Predictors of isolated pulmonary hypertension in patients with systemic sclerosis and limited cutaneous involvement

Endothelin receptor antagonism: role in the treatment of pulmonary arterial hypertension related to scleroderma

Pulmonary arterial hypertension (PAH) is a devastating disease, which is associated with a 1-year survival of about 50% without specific treatment. Pulmonary vascular remodelling, thrombosis and vasoconstriction are thought to be directly involved in increasing pulmonary vascular resistance (PVR), which, left untreated, ultimately leads to right ventricular failure and death. A total of 10-12% of patients with systemic sclerosis (SSc) develop PAH, which is a leading cause of mortality in these patients. Targeted treatment regimens involving oral therapies, in particular endothelin receptor antagonists (ERAs), such as bosentan, sitaxsentan (sitaxentan) and ambrisentan, are now being used and this approach has improved symptoms as well as survival. 1-Year survival has improved to about 80%, while 3-year survival in advanced SSc-PAH has improved from 44% to 65% since the introduction of ERAs. Subanalysis of BREATHE-1, a pilot study and the STRIDE-2X randomized controlled trials has reported improvements in time to clinical worsening, 6-minute walk distance (6mwd) and right heart haemodynamics in SSc-PAH patients given bosentan and sitaxsentan, respectively, compared with placebo. The ARIES studies have also demonstrated a delay in the time to clinical worsening and improvement in 6mwd in connective tissue associated-PAH patients given ambrisentan compared with placebo. Unfortunately, these drugs are expensive and also have the potential for adverse interactions with other PAH and supportive therapies. Mandatory monthly liver function tests are required for safe administration of bosentan, ambrisentan and sitaxsentan, while dose adjustment of warfarin and careful monitoring are required when sitaxsentan is initiated. Earlier diagnosis and treatment of PAH may further improve outcomes with current ERAs. WHO functional class (FC) has traditionally been used to determine which patients with PAH will start therapy. The EARLY study has reported significant reductions in PVR and time to clinical worsening in mildly symptomatic PAH patients treated with bosentan, and many PAH clinicians now believe WHO FC should be used as a monitoring tool once targeted therapies have been initiated and not as a tool for deciding when to start PAH specific therapies.Many pathways are thought to be involved in the pathophysiology of the PAH. There is growing evidence that combination therapies targeting different pathophysiological steps may be necessary to effectively treat SSc-PAH. The COMPASS-1 study has reported an acute haemodynamic benefit in PAH when a single-dose of sildenafil is used in combination with bosentan and COMPASS-2 will investigate whether this acute response translates into long-term benefit. Well designed morbidity and mortality trials in SSc-PAH should help increase our understanding and treatment of this orphan disease.

[Interdisciplinary point of contact between rheumatology and pneumology]

The lungs are involved in many inflammatory rheumatic diseases. We will focus on the most common clinical problems. In systemic sclerosis interstitial lung disease resulting in fibrosis and pulmonary arterial hypertension (PAH) resulting in right heart failure are the leading complications requiring close cooperation between specialists in rheumatology and pulmonology. In Sjogren's syndrome interstitial pneumonia, pleural and bronchial inflammation and rarely PAH will be the main pulmonary complications. Hypereosinophilic syndrome, eosinophilic pneumonia, and Churg-Strauss syndrome are conditions that show marked eosinophilia and can clinically be confused with asthma and allergic bronchopulmonary aspergillosis. These conditions mandate thorough investigation of the lungs including bronchoscopy and possibly open lung biopsy. Finally, patients for whom treatment with tumour necrosis factor blocking agents is planned should undergo interdisciplinary management to prevent tuberculosis activation or infection.

Membrane diffusion- and capillary blood volume measurements are not useful as screening tools for pulmonary arterial hypertension in systemic sclerosis: a case control study

BACKGROUND

There is no optimal screening tool for the assessment of pulmonary arterial hypertension (PAH) in patients with systemic sclerosis (SSc). A decreasing transfer factor of the lung for CO (TLCO) is associated with the development of PAH in SSc. TLCO can be partitioned into the diffusion of the alveolar capillary membrane (Dm) and the capillary blood volume (Vc). The use of the partitioned diffusion to detect PAH in SSc is not well established yet. This study evaluates whether Dm and Vc could be candidates for further study of the use for screening for PAH in SSc.

METHODS

Eleven SSc patients with PAH (SScPAH+), 13 SSc patients without PAH (SScPAH-) and 10 healthy control subjects were included. Pulmonary function testing took place at diagnosis of PAH. TLCO was partitioned according to Roughton and Forster. As pulmonary fibrosis in SSc influences values of the (partitioned) TLCO, these were adjusted for fibrosis score as assessed on HRCT.

RESULTS

TLCO as percentage of predicted (%) was lower in SScPAH+ than in SScPAH- (41 +/- 7% vs. 63 +/- 12%, p < 0.0001, respectively). Dm% in SScPAH+ was decreased as compared with SScPAH- (22 +/- 6% vs. 39 +/- 12%, p < 0.0001, respectively), also after adjustment for total fibrosis score (before adjustment: B = 17.5, 95% CI 9.0-25.9, p = < 0.0001; after adjustment: B = 14.3, 95% CI 6.0-21.7, p = 0.008). No difference was found in Vc%. There were no correlations between pulmonary hemodynamic parameters and Dm% in the PAH groups.

CONCLUSION

SScPAH+ patients have lower Dm% than SScPAH- patients. There are no correlations between Dm% and hemodynamic parameters of PAH in SScPAH+. These findings do not support further study of the role of partitioning TLCO in the diagnostic work- up for PAH in SSc.

Pulmonary hypertension caused by sarcoidosis

Pulmonary hypertension is an uncommon complication of sarcoidosis, but in severe pulmonary disease it occurs frequently. It is an important cause of cryptogenic dyspnea in sarcoidosis patients and can occur despite the absence of pulmonary fibrosis. The true prevalence is unknown. With the advent of specific therapies for pulmonary hypertension, there has been a resurgence of interest in the pathophysiology, diagnosis, and treatment of sarcoidosis-associated pulmonary hypertension. This article reviews the status of the current epidemiologic, pathophysiologic, and therapeutic knowledge regarding this entity.

Detection of subclinical cardiac involvement in systemic sclerosis by echocardiographic strain imaging

BACKGROUND

Cardiac involvement is one of the major problems in systemic sclerosis (SSc). Subclinical cardiac involvement has a higher frequency than thought previously. In this study we investigated whether subclinical cardiac involvement can be detected by using echocardiographic strain imaging in SSc patients without pulmonary hypertension.

METHODS

Echocardiographic examinations were performed to 27 SSc patients and 26 healthy controls. Left ventricular strain parameters were obtained from apical views and average strain value was calculated from these measurements.

RESULTS

There were no significant differences between patients and controls regarding two-dimensional (2D), conventional Doppler and tissue Doppler velocity measurements. Strain was reduced in 6 of 12 segments of the left ventricle (LV) and in 1 of 2 segments of the right ventricle (RV). Strain rate (SR) was reduced in 2 of 12 segments of the LV and 1 of 2 segments of the RV in SSc patients as compared to controls (P < 0.05 for all). These involvements did not match any particular coronary artery distribution. More important differences were detected by average strain and SR values of the LV between patients and controls (19.78 +/- 3.00% vs 23.41 +/- 2.73%, P < 0.001; 2.01 +/- 0.41 vs 2.23 +/- 0.27/sec, P = 0.026, respectively). Furthermore, carbon monoxide diffusion capacity (DLCO) in scleroderma patients significantly correlated with LV average strain (r = 0.59; P = 0.001).

CONCLUSION

Evaluation of ventricular function by using echocardiographic strain imaging appears to be useful to detect subclinical cardiac involvement in SSc patients with normal standard echocardiographic and tissue Doppler velocity findings.

Pulmonary capillary endothelial metabolic dysfunction: severity in pulmonary arterial hypertension related to connective tissue disease versus idiopathic pulmonary arterial hypertension

OBJECTIVE

Pulmonary endothelial dysfunction is intertwined with the development and progression of pulmonary arterial hypertension (PAH). Pulmonary endothelium is an active metabolic tissue in healthy human subjects. This study was undertaken to determine the effects of PAH on pulmonary endothelial angiotensin-converting enzyme (ACE) activity and to identify differences between common PAH types, i.e., PAH related to connective tissue disease (PAH-CTD) versus idiopathic PAH (IPAH).

METHODS

Nineteen patients with PAH-CTD, 25 patients with IPAH, and 23 control subjects were evaluated. The single-pass transpulmonary percent metabolism (%M) and hydrolysis (both reflecting enzyme activity per capillary) of an ACE synthetic substrate were determined. In addition, the calculated functional capillary surface area (FCSA), normalized to body surface area (BSA), was determined.

RESULTS

The %M values in patients with PAH-CTD (mean+/-SEM 53.6+/-3.6%) were significantly reduced compared with those in control subjects (P<0.01) and those in patients with IPAH (P<0.03), but were similar between the IPAH and control groups (mean+/-SEM 66.2+/-3.6% and 74.7+/-2.7%, respectively). Substrate hydrolysis was also significantly reduced in patients with PAH-CTD. The FCSA/BSA was significantly reduced in patients with PAH-CTD (mean+/-SEM 1,068+/-118 ml/minute/m2) and in patients with IPAH (1,443+/-186 ml/minute/m2) compared with that in controls (2,948+/-245 ml/minute/m2; P<0.01 for both). At a given cardiac index, the FCSA/BSA tended to be lower in the PAH-CTD group than in the IPAH group. Moreover, unlike in IPAH, a linear relationship between the FCSA/BSA and the diffusing capacity for carbon monoxide (DLCO) was observed in PAH-CTD (r=0.54, P<0.03).

CONCLUSION

The metabolically functional pulmonary capillary bed appears to be reduced to an equal extent in PAH-CTD and IPAH. However, %M and hydrolysis appear to be reduced in PAH-CTD but not in IPAH, reflecting relatively diminished ACE activity on the pulmonary capillary endothelial cells of patients with PAH-CTD, and showing that pulmonary endothelial metabolic function differs between PAH types. This study also provides the first functional evidence that a reduced DLCO value in patients with PAH-CTD is related to the degree of FCSA loss.

High N-terminal pro-brain natriuretic peptide levels and low diffusing capacity for carbon monoxide as independent predictors of the occurrence of precapillary pulmonary arterial hypertension in patients with systemic sclerosis

OBJECTIVE

To evaluate predictors of pulmonary arterial hypertension (PAH) in a prospective cohort of patients with systemic sclerosis (SSc).

METHODS

Routine clinical assessments as well as measurements of the diffusing capacity for carbon monoxide/alveolar volume (DLCO/VA) ratio and N-terminal pro-brain natriuretic peptide (NT-proBNP) level were performed in a prospective cohort of 101 SSc patients who did not have PAH or severe comorbidities. After a planned 36-month followup, we evaluated the predictive value of these parameters for the development of precapillary PAH, as demonstrated by cardiac catheterization, disease progression, and death. Criteria for cardiac catheterization were a systolic pulmonary artery pressure (PAP) of >40 mm Hg on echocardiography, a DLCO value of <50% without pulmonary fibrosis, and unexplained dyspnea.

RESULTS

Eight patients developed PAH, 29 had disease progression, and 10 died during a median followup of 29 months. Kaplan-Meier analysis identified the following baseline parameters as being predictors of PAH: DLCO/VA ratio <70% or <60% (P<0.01 for each comparison), elevated plasma NT-proBNP level (>97th percentile of normal; P = 0.005), echocardiographically estimated systolic PAP >40 mm Hg (P=0.08), and erythrocyte sedimentation rate >28 mm/hour (P=0.015). In multivariate analyses, an elevated baseline NT-proBNP level (hazard ratio [HR] 9.97 [95% confidence interval (95% CI) 1.69-62.42]) and a DLCO/VA ratio <60% (HR 36.66 [95% CI 3.45-387.6]) were predictors of the occurrence of PAH during followup. An increased NT-proBNP level together with a decreased DLCO/VA ratio of <70% was highly predictive of the occurrence of PAH during followup (HR 47.20 [95% CI 4.90-450.33]).

CONCLUSION

This prospective study identified a decreased DLCO/VA ratio and an increased NT-proBNP as predictors of PAH in SSc. Use of these markers should result in improved PAH risk stratification and allow earlier initiation of therapy.

Diagnosis of pulmonary arterial hypertension in a patient with systemic sclerosis

BACKGROUND

A 42-year-old woman with limited cutaneous systemic sclerosis presented with rapid-onset dyspnea on exertion, which had developed over the previous 8 weeks. She had not experienced any dyspnea before this period. Transthoracic Doppler echocardiography performed 6 months before presentation demonstrated an estimated right ventricular systolic pressure of 32 mmHg. Lung function tests also performed at that time revealed a decreased diffusion capacity for carbon monoxide of 54% and normal lung volumes, and high-resolution CT scan of the lungs was normal.

INVESTIGATIONS

Physical investigation, CBC, analysis of C-reactive protein and pro-brain natriuretic peptide, transthoracic Doppler echocardiography, six-minute walk test, lung function tests including diffusion capacity for carbon monoxide, right heart catheter, high-resolution CT scan, and ventilation/perfusion scan.

DIAGNOSIS

Pulmonary arterial hypertension associated with limited cutaneous systemic sclerosis.

MANAGEMENT

Treatment with oral anticoagulation therapy and the endothelin-receptor antagonist bosentan. Monitoring of adverse effects of bosentan therapy was performed using liver function tests.

Non-invasive diagnostic and functional evaluation of cardiac involvement in patients with systemic sclerosis

Elevated serum brain natriuretic peptide (BNP) released from myocytes of ventricles upon stretch have been found in patients with isolated right ventricular (RV) pressure overload. However, limited data suggest that serum BNP may be elevated in systemic sclerosis (SSc) patients, especially with RV dysfunction. We assessed serum N-terminal proBNP (NT-proBNP) in SSc and evaluated whether it reflects the severity of RV overload. We prospectively studied 51 consecutive patients (47F, mean age 53.3 +/- 15.2 years) with SSc (mean disease duration 9 +/- 12.4 years). The control group formed 31 healthy subjects (27F, mean age 52.6 +/- 12.1 years). NT-proBNP level, 6-minute walking test (6MWT), and transthoracic echocardiography (TTE) for the assessment of RV overload were performed. Serum NT-proBNP exceeded the reference value of 125 pg/mL in 31 (61%) SSc patients. The mean serum log NT-proBNP concentration in SSc was higher than in controls (2.138 +/- 0.527 vs. 1.634 +/- 0.420 pg/mL, p < 0.001). 13 (25%) SSc patients have tricuspid regurgitation peak gradient (TRPG) exceeding 31 mmHg reflecting pulmonary arterial hypertension (PAH). The SSc presented other echocardiographic signs of RV overload. Mean 6MWT distance was shorter in SSc than in controls (528 +/- 100 vs. 617 +/- 80 m, p < 0.001). NT-proBNP level correlated positively with TRPG, RV diameter, RV Tei index and negatively with 6MWT distance. ROC analysis identified >115 pg/ml as the best NT-proBNP threshold predicting PAH for SSc patients (sensitivity 92%, specificity 44%). Results of our study suggest that NT-proBNP measurement is a useful screening method for PAH in SSc patients. Since elevated plasma NT-proBNP level reflects the degree of right ventricular overload and limitation of exercise capacity, abnormal NT-proBNP levels should imply further evaluation including echocardiography.

Screening and therapy of pulmonary hypertension in systemic sclerosis

PURPOSE OF REVIEW

Systemic sclerosis is a major risk factor for the development of pulmonary arterial hypertension. Often this disease is far advanced by the time it is detected in the individual patient, severely impacting quality of life and survival.

RECENT FINDINGS

Therapeutic options available for patients with scleroderma-associated pulmonary arterial hypertension have increased significantly over the last few years, fueling our desire to improve early detection of disease.

SUMMARY

During the course of this manuscript I will review the literature examining approaches towards screening for scleroderma-associated pulmonary arterial hypertension. I will then discuss the most recent studies examining therapeutic options for patients with this disease.

Collagen Vascular Diseases and Disorders of Connective Tissue

The collagen vascular diseases, also referred to as connective tissue diseases, are a diverse group of systemic inflammatory disorders thought to be immunologically mediated. The concept of collagen vascular disease began to take shape in the 1930s, when it was recognized that rheumatic fever and rheumatoid arthritis can affect connective tissues throughout the body.1,2 During the following decade, as conditions such as systemic lupus erythematosus (SLE) and scleroderma came to be viewed as systemic diseases of connective tissue, the terms diffuse connective disease and diffuse collagen disease were proposed.3,4 During the same period, the designation of diffuse vascular disease was proposed for diseases such as scleroderma, polymyositis, SLE, and polyarteritis nodosa, which featured widespread vascular involvement.5 With the realization that many of these entities can exhibit both systemic connective tissue manifestations and vascular abnormalities, the unifying designation of collagen vascular disease was introduced.6

Interstitial lung disease in systemic sclerosis

Lung involvement frequently complicates systemic sclerosis (SSc), provoking loss of quality of life and a poor expectation of survival. For this reason an early diagnosis of lung involvement is warranted: high-resolution computed tomography (HRCT), pulmonary function tests (PFT), lung scintigraphy with DTPA and bronchoalveolar lavage (BAL) are mandatory to define and follow-up pulmonary interstitium. Coughing and a sensation of breathlessness on exertion are the earliest symptoms of lung involvement. Lung involvement may be investigated with PFTs, which are non-invasive and require breathing into a tube via a mouthpiece. Forced vital capacity, which measures the total amount of air capable of being blown forcefully, and the diffusion capacity for carbon monoxide, a measure of how well oxygen diffuses into blood, are the most important functional measures. A routine chest X-ray may demonstrate fibrosis, but it is not very sensitive for detecting early or mild disease. For this reason, a HRCT scan is required. This non-invasive investigation provides images of multiple slices through the lung, from top (apex) to bottom (base), and can even detect lung involvement in early phases when no symptoms are present. (99m)T-DTPA is recommended in those patients with isolated diffusion deficits on lung function tests and in addition to HRCT in confirming the suspicion of vascular disease rather than early fibrosing alveolitis. Bronchoscopy with BAL is an invasive test that also may provide information about the inflammatory status of the affected areas of the lung detected during HRCT. In order to detect alveolitis, it should be performed as early as possible, to start prompt immunosuppressive treatment.

[Clinical risk-adapted therapies in systemic sclerosis]

Systemic sclerosis is a challenging disease in terms of early risk assessment and the implications for therapy. The current article draws on a literature analysis and on personal experience of over 450 patients with systemic sclerosis and related illnesses, describing an attempt at a risk-adapted treatment strategy for patients with systemic sclerosis, and is intended to be used as a discussion paper. A major point of emphasis is on novel therapeutic options for patients who are refractory to current treatment strategies and who are at a high risk of serious complications or a limited prognosis. The paper also highlights possible future treatment options, including vasoactive, cellular and immune suppressant treatments.

Clinical trials in systemic sclerosis: lessons learned and outcomes

The pathogenesis of systemic sclerosis (SSc) is complex and largely unclear. The clinical heterogeneity of the disease and its progression over a number of years makes the choice of endpoints in the design of clinical trials difficult. The overwhelming need in this disease is to diagnose it early and identify those patients who will benefit most from early, aggressive treatment that potentially can alter the clinical disease course. To achieve this, innumerable challenges must be overcome. This article reviews data from recent clinical trials and the lessons derived from retrospective observational studies, databases, and patient registries. Taken together, these observations will help to improve our understanding of the diverse clinical course of SSc and permit refinement of existing outcome measures for the design of future clinical trials, in which the likelihood of observing a positive treatment effect with the drugs at our disposal will be maximized.

Lung scintigraphy with nonspecific human immunoglobulin G ((99m)Tc-HIG) in the evaluation of pulmonary involvement in connective tissue diseases: correlation with pulmonary function tests (PFTs) and high-resolution computed tomography (HRCT)

PURPOSE

In patients with connective tissue diseases (CTD), the early detection and evaluation of the severity of the pulmonary involvement is mandatory. High-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) are considered to be valuable noninvasive diagnostic modalities. Radiopharmaceuticals have also been used for this purpose. Our aim was the evaluation of technetium-labeled human polyclonal immunoglobulin G (HIG) lung scintigraphy in the early detection and assessment of the severity of the pulmonary involvement in CTD patients.

METHODS

Fifty-two nonsmoking CTD patients were studied by PFTs, HRCT, and HIG. According to PFTs, patients were divided in group A (impaired PFTs-abnormal pulmonary function) and group B (normal pulmonary function). Semiquantitative analysis was done on HIG and HRCT and corresponding scores were obtained.

RESULTS

Significant difference was found between HIG scores in the two groups (0.6 +/- 0.07 vs 0.51 +/- 0.08, P < 0.001). There was a statistically significant negative correlation between HIG scores and PFTs results and a positive correlation between HIG and HRCT scores. HIG demonstrated similar clinical performance to HRCT. At the best cut-off levels of their score (0.56 and 7, respectively), HIG had a superior sensitivity (77.5 vs 57.5%) with lower specificity (75 vs 91.7%). The combination of the two methods increased the sensitivity of abnormal findings at the expense of specificity.

CONCLUSIONS

HIG scintigraphy can be used in the early detection and evaluation of the severity of the pulmonary involvement in CTD, whereas, when used in combination with HRCT, the detection of affected patients can be further improved.

Lupus-associated pulmonary hypertension: long-term response to vasoactive therapy

INTRODUCTION

Pulmonary hypertension (PH) is a serious complication of lupus. The effectiveness of current vasoactive therapy has not been well described.

METHODS

Retrospective analysis of 12 patients with lupus-associated PH (age 43+/-10 years, mean+/-SD, all female) treated with pulmonary vasodilators.

RESULTS

At baseline, patients had severe PH: median six-minute walk distance (6MWD) 266 m (95% confidence interval [CI], 106 to 362); functional class III (n=7) and IV (n=5); mean pulmonary artery pressure (mPAP) 52 mmHg and cardiac index 2.23 L/min/m(2). Eight patients were started on epoprostenol and 2 each on bosentan or treprostinil. After a mean follow-up of 41+/-25 months, 5 patients were on combination therapy (3 epoprostenol plus bosentan, 1 treprostinil plus bosentan, 1 bosentan plus sildenafil) and 7 were on monotherapy (2 epoprostenol, 4 bosentan, 1 sildenafil); 6MWD increased by 139 m (95% CI, 36 to 259, p=0.007), 8 patients were functional class I or II and 4 were class III; right ventricular systolic pressure (RVSP) decreased by 22 mmHg (95% CI, 6 to 36; p=0.012), mPAP decreased by 18 mmHg (95% CI, 8 to 29; p=0.014), and cardiac index increased by 1.44 L/min/m(2) (95% CI, 0.76 to 2.08; p=0.016). There was no mortality or need for lung transplantation. Therapy was well tolerated.

CONCLUSIONS

Vasoactive therapy can achieve sustained clinical and hemodynamic improvement in lupus-associated PH.

Pulmonary arterial hypertension in systemic sclerosis: the need for early detection and treatment

Pulmonary arterial hypertension (PAH) is an important cause of mortality in systemic sclerosis (SSc). The symptoms are non-specific and can be ascribed to other features of the disease, so it is often underrecognized until the late stages. Earlier treatment with new agents is associated with better treatment outcomes. The aim of this article is to develop evidence-based guidelines for screening for PAH and interstitial lung disease (ILD) in SSc. PAH occurs in up to 27% of patients with SSc. Abnormal pulmonary function, particularly a disproportionate fall in carbon monoxide diffusing capacity (DLCO), can identify patients in the early stages of PAH, prompting further investigation in high-risk patients (limited SSc of >10 years' duration, symptoms and/or signs of PAH, DLCO <50% predicted, a rapid or large fall in DLCO without evidence of ILD and/or estimated systolic pulmonary artery pressure >45 mmHg on echocardiography). Right heart catheter remains the diagnostic gold standard. An algorithm for screening with regular pulmonary function tests for the early detection of PAH and ILD in SSc is proposed.

Measuring Outcomes in PAH: The Gap between the Measures That Are Used and Their Validity

Pulmonary arterial hypertension (PAH) has poor prognosis in systemic sclerosis (SSc), and at present the "gold standard" for diagnosis and follow-up of PAH in SSc is right heart catheterization (RHC) but it would be very useful to have a noninvasive way to follow these patients. Using the OMERACT criteria for validation of measures of response, the only fully validated measure for PAH in SSc has been the 6-min walking test. Multiple other measures are particularly valid (e.g., echocardiography, brain natriuretic protein [BNP], FV/DLCO) while a few are unlikely ever to be validated for various reasons (e.g., symptoms, MRA). A Delphi exercise among 78 experts (EPOSS) has been done and has developed a consensus document consisting of eight domains (lung vascular/PAP, exercise capacity, cardiac function, dyspnea, discontinuation of treatment, quality of life, lung parenchymal, and global state), which can be used and must be tested.

Determinants of Pulmonary Arterial Hypertension in Scleroderma

OBJECTIVE

To define risk factors associated with pulmonary arterial hypertension (PAH) in a large cohort of patients with systemic sclerosis (SSc).

METHODS

SSc patients undergoing screening for PAH by means of Doppler echocardiography were identified and their charts were retrospectively reviewed. In all patients, we recorded systolic pulmonary artery pressure along with pulmonary function testing, clinical, and laboratory data. PAH was defined as right ventricular systolic pressure equal or greater than 40 mm Hg.

RESULTS

Of 114 SSc patients with echocardiographic measurements, PAH was found in 33 (29%) patients. In a multiple logistic regression analysis, the presence of pulmonary fibrosis on thoracic computed tomography (OR 6.78, CI 1.54 to 29.9), forced vital capacity less than 80% predicted (OR 3.03, CI 1.1 to 8.35), and duration of Raynaud's phenomenon preceding the onset of skin changes for at least 3 years (OR 5.75, CI 1.9 to 17.41) were found to be independent predictors of PAH. Age, disease duration, disease subtype, or autoantibodies were not associated with PAH in our patients.

CONCLUSIONS

The present analysis identified pulmonary fibrosis and Raynaud's phenomenon preceding SSc skin manifestations by at least 3 years as risk factors for PAH in our scleroderma cohort. Screening for PAH in these high-risk patients may detect PAH at an earlier stage and guide decisions on therapeutic interventions.

Pulmonary involvement in systemic sclerosis: associations with genetic, serologic, sociodemographic, and behavioral factors

OBJECTIVE

To determine the relative contributions of genetic, clinical, serologic, sociodemographic, and behavioral/psychological variables to early pulmonary involvement in the Genetics versus Environment in Scleroderma Outcome Study cohort.

METHODS

At the baseline visit (V0), 203 patients with systemic sclerosis (SSc) were examined (104 whites, 39 African Americans, and 60 Hispanics). We obtained sociodemographic, behavioral/psychological (illness behavior, social support, learned helplessness, smoking, drinking), clinical, serologic (autoantibodies), and genetic (HLA class II and FBN1 genotypes) factors; pulmonary function test results; electrocardiograms; and chest radiographs. Data analysis included Fisher's exact test, chi-square test, Student's t-test, analysis of variance, and stepwise linear and logistic regression methods.

RESULTS

Significant pulmonary involvement was seen in 25% of patients within 2.8 years of SSc diagnosis. At V0, pulmonary fibrosis was significantly higher in African Americans compared with whites or Hispanics. African Americans had significantly lower percent predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) compared with whites and significantly lower percent predicted diffusing capacity for carbon monoxide (DLCO) compared with whites and Hispanics. Significant, independent associations impacting early pulmonary involvement included African American ethnicity, skin score, serum creatinine and creatine phosphokinase values, hypothyroidism, and cardiac involvement. Anticentromere antibody seropositivity was a significant, independent, protective factor for restrictive lung disease and FVC or DLCO values. African Americans had significantly increased frequencies of anti-topoisomerase I, fibrillarin, and RNP autoantibodies compared with whites. African Americans scored significantly lower on the Interpersonal Support Evaluation List and significantly higher on the Illness Behavior Questionnaire.

CONCLUSION

Early pulmonary involvement in SSc appears to be influenced by several factors delineated by ethnicity, including racial, socioeconomic, behavioral, and serologic determinants.

Pericardial Abnormalities Predict the Presence of Echocardiographically Defined Pulmonary Arterial Hypertension in Systemic Sclerosis-Related Interstitial Lung Disease

OBJECTIVES

To determine the prevalence and significance of pericardial abnormalities in systemic sclerosis (SSc)-related interstitial lung disease (ILD).

METHODS

Retrospective study of 41 subjects with SSc-related ILD who underwent evaluation including thoracic high-resolution CT (HRCT) imaging, transthoracic echocardiography (TTE), and pulmonary function testing. HRCT review evaluated the pericardium for the presence of pericardial effusion (PEf), thickness of the anterior pericardial recess (APR) [abnormal defined as > 10 mm], and pericardial thickening as calculated by total pericardial score (TPS) [abnormal defined as > 8 mm]. Pulmonary arterial hypertension (PAH) was defined as a pulmonary artery pressure > 35 mm Hg estimated by TTE.

RESULTS

Fifty-nine percent had an abnormal pericardium, 49% had a PEf, 56% had an abnormal APR, and 49% had an abnormal TPS. An abnormal pericardium was more common in men than women. Subjects with and without pericardial abnormalities were otherwise similar with respect to age, SSc classification, autoantibodies, ILD radiographic pattern, and presence of esophageal dilation. Both groups had similar median percentage of predicted total lung capacity, percentage of predicted FVC, percentage of predicted FEV(1), and percentage of predicted diffusion capacity of the lung for carbon monoxide. Subjects with pericardial abnormalities were more likely to have coexistent PAH (35% vs 75%; p = 0.02) and a higher median right ventricular systolic pressure (31 mm Hg vs 44 mm Hg; p = 0.03). Multiple logistic regression revealed that TPS was the best individual predictor of the presence of TTE-defined PAH.

CONCLUSIONS

In patients with SSc-related ILD, pericardial abnormalities are commonly seen on HRCT, and their presence is strongly associated with echocardiographically defined PAH, with abnormal TPS as the best individual predictor.

Bosentan for the treatment of systemic sclerosis-associated pulmonary arterial hypertension, pulmonary fibrosis and digital ulcers

Systemic sclerosis (SSc) is a devastating multisytemic autoimmune disease associated with widespread vascular damage. Pulmonary arterial hypertension (PAH) occurs in a significant proportion of patients and contributes to the morbidity and mortality that occurs in this disease. The recent development of specific therapies for the treatment of PAH mandates the early recognition, appropriate evaluation and judicious management of PAH in patients with SSc. Because endothelin (ET)-1 plays an important role in the development of PAH in SSc, and may also contribute to the vascular damage and fibrosis that occur in multiple organs in patients with the disease, inhibiting the production and activity of ET-1 is an appealing strategy for the treatment of SSc. This article reviews the pathophysiology of SSc and its vascular complications, and critically evaluates the current knowledge regarding the potential role of the ET-1 receptor blocker bosentan in the management of patients with SSc.

Hypertension artérielle pulmonaire associée à la sclérodermie systémique

Pulmonary arterial hypertension (PAH) is a serious complication of systemic sclerosis (SSc) and a leading cause of death in patients with it. Recent publications suggest that a prevalence of 10-15% is likely. The prognosis remains poor compared to that of idiopathic PAH. WHO recommends annual echocardiography for PAH screening of patients with SSc. Right heart catheterization is necessary to confirm the diagnosis. Nevertheless, more than half of all SSc patients have symptoms classified as WHO functional class III or IV at diagnosis. Prostacyclin therapy, delivered via continuous intravenous infusion (epoprostenol), has been demonstrated to be effective in patients with severe PAH (both idiopathic and scleroderma-related). Prostacyclin analogs (such as treprostinil and iloprost) are other options. Bosentan is the first endothelin receptor antagonist approved in the EU for the treatment of PAH, both idiopathic and related to connective tissue diseases such as scleroderma, in patients in WHO functional class III. Sildenafil by its selective inhibition of phosphodiesterase type 5 is also effective against both types of PAH. It too is now approved in the EU for this purpose in patients in WHO functional class III, but we do not yet have any information about its long-term effects in scleroderma.

HLA-B35 upregulates the production of endothelin-1 in HLA-transfected cells: a possible pathogenetic role in pulmonary hypertension

HLA-B35 is associated with an increased risk for developing isolated pulmonary hypertension (iPHT) in systemic sclerosis, but the mechanisms underlying this association have not been fully elucidated yet. Endothelin-1 (ET-1) is the main pathogenetic molecule implied in the development of iPHT; therefore, we sought to determine if ECV304 cells transfected with the HLA-B35 allele produce increased amounts of ET-1 after incubation with physiological concentrations of interleukin-1 beta (IL-1beta). ECV304 cells transfected with HLA-B*3501 and HLA-B*0801 polymorphic alpha chain or with pIRESneo2 were incubated with 100 U/ml of IL-1beta for 6, 12, 24, 36 and 48 h. ET-1 levels were determined using EIA kit (CAYMAN Chemical, Ann Arbor, MI) in supernatants from different cell cultures; the relative expression of the preproendothelin-1 (PPET-1) gene was also determined by reverse transcription-polymerase chain reaction. Cells expressing the HLA-B35 allele showed significantly increased levels of ET-1 at all the selected times compared with controls or HLA-B8-transfected cells. The relative expression of the PPET-1 gene was also increased in a proportionally direct manner. The HLA-B35 allele influences the production of ET-1 in HLA-B35-transfected ECV304 cells by promoting the expression of its precursor, PPET-1. Our results provide an explanation for the epidemiological association existing between iPHT and HLA-B35.

Mechanisms and consequences of fibrosis in systemic sclerosis

Systemic sclerosis (SSc), also known as scleroderma, is a complex connective tissue disease that is associated with a high mortality and is challenging to treat because of its clinical heterogeneity and a lack of effective antifibrotic therapies. SSc has vascular, immunologic and fibrotic components that are pathologically interconnected. A growing understanding of the molecular and cellular mechanisms that underlie SSc pathogenesis provides logical and novel approaches to treatment. At present most therapies are organ-based. Vascular and inflammatory components of the disease can also be treated, but effective antifibrotic therapies are lacking. A number of key molecular mediators have the potential to alter immune-cell, vascular and fibrotic processes and these mediators, which include transforming growth factor-beta isoforms, endothelin-1, connective-tissue growth factor, chemokines and members of the interleukin family, are attractive targets for therapeutic modulation. Key mediators can be blocked using antibodies, soluble receptors, endogenous inhibitors or small-molecule antagonists of ligands, receptors or signaling intermediates. Overall, this is an exciting time for new therapies in SSc and advances are being made in synchrony with an improved understanding of the molecular and biochemical basis of the disease.

Unique Characteristics of Systemic Sclerosis Sine Scleroderma-Associated Interstitial Lung Disease

STUDY OBJECTIVES

To describe the characteristics of systemic sclerosis sine scleroderma (ssSSc)-associated interstitial lung disease (ILD) presenting as idiopathic interstitial pneumonia (IIP).

DESIGN

Retrospective review of six patients with ssSSc-associated ILD diagnosed after referral for evaluation of IIP.

MEASUREMENT AND RESULTS

All patients were white, their mean age was 56 years (range, 37 to 86), and gender was evenly divided. Sclerodactyly, skin thickening, and digital edema were absent in all patients. All patients had scattered telangiectasia, and four patients had Raynaud phenomenon with abnormal nailfold capillaroscopy findings. All described gastroesophageal reflux, and three patients had esophageal dysmotility by esophagography. All had restrictive pulmonary physiology and a reduced diffusion capacity. High-resolution CT revealed nonspecific interstitial pneumonia (NSIP) or usual interstitial pneumonia (UIP) radiographic patterns. Of the three patients who underwent surgical lung biopsy, two patients had NSIP and one patient had UIP pathologic patterns. Five patients had asymptomatic pericardial effusions and elevated pulmonary artery pressures by echocardiography. All patients had nucleolar-staining anti-nuclear antibodies (ANAs), and one patient was anti-Scl-70 positive. All five anti-Scl-70-negative patients were anti-Th/To positive, and the anti-Scl-70-positive patient was anti-Th/To negative.

CONCLUSIONS

In the presentation of an IIP, the presence of a nucleolar-staining ANA, telangiectasia, Raynaud phenomenon with abnormal capillaroscopy findings, gastroesophageal reflux, or pericardial disease suggests underlying systemic sclerosis. These findings should aid clinicians in the evaluation and treatment of patients with otherwise undefined ILD.

Pulmonary arterial hypertension and rheumatic diseases—from diagnosis to treatment

Survival rates in pulmonary arterial hypertension (PAH) associated with rheumatic diseases, in particular connective tissue diseases such as systemic sclerosis, are even lower than in idiopathic PAH. These low survival rates highlight the need for early diagnosis and treatment in these patients. Transthoracic Doppler-echocardiography is most often used for diagnostic screening of patients at risk. Other screening tests are serum pro-brain-natriuretic peptide (pro-BNP) and diffusion capacity for carbon monoxide (DLCO), which appear to be changed early in the course of the PAH associated with connective tissue diseases. The diagnosis needs to be confirmed by right heart catheterization, which is recommended in all patients with suspected PAH. Besides the conventional background therapy, a number of specific therapies have been evaluated in randomized controlled trials in the recent years. These therapies include prostacyclins and prostacyclin analogues, endothelin-receptor antagonists and phosphodiesterase-5 inhibitors. Response to treatment can be measured by exercise capacity (e.g. 6 min walk distance) and pro-BNP, although certain aspects of validation for these outcome measures are lacking in PAH associated with connective tissue diseases.

Treatment of systemic sclerosis

Systemic sclerosis is the most severe of all connective tissue diseases. The distinctive pathogenic process involves sequential or concomitant abnormalities in blood vessel function, immunity and, ultimately, fibroblast function. These specific characteristics may explain the results of treatment evaluations. The decrease in excess mortality shown in recent studies seems chiefly ascribable to the use of cardiovascular drugs. Angiotensin-converting enzyme (ACE) inhibitors are effective in resolving renal crisis, prostacyclins and endothelin antagonists improve pulmonary hypertension, and calcium antagonists and ACE inhibitors benefit patients with myocardial involvement. On the other hand, immunomodulatory drugs and other agents investigated for their disease-modifying potential failed to influence skin fibrosis in controlled trials. Trials of immunosuppressants are ongoing. Available results indicate that emphasis should be put on cardiovascular drugs. The development of criteria for disease activity and severity would facilitate future research on the treatment of systemic sclerosis.

Systemic sclerosis: hypothesis-driven treatment strategies

We review data from controlled trials and randomised controlled trials to examine the hypothesis for the pathogenesis of systemic sclerosis. Strategies used to treat the vascular complications in systemic sclerosis have so far shown the biggest successes, especially in the management of renal crisis and pulmonary arterial hypertension. Because these drugs have improved function and quality of life and have increased survival rates, they can truly be classified as disease-modifying compounds. Immunosuppressive therapy with cyclophosphamide in particular has also shown evidence of efficacy, and randomised controlled trials of autologous stem-cell transplantation are underway. So far, strategies to reduce or control fibrosis directly (bosentan, interferon gamma, and relaxin) have been disappointing but new strategies against fibrosis based on advanced understanding of the molecular biology of systemic sclerosis hold promise. Treatments against several cardinal features of the disorder simultaneously have not yet been examined but are being considered for future trials.

Microvascular damage in systemic sclerosis: Detection and monitoring with biomarkers

Vascular disease is universal in patients with systemic sclerosis (SSc), but there is a wide variability in its severity. It is clear that there is an early insult to the microvasculature, followed-up by on-going chronic process. This results in profound vascular damage in a subset of patients who develop severe events such as digital loss and pulmonary arterial hypertension. Although there is abundant evidence of vascular perturbation from studies of peripheral blood in SSc, there are few data about the ability to use these biomarkers to predict vascular outcomes. This paper examines the possibility of using circulating biomarkers to assess vascular disease activity and to predict severe vascular events among patients with SSc.

Abnormal pulmonary function in adults with sickle cell anemia

RATIONALE

Pulmonary complications of sickle cell anemia (Hb-SS) commonly cause morbidity, yet few large studies of pulmonary function tests (PFTs) in this population have been reported.

OBJECTIVES

PFTs (spirometry, lung volumes, and diffusion capacity for carbon monoxide [DLCO]) from 310 adults with Hb-SS were analyzed to determine the pattern of pulmonary dysfunction and their association with other systemic complications of sickle cell disease.

METHODS

Raw PFT data were compared with predicted values. Each subject was subclassified into one of five groups: obstructive physiology, restrictive physiology, mixed obstructive/restrictive physiology, isolated low DLCO, or normal. The association between laboratory data of patients with decreased DLCO or restrictive physiology and those of normal subjects was assessed by multivariate linear regression.

MEASUREMENTS AND MAIN RESULTS

Normal PFTs were present in only 31 of 310 (10%) patients. Overall, adults with Hb-SS were characterized by decreased total lung capacities (70.2 +/- 14.7% predicted) and DLCO (64.5 +/- 19.9%). The most common PFT patterns were restrictive physiology (74%) and isolated low DLCO (13%). Decreased DLCO was associated with thrombocytosis (p = 0.05), with hepatic dysfunction (elevated alanine aminotransferase; p = 0.07), and a trend toward renal dysfunction (elevated blood urea nitrogen and creatinine; p = 0.05 and 0.07, respectively).

CONCLUSIONS

Pulmonary function is abnormal in 90% of adult patients with Hb-SS. Common abnormalities include restrictive physiology and decreased DLCO. Decreased DLCO may indicate more severe sickle vasculopathy characterized by impaired hepatic and renal function.

Pulmonary arterial hypertension in France: results from a national registry

RATIONALE

Pulmonary arterial hypertension (PAH) is an orphan disease for which the trend is for management in designated centers with multidisciplinary teams working in a shared-care approach.

OBJECTIVE

To describe clinical and hemodynamic parameters and to provide estimates for the prevalence of patients diagnosed for PAH according to a standardized definition.

METHODS

The registry was initiated in 17 university hospitals following at least five newly diagnosed patients per year. All consecutive adult (> or = 18 yr) patients seen between October 2002 and October 2003 were to be included.

MAIN RESULTS

A total of 674 patients (mean +/- SD age, 50 +/- 15 yr; range, 18-85 yr) were entered in the registry. Idiopathic, familial, anorexigen, connective tissue diseases, congenital heart diseases, portal hypertension, and HIV-associated PAH accounted for 39.2, 3.9, 9.5, 15.3, 11.3, 10.4, and 6.2% of the population, respectively. At diagnosis, 75% of patients were in New York Heart Association functional class III or IV. Six-minute walk test was 329 +/- 109 m. Mean pulmonary artery pressure, cardiac index, and pulmonary vascular resistance index were 55 +/- 15 mm Hg, 2.5 +/- 0.8 L/min/m(2), and 20.5 +/- 10.2 mm Hg/L/min/m(2), respectively. The low estimates of prevalence and incidence of PAH in France were 15.0 cases/million of adult inhabitants and 2.4 cases/million of adult inhabitants/yr. One-year survival was 88% in the incident cohort.

CONCLUSIONS

This contemporary registry highlights current practice and shows that PAH is detected late in the course of the disease, with a majority of patients displaying severe functional and hemodynamic compromise.

Targeted therapy for systemic sclerosis

Systemic sclerosis is a multisystem disease whose therapy is focused at pathogenic pathways causing variable types of damage in the individual organs. There are 3 major pathways that cause organ damage in scleroderma. First, t-cells, cytokines and inflammation are prominent very early in the disease. Early alveolitis which occurs before interestial fibrosis in the lungs is the best example of inflammation. Second, endothelial cell damage causes severe thickening of vessels and two of the most deadly complications in scleroderma, pulmonary arterial hypertension and renal crisis. Scleroderma renal crisis is now very treatable with angiotensin converting enzyme inhibitors. There are now treatments for pulmonary arterial hypertension which should improve outcome in these patients as well. Third, fibroblasts lead to severe cutaneous fibrosis or skin thickening that is the hallmark of the disease. No treatment is available but we are hopeful that new antagonists to the cytokine, TGF beta, will prove helpful. B cells and autoantibodies are not involved in the pathogenesis of the disease, but there are scleroderma specific antibodies that help in defining patient subsets. All of these factors are influenced by unknown inciting agents and the permissive genetic background.

Early detection of pulmonary arterial hypertension in systemic sclerosis: a French nationwide prospective multicenter study

OBJECTIVE

Screening allows for early management of pulmonary arterial hypertension (PAH), a severe complication of systemic sclerosis (SSc). Since no consensus has been reached on the method and criteria for optimal screening, we sought to develop an algorithm based on symptoms, Doppler echocardiography, and right heart catheterization (RHC) for application to a nationwide multicenter SSc population in France.

METHODS

This prospective study was conducted from September 2002 to July 2003 by experts at 21 SSc centers. At each center, SSc patients without severe pulmonary function abnormalities underwent Doppler echocardiography by an experienced cardiologist. Patients with a peak velocity of tricuspid regurgitation (VTR) of >3 meters/second or 2.5-3 meters/second with unexplained dyspnea were asked to undergo RHC to confirm PAH according to international guidelines.

RESULTS

Of the 599 patients analyzed, 29 had known PAH and 33 had suspected PAH, based on Doppler echocardiography, and underwent RHC. Of these 33, 18 were found to have PAH, 3 had left ventricular dysfunction, and 12 had no PAH. Newly diagnosed cases of PAH were of mild severity (mean +/- SD pulmonary artery pressure [mPAP] 30 +/- 9 mm Hg, mean +/- SD total pulmonary resistance [TPR] 524 +/- 382 dynes x second/cm(5)). Hemodynamic findings in patients with known PAH were mPAP 49 +/- 17 mm Hg and TPR 1,007 +/- 615 dynes x second/cm(5). The estimate of PAH prevalence was 7.85% (95% confidence interval 5.70-10.00).

CONCLUSION

This screening algorithm, based on dyspnea, Doppler echocardiographic evaluation of VTR, and RHC, enabled early detection of PAH at a mild stage. Whether mild PAH will evolve to severe PAH in reported cases and whether this early diagnosis translates into improved prognosis for patients with mild PAH will be evaluated in the ongoing 3-year followup of this cohort.

Scleroderma lung: Initial forced vital capacity as predictor of pulmonary function decline

OBJECTIVE

To determine the ability of initial forced vital capacity (FVC) of patients with scleroderma to predict subsequent pulmonary function deterioration.

METHODS

Data on 78 patients with scleroderma were retrospectively collected and analyzed. FVC (percent predicted), diffusing capacity for carbon monoxide (percent predicted), and various clinical and laboratory parameters were recorded. Pulmonary function decline (outcome) was defined as at least a 15-point sustained decrease in FVC (percent predicted). Kaplan-Meier analyses were performed separately for 60 patients initially assessed within the first 3 years from disease onset (group A) and 16 patients whose FVC values in the fourth or fifth year from disease onset were ascribed as baseline measurements (group B).

RESULTS

Based on baseline FVC, patients in each group were categorized into those with normal FVC (> or =80% predicted) and those with decreased FVC (<80% predicted). In group A, the percent-predicted FVC of 89% of patients with normal initial FVC and of 75% of patients with reduced baseline FVC did not decrease by > or =15 points at 5 years (log rank P = 0.04). Four patients with decreased baseline FVC developed respiratory failure (FVC <50% predicted) versus none with normal initial FVC. Analysis of group B showed no difference between patients with normal baseline FVC and those with decreased FVC in the ability to further predict pulmonary function decline (log rank P = 0.13). Clinical and laboratory parameters (age, male sex, baseline diffusion capacity, anti-topoisomerase I, or duration of Raynaud's phenomenon preceding skin manifestations) were not associated with pulmonary function decline.

CONCLUSION

Measured within the first 3 years from disease onset, baseline FVC (percent predicted) may predict deterioration of pulmonary function in patients with scleroderma. Patients with normal pulmonary function at initial assessment are at low risk to develop considerable impairment of pulmonary function.

Pulmonary arterial hypertension

Pulmonary arterial hypertension is a disease of the small pulmonary arteries characterized by vascular narrowing and increased pulmonary vascular resistance, which eventually leads to right ventricular failure. Vasoconstriction, vascular proliferation, remodeling of the pulmonary vessels, and thrombosis are all contributing factors to the increased vascular resistance seen in this disease. Pulmonary arterial hypertension develops as a sporadic disease (idiopathic), as an inherited disorder (familial), or in association with certain conditions (collagen vascular diseases, portal hypertension, human immunodeficiency virus infection, congenital systemic-to-pulmonary shunts, ingestion of drugs or dietary products, or persistent fetal circulation). The pathogenesis of pulmonary arterial hypertension is a complicated, multifactorial process. It seems doubtful that any one factor alone is sufficient to activate the necessary pathways leading to the development of this disease. Rather, clinically apparent pulmonary arterial hypertension most likely develops after a second insult occurs in an individual who is already susceptible owing to genetic factors, environmental exposures, or acquired disorders. Currently, there is no cure for pulmonary arterial hypertension but several novel therapeutic options are now available that can improve symptoms and increase survival.