Haploinsufficiency of the folliculin gene leads to impaired functions of lung fibroblasts in patients with Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant inherited disorder caused by germline mutations in the FLCN gene, and characterized by skin fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax, and renal neoplasms. Pulmonary manifestations frequently develop earlier than other organ involvements, prompting a diagnosis of BHDS However, the mechanism of lung cyst formation and pathogenesis of pneumothorax have not yet been clarified. Fibroblasts were isolated from lung tissues obtained from patients with BHDS (n = 12) and lung cancer (n = 10) as controls. The functional abilities of these lung fibroblasts were evaluated by the tests for chemotaxis to fibronectin and three-dimensional (3-D) gel contraction. Fibroblasts from BHDS patients showed diminished chemotaxis as compared with fibroblasts from controls. Expression of fibronectin and TGF-ß1 was significantly reduced in BHDS fibroblasts when assessed by qPCR Addition of TGF-ß1 in culture medium of BHDS lung fibroblasts significantly restored these cells' abilities of chemotaxis and gel contraction. Human fetal lung fibroblasts (HFL-1) exhibited reduced chemotaxis and 3-D gel contraction when FLCN expression was knocked down. To the contrary, a significant increase in chemotactic activity toward to fibronectin was demonstrated when wild-type FLCN was overexpressed, whereas transduction of mutant FLCN showed no effect on chemotaxis. Our results suggest that FLCN is associated with chemotaxis in lung fibroblasts. Together with reduced TGF-ß1 expression by BHDS lung fibroblasts, a state of FLCN haploinsufficiency may cause lung fibroblast dysfunction, thereby impairing tissue repair. These may reveal one mechanism of lung cyst formation and pneumothorax in BHDS patients.

Benign clear cell "sugar" tumor of the lung in a patient with Birt-Hogg-Dubé syndrome: a case report.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is a rare inherited autosomal genodermatosis and caused by germline mutation of the folliculin (FLCN) gene, a tumor suppressor gene of which protein product is involved in mechanistic target of rapamycin (mTOR) signaling pathway regulating cell growth and metabolism. Clinical manifestations in BHD syndrome is characterized by fibrofolliculomas of the skin, pulmonary cysts with or without spontaneous pneumothorax, and renal neoplasms. There has been no pulmonary neoplasm reported in BHD syndrome, although the condition is due to deleterious sequence variants in a tumor suppressor gene. Here we report, for the first time to our knowledge, a patient with BHD syndrome who was complicated with a clear cell "sugar" tumor (CCST) of the lung, a benign tumor belonging to perivascular epithelioid cell tumors (PEComas) with frequent causative relation to tuberous sclerosis complex 1 (TSC1) or 2 (TSC2) gene. CASE PRESENTATION: In a 38-year-old Asian woman, two well-circumscribed nodules in the left lung and multiple thin-walled, irregularly shaped cysts on the basal and medial area of the lungs were disclosed by chest roentgenogram and computer-assisted tomography (CT) during a preoperative survey for a bilateral faucial tonsillectomy. Analysis of the resected tumor showed large polygonal cells with clear cytoplasm proliferating in a solid pattern. Immunohistochemistry revealed that these tumor cells were positive for microphthalmia-transcription factor, S100, and CD1a but negative for HMB45, indicating that the tumor was a CCST. Genetic testing indicated that the patient had a germline mutation on exon 12 of the FLCN gene, i.e., insertion of 7 nucleotides (CCACCCT) (c.1347_1353dupCCACCCT). Direct sequencing of the FLCN exon 12 using genomic DNA obtained from her microdissected CCST cells clearly revealed loss of the wild-type FLCN sequence, which confirmed complete functional loss of the FLCN gene. On the other hand, no loss of heterozygosity around TCS1- or TSC2-associated genetic region was demonstrated. CONCLUSION: To our knowledge, this is the first report of CCST of the lung in a patient with BHDS, indicating that CCST should be added to the spectrum of pulmonary manifestations of BHDS.

Isolation of individual cellular components from lung tissues of patients with lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease entailing cystic destruction of the lungs and progressive respiratory failure. LAM lungs are histologically characterized by the proliferation of smooth muscle-like cells (LAM cells) and an abundance of lymphatic vessels. To elucidate the pathophysiological processes of LAM, cell-type-specific analyses are required. However, no method exists for isolating the individual types of cells in LAM lesions. Therefore, we established a fluorescence-activated cell sorting (FACS)-based method for the direct isolation of LAM cells and other various cellular components from LAM-affected lung tissue. We obtained LAM-affected lung tissue from resections or transplant recipients and prepared single-cell suspensions. FACS, immunohistochemical, and molecular analysis were used cooperatively to isolate HMB45-positive LAM cells with tuberous sclerosis complex (TSC) 2 loss of heterozygosity (LOH). Using a combination of antibodies against an epithelial cell adhesion molecule (EpCAM) and podoplanin, we fractionated CD45-negative lung cells into three groups: lymphatic endothelial cells (LEC) (EpCAM(-)/podoplanin(hi) subset), alveolar type II cells (EpCAM(hi)/podoplanin(-) subset), and mesenchymal cells (EpCAM(-)/podoplanin(-/low) subset). During subsequent analysis of HMB45 expression, as a LAM-specific marker, we clearly identified LAM cells in the mesenchymal cell population. We then discovered that CD90(+)/CD34(-) cells in the mesenchymal cell population are not only positive for HBM45 but also had TSC2 LOH. These isolated cells were viable and subsequently amenable to cell culture. This method enables us to isolate LAM cells and other cellular components, including LAM-associated LEC, from LAM-affected lung tissues, providing new research opportunities in this field.

A Model of Lymphangioleiomyomatosis in a Three-Dimensional Culture System.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a tumor consisting of benign-looking neoplastic cells, but its wretched clinical outcome often resembles a malignant disease. LAM cell clusters (LCCs), unique microstructures commonly found in LAM-associated chylous effusion, are aggregates of LAM cells rimmed by lymphatic endothelium. LCCs seem to be crucial participants in the dissemination and progression of LAM. METHODS AND RESULTS: LCCs isolated from LAM-associated chylous effusion were embedded in a three-dimensional (3-D) culture gels, and then placed in a humidified CO2 incubator. During serial observations of their morphological changes, we found tube formations with lymphatic endothelial cells when LCCs settled side by side in 3-D gels. On the other hand, when LCCs were embedded separately enough to be isolated at their initial sites of settlement in the gels, each of LCCs gradually broke down, leaving a "cyst-like" hole after 7 days at the site where LCCs initially resided. Finally, we demonstrated that "cyst-like" hole formation in 3-D gels was inhibited with treatment with doxycycline or recombinant human VEGF receptor-3. CONCLUSIONS: We consider that our observation of this sequence in vitro illustrates how LCCs behave in vivo while enacting their important role in the progression of LAM. Our results indicate that the 3-D gel culture system for LCCs is a useful tool for exploring the effects of new therapeutic drugs under conditions when LCCs are constantly available.

Potential Role of CT Metrics in Chronic Obstructive Pulmonary Disease with Pulmonary Hypertension.

PURPOSE: Recent imaging studies demonstrated the usefulness of quantitative computed tomographic (CT) analysis assessing pulmonary hypertension (PH) in patients with chronic obstructive lung disease (COPD-PH). The aim of this study was to investigate whether it would be also valuable for predicting and evaluating the effect of pulmonary vasodilators in patients with COPD-PH. METHODS: We analyzed a correlation between the extent of cystic destruction (LAA%) and total cross-sectional areas of small pulmonary vessels less than 5 mm(2) (%CSA <5) in many CT slices from each of four COPD-PH patients before and after the initiation of pulmonary vasodilator. To evaluate those generalized data from patients with COPD, we evaluated multiple slices from 42 patients whose PH was not clinically suspicious. We also selected five PH patients with idiopathic interstitial pneumonia (IIP-PH) and analyzed serial changes of pulmonary artery enlargement (PA:A ratio). RESULTS: In 42 COPD patients without PH, LAA% had a statistically significant negative correlation with %CSA <5. However, three of four COPD-PH patients manifested no such correlation. In two patients, clinical findings were dramatically improved after the initiation of pulmonary vasodilator. Notably, LAA% and %CSA <5 in those patients correlated significantly after its treatment. In COPD-PH, the PA:A ratio was significantly decreased after the initiation of pulmonary vasodilator therapy (1.25 ± 0.13 vs. 1.13 ± 0.11, p = 0.019), but not in IIP-PH. CONCLUSIONS: Our study demonstrates that the use of quantitative CT analysis is a plausible and beneficial tool for predicting and evaluating the effect of pulmonary vasodilators in patients with COPD-PH.

Prevalence and clinical features of lymphedema in patients with lymphangioleiomyomatosis.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease predominantly affecting young women. Some of these patients develop lymphedema of the lower extremities and buttocks; however, neither the exact frequency of LAM-associated lymphedema nor the clinical features of such patients is well delineated. OBJECTIVES: To document the frequency, features, and treatment of LAM-associated lymphedema. METHODS: We reviewed all medical records of patients listed in the Juntendo University LAM registry for the 30 years preceding August 2010. RESULTS: Of 228 patients registered with a diagnosis of LAM, eight (3.5%) had LAM-associated lymphedema of the lower extremities. All were females with sporadic LAM, and their mean age when diagnosed was 32.5 years (range 23-44). Lymphedema of the lower extremities was the chief or a prominent presenting feature in five of these LAM patients. CT scans showed that all eight patients had enlarged lymph nodes (lymphangioleiomyomas) in the retroperitoneum and/or pelvic cavity. Yet, cystic destruction of the lungs was mild in four patients, moderate in two and severe only in two. Seven of these patients were treated by administering a fat-restricted diet and complex decongestive physiotherapy, and four received a gonadotropin-releasing hormone analog. With this combined protocol, all eight patients benefitted from complete relief or good control of the lymphedema. CONCLUSIONS: Lymphedema is a rare complication of LAM and may be associated with axial lymphatic involvement or dysfunction rather than severe cystic lung destruction. The combined multimodal treatments used here effectively resolved or controlled LAM-associated lymphedema.

Quantitative CT analysis of small pulmonary vessels in lymphangioleiomyomatosis.

BACKGROUNDS: Lymphangioleiomyomatosis (LAM) is a destructive lung disease that share clinical, physiologic, and radiologic features with chronic obstructive pulmonary disease (COPD). This study aims to identify those features that are unique to LAM by using quantitative CT analysis. METHODS: We measured total cross-sectional areas of small pulmonary vessels (CSA) less than 5mm(2) and 5-10mm(2) and calculated percentages of those lung areas (%CSA), respectively, in 50 LAM and 42 COPD patients. The extent of cystic destruction (LAA%) and mean parenchymal CT value were also calculated and correlated with pulmonary function. RESULTS: The diffusing capacity for carbon monoxide/alveolar volume (DL(CO)/VA %predicted) was similar for both groups (LAM, 44.4 ± 19.8% vs. COPD, 45.7 ± 16.0%, p=0.763), but less tissue damage occurred in LAM than COPD (LAA% 21.7 ± 16.3% vs. 29.3 ± 17.0; p<0.05). Pulmonary function correlated negatively with LAA% (p<0.001) in both groups, yet the correlation with %CSA was significant only in COPD (p<0.001). When the same analysis was conducted in two groups with equal levels of LAA% and DL(CO)/VA %predicted, %CSA and mean parenchymal CT value were still greater for LAM than COPD (p<0.05). CONCLUSIONS: Quantitative CT analysis revealing a correlation between cystic destruction and CSA in COPD but not LAM indicates that this approach successfully reflects different mechanisms governing the two pathologic courses. Such determinations of small pulmonary vessel density may serve to differentiate LAM from COPD even in patients with severe lung destruction.

Breakthrough lung Scedosporium prolificans infection with multiple cavity lesions in a patient receiving voriconazole for probable invasive aspergillosis associated with monoclonal gammopathy of undetermined significance (MGUS).

Breakthrough non- Aspergillus mold infections among patients receiving the anti-mold azole antifungal agents like voriconazole or posaconazole have been increasingly reported. We report a case of lung Scedosporium prolificans infection with multiple cavities in a 58-year-old man with monoclonal gammopathy of undetermined significance (MGUS) during voriconazole treatment for probable invasive aspergillosis. Cultures of repeated sputum specimens yielded the same fungus until his death 83 days after diagnosis. S. prolificans should be considered in patients with breakthrough infections receiving voriconazole.

[Case of rapidly progressed pulmonary metastases of superficial bladder cancer].

The patient was a 95-year-old-man admitted to the urological section of our hospital because of hematuria. Transurethral resection of the bladder tumor (TUR-Bt) was performed. This tumor was diagnosed pathologically as bladder cancer (transitional cell carcinoma Grade 3 pT1). After 8 months, local reccurence was seen and TUR-Bt was performed. (pTa). After 1 month, his chest radiograph and computed tomogram showed a mass shadow in the left upper lung field. Cystoscopy did not reveal a local reccurence. The patient's condition worsened, and he died of respiratory failure after about 1 month. At autopsy, pathologic studies of the lung tumor revealed transitional cell carcinoma, and local recurrence was not seen. We report a rare case of pulmonary metastases from superficial bladder cancer without local reccurence.