE AND KEY POINTS

The date of onset of interstitial lung disease remains undetermined, and only in rare cases does it reveal the presence of systemic sclerosis. The clinical signs are only observable at a later stage, when at least 50% of the lung parenchyma is affected. The methods of choice adopted for early diagnosis of this disease are high resolution computed tomography and pulmonary functional investigations; they should be carried out during the preliminary investigation and at follow-up once a year. Moreover, high resolution computed tomography also provides prognostic data, for there is a correlation between the type of lesion and its severity as determined by high resolution computed tomography and by histological findings. The value of other methods of investigation, in particular bronchoalveolar lavage, has not yet been clearly established. The association of cyclophosphamide and corticoids is currently being evaluated (indications, administration modalities, duration), and this combination may be the most effective treatment.

FUTURE PROSPECTS AND PROJECTS

Interstitial lung disease is one of the major causes of morbidity and mortality in systemic sclerosis. Early diagnosis and management of this disease is therefore of utmost importance.

[Pulmonary involvement in systemic scleroderma. Part II. Isolated pulmonary arterial hypertension, bronchopulmonary cancer, alveolar hemorrhage]

INTRODUCTION

Pulmonary interstitial fibrosis is the most frequent cause of lung disease in systemic sclerosis. However, other pulmonary complications exist, including lung cancer, alveolar hemorrhage, and in particular isolated pulmonary arterial hypertension, which is still considered the bête noire as regards this disease.

CURRENT KNOWLEDGE AND KEY POINTS

The prevalence of pulmonary arterial hypertension has been reported to range from 5 to 60% in cases of systemic sclerosis; isolated pulmonary arterial hypertension has been principally observed in subjects with a ten-year history of limited forms of the disease. As the patient remains asymptomatic for a long period, with nonspecific respiratory clinical manifestations, the diagnosis is made at a much later stage in the course of the disease. The diagnostic method of choice is echocardiography-doppler, which should be performed during the preliminary investigation, and at follow-up. The prognosis is poor, and patient survival rate at 2 years after onset of symptoms amounts to 40%. To date, no curative therapy for pulmonary arterial hypertension has yet been found.

FUTURE PROSPECTS AND PROJECTS

A knowledge of the mechanisms involved in the development of isolated pulmonary arterial hypertension is essential to the determination of new and relevant therapeutic strategies. Vasodilatory treatment, notably calcium channel blockers, prostacyclin and analogs such as iloprost, may be effective at an early stage of the disease before the appearance of permanent vascular damage.

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

African-American race and antibodies to topoisomerase I are associated with increased severity of scleroderma lung disease

STUDY OBJECTIVES

To determine whether African-American race is independently associated with lung disease in scleroderma.

DESIGN

Retrospective review.

SETTING

University medical center in Baltimore.

PATIENTS

One hundred one patients with diffuse cutaneous scleroderma with available serum samples.

MEASUREMENTS

Patients underwent lung function testing as part of their routine clinical care. Percent predicted values adjusted for race were calculated for FVC, single-breath carbon monoxide diffusing capacity (Dco), and FEV1. Serum samples were assayed for the presence of antibodies to topoisomerase I and RNA polymerase II.

RESULTS

Scleroderma patients of African-American race had lower percent predicted values than white patients for FVC (p<0.002), Dco (p<0.0001), and FEV1 (p<0.0001). Antibodies to topoisomerase I but not antibodies to RNA polymerase II were also associated with lung function. African-American scleroderma patients were distinct from white patients in having younger age of onset and higher prevalence of antibodies to topoisomerase I. In multivariate analyses accounting for sex, age, smoking history, years of scleroderma symptoms, and RNA polymerase II antibody status, African-American race and topoisomerase I antibody status independently predicted lower lung function.

CONCLUSION

African-American race and antibodies to topoisomerase I are independent risk factors for scleroderma lung disease.

Clinical manifestations of systemic sclerosis

Systemic sclerosis is a multisystem disease characterized by inflammation and fibrosis of many organs. There are two major subsets, limited cutaneous (the old CREST syndrome) and diffuse cutaneous scleroderma. The major difference is the pace of disease. Limited scleroderma patients often have a long history of Raynaud's phenomenon before other symptoms. They have skin thickening limited to hands and frequently have problems with digital ulcers and esophageal dysmotility. Although generally a milder form than diffuse scleroderma, they can have life-threatening complications from small intestine hypomotility and pulmonary hypertension. Diffuse scleroderma patients have a much more acute onset, with many constitutional symptoms, arthritis, carpal tunnel syndrome, and marked swelling of hands and legs. They get widespread skin thickening, progressing from their fingers to their trunk. Internal organ problems, including gastrointestinal and pulmonary fibrosis, are common, but severe life-threatening involvement of the heart and kidneys occurs. Understanding the type of disease that occurs in these two subsets will enable the physician to anticipate problems, aggressively treat those that can be treated, and give the patient a better understanding of their disease.

The acute effects of prostacyclin on pulmonary hemodynamics in patients with pulmonary hypertension secondary to systemic sclerosis

OBJECTIVE

To determine whether patients with isolated pulmonary hypertension secondary to systemic sclerosis (SSc) have a pulmonary vasculature that is responsive to treatment with vasodilators.

METHODS

Seven SSc patients with pulmonary hypertension underwent right heart catheterization. Pulmonary pressures and cardiac output were measured before and during a systemic intravenous infusion of prostacyclin.

RESULTS

Both pulmonary arterial mean pressure and pulmonary vascular resistance decreased significantly with prostacyclin infusion (median decrease 11% and 32%, respectively), with a concomitant increase in cardiac output (median increase 26%). No adverse hemodynamic effects were noted during the infusion.

CONCLUSION

Vasospasm contributes to the pulmonary hypertension complicating SSc. This feature may be amenable to treatment with vasodilators.

Decreased nitric oxide in the exhaled air of patients with systemic sclerosis with pulmonary hypertension

BACKGROUND

Systemic sclerosis (SSc) may be complicated by pulmonary hypertension (PHT), which can occur both in the setting of fibrosing alveolitis or as lone pulmonary vascular disease. Nitric oxide (NO) is a powerful vasodilator and is produced by various cells in the respiratory tract including pulmonary vascular endothelial cells and can be measured in expired air. A study was undertaken to test the hypothesis that exhaled NO levels would be decreased in patients with SSc with PHT and to assess the utility of this measurement in discriminating between patients with and without PHT, regardless of concurrent fibrosing alveolitis.

METHODS

Exhaled NO was measured with a chemiluminescence analyser in 23 patients with SSc (six with PHT, 17 subjects without) and in 67 normal individuals. Doppler echocardiography was used to assess pulmonary artery pressure in subjects with SSc, and lung function tests were performed at the same visit as NO measurements. Thin section CT scans were analysed for the presence of abnormality consistent with fibrosing alveolitis.

RESULTS

Patients with SSc with PHT had a greater reduction in arterial oxygen tension (PaO2) and carbon monoxide gas transfer (TLCO) than patients with SSc without PHT. Exhaled NO was significantly higher in patients with SSc without PHT than in normal individuals, and was significantly decreased in patients with SSc with PHT (mean (SD) 20 (6) ppb) compared with 149 (19) ppb in those with SSc without PHT (mean difference 129 (95% CI 112 to 146) ppb) and 80 (7) ppb in normal individuals (mean difference 60 (95% CI 54 to 66) ppb).

CONCLUSION

Exhaled NO is decreased in patients with SSc with PHT compared with both normal individuals and patients with SSc without PHT.

Fibrosing alveolitis in systemic sclerosis: indices of lung function in relation to extent of disease on computed tomography

OBJECTIVE

Thin-section computed tomography (CT) provides a sensitive and reproducible method of quantifying the morphologic extent of disease in the clinical management of fibrosing alveolitis associated with systemic sclerosis (FASSc). The aim of this study was to determine which indices of lung function best reflect the extent of disease on CT in FASSc, and to determine the independent influences of smoking history, extent of fibrosing alveolitis, demographic features, and concurrent treatment upon functional impairment in FASSc.

METHODS

Sixty-four patients with FASSc were studied using CT and static and exercise lung function testing. Statistical relationships were determined by multiple regression analyses.

RESULTS

Five patients with overt pulmonary hypertension were characterized by severe impairment in 3 indices of lung function: diffusing capacity for carbon monoxide (DLCO), DLCO adjusted for alveolar volume (KCO), and arterial partial pressure of oxygen. On multiple regression analysis, the major determinant of functional impairment was the extent of fibrosing alveolitis on CT. A history of smoking was independently associated with preservation of total lung capacity and depression of KCO, but did not otherwise influence functional-morphologic correlations. The percent predicted DLCO correlated better with extent of disease on CT (r = -0.70) than did oxygen desaturation on exercise (r = 0.55), the physiologic component of the clinical-radiographic-physiologic score (CRP index) (r = 0.52), or other indices of lung function. Lung volume measures correlated poorly with disease extent on CT.

CONCLUSION

The percent predicted DLCO best reflects the extent of fibrosing alveolitis in FASSc, and therefore should be measured in routine evaluations. Exercise testing may also have a useful role in staging the severity of pulmonary fibrosis, but the CRP index offers no additional advantage over the DLCO and exercise testing.

A longitudinal study of pulmonary function in Danish patients with systemic sclerosis

OBJECTIVE

To determine the types, prevalence and development of respiratory abnormalities in patients with systemic sclerosis (SSc), and to correlate the results with clinical and serological findings.

METHODS

176 patients with SSc observed longitudinally were retrospectively included in the study. The change per year of vital capacity (VC), forced expiratory volume in one second/vital capacity (FEV1/VC), diffusing capacity (DLco) and diffusing constant (Kco) of carbon monoxide from the first till the latest pulmonary function test were correlated to clinical and serological findings, including anti-centromere, anti-Scl-70, and antinucleolar antibodies.

RESULTS

An isolated reduction of DLco was seen in 47% and a restrictive ventilatory pattern in 25% of the patients. Restrictive ventilatory pattern correlated to pulmonary fibrosis, dyspnoea, a low prevalence (13%) of anti-centromere antibodies and a high prevalence of anti-Scl-70 antibodies (36%). Progression of DLco reduction was related to long disease duration, presence of anti-centromere antibodies and absence of treatment with penicillamine.

CONCLUSION

Pulmonary involvement is common in patients with SSc. The occurrence of different serological abnormalities in patients with restrictive disease and in patients with progressive isolated reduction of DLco, suggests that the two types of pulmonary damage may have different pathogeneses rather than being different stages in the progression of pulmonary damage.

Prevalence of pulmonary hypertension in limited and diffuse scleroderma

STUDY OBJECTIVES

To characterize the prevalence of undiagnosed pulmonary hypertension in patients with limited and diffuse scleroderma.

DESIGN

Prospective cross-sectional study.

SETTING

University-based outpatient clinic.

PATIENTS

Thirty-four consecutive patients with limited (n = 29) or diffuse (n = 5) scleroderma but without the clinical diagnosis of pulmonary hypertension.

MEASUREMENTS AND RESULTS

All patients had 12-lead ECGs and two-dimensional and Doppler echocardiograms. The pulmonary artery systolic pressure (PAs) was calculated as the sum of the Doppler transtricuspid pressure gradient and the right atrial pressure as estimated by the caval respiratory index. Thirty-three patients (97%) had adequate spectral signals of tricuspid regurgitation. The velocity of tricuspid regurgitation ranged from 1.6 to 4.5 m/s. The calculated PAs ranged from 15 to 95 (mean +/- SD = 30 +/- 14 mm Hg). Twelve patients (35% of the total cohort) had pulmonary hypertension defined as PAs of 30 mm Hg or greater.

CONCLUSIONS

Undiagnosed elevation of PAs is common in patients with scleroderma. Noninvasive assessment of PAs can be performed accurately in most patients independent of clinical signs of pulmonary hypertension. If successful treatment strategies are identified, it may be possible to identify patients early in the development of pulmonary hypertension and intervene before significant end-organ damage occurs.

Scleroderma. Clinical problems. The lungs

A recent follow-up study found that patients with pulmonary involvement (with no renal or cardiac involvement) survived a median of 78 +/- 17 months. Another study found death from SSc was most frequently due to pulmonary hypertension. Improved diagnostic modalities and better understanding of the pathophysiology of SSc lung disease are essential, because mortality from this SSc lung disease remains high. During the past decade, advances have been made in the understanding of the alveolitis of SSc lung disease. Although the inciting injury remains uncertain, a cascade of inflammatory and fibrosing mediators culminates in a chronic state of interstitial lung disease. There is increasing evidence that the fibrogenic cytokines PDGF and TGF-beta are major contributors to the pathophysiology of interstitial lung disease, including that of SSc. Future research aimed at modifying the biologic response to such cytokines may yield novel therapeutic approaches to the management of this type of lung disease. Similarly, improved understanding of mediators of vascular tone, such as endothelin and nitric oxide, may yield much-needed treatments for pulmonary hypertension.

Early and late morbidity in patients undergoing pulmonary resection with low diffusion capacity

BACKGROUND

We sought to determine whether low diffusion capacity of the lung to carbon monoxide (DLCO) is a predictor of high postoperative mortality and morbidity after major pulmonary resection and whether major pulmonary resection in patients with low DLCO results in substantial long-term morbidity.

METHODS

Sixty-two major pulmonary resections were performed in 61 patients with low DLCO (DLCO < or = 60% predicted for pneumonectomy or bilobectomy; < or = 50% predicted for lobectomy). Contemporaneously, 262 other patients underwent 263 major pulmonary resections (group II). Long-term morbidity was assessed in subsets of patients with low (n = 24) and high (n = 22; DLCO > 60% predicted) DLCO.

RESULTS

The hospital mortality rates were equivalent (4.8% low DLCO versus 4.9% group II), whereas respiratory complications were more frequent in patients with low DLCO (18% versus 9.5%; p = 0.05). In the subgroup analyses, patients with low DLCO had more hospitalizations for respiratory compromise and worse median dyspnea scores. Analysis of patients with substantial dyspnea revealed an association with extended pulmonary resection and postoperative radiation therapy in patients with low DLCO.

CONCLUSIONS

Patients with low DLCO underwent major pulmonary resection with a low mortality rate and an acceptable, but increased, respiratory complication rate. Long-term respiratory morbidity was increased in patients with low DLCO; however, the extent of pulmonary resection and the use of postoperative radiation therapy may have contributed to the development of dyspnea in these patients.

Density gradient of the lung parenchyma at computed tomographic scanning in patients with pulmonary hypertension and systemic sclerosis

RATIONALE AND OBJECTIVES

Pulmonary hypertension may complicate systemic sclerosis in the absence of fibrosing alveolitis. Abnormal pulmonary perfusion is known to result in regional differences in lung density at computed tomographic (CT) scanning. We assessed possible disturbances in the normal CT density gradient in patients with systemic sclerosis and reduced gas transfer but no clinical or radiologic evidence of fibrosing alveolitis.

METHODS

We analyzed the CT scans of 15 patients with systemic sclerosis. Regions of interest were drawn in the most dependent and nondependent zones in the upper and lower lobes of each lung. Average densities for the most dependent and nondependent zones were calculated for the upper and lower lobes, and a global lung density measurement was derived. Zonal and global density gradients were derived from mean density measures (mean density of dependent areas minus mean densities of nondependent areas).

RESULTS

Five of the 15 patients had pulmonary hypertension, defined as an estimated systolic pressure in the pulmonary artery of greater than 30 mm Hg shown by Doppler echocardiography. Patients with pulmonary hypertension were characterized by higher global lung density for nondependent zones (median, -821 H versus -853 H; p = .07) but not for dependent zones (-800 H versus -815 H, p = .71). The lung density gradient was reduced globally and in the lower zones in patients with pulmonary hypertension (p = .05).

CONCLUSION

In cases of systemic sclerosis without fibrosing alveolitis, we found a significantly smaller density gradient between dependent and nondependent lung regions in patients with pulmonary hypertension compared with patients without pulmonary hypertension. This finding suggests that the normal CT density gradient depends in part on normal compliance of the pulmonary vasculature.

Therapy for severe interstitial lung disease in systemic sclerosis. A retrospective study

OBJECTIVE

This retrospective observational study attempted to determine whether any of the therapies used in the management of systemic sclerosis (SSc) patients held potential benefit for patients with interstitial lung disease.

METHODS

All patients with SSc who had a pulmonary function test (PFT) showing a forced vital capacity (FVC) of < 70% predicted and an additional PFT at least 4 months later were grouped according to the treatment they received. Changes in pulmonary function were analyzed by the mean percent predicted FVC from the initial and the final test, and by the rate of percent change in FVC (ml/year) in the first 2 years after therapy. Bronchoalveolar lavage was performed in a subset of these patients.

RESULTS

Of 363 SSc patients who had an FVC < 70% predicted, 122 had a second PFT and fulfilled the criteria for one of the following drug groups: high-dose prednisone (n = 21), immunosuppressive other than cyclophosphamide (CYC) (n = 16), CYC (n = 14), D-penicillamine (n = 37), or no drug (n = 34). In both analyses, the CYC-treated group showed significantly more improvement in FVC than did the other groups. Patients with early disease had the greatest likelihood of responding to any drug.

CONCLUSION

This retrospective study shows that patients treated with CYC had a significant improvement in FVC over time. Prospective controlled studies of CYC treatment in early disease are necessary to determine if it can significantly alter the natural history of interstitial lung disease.

Severe restrictive lung disease in systemic sclerosis

OBJECTIVE

We sought to identify risk factors for developing severe restrictive lung disease and to determine the time of onset and rate of progression in patients with systemic sclerosis (SSc).

METHODS

Using the University of Pittsburgh Scleroderma Databank, we grouped patients according to their lowest forced vital capacity (FVC) value: > 75% predicted, 50-75% predicted, and < 50% predicted. In patients with severe restrictive disease, we examined serial pulmonary function test (PFT) results to determine the rate of loss of lung volume over time.

RESULTS

Of 890 SSc patients, 60% (n = 531) never had an FVC < or = 75% predicted; 27% (n = 243) had moderate restrictive disease, with an FVC value of 50-75% predicted; and only 13% (n = 116) of the patients had severe restrictive disease, with FVC < or = 50% predicted. Black race, male sex, early disease, and primary cardiac involvement due to SSc were the features most frequently associated with severe restrictive lung disease (by multiple logistic regression). Fifty-five patients with severe restrictive lung disease had their first of at least 2 PFTs during the first 5 years after onset of any SSc (not pulmonary) symptoms. In 30 patients, the FVC declined by 32% per year in the first 2 years of illness, in 16 patients the annual loss was 12% in years 2-4 after disease onset, and in 9 patients annual loss was 3% during years 4-6 of disease (P < 0.005 by 1-way analysis of variance).

CONCLUSION

In SSc patients, black men with early disease who have cardiac involvement are the most likely to have factors associated with the development of severe restrictive lung disease (which is increasingly becoming a major cause of death). Disease subtype (diffuse versus limited cutaneous) and serum anti-topoisomerase I antibody do not differentiate between moderate and severe restrictive disease. Careful monitoring of pulmonary function early in the disease, when the greatest loss of lung function occurs, may help identify patients likely to respond to new therapy.

Improved pulmonary function in systemic sclerosis after treatment with cyclophosphamide

OBJECTIVE

Pulmonary fibrosis is a common feature of systemic sclerosis (SSc) and a major cause of morbidity and mortality. Since alveolitis may be an essential step in the development of pulmonary fibrosis, we investigated the use of immunosuppressive drug therapy to improve pulmonary function in patients with SSc.

METHODS

Eighteen patients with progressive pulmonary dysfunction, diminished vital capacity (VC), and/or decreased static lung compliance (Cst) were treated with cyclophosphamide and corticosteroids for 1 year. Eight patients had diffuse cutaneous SSc and 10 had limited cutaneous SSc. The median disease duration was 2.5 years (range 0.5-17 years).

RESULTS

VC increased in 14 of 18 patients and the median VC rose from 74% to 80% of predicted. Cst improved in 8 of 12 patients and the median Cst increased from 59% to 66% of predicted. Pulmonary nonfibrotic opacities disappeared in 9 of 12 patients. The erythrocyte sedimentation rate (ESR) and serum concentrations of orosomucoid, C-reactive protein, and aminopropeptide type III collagen all improved. The patients were divided into 2 groups based on the presence or absence of elevations in acute-phase protein levels and ESR before therapy. Among the 12 patients with biochemical signs of inflammation, VC increased in 11, and Cst improved or was unchanged in 7 of the 8 who were tested. The median VC in this subgroup increased from 73% to 80% of predicted and the median Cst increased from 57% to 60% of predicted. In the group of 18 patients overall, the skin score decreased, while esophageal and renal function remained stable.

CONCLUSION

Cyclophosphamide may have a beneficial effect on pulmonary fibrosis in patients with SSc and elevated levels of acute-phase proteins. Controlled trials of cyclophosphamide in pulmonary SSc should be performed and should focus on such patients.

Lung disease in systemic sclerosis (scleroderma)

Scleroderma (SSc) is a disease characterized by skin fibrosis but it is the end-organ effect of microvascular injury and fibrosis that is important prognostically. Pulmonary involvement in SSc patients, either of parenchymal fibrosis and/or pulmonary hypertension, is a major cause of morbidity and mortality. Interstitial lung disease occurs more commonly in patients with diffuse SSc and is associated with a loss of lung volume, as well as a defect of gas exchange. Parenchymal fibrosis may also cause pulmonary hypertension. Isolated pulmonary hypertension occurs exclusively in patients with limited SSc and is detectable by a reduced DCO. The early identification of either manifestation is difficult. Patients may have minimal symptoms, unremarkable physical findings, normal chest radiographs and/or minimally abnormal pulmonary function tests at a time when significant lung pathology is present. It is essential to attempt to identify pulmonary disease early, at a potentially reversible stage. Multiple therapeutic endeavours have yielded only short-term or minimal benefits in symptoms and pulmonary function, and thus a major alteration in SSc pulmonary prognosis has not been achieved. Further study of the pathogenesis of this disease manifestation will be helpful in its earlier identification and intervention.