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Background: Lymphangioleiomyomatosis is a progressive diffuse cystic lung disease with approximately 85% survival at 10 years. The determinants of disease progression and mortality after the introduction of sirolimus therapy and vascular endothelial growth factor D (VEGF-D) as a biomarker have not been well defined., Research Question: Which factors, including VEGF-D and sirolimus therapy, influence disease progression and survival prognosis in patients with lymphangioleiomyomatosis?, Study Design and Methods: The progression dataset and the survival dataset included 282 and 574 patients, respectively, from Peking Union Medical College Hospital, Beijing, China. A mixed-effects model was used to compute the rate of decline in FEV 1 , and generalized linear models were used to identify variables affecting FEV 1 decline. A Cox proportional hazards model was used to explore the association between clinical variables and the outcomes of death or lung transplantation in patients with lymphangioleiomyomatosis., Results: VEGF-D levels and sirolimus treatment were associated with FEV 1 changes and survival prognosis. Compared with patients with VEGF-D of < 800 pg/mL at baseline, patients with VEGF-D of ≥ 800 pg/mL lost FEV 1 faster (SE, -38.86 mL/y; 95% CI, -73.90 to -3.82 mL/y; P = .031). The 8-year cumulative survival rates of patients with VEGF-D of ≥ 2,000 pg/mL and < 2,000 pg/mL were 82.9% and 95.1%, respectively (P = .014). The generalized linear regression model also demonstrated the benefit of delaying the decline of FEV 1 by 65.56 mL/y (95% CI, 29.06-102.06 mL/y) in patients treated with sirolimus compared with those without sirolimus (P < .001). The 8-year risk of death was reduced by 85.1% (hazard ratio, 0.149; 95% CI, 0.075-0.299) after sirolimus treatment. After inverse treatment probability weighting, the risks of death in the sirolimus group were reduced by 85.6%. CT scan results of grade III severity were associated with worse progression than results of grades I or II severity. Patients with baseline FEV 1 of 70% predicted or St. George's Respiratory Questionnaire Symptoms domain 50 or higher predicted a higher risk of worse survival., Interpretation: Serum VEGF-D levels, a biomarker of lymphangioleiomyomatosis, are associated with disease progression and survival. Sirolimus therapy is associated with slower disease progression and better survival in patients with lymphangioleiomyomatosis., Trial Registry: ClinicalTrials.gov; No.: NCT03193892; URL: www., Clinicaltrials: gov., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Sporadic lymphangioleiomyomatosis (S-LAM) is a rare neoplasm with heterogeneous clinical features that is conventionally considered to be related to TSC2. This study serves to elucidate the mutation landscape and potential correlation between S-LAM genomic profiles and clinical phenotypes., Methods: Genomic profiles of 22 S-LAM patients were obtained by sequencing genomic DNA and cell-free DNA from various specimens using an NGS (next-generation sequencing)-based tumor-driver gene panel. Detected mutations were summarized. Symptoms, serum vascular endothelial growth factor D (VEGF-D) values, pulmonary function, and six-minute walk distance (6MWD) were compared among groups with different TSC2 status and genotypes to analyze genotype-phenotype correlations., Results: 67 Variants in 43 genes were detected, with a TSC2 mutation detection rate of 68.2%. The TSC2 detection rate was similar in specimens obtained either through transbronchial lung biopsy (TBLB) or surgical lung biopsy (70.0% vs. 69.2%, p > 0.05). A novel mutation in VEZF1 (c.A659G) was detected in four participants and may represent a mild disease state. TSC2 mutation was significantly related to a shorter 6MWD (p < 0.05), and a higher percentage of VEGF-D over 800 pg/mL (p < 0.05); stop-gain mutation was significantly related to a higher prevalence of pneumothorax., Conclusions: Tumor-driver mutations in genes other than TSC2 may have a role in S-LAM, and TBLB specimens are practical alternatives for genomic analysis. TSC2 mutation detectability and types are related to the disease severity and phenotypes of S-LAM., (© 2022. The Author(s).)

Background: The differential diagnosis of diffuse cystic lung disease (DCLD) is a clinical challenge. We wish to analyze the distribution of the etiology of DCLD based on data from a single lymphangioleiomyomatosis (LAM) clinic., Methods: All DCLD patients at the LAM Clinic of Peking Union Medical College Hospital between January 2006 and December 2019 were analyzed. Information on the demographic, clinical, radiological, and pathological features was collected., Results: A total of 1010 patients with DCLD on CT scan were evaluated. A sum of 711(70.4%) patients were diagnosed with definite or probable LAM. Other diagnoses included Birt-Hogg-Dubé syndrome (46), Sjogren's syndrome (38), pulmonary Langerhans cell histiocytosis (14), lung tumors (3), Castleman disease (2), antineutrophil cytoplasmic antibody-associated vasculitis (2), systemic lupus erythematosus (1), Marfan syndrome (1), amyloidosis (1), congenital cystic adenomatoid malformation of the lung (1), and pleuroparenchymal fibroelastosis (1). In the 38 patients diagnosed with Sjogren's syndrome, 2 were diagnosed with light-chain deposition disease, 2 were diagnosed with amyloidosis and 1 was diagnosed with lymphocytic interstitial pneumonia. One hundred and eighty-nine patients (18.7%) were undiagnosed. Lung biopsy results were available in 27 patients in the undiagnosed DCLD group but did not provide a diagnosis., Conclusion: Approximately 70% of DCLD patients in our LAM clinic had LAM. The common differential diagnoses included Birt-Hogg-Dubé syndrome, Sjogren's syndrome, and pulmonary Langerhans cell histiocytosis. Detailed clinical information and laboratory, genetic, and pathological investigations provide correct diagnoses in most patients with DCLD.

Lymphangioleiomyomatosis (LAM) is a slow albeit progressive rare neoplastic disease featured with diffuse thin-walled cysts in lungs and angiomyolipomas in kidneys. LAM affects almost exclusively women and has one of the strongest gender predispositions of any extragenital human disease. Two forms of LAM present clinically, sporadic (S-LAM) and tuberous sclerosis complex-associated (TSC-LAM). TSC is an autosomal dominant genetic multisystems neoplastic disease. A high prevalence of LAM can be detected in adult female TSC patients. Tremendous progress has been made in our understanding and management of this rare disease. Both LAM and TSC are TSC2 or TSC1 mutated diseases that result in overactivation of the mechanistic target of rapamycin (mTOR) pathway. Sirolimus, an mTOR inhibitor, has been approved for LAM treatment in the United States and many other countries. Therapies targeting female sex hormones have shown preclinical efficacy in animal and cell culture-based experiments, but have not been properly investigated clinically. In this review, we summarize current recommendations in the diagnosis and treatment of LAM., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Background: Sirolimus has been shown to be effective in patients with lymphangioleiomyomatosis (LAM). We wish to summarize our experience using sirolimus and its effectiveness in LAM patients., Methods: We analyzed data from 98 patients who were diagnosed with definite or probable sporadic LAM based on the European Respiratory Society diagnosis criteria for LAM in 2010 at Peking Union Medical College Hospital and who had received sirolimus during January 2007 to June 2015. The data before and after the initiation of sirolimus therapy included pulmonary function tests, arterial blood gas analysis, 6-min walking distance (6MWD), size of chylous effusion and renal angiomyolipomas (AML), St. George's Respiratory Questionnaires (SGRQ) and vascular endothelial growth factor-D (VEGF-D) levels. Serum levels of sirolimus and adverse events were collected., Results: Median follow-up was 2.5 years. Most patients had forced expiratory volume in 1 s (FEV 1 ) values less than 70% predicted or symptomatic chylothorax. The mean changes before and after the initiation of sirolimus were - 31.12 ± 30.78 mL/month and 16.11 ± 36.00 mL/month (n = 18,p = 0.002) for FEV 1 change, and - 0.55 ± 0.60 mmHg/month and 0.30 ± 1.19 mmHg/month (n = 17, p = 0.018) for P a O 2 change. 6MWD improved from 358.8 ± 114.4 m to 415.6 ± 118.6 m (n = 46, p = 0.004) and SGRQ total score from 57.2 ± 21.0 to 47.5 ± 22.8 (n = 50, p < 0.001). The median VEGF-D concentration decreased to 1609.4 pg/mL from 3075.6 pg/mL after sirolimus therapy (n = 41, p < 0.001). Patients with sirolimus trough levels of 5-9.9 ng/mL had an increase in FEV 1 (p < 0.05). Sixty-five percent of patients (13/20) had almost complete resolution of chylous effusions. The most frequent adverse events were mouth ulcers, menstrual disorder, hyperlipidemia and acneiform rash, all were mild., Conclusion: Long-term use of sirolimus is safe in patients with LAM. LAM patients with FEV 1 less than 70% predicted and symptomatic chylothorax are suitable for receiving sirolimus therapy. The maintaining serum trough levels of sirolimus are recommended between 5 to 9.99 ng/mL.

Background: Definite diagnosis of lymphangioleiomyomatosis (LAM) depends on either transbronchial lung biopsy or video-assisted thoracic surgery, unless there is a history of chylothorax, kidney angiomyolipoma (AML), or tuberous sclerosis complex (TSC). Vascular endothelial growth factor-D (VEGF-D) was recently considered as a novel diagnostic marker for LAM. Herein, we evaluated diagnostic value of serum VEGF-D in LAM patients., Methods: Serum samples were obtained from 78 cases of LAM (50 definite and 28 probable LAM based on European Respiratory Society guidelines), and 40 healthy female volunteers. VEGF-D was measured using enzyme-linked immunosorbant assay according to product instruction (R&D)., Results: Serum VEGF-D was significantly increased in definite LAM group, compared with that of health control (median: 3841.9 pg/mL vs 405.5 pg/mL respectively, p < 0.001). The optimal cut-off point for definite LAM diagnosis was 850.7 pg/mL. In probable LAM group, the majority of patients (92.9%) had serum VEGF-D level over 850.7 pg/mL. The serum levels of VEGF-D in LAM patients with pulmonary cystic lesions only were lower than that in patients with any of evidences of AML, chylous effusions, adenopathy, lymphangioleiomyomas, or TSC, but higher than that in the health control. In addition, VEGF-D levels were correlated with disease severity measured as LAM CT grade, and presentations of chylous effusions and/or lymphatic involvement (p < 0.05)., Conclusion: Serum VEGF-D should be added to the current diagnosis algorithm to enhance definitive diagnosis for LAM., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Diffuse cystic lung disease (DCLD) is a group of heterogeneous diseases that present as diffuse cystic changes in the lung on computed tomography of the chest. Most DCLD diseases are rare, although they might resemble common diseases such as emphysema and bronchiectasis. Main causes of DCLD include lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, pulmonary Langerhans cell histiocytosis, lymphoid interstitial pneumonia, amyloidosis, light-chain deposition disease, Sjögren syndrome, and primary or metastatic neoplasm. We discuss clinical factors that are helpful in the differential diagnosis of DCLDsuch as sex and age, symptoms and signs, extrapulmonary presentations, cigarette smoking, and family history. Investigations for DCLD include high-resolution computed tomography, biochemical and histopathological studies, genetic tests, pulmonary function tests, and bronchoscopic and video-assisted thoracoscopic biopsies. A proposed diagnostic algorithm would enhance ease of diagnosing most cases of DCLD. [ABSTRACT FROM AUTHOR]