Pulmonary hypertension associated with sarcoidosis: mechanisms, haemodynamics and prognosis

Pulmonary veno-occlusive disease following hematopoietic stem cell transplantation: a rare model of endothelial dysfunction

Veno-occlusive disease is among the most serious complications following hematopoietic stem cell transplantation. While hepatic veno-occlusive disease occurs more commonly, the pulmonary variant remains quite rare and often goes unrecognized antemortem. Endothelial damage may represent the pathophysiologic foundation of these clinical syndromes. Recent advances in the treatment of hepatic veno-occlusive disease may have application to its pulmonary counterpart.

Intravascular sarcoidosis presenting as pulmonary vein occlusion: CT and pathologic findings

It is well known that destruction of the distal capillary bed from extensive fibrosis and honeycombing in the setting of sarcoidosis may lead to pulmonary hypertension. However, we report an unusual manifestation of sarcoidosis where pulmonary hypertension resulted from granulomatous involvement of the pulmonary veins and venules. This presented as venous occlusion and intraluminal filling defects that simulated thrombus on chest computed tomography. To our knowledge, this is the first reported imaging case of such a presentation.

Sarcoidosis

Sarcoidosis is a multisystemic disorder of unknown cause characterized by the formation of immune granulomas in involved organs. It is an ubiquitous disease with incidence (varying according to age, sex, race and geographic origin) estimated at around 16.5/100,000 in men and 19/100,000 in women. The lung and the lymphatic system are predominantly affected but virtually every organ may be involved. Other severe manifestations result from cardiac, neurological, ocular, kidney or laryngeal localizations. In most cases, sarcoidosis is revealed by persistent dry cough, eye or skin manifestations, peripheral lymph nodes, fatigue, weight loss, fever or night sweats, and erythema nodosum. Abnormal metabolism of vitamin D3 within granulomatous lesions and hypercalcemia are possible. Chest radiography is abnormal in about 90% of cases and shows lymphadenopathy and/or pulmonary infiltrates (without or with fibrosis), defining sarcoidosis stages from I to IV. The etiology remains unknown but the prevailing hypothesis is that various unidentified, likely poorly degradable antigens of either infectious or environmental origin could trigger an exaggerated immune reaction in genetically susceptible hosts. Diagnosis relies on compatible clinical and radiographic manifestations, evidence of non-caseating granulomas obtained by biopsy through tracheobronchial endoscopy or at other sites, and exclusion of all other granulomatous diseases. The evolution and severity of sarcoidosis are highly variable. Mortality is estimated at between 0.5–5%. In most benign cases (spontaneous resolution within 24–36 months), no treatment is required but a regular follow-up until recovery is necessary. In more serious cases, a medical treatment has to be prescribed either initially or at some point during follow-up according to clinical manifestations and their evolution. Systemic corticosteroids are the mainstay of treatment of sarcoidosis. The minimal duration of treatment is 12 months. Some patients experience repeated relapses and may require long-term low-dose corticosteroid therapy during years. Other treatments (immunosuppressive drugs and aminoquinolins) may be useful in case of unsatisfactory response to corticosteroids, poor tolerance and as sparing agents when high doses of corticosteroids are needed for a long time. In some strictly selected cases refractory to standard therapy, specific antiTNF-α agents may offer precious improvement. Some patients benefit from topical corticosteroids.

Pulmonary hypertension associated with sarcoidosis

Pulmonary involvement is common in sarcoidosis, an immune-mediated inflammatory disorder that is characterized by non-caseating granulomas in tissue. Sarcoid patients with advanced pulmonary disease, especially end-stage pulmonary fibrosis, risk developing pulmonary hypertension (World Health Organization group III pulmonary hypertension secondary to hypoxic lung disease). Increased levels of endothelin (ET)-1 in plasma and bronchoalveolar lavage of some sarcoid patients suggest that ET-1 may be driving pulmonary fibrosis and sarcoidosis-associated pulmonary hypertension. Although a relationship between raised levels of ET-1 and clinical phenotype is yet to be identified, early evidence from studies of ET-1 blockade with drugs such as bosentan is encouraging. Such therapy possibly could be combined with standard anti-inflammatory agents to improve outcome.

Sarcoidosis: clinical, hormonal, and magnetic resonance imaging (MRI) manifestations of hypothalamic-pituitary disease in 9 patients and review of the literature

Hypothalamic-pituitary (HP) sarcoidosis has 2 main endocrine manifestations: diabetes insipidus and hyperprolactinemia. We conducted the current study to investigate pituitary dysfunction and perform imaging of the HP area in patients both immediately following diagnosis and after treatment. The study included 6 men and 3 women, with a mean age of 30 years at the onset of sarcoidosis. All patients had both hormonal and magnetic resonance imaging (MRI) HP disorders. All patients had anterior pituitary dysfunction, 7 of them with associated diabetes insipidus. Nine patients had gonadotropin deficiency and 3 had hyperprolactinemia. MRI revealed infundibulum involvement in 5 patients, pituitary stalk thickness abnormality in 5, and involvement of the pituitary gland in 2, associated with other parenchymal brain or spinal cord lesions in 6 patients. All patients had multiple localizations of sarcoidosis, and 5 had histologically confirmed sinonasal localizations. Mean follow-up of the HP disorder was 7.5 years. All patients received prednisone. There was no correlation between the number of hormonal dysfunctions and the area of the HP axis involved as assessed by MRI. Although corticoid treatment was associated with a reduction of radiologic lesions, only 2 patients had partial recovery of hormonal deficiency. In conclusion, hormonal deficiencies associated with HP sarcoidosis frequently include hypogonadism (all patients) and to a lesser degree diabetes insipidus (7 of 9 patients). MRI abnormalities improved or disappeared in 7 cases under corticosteroid treatment, but most endocrine defects were irreversible despite regression of the granulomatous process. Most cases presented with multivisceral localizations and an abnormally high proportion of sinonasal localizations.

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.

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.

Sarcoidosis-Associated Pulmonary Hypertension

RATIONALE

Pulmonary hypertension is a known complication of sarcoidosis and is associated with increased mortality. Little is known about the outcome of sarcoidosis-associated pulmonary hypertension, including response to treatment.

OBJECTIVE

To determine the characteristics and outcome of patients with sarcoidosis-associated pulmonary hypertension treated with IV epoprostenol.

DESIGN

Retrospective chart review of all cases of pulmonary hypertension with a concomitant diagnosis of sarcoidosis evaluated in the Boston University Pulmonary Hypertension Center from 2000 to 2004.

MEASUREMENTS

Data collected included patient demographics, sarcoidosis stage, pulmonary function, echocardiography results, treatment, baseline and posttreatment hemodynamic measurements, and clinical outcome.

RESULTS

Eight patients were identified; four of the patients had stage IV pulmonary sarcoidosis. Pulmonary function test results were notable for severe diffusion impairment (mean diffusion capacity of the lung for carbon monoxide, 30% of predicted), with only mild-to-moderate restrictive physiology (mean FVC, 59% of predicted). Seventy-five percent of patients required supplemental oxygen at the time of presentation. All patients had moderate or severe pulmonary hypertension and were New York Heart Association (NYHA)/World Health Organization (WHO) class III or IV. A vasodilator trial with epoprostenol was performed in seven of the eight patients; six of the seven patients had a significant hemodynamic response (> 25% reduction in pulmonary vascular resistance). All but one of the responders (five of six patients) continued on therapy. Average clinical improvement was one to two NYHA/WHO classes at a mean follow-up of 29 months (range, 15 to 49 months).

CONCLUSIONS

In patients with sarcoidosis-associated pulmonary hypertension, the severity of pulmonary vascular disease occurs out of proportion to lung function abnormalities. The majority of our patients responded to epoprostenol; survival may be improved in this group.