Severe pulmonary hypertension in histiocytosis X

Severe pulmonary hypertension in adult pulmonary Langerhans cell histiocytosis: the effect of sildenafil as a bridge to lung transplantation

Severe pulmonary hypertension (PH) often develops in patients with pulmonary Langerhans cell histiocytosis (PLCH). Supplemental oxygen treatment is often used, whereas pulmonary arterial hypertension-specific vasodilators are generally considered hazardous because of the possible development of pulmonary edema and deterioration of hypoxia. In the present report, we herein describe a PLCH patient with severe PH in whom sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, substantially improved the pulmonary hemodynamics before lung transplantation. An immunohistochemical study of the resected lung revealed positive staining for PDE5 on the diseased pulmonary arteries. These observations suggest that sildenafil can be a promising therapeutic option for PH in patients with PLCH.

Rare causes of pulmonary hypertension: spectrum of radiological findings and review of the literature

Following a brief introduction covering the clinical signs and symptoms of pulmonary hypertension (PH), its most recent classification into six groups, and the computed tomography (CT) features common to all forms of PH, this paper illustrates the typical patterns that can be found on chest radiography and CT in rare causes of PH. We present and compare with the existing literature our personal series of cases of rare forms of PH, found in the following diseases: veno-occlusive disease, pulmonary capillary haemangiomatosis, non-thrombotic pulmonary embolism (tumour embolism and carcinomatous lymphangitis, talcosis, hydatid disease), pulmonary artery sarcoma, neurofibromatosis, sarcoidosis, and Langerhans cell histiocytosis. Rare forms of PH show low incidence and prevalence, and are, therefore, poorly recognised. Their diagnosis is a challenge for clinicians, pathologists, and radiologists, and any additional knowledge about the CT findings may help the diagnosis in the case of patients affected by PH of unknown origin.

World Health Organization group 5 pulmonary hypertension

World Health Organization (WHO) group 5 pulmonary hypertension (PH) entails a heterogeneous group of disorders that may cause PH by unclear and/or multiple mechanisms. In particular, group 5 includes PH caused by hematologic disorders, systemic diseases, metabolic disorders, chronic renal failure, and disorders leading to pulmonary vascular occlusion or compression. This article discusses common pathogenic mechanisms leading to group 5 PH, followed by a detailed overview of epidemiology, pathogenesis, and disease-specific management of the individual group 5 conditions. Off-label use of vasomodulatory therapies, typically indicated for pulmonary arterial hypertension (WHO group 1 PH), in group 5 conditions is also discussed.

Pulmonary hypertension due to lung disease and/or hypoxia

Pulmonary hypertension may complicate the course of patients with many forms of advanced lung disease. The cause is likely multifactorial with pathogenic pathways both common and unique to the specific disease entities. The occurrence of pulmonary hypertension is associated with worse outcomes, but whether this is an adaptive or maladaptive phenomenon remains unknown. The treatment of pulmonary hypertension with vasoactive medications in lung disease remains unproved. Specific disease phenotypes that might benefit, and those in which such therapies might be deleterious, remain to be determined.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy. Diuretics are one of the most important treatment in the setting of PH because right heart failure leads to fluid retention, hepatic congestion, ascites and peripheral edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2–3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including prostanoids (epoprostenol, trepoprostenil, iloprost), endothelin receptor antagonists (bosentan, ambrisentan) and phosphodiesterase type 5 inhibitors (sildenafil, tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH therapy is discussed as well as future treatments.

Pulmonary heart disease: The heart-lung interaction and its impact on patient phenotypes

Pulmonary heart disease (PHD) refers to altered structure or function of the right ventricle occurring in association with abnormal respiratory function. Although nearly always associated with some degree of PH, the degree, nature, severity, and causality of PH in relation to the PHD is not necessarily linear and direct. Abnormal gas exchange is a fundamental underpinning of PHD, affecting pulmonary vascular, cardiac, renal, and neurohormonal systems. Direct and indirect effects of chronic respiratory disease can disrupt the right ventricular-pulmonary arterial (RV-PA) interaction and, likewise, factors such as sympathetic nervous system activation, altered blood viscosity, and salt and water retention can function in a feedback loop to further influence RV-PA function. Left heart function may also be affected, especially in those with pre-existing left heart disease. Thus, the physiologic interactions between abnormal respiratory and cardiovascular function are complex, with PHD representing a heterogeneous end organ effect of an integrated multisystem process. In this review, we propose to separate PHD into two distinct entities, “Type I” and “Type II” PHD. Type I PHD is most common, and refers to subjects with chronic respiratory disease (CRD) where the perturbations in respiratory function dominate over more mild cardiac and circulatory disruptions. In contrast, Type II PHD refers to the smaller subset of patients with more severe pulmonary vascular and right heart dysfunction, whom often present in a fashion similar to patients with PAH. Phenotypic differences are not made by PA pressure alone, but instead by differences in the overall physiology and clinical syndrome. Thus, key differences can be seen in symptomatology, physical signs, cardiac imaging, hemodynamics, and the cardiovascular and gas exchange responses to exercise. Such key baseline differences in the overall physiologic phenotype are likely critical to predicting response to PH specific therapy. Recognizing PHD as distinct phenotypes assists in the necessary distinction of these patients, and may also provide a key clinical and pathophysiologic framework for improved patient selection for future studies investigating the role of pulmonary hypertension-specific therapies in PHD.

Pulmonary Langerhans cell histiocytosis-associated pulmonary hypertension: clinical characteristics and impact of pulmonary arterial hypertension therapies

BACKGROUND

Precapillary pulmonary hypertension (PH) is a complication of pulmonary Langerhans cell histiocytosis (PLCH) associated with increased mortality. However, outcomes and efficacy of pulmonary arterial hypertension (PAH) therapies in patients with PH complicating PLCH(PLCH-PH) remain unknown.

METHODS

Consecutive patients with PLCH with PH confirmed by right-sided heart catheterization were included in the study. Characteristics at baseline and during follow-up as well as survival were analyzed.

RESULTS

Twenty-nine patients were studied. Baseline characteristics of patients with PLCH-PH wereas follows: 83% of patients in World Health Organization (WHO) functional class III to IV, mean 6-min walk distance of 355 ±95 m, mean pulmonary arterial pressure (mPAP) of 45 ±14 mm Hg,cardiac index of 3.2± 0.9 L/min/m 2 , and pulmonary vascular resistance (PVR) of 555 ±253 dyne/s/cm 5. Use of PAH therapy in 12 patients was followed by an improvement in mPAP (56±14 mm Hg and 45±12 mm Hg, P 5 .03) and PVR (701±239 dyne/s/cm 5 and 469±210 dyne/s/cm 5 , P = .01) between baseline and follow-up evaluations. No significant oxygen worsening was observed in the treated group. The 1-, 3-, and 5-year survival estimates of the 29 patients were 96%, 92%, and 73%,respectively. Except a trend toward a better survival rate associated with the use of PAH therapy,WHO functional class was the only variable significantly associated with death.

CONCLUSIONS

In this group of patients, PAH therapies improved hemodynamics without oxygen worsening or pulmonary edema. WHO functional class was the only prognostic factor identified.Prospective clinical trials focusing on this population of patients are warranted

Classification of pulmonary hypertension

Pulmonary hypertension (PH) can develop in association with many different diseases and risk factors, and its presence is nearly always associated with reduced survival. The prognosis and management of PH is largely dependent upon its underlying etiology and severity of disease. The combination of clinical and hemodynamic classifications of PH provides a framework for the diagnostic evaluation of PH to establish a final clinical diagnosis that guides therapy. As our understanding of the different pathologic mechanisms that underlie the syndrome of PH evolves, so too will the classification and treatment of PH.

Pulmonary langerhans cell histiocytosis

Pulmonary Langerhans Cell Histiocytosis (PLCH) is a relatively uncommon lung disease that generally, but not invariably, occurs in cigarette smokers. The pathologic hallmark of PLCH is the accumulation of Langerhans and other inflammatory cells in small airways, resulting in the formation of nodular inflammatory lesions. While the overwhelming majority of patients are smokers, mechanisms by which smoking induces this disease are not known, but likely involve a combination of events resulting in enhanced recruitment and activation of Langerhans cells in small airways. Bronchiolar inflammation may be accompanied by variable lung interstitial and vascular involvement. While cellular inflammation is prominent in early disease, more advanced stages are characterized by cystic lung destruction, cicatricial scarring of airways, and pulmonary vascular remodeling. Pulmonary function is frequently abnormal at presentation. Imaging of the chest with high resolution chest CT scanning may show characteristic nodular and cystic abnormalities. Lung biopsy is necessary for a definitive diagnosis, although may not be required in instances were imaging findings are highly characteristic. There is no general consensus regarding the role of immunosuppressive therapy in smokers with PLCH. All smokers must be counseled on the importance of smoking cessation, which may result in regression of disease and obviate the need for systemic immunosuppressive therapy. The prognosis for most patients is relatively good, particularly if longitudinal lung function testing shows stability. Complications like pneumothoraces and secondary pulmonary hypertension may shorten life expectancy. Patients with progressive disease may require lung transplantation.

Pulmonary hypertension in pulmonary langerhans cell granulomatosis

Introduction. Pulmonary Langerhans cell granulomatosis is a rare disease with a variable course. In pulmonary Langerhans cell granulomatosis pulmonary hypertension is frequent and has an independent prognostic impact. A vasculopathy which ist not related to ventilatory disturbance and fibrosis has been identified. An arteriopathy and even a venulopathy have been described. Due to this possible venulopathy vasodilators carry a significant risk for pulmonary congestion and edema. No drugs have been approved until now. Case Presentation. One female with PLCG developed severe PH four years after primary diagnosis of pulmonary Langerhans cell granulomatosis. Retrospective analysis of lung biopsies revealed an arterial vasculopathy at the time of primary diagnosis without clinical signs of PH at this time. Sildenafil led to a sustained improvement of hemodynamic features and exercise capacity. Conclusion. This paper underlines that patients with PLCG with an arterial vasculopathy-related PH might improve under sildenafil. Further trials addressing treatment of PH and vasculopathy are needed.

[Disproportionate pulmonary arterial hypertension and lung respiratory diseases: distinctive clinical, hemodynamic and prognosis of patients versus primary pulmonary arterial hypertension]

OBJECTIVES

To characterize and compare patients with disproportionate PH versus patients with primary pulmonary arterial hypertension (PAH).

METHODS

All patients referred to our cardiology unit for echocardiography from November 2006 to May 2008 and who have been followed by our pneumologist were screened for severe PH (i.e mean arterial pulmonary pressure>35-40 mmHg at rest). Patients were excluded if a factor that could influence pulmonary hemodynamics was present. We investigated these patients by pulmonary function tests, echocardiography and right heart catheterisation.

RESULTS

We reported 16 cases of severe PH in stable patients (n=8, chronic obstructive pulmonary disease-emphysema) and 13 patients with PAH. Our findings suggest that the patients with disproportionate PH had right heart dysfunction similar to that observed in PAH. But their outcomes were more severe. It seemed that specific vasodilatator therapy was not efficient.

Respiratory Diseases

▪

Pulmonary arteriovenous fistulas have congenital and hereditary etiology, and patients are at risk for life-threatening rupture requiring surgery.

▪

Wegener's granulomatosis can affect any organ system, although renal and pulmonary involvement is most common; men ages 40 to 50 are at increased risk.

▪

Lymphomatoid granulomatosis affects cardiopulmonary, neurologic, and myeloproliferative systems; may result from opportunistic infection, and frequently progresses to lymphoma; men age 50 to 60 are at increased risk. Spontaneous remission occurs in some cases; mortality is 60% to 90% at 5 years.

▪

Churg-Strauss syndrome is usually associated with long-standing asthma, with men and women affected equally, and can affect any organ system; major cause of death is cardiac related.

▪

Primary pulmonary hypertension is a diagnosis of exclusion; women are affected twice as likely as men; right-to-left shunt may occur in 30%, secondary to patent foramen ovale; hypoxia with resultant heart failure is typical cause of death.

▪

Cystic fibrosis is an autosomal recessive disease, eventually fatal, with increased risk for airway obstruction, fluctuating pulmonary function, and chronic hypoxia; risk for spontaneous pneumothorax is 20%.

▪

Bronchiolitis obliterans organizing pneumonia is a pulmonary obstructive disease that may be reversible and usually resolves spontaneously.

▪

Idiopathic pulmonary hemosiderosis is associated with autoimmune disorders; patients have recurrent hemorrhage, pulmonary fibrosis, restrictive lung disease, and pulmonary hypertension, with some cases of spontaneous remission.

▪

Chronic eosinophilic pneumonia may be preceded by adult-onset asthma; women are at increased risk; prognosis is good.

▪

Goodpasture's syndrome is a genetic autoimmune disorder involving the pulmonary and renal systems.

▪

Pulmonary alveolar proteinosis, a lipoprotein-rich accumulation in alveoli, has three forms: congenital, decreased alveolar macrophage activity, and idiopathic; some cases of spontaneous remission occur.

▪

Sarcoidosis may affect any organ system; African American, northern European, and females are at greater risk; many patients are asymptomatic.

▪

Systemic lupus erythematosus may affect any organ system; women of childbearing age are at increased risk.

▪

Idiopathic pulmonary fibrosis is a rare interstitial lung disease, with smokers at increased risk for pulmonary malignancy; survival is usually 2 to 3 years from diagnosis; no effective treatment exists, with lung transplant the only therapeutic option.

▪

Acute respiratory distress syndrome (ARDS) is associated with underlying critical illness or injury, developing acutely in 1 to 2 days; mortality is 25% to 35%.

▪

Pulmonary histiocytosis X is an interstitial lung disease associated with cigarette smoking and an unpredictable course; some spontaneous remission occurs.

▪

Lymphangioleiomyomatosis involves progressive deterioration of lung function, associated with tuberous sclerosis and exacerbated by pregnancy, with women at increased risk; possible spontaneous pneumothorax and chylothorax; death usually results from respiratory failure.

▪

Ankylosing spondylitis is a genetic inflammatory process resulting in fusion of axial skeleton and spinal deformities, with men at increased risk; radiologic bamboo spine, sacral to cervical progression, and restrictive lung disease with high reliance on diaphragm; extraskeletal manifestations may occur.

▪

Kyphosis (exaggerated anterior flexion) and scoliosis (lateral rotational deformity) are spinal/rib cage deformities with idiopathic, congenital, or neuromuscular etiology; corrective surgery done if Cobb thoracic angle >50% lumbar angle >40%.

▪

Bleomycin is an antineoplastic antibiotic used in combination chemotherapy, with no myelosuppressive effect; toxicity can cause life-threatening pulmonary fibrosis.

▪

Influenza A is highly infectious, presenting with flulike symptoms and possible progression to ARDS; human-to-human exposure is through droplets or contaminated surfaces, with high risk for infants, children, pregnancy, chronically ill, or renal replacement therapy patients. No prophylactic treatment exists; treat patients with high index of suspicion without definitive testing; rRT-PCR and viral cultures are sensitive for pandemic H1N1 strain.

▪

Severe acute respiratory syndrome (SARS) is highly infectious, transmitted by coronavirus with human-to-human exposure via droplets or surfaces, and may progress to ARDS.

▪

Echinococcal disease of lung is from canine tapeworm, transmitted by eggs from feces; rupture of cyst may result in anaphylactic reaction or spread of disease to other organs; children are at increased risk. No transthoracic needle aspiration is done; surgery is only option.

Smoking-related interstitial lung diseases

Cigarette smoke, a toxic collection of thousands of chemicals generated from combustion of tobacco, is recognized as the primary causative agent of certain diffuse interstitial and bronchiolar lung diseases. Most patients afflicted with these disorders are cigarette smokers, and smoking cessation has been shown to be capable of inducing disease remission and should occupy a pivotal role in the management of all smokers with these diffuse lung diseases. The role of pharmacotherapy with corticosteroids or other immunomodulating agents is not well established but may be considered in patients with progressive forms of smoking-related interstitial lung diseases.

Smoking-related interstitial lung diseases

Cigarette smoke, a toxic collection of thousands of chemicals generated from combustion of tobacco, is recognized as the primary causative agent of certain diffuse interstitial and bronchiolar lung diseases. Most patients afflicted with these disorders are cigarette smokers, and smoking cessation has been shown to be capable of inducing disease remission and should occupy a pivotal role in the management of all smokers with these diffuse lung diseases. The role of pharmacotherapy with corticosteroids or other immunomodulating agents is not well established but may be considered in patients with progressive forms of smoking-related interstitial lung diseases.

Pulmonary hypertension secondary to interstitial lung disease

Interstitial lung diseases (ILDs) may be complicated by the development of pulmonary hypertension (PH), which is associated with worse functional impairment and a poorer prognosis. This article reviews the current state of knowledge on the prevalence, pathogenesis, diagnosis and prognosis of ILD-related PH. Whether the treatment of ILD-related PH changes clinical outcomes is currently unknown, but the current studies are summarized and the authors' perspective is offered.

Rare lung diseases III: pulmonary Langerhans' cell histiocytosis

Pulmonary Langerhans' cell histiocytosis (PLCH) is an unusual cystic lung disease that is also characterized by extrapulmonary manifestations. The current review discusses the presenting features and relevant diagnostic testing and treatment options for PLCH in the context of a clinical case. While the focus of the present article is adult PLCH and its pulmonary manifestations, it is important for clinicians to distinguish the adult and pediatric forms of the disease, as well as to be alert for possible extrapulmonary complications. A major theme of the current series of articles on rare lung diseases has been the translation of insights gained from fundamental research to the clinic. Accordingly, the understanding of dendritic cell biology in this disease has led to important advances in the care of patients with PLCH.

Pulmonary hypertension in patients with neurofibromatosis type I

Neurofibromatosis type I (NF1) is a rare genetic disease caused by mutations in the NF1 gene, which codes for tumor suppressor neurofibromin. NF1 is transmitted as an autosomal dominant and fully penetrant trait with no sex predominance. Precapillary pulmonary hypertension (PH) is a severe complication of NF1, initially described in patients with advanced parenchymal lung disease, which may complicate the course of NF1. We conducted this study to describe clinical, functional, radiologic, and hemodynamic characteristics and outcome of patients with NF1-associated PH. We identified 8 new cases of NF1-associated PH in patients carrying a NF1 gene mutation. No bone morphogenic protein receptor 2 (BMPR2) point mutation or large size rearrangements were identified. Seven female patients and 1 male patient were reported, suggesting a possible female predominance. PH occurred late in the course of the disease (median age, 62 yr; range, 53-68 yr). Dyspnea and signs of right heart failure were the major symptoms leading to the diagnosis of PH. At diagnosis, patients had severe hemodynamic impairment with low cardiac index (median, 2.3 L/min per m2; range, 1.9-4.7) and elevated indexed pulmonary vascular resistance (median, 15.1 mm Hg/L/min per m2; range, 4.5-25.9). All patients were in New York Heart Association functional class III with severe exercise limitation (median 6-min walk distance, 180 m; range, 60-375 m). Most patients had associated parenchymal lung disease, but some had no or mild lung involvement with disproportionate pulmonary vascular disease. Overall, the impact of PH therapy was limited and outcomes were poor. In conclusion, PH represents a rare but severe complication of NF1, characterized by female predominance, late onset in the course of NF1, and severe functional and hemodynamic impairment. Because of poor outcome and limited impact of specific PH therapy, eligible patients require early referral for lung transplantation. Further studies are needed to better understand the pathophysiology and the role, if any, of neurofibromin in NF1-associated PH.

Smoking-related lung disease

Dyspneic smokers who come to clinical attention demonstrate varying combinations of emphysema, airway inflammation, and fibrosis in addition to the changes of pulmonary Langerhans' cell histiocytosis. There is also growing acceptance of a link between cigarette smoke and alveolar wall fibrosis. Acute eosinophilic pneumonia is a dramatic response to recent-onset smoking seen in a small number of individuals. The interconnected pathways that lead to lung inflammation and fibrosis in cigarette smokers are slowly coming into focus.

Common diagnostic challenges in the pathology of nonneoplastic lung diseases: a case-based review

We use a case-based format to review 4 relatively common, diagnostic challenges in surgical pathology of nonneoplastic lung diseases. All cases are linked to virtual slides so that the reader can participate in a manner that simulates the breakout session held at the 2008 New Frontiers in Pathology course at the University of Michigan, from which, this material was excerpted. Brief clinical histories and a summary of radiologic findings are followed by a description of the pertinent histologic findings and a concise topic review, intended to focus on practical diagnostic considerations. Our goal is that readers gain a greater understanding of those features most helpful in recognizing usual interstitial pneumonia, Langerhans cell histiocytosis, aspiration pneumonia, and Wegener granulomatosis.

Updated clinical classification of pulmonary hypertension

The aim of a clinical classification of pulmonary hypertension (PH) is to group together different manifestations of disease sharing similarities in pathophysiologic mechanisms, clinical presentation, and therapeutic approaches. In 2003, during the 3rd World Symposium on Pulmonary Hypertension, the clinical classification of PH initially adopted in 1998 during the 2nd World Symposium was slightly modified. During the 4th World Symposium held in 2008, it was decided to maintain the general architecture and philosophy of the previous clinical classifications. The modifications adopted during this meeting principally concern Group 1, pulmonary arterial hypertension (PAH). This subgroup includes patients with PAH with a family history or patients with idiopathic PAH with germline mutations (e.g., bone morphogenetic protein receptor-2, activin receptor-like kinase type 1, and endoglin). In the new classification, schistosomiasis and chronic hemolytic anemia appear as separate entities in the subgroup of PAH associated with identified diseases. Finally, it was decided to place pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis in a separate group, distinct from but very close to Group 1 (now called Group 1'). Thus, Group 1 of PAH is now more homogeneous.

[Interstitial lung diseases and pulmonary hypertension]

The prevalence of pulmonary hypertension in interstitial lung disease (ILD) is high (30-40%). However, diagnosis of pulmonary hypertension in ILD is often delayed. Pulmonary hypertension can occur in the absence of advanced pulmonary dysfunction or severe hypoxia and is associated with a worse prognosis. A number of pathogenic mechanisms such as oxidative stress, cytokines, and the endothelin system have been implicated in remodeling of both the lung parenchyma and the vessels. In addition, hypoxic vasoconstriction, vascular destruction and progressive fibrosis play an important role. Since clinical signs are often non-specific echocardiography, radiology and laboratory parameters such as NT-proBNP may be helpful. However, the definitive diagnosis of pulmonary hypertension is still confirmed by right heart catheterization. Treatment options of pulmonary hypertension in ILD are limited to the treatment of the underlying diseases. Newer vasodilating drugs may improve the prognosis but have first to be evaluated in clinical trials. Lung or lung and heart transplantation is the therapeutic option in end stage disease.

Smoking-related interstitial lung disease

Pulmonary diseases associated with tobacco smoking are a complex group of disorders ranging from chronic obstructive pulmonary disease (COPD) to lung cancer. Interstitial lung diseases (ILDs) have only recently been linked to smoking. The ILDs related to smoking include respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, and pulmonary Langerhans cell histiocytosis. The relationship of smoking with each of these entities has been largely established on the weight of epidemiologic evidence. Although they have been retained as distinct and separate conditions in various classifications of interstitial lung diseases, these 3 entities share a number of clinical, radiologic, and pathologic features suggesting that they represent a spectrum of patterns of interstitial lung disease occurring in predisposed individuals who smoke. Evaluation of histologic features, particularly in surgical lung biopsy samples, is important in making the distinction between these disorders. However, even after tissue biopsy, it may sometimes be difficult to clearly separate these entities. The importance of making the distinction between them lies in the different clinical management strategies used. Further experimental evidence, including genetic information, may be important in improving our understanding of these diseases.

Smoking-related interstitial lung disease: radiologic-clinical-pathologic correlation

Cigarette smoking is a recognized risk factor for development of interstitial lung disease (ILD). There is strong evidence supporting a causal role for cigarette smoking in development of respiratory bronchiolitis ILD (RB-ILD), desquamative interstitial pneumonitis (DIP), and pulmonary Langerhans cell histiocytosis (PLCH). In addition, former and current smokers may be at increased risk for developing idiopathic pulmonary fibrosis (IPF). The combination of lower lung fibrosis and upper lung emphysema is being increasingly recognized as a distinct clinical entity in smokers. High-resolution computed tomography is sensitive for detection and characterization of ILD and may allow recognition and classification of the smoking-related ILDs (SR-ILDs) into distinct individual entities. However, the clinical, radiologic, and histologic features overlap among the different SR-ILDs, and mixed patterns of disease frequently coexist in the same patient. The overlap is most significant between RB-ILD and DIP. Macrophage accumulation is bronchiolocentric in RB-ILD, producing centrilobular ground-glass opacity, and more diffuse in DIP, producing widespread ground-glass changes. The coexistence of upper lung nodules and cysts in a smoker allows confident diagnosis of PLCH. Final diagnosis of an SR-ILD and identification of the specific entity can be achieved with certainty only after the pulmonologist, radiologist, and pathologist have reviewed all of the clinical, radiologic, and pathologic data.

Pulmonary hypertension in interstitial lung disease

Pulmonary hypertension (PH) may complicate the course of many forms of advanced interstitial lung disease (ILD) and has been shown to portend a worse outcome. The aetiology of PH is likely multifactorial with variable contribution of factors amongst the different diseases. The most common such conditions include idiopathic pulmonary fibrosis, sarcoidosis, connective tissue disease-related ILD and pulmonary langerhans cell histiocytosis. Whether the course and impact of PH in these conditions can be modified by therapy requires further study.

Pulmonary hypertension in interstitial lung disease

PURPOSE OF REVIEW

To examine recent advances in the understanding of the prevalence, pathophysiology, natural history, diagnosis, and treatment of pulmonary hypertension associated with interstitial lung disease.

RECENT FINDINGS

Significant progress has recently been made in understanding the etiology of various causes of pulmonary hypertension, including those associated with interstitial lung disease, and new data regarding the various pathophysiologic mechanisms of pulmonary hypertension in interstitial lung disease have been published. Therapeutic agents that were initially studied in patients with idiopathic pulmonary arterial hypertension are now being applied to interstitial lung disease-related pulmonary hypertension. Short-term hemodynamic benefits and disease-related quality of life outcomes that are associated with these advanced therapies are now better understood, but data regarding long-term outcomes and the efficacy of combination therapies remain lacking for interstitial lung disease-related pulmonary hypertension. Lung transplantation outcomes in the treatment of pulmonary hypertension associated with interstitial lung disease have been further defined.

SUMMARY

Pulmonary hypertension associated with interstitial lung disease is now frequently recognized and is associated with substantial morbidity and mortality. Various new pharmacotherapies as well as lung transplantation are increasing the treatment options for these disorders, although timing of advanced therapies and long-term benefits and toxicities remain uncertain.

Pulmonary hypertension associated with lung transplantation obliterative bronchiolitis and vascular remodeling of the allograft

Pathologic obliterative bronchiolitis (OB)/Bronchiolitis obliterans syndrome (pathologic OB/BOS) is the major obstacle to long-term survival post-lung transplantation (LT). Our group has demonstrated that pulmonary hypertension (PH) complicates the course of chronic inflammatory lung diseases that have similarities to pathologic OB/BOS and that vascular remodeling of the bronchial circulation occurs during BOS. Consequently, we hypothesized that PH is associated with pathologic OB/BOS and may result from a vasculopathy of the allograft pulmonary circulation. We conducted a single-center, retrospective study and examined the presence of PH and vasculopathy in patients with pathologic OB/BOS. Fifty-two pathologic specimens post-LT were recovered from January 10, 1997 to January 5, 2007 and divided into two groups, those with and without pathologic OB/BOS.PH was defined as a mean pulmonary artery pressure (mPAP) > 25 mmHg by right heart catheterization (RHC) or right ventricular systolic pressure (RVSP) > or = 45 mmHg by transthoracic echocardiogram (TTE). PH was more prevalent in those LT recipients with pathologic OB/BOS (72% vs. 0%, p = 0.003). Furthermore, pulmonary arteriopathy and venopathy were more prevalent in patients with pathologic OB/BOS (84% vs. 4%, p < 0.0001, and 77% vs. 35%, p = 0.004, respectively). PH is common in LT recipients with pathologic OB/BOS and is associated with a vasculopathy of the allograft pulmonary circulation.

Pulmonary Langerhans cell histiocytosis and other pulmonary histiocytic diseases: a review

CONTEXT

Pulmonary Langerhans cell histiocytosis is the most common and best known pulmonary histiocytic lesion; however, the realm of pulmonary histiocytic lesions also includes an assortment of uncommon diseases that may exhibit pulmonary involvement.

OBJECTIVE

To review pulmonary Langerhans cell histiocytosis and other pulmonary histiocytoses to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the author's institution.

CONCLUSIONS

This review discusses the most common pulmonary histiocytosis, pulmonary Langerhans cell histiocytosis, and also reviews the uncommon pulmonary histiocytic lesions, which are distinct from pulmonary Langerhans cell histiocytosis.

Pulmonary veno-occlusive disease: clinical, functional, radiologic, and hemodynamic characteristics and outcome of 24 cases confirmed by histology

Pulmonary veno-occlusive disease (PVOD) is defined by specific pathologic changes of the pulmonary veins. A definite diagnosis of PVOD thus requires a lung biopsy or pathologic examination of pulmonary explants or postmortem lung samples. However, lung biopsy is hazardous in patients with severe pulmonary hypertension, and there is a need for noninvasive diagnostic tools in this patient population. Patients with PVOD may be refractory to pulmonary arterial hypertension (PAH)-specific therapy and may even deteriorate with it. It is important to identify such patients as soon as possible, because they should be treated cautiously and considered for lung transplantation if eligible. High-resolution computed tomography of the chest can suggest PVOD in the setting of pulmonary hypertension when it shows nodular ground-glass opacities, septal lines, lymph node enlargement, and pleural effusion. Similarly, occult alveolar hemorrhage found on bronchoalveolar lavage in patients with pulmonary hypertension is associated with PVOD. We conducted the current study to identify additional clinical, functional, and hemodynamic characteristics of PVOD. We retrospectively reviewed 48 cases of severe pulmonary hypertension: 24 patients with histologic evidence of PVOD and 24 randomly selected patients with idiopathic, familial, or anorexigen-associated PAH and no evidence of PVOD after meticulous lung pathologic evaluation. We compared clinical and radiologic findings, pulmonary function, and hemodynamics at presentation, as well as outcomes after the initiation of PAH therapy in both groups. Compared to PAH, PVOD was characterized by a higher male:female ratio and higher tobacco exposure (p < 0.01). Clinical presentation was similar except for a lower body mass index (p < 0.02) in patients with PVOD. At baseline, PVOD patients had significantly lower partial pressure of arterial oxygen (PaO2), diffusing lung capacity of carbon monoxide/alveolar volume (DLCO/VA), and oxygen saturation nadir during the 6-minute walk test (all p < 0.01). Hemodynamic parameters showed a lower mean systemic arterial pressure (p < 0.01) and right atrial pressure (p < 0.05), but no difference in pulmonary capillary wedge pressure. Four bone morphogenetic protein receptor II (BMPR2) mutations have been previously described in PVOD patients; in the current study we describe 2 additional cases of BMPR2 mutation in PVOD. Computed tomography of the chest revealed nodular and ground-glass opacities, septal lines, and lymph node enlargement more frequently in patients with PVOD compared with patients with PAH (all p < 0.05). Among the 16 PVOD patients who received PAH-specific therapy, 7 (43.8%) developed pulmonary edema (mostly with continuous intravenous epoprostenol, but also with oral bosentan and oral calcium channel blockers) at a median of 9 days after treatment initiation. Acute vasodilator testing with nitric oxide and clinical, functional, or hemodynamic characteristics were not predictive of the subsequent occurrence of pulmonary edema on treatment. Clinical outcomes of PVOD patients were worse than those of PAH patients.

[Investigation of pulmonary hypertension]

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure (PAPm) superior than 25mmHg at rest or superior than 30mmHg with exercise. The classification of PH differentiates between "secondary" PH which results from a well-known disease, such as PH due to thromboembolic disease (obstructive PH), left cardiac failure (passive PH), or chronic respiratory diseases (hypoxic PH), and pulmonary arterial hypertension (PAH). PAH is a rare disease characterized by a progressive increase of pulmonary vascular resistance leading to right ventricular failure. PAH is classified as idiopathic, familial, or associated with various conditions (connective tissue diseases, congenital heart diseases with systemic-to-pulmonary shunts, portal hypertension, infection with the human immunodeficiency virus, or appetite-suppressant drugs). Transthoracic Doppler echocardiography is the investigation of choice for non invasive detection of PAH but right-heart catheterization is necessary to confirm the diagnosis of PAH and determine its mechanism. Pulmonary function tests and chest CT scan may detect an underlying chronic pulmonary disease (hypoxic PH). Lung perfusion scan and contrast-enhanced chest spiral CT scan can lead to the diagnosis of thromboembolic PH, which is to be confirmed by pulmonary angiography. Assessment of the severity of PH is based on clinical parameters (NYHA, right heart failure), functional tests (six-minute walk test), echocardiography and hemodynamics. Characterization of PH is essential in the management of PH because it determines the appropriate treatment: an etiological treatment in passive, obstructive or hypoxemic PH, or vasodilatator and antiproliferative therapies in PAH.

Challenges in pulmonary fibrosis. 3: Cystic lung disease

Cystic lung disease is a frequently encountered problem caused by a diverse group of diseases. Distinguishing true cystic lung disease from other entities, such as cavitary lung disease and emphysema, is important given the differing prognostic implications. In this paper the features of the cystic lung diseases are reviewed and contrasted with their mimics, and the clinical and radiographic features of both diffuse (pulmonary Langerhans' cell histiocytosis and lymphangioleiomyomatosis) and focal or multifocal cystic lung disease are discussed.

Diagnosis of interstitial lung diseases

Interstitial lung diseases (ILDs), a broad heterogeneous group of parenchymal lung disorders, can be classified into those with known and unknown causes. The definitions and diagnostic criteria for several major forms of ILDs have been revised in recent years. Although well over 100 distinct entities of ILDs are recognized, a limited number of disorders, including idiopathic pulmonary fibrosis, sarcoidosis, and connective tissue disease-related ILDs, account for most ILDs encountered clinically. In evaluating patients with suspected ILD, the clinician should confirm the presence of the disease and then try to determine its underlying cause or recognized clinicopathologic syndrome. Clues from the medical history along with the clinical context and radiologic findings provide the initial basis for prioritizing diagnostic possibilities for a patient with ILD. High-resolution computed tomography of the chest has become an invaluable tool in the diagnostic process. A confident diagnosis can sometimes be made on the basis of high-resolution computed tomography and clinical context. Serologic testing can be helpful in selected cases. Histopathologic findings procured through bronchoscopic or surgical lung biopsy are often needed in deriving a specific diagnosis. An accurate prognosis and optimal treatment strategy for patients with ILDs depend on an accurate diagnosis, one guided by recent advances in our understanding of the causes and pathogenetic mechanisms of ILDs.

High-resolution chest CT findings do not predict the presence of pulmonary hypertension in advanced idiopathic pulmonary fibrosis

BACKGROUND

Reliable, noninvasive approaches to the diagnosis of pulmonary hypertension (PH) in patients with idiopathic pulmonary fibrosis (IPF) are needed. We tested the hypothesis that chest CT-determined extent of pulmonary fibrosis and/or main pulmonary artery diameter (MPAD) can be used to identify the presence of PH in patients with advanced IPF.

METHODS

Cross-sectional study of 65 patients with advanced IPF and available right-heart catheterization and high-resolution chest CT. An expert radiologist scored ground-glass opacity, lung fibrosis, and honeycombing in the CT images on a scale of 0 to 4. These scores were also summed into a total profusion score. The main pulmonary artery was measured at its widest dimension on the supine full-chest sequence. At this same level, the widest aorta diameter was measured.

RESULTS

Chest CT-determined fibrosis score, ground-glass opacity score, honeycombing score, total profusion score, diameter of the main pulmonary artery, and the ratio of the pulmonary artery to aorta diameter did not differ between those with and without PH. There was no significant correlation between mean pulmonary artery pressure and any of the chest CT-determined measures.

CONCLUSIONS

High-resolution chest CT-determined extent of pulmonary fibrosis and/or MPAD cannot be used to screen for PH in advanced IPF patients.

Pulmonary hypertension associated with chronic respiratory disease

Pulmonary hypertension (PH) has long been recognized as a complication of chronic respiratory disease. Recent studies have highlighted the adverse impact PH has on the clinical course of these conditions and have cast doubt on the role of hypoxia in their pathogenesis. Clinicians should carefully consider the possibility of PH during the diagnostic evaluation of chronic respiratory disorders. The usefulness of pharmacologic therapy directed toward PH remains to be determined.

Hypertension pulmonaire des affections respiratoires chroniques

Pulmonary hypertension of chronic respiratory disease is defined as elevation of the mean resting pulmonary artery pressure to over 20 mm Hg. It is the commonest cause of pre-capillary pulmonary hypertension on account of the high prevalence of chronic obstructive pulmonary disease. It is primarily due to alveolar hypoxia that leads to remodelling of the distal pulmonary vasculature and consequently to an increase in pulmonary resistance. It is not as severe as idiopathic pulmonary hypertension. The mean pulmonary artery pressure is usually moderately increased (20-35 mm Hg) when patients are seen during a stable period of the disease. There are, however, more severe cases of pulmonary hypertension called, in some cases, disproportionate but these are uncommon. Increased right ventricular afterload can lead to the development of right ventricular failure that is a definite prognostic factor. The clinical symptoms of pulmonary hypertension are at a secondary level compared with those of the causal disease. Non-invasive diagnosis depends on Doppler echocardiography. Currently the most effective treatment is long term oxygen therapy (16-18 hr/24 hr). This improves or, at least stabilises, the pulmonary hypertension.

Pulmonary hypertension in patients with interstitial lung diseases

Pulmonary hypertension (PH) in patients with interstitial lung diseases (ILDs) is not well recognized and can occur in the absence of advanced pulmonary dysfunction or hypoxemia. To address this topic, we identified relevant studies in the English language by searching the MEDLINE database (1966 to November 2006) and by individually reviewing the references of identified articles. Connective tissue disease-related ILD, sarcoidosis, idiopathic pulmonary fibrosis, and pulmonary Langerhans cell histiocytosis are the ILDs most commonly associated with PH. Pulmonary hypertension is an underrecognized complication in patients with ILDs and can adversely affect symptoms, functional capacity, and survival. Pulmonary hypertension can arise in patients with ILDs through various mechanisms, Including pulmonary vasoconstriction and vascular remodeling, vascular destruction associated with progressive parenchymal fibrosis, vascular inflammation, perivascular fibrosis, and thrombotic angiopathy. Diagnosis of PH in these patients requires a high index of suspicion because the clinical presentation tends to be nonspecific, particularly in the presence of an underlying parenchymal lung disease. Doppler echocardiography is an essential tool in the evaluation of suspected PH and allows ready recognition of cardiac causes. Right heart catheterization is needed to confirm the presence of PH, assess its severity, and guide therapy. Management of PH in patients with ILDs is guided by identification of the underlying mechanism and the clinical context. An increasing number of available pharmacologic agents in the treatment of PH allow possible treatment of PH in some patients with ILDs. Whether specific treatment of PH in these patients favorably alters functional capacity or outcome needs to be determined.

Prevalence and outcomes of pulmonary arterial hypertension in advanced idiopathic pulmonary fibrosis

STUDY OBJECTIVES

The development of pulmonary arterial hypertension (PAH) can complicate many interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF). We sought to characterize the prevalence of PAH and its impact on survival in patients with advanced IPF.

DESIGN

Retrospective analysis of consecutive IPF patients undergoing pretransplantation right heart catheterization.

SETTING

Lung transplant and IPF referral center.

METHODS

PAH was defined as a mean pulmonary artery pressure (mPAP) of > 25 mm Hg. We compared demographic, spirometric, 6-min walk test (6MWT) results, and survival outcomes between those with PAH and those without PAH.

MEASUREMENTS AND RESULTS

Seventy-nine patients were included in the study. PAH was present in 31.6% of patients (mean [+/- SD] mPAP, 29.5 +/- 3.3 vs 19.1 +/- 3.7 mm Hg, respectively). Those patients with PAH had a lower mean diffusing capacity of the lung for carbon monoxide (Dlco) (37.6 +/- 11.3% vs 31.1 +/- 10.1%, respectively; p = 0.04) and were more likely to require supplemental oxygen (66.7% vs 17.6%, respectively; p < 0.0001). Mean distance walked (143.5 +/- 65.5 vs 365.9 +/- 81.8 m, respectively; p < 0.001) and mean pulse oximetric saturation nadir (80.1 +/- 3.7% vs 88.0 +/- 3.5%, respectively; p < 0.001) during the 6MWT were also lower among those with PAH. PAH was associated with a greater risk of death during the study period (mortality rate, 60.0% vs 29.9%, respectively; odds ratio, 2.6; 95% confidence interval [CI], 2.3 to 3.1; p = 0.001). One-year mortality rates were higher in those with PAH (28.0% vs 5.5%, respectively; p = 0.002). As a predictor of mortality, PAH had a sensitivity, specificity, and accuracy of 57.1%, 79.3%, and 73.4%, respectively. There was a linear correlation between mPAP and outcomes with higher pressures associated with a greater risk of mortality (hazard ratio, 1.09; 95% CI, 1.02 to 1.16). FVC and Dlco did not predict outcomes.

CONCLUSIONS

PAH is common in advanced cases of IPF and significantly impacts survival. A reduced Dlco, supplemental oxygen requirement, or poor 6-min walk performance should raise suspicion of the presence of underlying PAH. Identifying PAH might be an important adjunct in monitoring disease progression, triaging for transplantation, and guiding therapy.

Lung Transplantation for Pulmonary Langerhans' Cell Histiocytosis: A Multicenter Analysis

BACKGROUND

Lung transplantation (LT) may represent a therapeutic option in case of advanced pulmonary Langerhans' cell histiocytosis (PLCH). Little is known however about the characteristics of the patients considered for LT or its results.

METHODS

We conducted a retrospective multicenter study by questionnaire on 39 patients who underwent LT for end-stage PLCH at seven centers in France.

RESULTS

Of the 39 patients, 15 received single lung transplantation, 15 double lung transplantation and 9 heart-lung transplantation. At evaluation, extrapulmonary involvement was present in 31% of the patients, pulmonary hypertension (PAPm>25 mm Hg) was observed in 92% of cases and was moderate-to-severe (PAPm> or =35 mm Hg) in 72.5%. The survival was 76.9% at 1 year, 63.6% at 2 years, 57.2% at 5 years, and 53.7% at 10 years. Recurrence of the disease occurred in eight cases (20.5%) with no impact on the survival rate. The sole risk factor for recurrence of the disease was the presence of preoperative extrapulmonary involvement.

CONCLUSION

Severe pulmonary hypertension is a common feature in patients with end-stage PLCH. Given the good postransplant survival rate and despite a recurrence rate of the disease of approximately 20% after LT, we conclude that LT is a therapeutic option in this setting.