Pulmonary involvement in Behçet's syndrome

Inhibiting Phosphatidylcholine Remodeling in Adipose Tissue Increases Insulin Sensitivity

Cell membrane phosphatidylcholine (PC) composition is regulated by lysophosphatidylcholine acyltransferase (LPCAT); changes in membrane PC saturation are implicated in metabolic disorders. Here, we identified LPCAT3 as the major isoform of LPCAT in adipose tissue and created adipocyte-specific Lpcat3-knockout mice to study adipose tissue lipid metabolism. Transcriptome sequencing and plasma adipokine profiling were used to investigate how LPCAT3 regulates adipose tissue insulin signaling. LPCAT3 deficiency reduced polyunsaturated PCs in adipocyte plasma membranes, increasing insulin sensitivity. LPCAT3 deficiency influenced membrane lipid rafts, which activated insulin receptors and AKT in adipose tissue, and attenuated diet-induced insulin resistance. Conversely, higher LPCAT3 activity in adipose tissue from ob/ob, db/db, and high-fat diet-fed mice reduced insulin signaling. Adding polyunsaturated PCs to mature human or mouse adipocytes in vitro worsened insulin signaling. We suggest that targeting LPCAT3 in adipose tissue to manipulate membrane phospholipid saturation is a new strategy to treat insulin resistance.

ARTICLE HIGHLIGHTS

Collagen Vascular Diseases and Disorders of Connective Tissue

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

Pulmonary involvement in Behçet's disease

BACKGROUND

Behçet's disease (BD) is a multisystem vasculitis and pulmonary involvement in BD is reported to indicate poor prognosis and high mortality.

OBJECTIVES

The aims of this study were to report on patients with pulmonary involvement and to discuss pulmonary artery thrombus and small-sized vasculitis associated with BD, with respect to previously published cases.

METHODS

Fifteen patients with BD and pulmonary involvement were included in this study. Massive hemoptysis was observed in all patients having pulmonary artery aneurysm (PAA).

RESULTS

Eleven patients had macroscopic pulmonary vascular disease (2 PAA, 3 PAA and thrombi and 6 only thrombi) and 3 patients had microscopic pulmonary vascular disease. The remaining patient had pulmonary cryptococcosis.

CONCLUSIONS

Data regarding treatment and outcomes of patients having BD-related pulmonary emboli/infarct and small-sized vasculitis are limited. Pulmonary vasculitis affects different levels of the pulmonary artery in BD and should be classified as macroscopic and microscopic vascular disease. 'Pulmonary artery thrombosis' should be used instead of 'pulmonary emboli'. Spiral CT angiography is the best radiological tool for evaluation of pulmonary problems in BD. Treatment of vasculitis should be based on the type of vascular disease and may vary among different types of vascular disease. Anticoagulation can be used in patients with microscopic vascular disease and nonaneurysmal macroscopic vascular disease. More studies are needed to clarify this issue.

Pulmonary vasculitis in behcet disease: a cumulative analysis

STUDY OBJECTIVES

The aims of this study were to investigate the frequency of pulmonary problems in Behçet disease (BD), and to discuss lesser-known features of pulmonary BD such as clinical characteristics, analysis of prognosis, and evaluation of treatment options with respect to the previously published cases.

DESIGN

We conducted a comprehensive review of the literature to analyze cumulated data about pulmonary involvement in BD.

SETTING

We found 159 articles regarding pulmonary disease associated with BD in May 2003.

PATIENTS

The evaluation of these articles demonstrated 598 pulmonary problems in 585 cases.

RESULTS

Pulmonary artery aneurysms (PAAs) are the most common pulmonary lesion in BD, and these are almost always associated with hemoptysis. Seventy-eight percent of patients with aneurysms have concomitant extrapulmonary venous thrombi or thrombophlebitis. Other pulmonary problems are reported in BD, and these are principally related to vascular lesions and radiologic abnormalities.

CONCLUSIONS

Pulmonary vascular problems, either PAA or involvement of small-sized vessels, are the main pulmonary disorders in BD. Immunopathologic findings indicate that the underlying pathogenesis is pulmonary vasculitis, which may result in thrombosis, infarction, hemorrhage, and PAA formation. Patients with small nonspecific radiologic abnormalities should be followed up closely since early diagnosis of vascular lesions may be life-saving. Immunosuppression is the main therapy for the treatment of a vasculitis. It is important that pulmonary angiitis is not mistaken for pulmonary thromboembolic disease since fatalities have occurred in BD shortly after initiation of anticoagulation/thrombolytic treatment.

Pulmonary involvement in Behçet's disease: evaluation of 123 I-MIBG retention

Pulmonary involvement in Behçet's disease (BD) is reported to indicate poor prognosis and high mortality. Our aim was to evaluate the pulmonary vascular status in BD. As 123I-meta-iodobenzylguanidine (123I-MIBG) shares the same uptake, storage and release mechanisms as norepinephrine, associated with the functional state of pulmonary endothelium, it may reflect endothelial injury. Twenty-five patients (13 males, 12 females; mean age, 36.44 years) and 12 age-matched controls were included. After intravenous injection of 123I-MIBG, thorax images were taken at 15 min and 4 h. Appropriate regions of interest were drawn, and heart to mediastinum (H/M) ratios and lung retention indices (LRI) were calculated. The difference between the LRI of controls (75.6+/-4%) and patients (87.7+/-10%) was found to be extremely significant (P<0.005). The LRIs of active (92.85+/-12%) and inactive (83.65+/-5%) states of BD were significantly different (P<0.05) from each other. There was no significant difference between the H/M ratios of controls (2.4+/-0.27) and patients (2.39+/-0.31) or between patients in active and inactive disease states. Our study revealed prolonged lung retention of 123I-MIBG in BD, probably reflecting the severity of the disease. In conclusion, 123I-MIBG lung retention is a valuable finding in the evaluation of pulmonary vascular status and may be a potential marker of prognosis in BD.

A case of rapidly progressive pulmonary aneurysm as a rare complication of Behçet's syndrome--a case report

One of the severe complications of Behçet's syndrome is pulmonary arterial involvement. The authors report a patient with Behçet's syndrome who had the complications of multiple pulmonary arterial aneurysms presenting with hemoptysis and right ventricular thrombus. He underwent emergency surgery because of failure of intensive immunotherapy and died 2 months after the surgery.

A fatal case of Behçet's disease associated with multiple cardiovascular lesions

Behçet's disease is recognised as a chronic multisystem disorder with vasculitis as its underlying pathological process. Cardiac involvement is rare and often associated with poor prognosis. A large right atrial thrombus, pulmonary aneurysms and aortic pseudoaneurysm that developed 17 years after surgery for bilateral renal artery stenosis is presented in a 26-year-old Behçet's disease patient. He was admitted to the hospital with fever of unknown origin associated with chest pain, dyspnea, cough, haemoptysis and pulmonary opacity in chest X-ray. Initial pulmonary CT demonstrated small subpleural infiltrates bilaterally, one of which was round and suspected as being metastatic. Examination of open lung biopsy demonstrated haemorrhagic infarct surrounded by some occluded pulmonary arteries. Subsequent CT showed pulmonary aneurysms compatible with Behçet's disease. Echocardiography demonstrated a large pedunculated mass in the right atrium. Injection of urographin showed a right atrial mass and a large right pulmonary artery aneurysm. The atrial mass was completely excised during open heart surgery and was identified as being an organising thrombus. Eight weeks later while taking prednisone, he was readmitted because of an infected mid sternal wound. CT showed slight separation of the stemum, retrosternal fluid, pulmonary arteries aneurysm and ascending aorta aneurysm. The next day, the patient died from massive bleeding from his ruptured ascending aortic pseudoaneurysm. Bizarre presentation of arterial and venous thromboses or arterial aneurysm formation, particularly in young patients, should suggest Behçet's disease.