Pulmonary hypertension in autoimmune rheumatic diseases: where are we now?

Systemic Lupus Erythematosus and Lung Involvement: A Comprehensive Review

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multiorgan manifestations, including pleuropulmonary involvement (20-90%). The precise mechanism of pleuropulmonary involvement in SLE is not well-understood; however, systemic type 1 interferons, circulating immune complexes, and neutrophils seem to play essential roles. There are eight types of pleuropulmonary involvement: lupus pleuritis, pleural effusion, acute lupus pneumonitis, shrinking lung syndrome, interstitial lung disease, diffuse alveolar hemorrhage (DAH), pulmonary arterial hypertension, and pulmonary embolism. DAH has a high mortality rate (68-75%). The diagnostic tools for pleuropulmonary involvement in SLE include chest X-ray (CXR), computed tomography (CT), pulmonary function tests (PFT), bronchoalveolar lavage, biopsy, technetium-99m hexamethylprophylene amine oxime perfusion scan, and (18)F-fluorodeoxyglucose positron emission tomography. An approach for detecting pleuropulmonary involvement in SLE includes high-resolution CT, CXR, and PFT. Little is known about specific therapies for pleuropulmonary involvement in SLE. However, immunosuppressive therapies such as corticosteroids and cyclophosphamide are generally used. Rituximab has also been successfully used in three of the eight pleuropulmonary involvement forms: lupus pleuritis, acute lupus pneumonitis, and shrinking lung syndrome. Pleuropulmonary manifestations are part of the clinical criteria for SLE diagnosis. However, no review article has focused on the involvement of pleuropulmonary disease in SLE. Therefore, this article summarizes the literature on the epidemiology, pathogenesis, diagnosis, and management of pleuropulmonary involvement in SLE.

Vascular Manifestations in Antiphospholipid Syndrome (APS): Is APS a Thrombophilia or a Vasculopathy?

PURPOSE OF REVIEW

Antiphospholipid antibody syndrome (APS) is characterized primarily by thrombosis and pregnancy morbidity. Chronic vascular lesions can also occur. While the underlying mechanisms of these vascular lesions are not entirely known, there have been multiple theories describing the potential process of vasculopathy in APS and the various clinical manifestations associated with it.

RECENT FINDINGS

Recently, it has been demonstrated that endothelial proliferation in kidneys can be explained by the activation of the mammalian target of rapamycin complex (mTORC) pathway by antiphospholipid antibodies (aPL). These data support the existence of an APS-related vasculopathy in different locations which can explain-in part-the different manifestations of APS. This review focuses on the various manifestations of APS as a result of APS-related vasculopathy, as well as pathophysiology, current screening, and treatment options for clinicians to be aware of.

Therapy with intermittent pulse cyclophosphamide for pulmonary hypertension associated with systemic lupus erythematosus

The aim of this study was to compare the efficacy of intravenouscyclophosphamide(IVCYC) versus oral enalapril in mild or moderate pulmonary hypertension (PH) in systemic lupus erythematosus (SLE). Thirty-four patients with SLE who had systolic pulmonary artery pressure (SPAP) > 30mmHg by Doppler echocardiography were randomized to receive IVCYC (0.5g/mt2 body surface area, monthly), or oral enalapril (10mg/day) for six months. The primary outcome was the significant decrease in SPAP. An additional outcome measure included the improvement in the heart functional class (NYHA). Sixteen patients received cyclophosphamide and 18 enalapril. IVCYC decreased the median values of SPAP from 41 to 28mmHg (P < 0.001), and enalapril from 35 to 27mmHg (P 0.02). IVCYC reduced more than twice as much SPAP than enalapril (P 0.04). In those patients with SPAP ≥35mmHg, cyclophosphamidedecreased from 43 to 27mmHg (P 0.003), but enalapril was not effective (P 0.14). The NYHA functional class improved only in those with cyclophosphamide (P 0.021). Also IVCYC had a higher frequency of side effects including infections (RR 1.6; 95% CI, 1.001-2.47), and gastrointestinal side effects (RR 14.6; 95% CI,2.15-99.68). We concluded that IVCYC was effective in mild and moderate PH associated with SLE. Further research is needed to evaluate its long-term efficacy.

Pulmonary arterial hypertension in primary amyloidosis

Amyloidosis involves extravascular deposition of fibrillar proteins within tissues and organs. Primary light chain amyloidosis represents the most common form of systemic amyloidosis involving deposition of monoclonal immunoglobulin light chains. Although pulmonary amyloid deposition is common in primary amyloidosis, clinically significant pulmonary amyloidosis is uncommon, and elevated pulmonary artery pressures are rarely observed in the absence of other underlying etiologies for pulmonary hypertension, such as elevated filling pressures secondary to cardiac amyloid. In this case report, we present a patient with primary light chain amyloidosis and pulmonary arterial hypertension in the setting of pulmonary vascular and right ventricular myocardial amyloid deposition.

Survival in rheumatoid arthritis-associated pulmonary arterial hypertension compared with idiopathic pulmonary arterial hypertension

BACKGROUND AND OBJECTIVE

In this study, we evaluated survival in rheumatoid arthritis-associated pulmonary arterial hypertension (RA-PAH) compared with idiopathic pulmonary arterial hypertension (IPAH) patients, and evaluate differences in disease severity and treatment.

METHODS

We conducted a retrospective cohort study of RA-PAH and IPAH at the University Health Network Pulmonary Hypertension Programme, Toronto, Canada. The primary outcome was time to all-cause mortality. We evaluated survival using Kaplan-Meier curves. Using a propensity score-matched cohort, we used Cox proportional hazards models to estimate survival.

RESULTS

Screening 1385 patients identified 18 RA-PAH and 155 IPAH patients. RA-PAH patients had an older median age of onset (64.0 vs 53.7 years) and lower baseline mean pulmonary arterial pressure (mPAP) (41 vs 50 mm Hg, P = 0.02). RA-PAH patients tended to have a higher proportion of females (83% vs 70%, relative risk 0.55, 95% confidence interval (CI): 0.19-1.57), lower proportion with baseline World Health Organization functional class III/IV (39% vs 52%), lower median baseline brain natriuretic peptide (58.4 vs 95.0 pg/mL) and longer baseline 6-min walk distance (440 vs 397 m). There were 35 deaths, 2/18 (11%) RA-PAH patients and 33/155 (21%) IPAH patients. The unadjusted 1-year survival was 93% for RA-PAH and 94% for IPAH. In the matched cohort, there were seven deaths: 2/18 (11%) RA-PAH and 5/18 (28%) IPAH patients, hazard ratio 1.53 (95% CI: 0.15-2.84). Separation of survival curves did not achieve statistical significance, log-rank 0.56.

CONCLUSIONS

Compared with IPAH patients, RA-PAH patients have an older age of onset and lower baseline mPAP. RA-PAH patients have comparable survival to IPAH patients.

Pulmonary hypertension in systemic lupus erythematosus

Systemic lupus erythematosus is associated with several forms of pulmonary hypertension. It can cause pulmonary hypertension through pulmonary thromboembolic disease, left heart disease and lung disease as well as causing an isolated pulmonary vasculopathy called pulmonary arterial hypertension. The true prevalence of pulmonary arterial hypertension in patients with lupus is not known but probably is no more than 1%. Currently, treatment for lupus-associated pulmonary arterial hypertension is with pulmonary vasodilators including phosphodiesterase-5 inhibitors, endothelin receptor antagonists and prostacyclin analogues, as it is for other causes of pulmonary arterial hypertension. Case series suggest there may be a special role for immunosuppression in this rare group of patients. We present two brief case histories and summarise our experience over 15 years. Prognosis is better in lupus-associated pulmonary arterial hypertension than in systemic sclerosis-associated pulmonary arterial hypertension, but unfortunately it remains a fatal condition in most patients.

Mortality risk as a function of the ratio of pulmonary trunk to ascending aorta diameter in patients with suspected coronary artery disease

Although an increased pulmonary trunk (PT) diameter to ascending aorta (AA) diameter ratio (PT/AA ratio) is associated with pulmonary hypertension, the prognostic utility of this metric remains unexamined. We investigated whether an increase in the PT/AA ratio, as measured using coronary computed tomographic angiography, is associated with the risk of all-cause death. We identified 1,326 consecutive patients (mean age 61 ± 13 years; 60% men) without known coronary artery disease who underwent coronary computed tomographic angiography. Patients with a history of congenital or valvular heart disease or aortic enlargement (≥4 cm) were excluded. The PT and AA diameters were measured at the PT bifurcation level. The patients were categorized by PT/AA deciles, with the ≥90th percentile (PT/AA ratio 0.9) considered elevated. All-cause death associated with a PT/AA ratio <0.9 versus ≥0.9 was evaluated using multivariate Cox proportional hazard models. During 2.9 ± 1.0 years of follow-up, 58 patients died. Patients with a PT/AA ratio ≥0.9 experienced 2.5-fold greater annualized mortality compared to those with <0.9 (3.1% vs 1.3%, p = 0.004). Adjusting for age, gender, heart rate, dyslipidemia, smoking, and coronary artery disease extent, the patients with a PT/AA ratio ≥0.9 experienced a greater mortality risk compared to patients with PT/AA ratio <0.9 (hazard ratio 3.2, 95% confidence interval 1.6 to 6.6, p = 0.001). In the 1,059 patients with left ventricular ejection fraction measurements, a lower left ventricular ejection fraction was observed in the PT/AA ratio ≥0.9 group (p <0.05). In conclusion, incrementally and independent of the traditional coronary artery disease risk factors, an elevated PT/AA ratio was associated with increased mortality risk in patients without known coronary artery disease undergoing coronary computed tomographic angiography.

Pulmonary hypertension in rheumatic diseases: epidemiology and pathogenesis

The focus of this review is to increase awareness of pulmonary arterial hypertension (PAH) in patients with rheumatic diseases. Epidemiology and pathogenesis of PAH in rheumatic diseases is reviewed, with recommendations for early screening and diagnosis and suggestion of possible role of immunosuppressive therapy in treatment for PAH in rheumatic diseases. A MEDLINE search for articles published between January 1970 and June 2012 was conducted using the following keywords: pulmonary hypertension, scleroderma, systemic sclerosis, pulmonary arterial hypertension, connective tissues disease, systemic lupus erythematosus, mixed connective tissue disease, rheumatoid arthritis, Sjogren's syndrome, vasculitis, sarcoidosis, inflammatory myopathies, dermatomyositis, ankylosing spondylitis, spondyloarthropathies, diagnosis and treatment. Pathogenesis and disease burden of PAH in rheumatic diseases was highlighted, with emphasis on early consideration and workup of PAH. Screening recommendations and treatment were touched upon. PAH is most commonly seen in systemic sclerosis and may be seen in isolation or in association with interstitial lung disease. Several pathophysiologic processes have been identified including an obliterative vasculopathy, veno-occlusive disease, formation of microthrombi and pulmonary fibrosis. PAH in systemic lupus erythematosus is associated with higher prevalence of antiphospholipid and anticardiolipin antibodies and the presence of Raynaud's phenomenon. Endothelial proliferation with vascular remodeling, abnormal coagulation with thrombus formation and immune-mediated vasculopathy are the postulated mechanisms. Improvement with immunosuppressive medications has been reported. Pulmonary fibrosis, extrinsic compression of pulmonary arteries and granulomatous vasculitis have been reported in patients with sarcoidosis. Intimal and medial hyperplasia with luminal narrowing has been observed in Sjogren's syndrome, mixed connective tissue disease and inflammatory myopathies. Pulmonary arterial hypertension (PAH) associated with rheumatic diseases carries a particularly grim prognosis with faster progression of disease and poor response to therapy. Though largely associated with systemic sclerosis, it is being increasingly recognized in other rheumatic diseases. An underlying inflammatory component may explain the poor response to therapy in patients with rheumatic diseases and is a rationale for consideration of immunosuppressive therapy in conjunction with vasodilator therapy in treatment for PAH. Further studies identifying pathogenetic pathways and possible targets of therapy, especially the role of immunomodulatory medications, are warranted.

Pulmonary hypertension associated with rheumatic diseases: baseline characteristics from the Korean registry

OBJECTIVES

The REgistry of Pulmonary Hypertension Associated with Rheumatic Disease (REOPARD) was established in Korea. The baseline data are described from the second year of the registry's operation.

METHODS

Patients with a connective tissue disease (CTD) who met the modified definition of the WHO group I pulmonary arterial hypertension (PAH) were enrolled. PAH was defined as a systolic pulmonary arterial pressure> 40 mmHg by echocardiography or mean pulmonary arterial pressure> 25 mmHg by right heart catheterization. Hemodynamic parameters and clinical data such as demographics, functional class, underlying disease, organ involvement, laboratory tests and current treatment were recorded.

RESULTS

A total of 321 patients were enrolled during the 2-year study period from 2008 to 2010. The mean age of the patients at registration was 51.9 years and 87.5% were female. Most patients were diagnosed by echocardiography and only 24 patients (7.5%) underwent cardiac catheterization. Exertional dyspnea was present in 63.6% of patients and 31.8% were New York Heart Association class III or IV. Among the patients, systemic lupus erythematosus accounted for 35.3%, systemic sclerosis 28.3%, rheumatoid arthritis 7.8%, overlap syndrome 9.0%, and mixed connective tissue disease 5.9%. There were no significant differences in hemodynamics, functional class, diffusing capacity and N-terminal pro-brain natriuretic peptide levels between the disease subgroups. Treatments consisted of calcium antagonists (57.0%), endothelin antagonists (32.7%), prostanoids (27.1%), phosphodiesterase-5 inhibitors (14.3%) and combinations (37.4%).

CONCLUSION

Compared with previous studies, the results showed some differences: underlying diseases, functional status and treatments. This may be due to differences in ethnic background and diagnostic methods of our study.

Pulmonary hypertension in systemic lupus erythematosus: a systematic review and analysis of 642 cases in Chinese population

Pulmonary hypertension (PH) is an increasingly recognized complication of systemic lupus erythematosus (SLE). To develop a more comprehensive understanding of the clinical and pathological characteristics of pulmonary hypertension associated with systemic lupus erythematosus (PH/SLE) in the Chinese population, a systematic review of the literature up to 2012 was conducted. Six hundred and forty-two Chinese PH/SLE cases from 22 studies were identified as well documented and further analyzed. Transthoracic echocardiography (TTE), X-ray, electrocardiogram and right heart catheterization (RHC) were performed to diagnose PH in SLE patients. The mean age of subjects was 35.5 years, the male to female ratio was 1:14, and the mean duration of SLE when PH was diagnosed was 10.7 years. The prevalence of PH in SLE was 2.8–23.3 %. Symptoms were usually nonspecific, and the observed clinical characteristics include Raynaud’s phenomenon (41.4 %), serous effusion (27.7 %), positive RNP (51.5 %) and positive ACL (46.6 %). Gold standard RHC is strongly recommended, especially for those who had resting pulmonary arterial systolic pressure >30 mmHg on TTE with the aforementioned clinical characteristics. Corticosteroids, immunosuppressants and vasodilators were the most common medications employed in treatment. Early identification and standard PH treatment with intensive SLE treatment can improve the prognosis.

Prospective, open-label, uncontrolled pilot study to study safety and efficacy of sildenafil in systemic sclerosis-related pulmonary artery hypertension and cutaneous vascular complications

Pulmonary artery hypertension (PAH) remains the leading cause of morbidity and mortality in systemic sclerosis, while Raynaud's phenomenon and digital ulcers significantly add to the morbidity in systemic sclerosis (SSc). This study was undertaken to evaluate the role of sildenafil in PAH, Raynaud's phenomenon, and digital ulcers in systemic sclerosis patients. A prospective, open-label, uncontrolled pilot study was done at a tertiary care centre in India to study the safety and efficacy of oral sildenafil in PAH, Raynaud's phenomenon, digital infarcts, and ulcers in SSc. Seventeen patients fulfilling ACR classification criteria for scleroderma and having PAH were recruited. Six-minute walk test, WHO class of dyspnoea, severity of Raynaud's phenomenon, and 2D ECHO were performed in all the study subjects at baseline and at 3 months post-treatment. All patients were treated with oral sildenafil 25 mg three times a day for a period of 3 months. The pre- and post-treatment values of mean pulmonary artery pressure (PAP), 6-min walk test, WHO class of dyspnoea, and severity of Raynaud's phenomenon were compared to look for any significant change. Sixteen patients who completed 3-month follow-up had shown statistically significant improvement in 6-min walk test, WHO class of dyspnoea, severity of Raynaud's phenomenon, and mPAP. Also, there was no occurrence of new digital infarcts or ulcers, and existing ulcers showed signs of healing. Sildenafil is highly efficacious cheaper and safe alternative to other available therapies for SSc-associated PAH, Raynaud's phenomenon, and digital infarcts/ulcers.

Primary pulmonary arterial hypertension and autoimmune polyendocrine syndrome in a pediatric patient

Both primary pulmonary artery hypertension (PPAH) and autoimmune polyendocrine syndrome (APS) are rare disorders in children. We report a boy who was diagnosed with severe PPAH at 12 years of age. He was treated with prostacyclin for 6 years, briefly with adjunct bosentan, and eventually sildenafil was added. Six years later, after his diagnosis of PPAH, he developed APS in the form of hyperthyroidism and type 1 diabetes mellitus. No mutations were identified through genetic testing of bone morphogenetic protein receptor type II and the autoimmune-regulator gene. To our knowledge this is the first description of the combination of these two extremely rare diseases in a child.

Pulmonary arterial hypertension in systemic sclerosis

Pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) is a complex clinical situation resulting from restricted flow through the pulmonary arterial circulation ending in increased pulmonary vascular resistance and right heart failure. PAH is a common and life-threatening complication in connective tissue diseases, specifically in SSc if not treated rapidly and adequately. Based on the emerging knowledge in SSc epidemiology by large scale patient cohorts such as EUSTAR, of PAH pathophysiology and advances in cardiopulmonary diagnostic techniques, several novel treatment approaches have been examined and have proceeded to licensing and daily use in the clinical practice. Amongst them are different endothelin receptor antagonists and PDE-5 inhibitors, but several other ideas are being currently pursued to improve the long-term outcome of the affected patients.

Integrated care and optimal management of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) may occur as an idiopathic process or as a component of a variety of diseases, including connective tissue diseases, congenital heart disease, and exposure to appetite suppressants or infectious agents such as HIV. Untreated, it is a potentially devastating disease; however, diagnosis can be difficult due to the non-specific nature of symptoms during the early stages, and the fact that patients often present to a range of different medical specialties. The past decade has seen remarkable improvements in our understanding of the pathology associated with the condition and the development of PAH-specific therapies with the ability to alter the natural history of the disease. This article reviews the evidence for screening and diagnosis of susceptible patient groups and discusses treatment selection and recommendations based on data available from randomized controlled trials. In addition, due to the complexity of the diagnostic evaluation required and the treatment options available, this review mandates for a multidisciplinary approach to the management of PAH. We discuss the roles and organizational structure of a specialized PAH center in Perth, Western Australia to highlight these issues.

Pulmonary arterial hypertension

Significant advances in the treatment of pulmonary arterial hypertension (PAH) have occurred over the last 10 years, starting with the approval of epoprostenol in 1998. Subsequently, multiple additional medications have received approval, including a subcutaneous prostacyclin, an inhaled prostacyclin, and oral medications in 2 separate classes. Over this same period, the classification of pulmonary hypertension has been revised with changes including the substitution of the term idiopathic for primary PAH and an expanded list of conditions felt to be associated with the development of PAH. Long-term follow-up studies have provided better information on prognosis and expected outcomes with treatment, with particularly valuable data on reassessment of prognosis after treatment with epoprostenol. Combination therapy is more frequently being used, and limited data on novel therapies such as stem cell transplantation have been published. The purpose of this review is to describe the current state of evidence for the diagnosis, prognosis, and treatment of the patient with PAH.

Immune pathogenesis of Mixed Connective Tissue Disease: a short analytical review

Mixed Connective Tissue Disease (MCTD) was first described 35 years ago by Gordon C. Sharp and his colleagues. In the ensuing decades, a clearer understanding of the clinical and serologic features of MCTD has emerged. Classification criteria now exist to define MCTD for study purposes, the long-term outcome of the disease has been established, and novel genetic associations within the major histocompatibility complex on chromosome 6 and select regions on chromosome 3 have been identified. Studies on immune pathogenesis have made substantial progress in advancing our understanding of MCTD. In MCTD, there is a complex interaction of the innate and adaptive immune system that culminates in autoimmune disease. Antigenic structural modification occurring during apoptosis or other modifications of self antigens leads to an autoantigen driven immune process with innate immune activation, immunoglobulin G autoantibody production directed against select components of the spliceosome, B lymphocyte activation, and CD4 and CD8 T lymphocyte participation.

Increased regulatory and decreased CD8+ cytotoxic T cells in the blood of patients with idiopathic pulmonary arterial hypertension

BACKGROUND

An association between pulmonary arterial hypertension (PAH) and various immune disorders is well established. Recently, the role of an intact immune system in protecting against pulmonary angioproliferation was shown in an animal model.

OBJECTIVE

To elucidate the role of T cells in human PAH, we comparatively studied T cell subclasses with emphasis on regulatory T cells (T(reg)) in the peripheral blood of patients with idiopathic pulmonary arterial hypertension (IPAH) and healthy controls.

METHODS

Isolated peripheral blood mononuclear cells from 36 patients diagnosed with IPAH and 33 healthy controls were stained with fluorescently labeled monoclonal antibodies against superficial T cell markers (CD3, CD4, CD8, CD25) and FoxP3, the intracellular marker of T(reg) cells. The relative cell distribution was analyzed by flow cytometry. The functionality of patient and control T(reg) cells was assessed by coculture of T(reg) with nonregulatory T cells from the same individual.

RESULTS

Significantly less CD8+ T cells (p = 0.02) and more CD25hi+ and FoxP3+CD4+ T cells were found in the peripheral blood of patients compared with controls (p = 0.009 and p < 0.001, respectively). The percentage of FoxP3+ cells within the CD25hi+CD4+ T(reg) cells was similar. T(reg) cell functionality was equal in patients and controls.

CONCLUSION

Our findings of decreased CD8+ T cells and increased T(reg) cells in the peripheral blood of patients with IPAH are novel and may have implications for directing future research in the field to elucidate the differential role of T cells and the immune system in IPAH.

Pulmonary hypertension in rheumatoid arthritis--relation with the duration of the disease

Isolated pulmonary hypertension with clinical implication is rare in rheumatoid arthritis. We sought to study the prevalence of pulmonary arterial hypertension in an unselected population of 45 patients with rheumatoid arthritis (classified according to the ARA criteria) without cardiac disease and corresponding age and sex matched controls by Doppler echocardiography. The pulmonary artery systolic pressure was higher in patients with Rheumatoid Arthritis (27.49+/-12.66 mm Hg) than in controls (20.40+/-8.88) (p=0.003). Incidence of pulmonary artery systolic pressure>30 mm Hg suggesting pulmonary hypertension was significantly higher in patients with RA (26.7% versus 4.5% in controls; p=0.03) and 20% of patients had pulmonary hypertension without lung disease or cardiac disease evident on pulmonary function testing, and echocardiogram respectively. There was also a strong correlation between the pulmonary artery pressure and the disease duration (r=0.68, p<0.0001) suggesting a subclinical involvement of the pulmonary vasculature with disease progression and may be relevant to the high incidence of cardiovascular deaths observed in patients with Rheumatoid Arthritis.

Increased circulating platelet–leucocyte complexes in patients with primary Raynaud's phenomenon and Raynaud's phenomenon secondary to systemic sclerosis: a comparative study

Platelet activation and circulating platelet-leucocyte complexes increase in vascular ischemic events and autoimmune inflammatory diseases. Platelet activation markers and platelet-leucocyte complexes were evaluated in primary Raynaud's phenomenon (RP) and in RP secondary to systemic sclerosis (SSc). Whole-blood flow cytometry was utilized to quantify CD62P, platelet microparticles (PMP), platelet-monocyte complexes (PMC) and platelet-neutrophil complexes (PNC) in primary RP and in SSc patients with secondary RP. SSc patients with secondary RP had significantly higher platelet CD62P expression than primary RP patients and controls (P = 0.017 and 0.004, respectively). Primary and secondary RP patients had higher mean PMC and PNC levels than controls (all P < or = 0.001). PMP level in SSc patients with pulmonary hypertension was significantly higher than in others (P = 0.048). All parameters were similar in SSc patients with and without digital ulcers, aspirin-users and nonusers (P > 0.05). CD62P level decreased significantly after iloprost administration in four patients with digital ulcers (16.1 +/- 17.4 vs 7.4 +/- 3.8%, P = 0.03). Our results suggest there is platelet-leucocyte complex formation in RP, and, despite antithrombotic therapy, platelet activation and platelet-leucocyte interaction are ongoing in SSc. This is important as it might have potential therapeutic implications with respect to using antiplatelet drugs in SSc.

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.

Clinical and Immunoserological Characteristics of Mixed Connective Tissue Disease Associated with Pulmonary Arterial Hypertension

We investigated the clinical characteristics and immunoserological alterations in patients with mixed connective tissue disease (MCTD) associated with pulmonary arterial hypertension (PAH). Anti-U1RNP autoantibodies, anti-endothelial cell antibodies (AECA) and serum thrombomodulin (TM) as well as von Willebrand factor antigen (vWFAg) concentrations were measured in 25 patients with MCTD associated with PAH and in 154 MCTD patients without PAH. The results showed that the probability of survival was lower in MCTD patients with PAH than in the 154 MCTD-non-PAH patients (5-year survival rate in MCTD with PAH: 73%, versus 96% in MCTD-non-PAH; P < 0.01). AECA were more frequently present in the sera of MCTD patients with PAH than in MCTD-non-PAH (P < 0.001). Serum TM and vWFAg levels were higher in MCTD-PAH patients than in MCTD-non-PAH patients (TM: P < 0.001; vWFAg: P < 0.001). Significant correlation was noticed between the quantity of AECA and TM level (r = 0.466) as well as the quantity of AECA and vWFAg level (r = 0.550). In conclusion, our results suggest that in MCTD the presence of AECA and endothelial cell activation may play a role in the development of PAH and in the maintenance of obliterative vascular processes.

Pulmonary arterial hypertension in mixed connective tissue disease: successful treatment with Iloprost

This paper describes a 61-year-old woman who presented with mixed connective tissue disease, which was complicated by the development of pulmonary arterial hypertension (PAH). Her condition worsened rapidly, with development of haemopthysis, tachypnoe and cardiac arrest. Doppler echocardiography showed a high systolic pulmonary arterial pressure (98 mmHg), confirmed by the right heart catheterization. Vasculopathy of the pulmonary artery vessels was detected following open lung biopsy. No pulmonary embolism was found. Because of suspicion of flare of her underlying disease, which leads to PAH, immunosuppressive treatment was started with high doses of corticosteroid and cyclophosphamide, in combination with the prostacyclin analogue, Iloprost, and low molecular weight heparin. The therapy resulted in slow recovery over 6 weeks, with control echocardiography showing normalization of the high pulmonary pressure, and the patient being capable of returning to everyday activities.

Pulmonary hypertension in autoimmune rheumatic diseases

Arterial pulmonary hypertension (PH) might be a complication of some autoimmune rheumatic diseases, specially systemic sclerosis. This form of arterial PH is indistinguishable from primary PH, characterised by the presence of plexiform lesions. Although for many years plexiform lesions have been considered end-stage scarring lesions, they are composed by actively proliferating endothelial cells that share many features with cancer cells. Endothelial cells within plexiform lesions in all forms of arterial PH show a decrease in the expression of vasodilator and anti-proliferative factors, and an increase in the expression of vasoconstrictor and angiogenic and mitogenic factors. These cells also show important alterations in growth and apoptosis key regulatory genes. Plexiform lesions are surrounded by inflammatory cell infiltrates, probably providing cytokines that may contribute to the endothelial cell proliferative process. All these data suggest that arterial PH might be seen as a proliferative endothelial cell process, which would open new therapeutic approaches for this devastating disease.

Soluble CD40 Ligand in Pulmonary Arterial Hypertension

Background— Inflammatory processes seem to be involved in pulmonary arterial hypertension (PAH). CD40 ligand (L) may promote inflammation and thrombus formation, and we hypothesized that CD40L could be involved in the pathogenesis of PAH.

Methods and Results— Several significant findings were revealed when examining the possible role of CD40L in PAH. (1) Patients with primary (n=13) and secondary (n=11) PAH but not those with chronic thromboembolic pulmonary hypertension (n=8) had increased plasma levels of soluble (s) CD40L compared with control subjects (n=8). (2) PAH patients using warfarin had markedly lower sCD40L levels than those without such therapy. (3) sCD40L levels were higher in arterial (femoral artery) compared with mixed venous blood (pulmonary artery), suggesting enhanced release or reduced clearance in the pulmonary vasculature. (4) Platelets from PAH patients showed enhanced spontaneous and SFLLRN-stimulated release of sCD40L compared with control subjects. (5) In vitro, recombinant sCD40L induced monocyte chemoattractant protein (MCP)-1 and interleukin-8 gene expression in endothelial cells, and plasma levels of these chemokines were raised in all PAH groups, significantly correlated to sCD40L and hemodynamic parameters. (6) Although prostacyclin therapy (3 months) showed clinical benefit, this therapy had no effect on sCD40L and increased MCP-1 levels in PAH patients, and prostacyclin enhanced MCP-1 in CD40L-stimulated endothelial cells.

Conclusions— Our findings suggest a role for CD40L in the pathogenesis of PAH, possibly operating through an interaction between platelets and endothelial cells involving chemokine-related mechanisms.

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.

Traitement de l’hypertension artérielle pulmonaire associée à la sclérodermie systémique

PURPOSE

Pulmonary arterial hypertension (PAH) is one of the main causes of death in patients with systemic sclerosis (SSc), particularly in its limited forms.

CURRENT KNOWLEDGE AND KEY POINTS

Survival with conventional treatment associated with Epoprostenol is two times less in SSc patients than in idiopathic PAH. WHO recommendations (annually heart echoscreening) must be applied in all patients with SSc. Conventional therapy associates anticoagulation, to avoid excessive exertion, pregnancy, warm baths, no pressurised flights. Calcium-channel blockers give long term survival in patients with positive acute vasodilatator test with nitric oxide (NO) but these patients are very rare in SSc. Diuretics are very useful in treating right heart insufficiency. Randomized control trials in PAH have demonstrated the short term efficacy of i.v. epoprostenol, nebulized iloprost, oral beraprost and oral bosentan, a dual endothelin-1 receptor antagonist. Results in SSc are very limited except for i.v. epoprostenol. Long-term efficacy in terms of survival has been demonstrated in non randomized studies for i.v. epoprostenol and oral bosentan in patients with idiopathic and familial PAH. Atrial septostomy and lung transplantation could be an alternative to treatment, even in SSc patients, in case of refractory evolution.

FUTURE PROSPECTS AND PROJECTS

Randomized control trials with sildenafil and selective endothelin-1 receptor antagonists are ongoing.

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.