Decline in lung function in lymphangioleiomyomatosis: relation to menopause and progesterone treatment

Lymphangioleiomyomatosis and pregnancy: a mini-review

Lymphangioleiomyomatosis(LAM) is a slow progressive, rare cystic lung disease in women of reproductive age, associated with infiltration of the lung by atypical smooth muscle like cells, leading to the cystic destruction of the lung parenchyma. As LAM exclusively affects women of childbearing age, it can arise or exacerbate during pregnancy. Many patients with LAM are discouraged from pregnancy, although there is not much objective evidence effect on fertility. Patients diagnosed with LAM during pregnancy experience worse outcomes, so the safety of pregnancy is a vexing problem. What was worse, treatment strategies are limited on the effects of LAM on pregnancy outcomes. Pregnancy could be considered in LAM patients. Successful delivery in women with LAM depends on the condition of the LAM, which is in turn dependent on obstetricians and respiratory physicians. In this review, we describe the epidemiology, pathogenesis, diagnosis, clinical features and the treatment strategies of LAM during pregnancy.

Lymphangioleiomyomatosis in patients with tuberous sclerosis: a national centre audit

BACKGROUND

Lymphangioleiomyomatosis (LAM) is common in tuberous sclerosis complex (TSC) yet under recognised with management mostly based upon evidence obtained from patients with sporadic LAM. We performed a prospective audit of patients with TSC-LAM attending a national referral centre to inform management guidelines.

METHODS

The UK LAM Centre was established in 2011 and conducts a prospective audit of pre-defined quality outcomes for all subjects. Audit data are reported on all patients with TSC-LAM and a comparator population of patients with sporadic LAM.

RESULTS

Between 2011 and 2022, 73 patients were seen with TSC-LAM. All were women with a mean (SD) age of 39 (12) years. Referral rates were similar over the study period including after the introduction of CT screening. Median age of diagnosis with TSC was 11 years (range 0-70) with one third diagnosed with TSC as adults. Compared with all TSC patients in the 'TOSCA' registry, TSC-LAM patients tended to have been diagnosed with TSC at an older age, had fewer neuro-cognitive manifestations and were more likely to have angiomyolipoma. The most common presentations of TSC-LAM were following workup for angiomyolipoma, pneumothorax or dyspnoea with only one fifth detected after CT screening. Baseline FEV1 and DLCO at first assessment were reduced to 77 and 63% predicted respectively and were similar to patients with sporadic LAM. During follow-up, FEV1 fell by a mean of 81 ml/year and DLCO fell by 0.309 mmol/ml/kPa/year in patients not being treated with an mTOR inhibitor. 55% required treatment with either sirolimus or Everolimus for LAM or angiomyolipoma respectively. For those treated with an mTOR inhibitor, mean FEV1 fell by 3 ml/year and DLCO increased by 0.032 mmol/ml/kPa/year and was similar to sporadic LAM. Risk of death due to LAM or need for lung transplant in patients with TSC-LAM was 0.67%/year.

CONCLUSIONS

Despite screening recommendations, LAM is often diagnosed in TSC after symptoms develop which may delay treatment. Complications including pneumothorax and loss of lung function are significant and similar to sporadic LAM. Work is needed to implement the recommended CT screening for LAM and improve respiratory care for TSC-LAM.

Diagnosis of cystic lung diseases: a position statement from the UK Cystic Lung Disease Rare Disease Collaborative Network

BACKGROUND

Rare cystic lung diseases are increasingly recognised due the wider application of CT scanning making cystic lung disease management a growing part of respiratory care. Cystic lung diseases tend to have extrapulmonary features that can both be diagnostic but also require surveillance and treatment in their own right. As some of these diseases now have specific treatments, making a precise diagnosis is crucial. While Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, lymphoid interstitial pneumonia and lymphangioleiomyomatosis are becoming relatively well-known diseases to respiratory physicians, a targeted and thorough workup improves diagnostic accuracy and may suggest other ultrarare diseases such as light chain deposition disease, cystic pulmonary amyloidosis, low-grade metastatic neoplasms or infections. In many cases, diagnostic information is overlooked leaving uncertainty over the disease course and treatments.

AIMS

This position statement from the Rare Disease Collaborative Network for cystic lung diseases will review how clinical, radiological and physiological features can be used to differentiate between these diseases.

NARRATIVE

We highlight that in many cases a multidisciplinary diagnosis can be made without the need for lung biopsy and discuss where tissue sampling is necessary when non-invasive methods leave diagnostic doubt. We suggest an initial workup focusing on points in the history which identify key disease features, underlying systemic and familial diseases and a clinical examination to search for connective tissue disease and features of genetic causes of lung cysts. All patients should have a CT of the thorax and abdomen to characterise the pattern and burden of lung cysts and extrapulmonary features and also spirometry, gas transfer and a 6 min walk test. Discussion with a rare cystic lung disease centre is suggested before a surgical biopsy is undertaken.

CONCLUSIONS

We suggest that this focused workup should be performed in all people with multiple lung cysts and would streamline referral pathways, help guide early treatment, management decisions, improve patient experience and reduce overall care costs. It could also potentially catalyse a national research database to describe these less well-understood and unidentified diseases, categorise disease phenotypes and outcomes, potentially leading to better prognostic data and generating a stronger platform to understand specific disease biology.

Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is an ultra-rare, slowly progressive neoplastic cystic disease, belonging to the group of PEComas. It can occur sporadically or associated to tuberous sclerosis complex disease and affects mainly women in child-birth age. Dyspnoea is the most frequent symptom referred to the time of diagnosis, however spontaneous pneumothorax may be a typical presentation associated to extrathoracic manifestations, such as renal angiomyolipomas. In the last decade, important advances in understanding molecular mechanisms underlying the LAM pathogenesis have been reached. It has allowed to obtain improvements in the research of novel biomarkers, treatment and a better management of the disease.

Predicting Individualized Lung Disease Progression in Treatment-Naive Patients With Lymphangioleiomyomatosis

BACKGROUND

Lung function decline varies significantly in patients with lymphangioleiomyomatosis (LAM), impeding individualized clinical decision-making.

RESEARCH QUESTION

Can we aid individualized decision-making in LAM by developing a dynamic prediction model that can estimate the probability of clinically relevant FEV1 decline in patients with LAM before treatment initiation?

STUDY DESIGN AND METHODS

Patients observed in the US National Heart, Lung, and Blood Institute (NHLBI) Lymphangioleiomyomatosis Registry were included. Using routinely available variables such as age at diagnosis, menopausal status, and baseline lung function (FEV1 and diffusing capacity of the lungs for carbon monoxide [Dlco]), we used novel stochastic modeling and evaluated predictive probabilities for clinically relevant drops in FEV1. We formed predictive probabilities of transplant-free survival by jointly modeling longitudinal FEV1 and lung transplantation or death events. External validation used the UK Lymphangioleiomyomatosis Natural History cohort.

RESULTS

Analysis of the NHLBI Lymphangioleiomyomatosis Registry and UK Lymphangioleiomyomatosis Natural History cohorts consisted of 216 and 185 individuals, respectively. We derived a joint model that accurately estimated the risk of future lung function decline and 5-year probabilities of transplant-free survival in patients with LAM not taking sirolimus (area under the receiver operating characteristic curve [AUC], approximately 0.80). The prediction model provided estimates of forecasted FEV1, rate of FEV1 decline, and probabilities for risk of prolonged drops in FEV1 for untreated patients with LAM with a high degree of accuracy (AUC > 0.80) for the derivation cohort as well as the validation cohort. Our tool is freely accessible at: https://anushkapalipana.shinyapps.io/testapp_v2/.

INTERPRETATION

Longitudinal modeling of routine clinical data can allow individualized LAM prognostication and assist in decision-making regarding the timing of treatment initiation.

French recommendations for the diagnosis and management of lymphangioleiomyomatosis

BACKGROUND

The present article is an English-language version of the French National Diagnostic and Care Protocol, a pragmatic tool to optimize and harmonize the diagnosis, care pathway, management and follow-up of lymphangioleiomyomatosis in France.

METHODS

Practical recommendations were developed in accordance with the method for developing a National Diagnosis and Care Protocol for rare diseases of the Haute Autorité de Santé and following international guidelines and literature on lymphangioleiomyomatosis. It was developed by a multidisciplinary group, with the help of patient representatives and of RespiFIL, the rare disease network on respiratory diseases.

RESULTS

Lymphangioleiomyomatosis is a rare lung disease characterised by a proliferation of smooth muscle cells that leads to the formation of multiple lung cysts. It occurs sporadically or as part of a genetic disease called tuberous sclerosis complex (TSC). The document addresses multiple aspects of the disease, to guide the clinicians regarding when to suspect a diagnosis of lymphangioleiomyomatosis, what to do in case of recurrent pneumothorax or angiomyolipomas, what investigations are needed to make the diagnosis of lymphangioleiomyomatosis, what the diagnostic criteria are for lymphangioleiomyomatosis, what the principles of management are, and how follow-up can be organised. Recommendations are made regarding the use of pharmaceutical specialties and treatment other than medications.

CONCLUSION

These recommendations are intended to guide the diagnosis and practical management of pulmonary lymphangioleiomyomatosis.

Estradiol Augments Tumor-Induced Neutrophil Production to Promote Tumor Cell Actions in Lymphangioleiomyomatosis Models

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease caused by smooth muscle cell-like tumors containing tuberous sclerosis (TSC) gene mutations and found almost exclusively in females. Patient studies suggest LAM progression is estrogen dependent, an observation supported by in vivo mouse models. However, in vitro data using TSC-null cell lines demonstrate modest estradiol (E2) responses, suggesting E2 effects in vivo may involve pathways independent of direct tumor stimulation. We previously reported tumor-dependent neutrophil expansion and promotion of TSC2-null tumor growth in an E2-sensitive LAM mouse model. We therefore hypothesized that E2 stimulates tumor growth in part by promoting neutrophil production. Here we report that E2-enhanced lung colonization of TSC2-null cells is indeed dependent on neutrophils. We demonstrate that E2 induces granulopoiesis via estrogen receptor α in male and female bone marrow cultures. With our novel TSC2-null mouse myometrial cell line, we show that factors released from these cells drive E2-sensitive neutrophil production. Last, we analyzed single-cell RNA sequencing data from LAM patients and demonstrate the presence of tumor-activated neutrophils. Our data suggest a powerful positive feedback loop whereby E2 and tumor factors induce neutrophil expansion, which in turn intensifies tumor growth and production of neutrophil-stimulating factors, resulting in continued TSC2-null tumor growth.

Determinants of Progression and Mortality in Lymphangioleiomyomatosis

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 FEV₁, and generalized linear models were used to identify variables affecting FEV₁ 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 FEV₁ 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 FEV₁ 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 FEV₁ 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 FEV₁ 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.

Disease monitoring using lung function trajectory in lymphangioleiomyomatosis: assessment in two national cohorts

STUDY QUESTION

In lymphangioleiomyomatosis, airflow obstruction and impairment of gas transfer progress at variable rates and serial lung function is recommended for disease monitoring. As these measurements are variable, recognising subjects needing treatment can be difficult. We used two prospective national cohorts to study change over time and variation in FEV₁ to inform clinical decision making.

PATIENTS AND METHODS

Clinical and lung function data for 141 UK and 148 American subjects were studied. Multilevel mixed effects modelling, route mean square analysis of errors and Bland-Altman analysis were used to analyse variability in lung function over time.

RESULTS

At baseline assessment, DL_CO was reduced to a greater degree than FEV₁. In untreated patients, FEV₁ and DL_CO declined at proportionately similar rates independent of initial lung function. In mechanistic target of rapamycin (mTOR) inhibitor treated patients, FEV₁ stabilised but DL_CO continued to decline. FEV₁/DL_CO per cent predicted ratio was 1.37 (0.43) at baseline and increased to 1.41 (0.50) after 42 (24) months (p=0.0002). At least five measurements were required before >70% of individuals had estimates of rate of FEV₁ loss within 50 mL/year and DL_CO loss within 0.1 mmol/min/kPa/year of the final values.

CONCLUSIONS

While FEV₁ and DL_CO fall proportionately in most, in early disease and during mTOR inhibitor treatment, DL_CO should also be monitored as it may fall independent of FEV₁. Since at least five observations over many months are required to make confident estimates of FEV₁ and DL_CO trajectories, new strategies are needed to measure disease activity and target early treatment appropriately.

Lung transplantation for lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease, associated with respiratory symptoms of dyspnea and spontaneous pneumothorax, along with various extra-thoracic manifestations. Often a progressive disease, albeit slowly, patients can develop chronic and severe respiratory failure and require supplemental oxygen. Lung transplantation (LTX) can offer improved duration and quality of life for patients with end-stage lung disease due to LAM. There are several unique considerations for LTX in LAM patients, and disease-specific complications of LAM prior to LTX can affect management decisions. Furthermore, there are several possible post-transplant issues specific to LAM. In this review, we discuss evaluation and management, disease-specific complications (both pre- and post-transplant), and outcomes for LAM patients undergoing lung transplantation.

Pelvic Lymph Node Lymphangiomyomatosis Found During Surgery for Gynecological Fallopian Tube Cancer: A Case Report and Literature Review

Background

Lymphangioleiomyomatosis (LAM) is a rare low-grade metastatic tumor with an unknown origin that spreads through lymphatic vessels. It is characterized by the proliferation of smooth muscle-like or epithelioid tumor cells in the lung and axial lymphatic system. Extrapulmonary LAM is a localized disease with a low incidence rate, and the location of the related lesions is atypical. It is difficult to diagnose. The LAM of pelvic lymph nodes is hidden. It is usually found through gynecological oncology surgery.

Case presentation

We report a 57-year-old postmenopausal woman with a pelvic mass and vaginal bleeding as the main symptoms. The patient had no history of pulmonary LAM, tuberous sclerosis complex (TSC), or renal angiomyolipoma and had not used exogenous hormones. We performed a total hysterectomy, bilateral adnexectomy, greater omentum resection, and pelvic lymphadenectomy under laparoscopy. The postoperative pathology confirmed high-grade serous carcinoma of the left fallopian tube, and four lymph nodes were found in the pelvic lymph nodes, suggesting lymphangiomyomatosis. Immunohistochemical results also showed that these cells could express markers of smooth muscle cells and melanoma cells. The patient was treated with chemotherapy after the operation. Chest CT did not suggest lung LAM during the postoperative follow-up, and there was no tumor recurrence.

Conclusion

The diagnosis of this disease is challenging. At the same time, due to insufficient clinical samples, it is still unknown whether there is a potential relationship between pelvic and peritoneal lymph node LAM found in the surgical staging of gynecological tumors and lung LAM and/or TSC. There is no evidence that pelvic and peritoneal lymph node LAM will increase the risk of pulmonary LAM. Therefore, additional clinical data are required to analyze and summarize the relationship between pelvic and peritoneal lymph node LAM, pulmonary LAM, and the source of LAM. We present a case of pelvic lymph node LAM and propose a hypothesis that the pathogenesis of endometriosis can be used for reference in the study of this disease.

Sirolimus reduces the risk of pneumothorax recurrence in patients with lymphangioleiomyomatosis: a historical prospective self-controlled study

Background

Spontaneous pneumothorax has a high incidence and high rate of recurrence in patients with lymphangioleiomyomatosis (LAM). The risk factors for pneumothorax and the effects of sirolimus on pneumothorax in patients with LAM are unknown. In our study, multivariate logistic regression was applied to a cross-sectional cohort to investigate factors associated with pneumothorax in LAM patients. Kaplan–Meier analysis was applied in the historical prospective self-controlled study to determine whether sirolimus reduces the risk of pneumothorax recurrence in patients with LAM.

Results

Of the 399 patients registered with LAM-CHINA at our center between May 10, 2017 and August 31, 2020, 142 had a history of pneumothorax at registration. High CT grade and age at presentation ≤ 35 years were associated with a higher risk of pneumothorax in patients with LAM. Postmenopausal status was correlated with a lower risk of pneumothorax. In the historical prospective self-controlled study, the 5-year probability of pneumothorax recurrence was 80% lower in the sirolimus group than in the control group (hazard ratio for pneumothorax recurrence, 0.20; 95% CI, 0.14 to 0.30, P < 0.001 by log-rank test).

Conclusion

Sirolimus reduced the risk of pneumothorax recurrence in LAM patients.

Hierarchical cluster analysis based on disease-associated manifestations of patients with lymphangioleiomyomatosis: An analysis of the national database of designated intractable diseases of Japan

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease with variable manifestations and differing rates of progression among individuals. Classification of its phenotypes is an issue for consideration. We hypothesized that clinical manifestations associated with LAM cluster together and identifying these associations would be useful for identifying phenotypes.

METHODS

Using cross-sectional data from the National Database of Designated Intractable Diseases of Japan, we performed a hierarchical cluster analysis based on disease-associated manifestations.

RESULTS

Four clusters were identified from 404 patients (50.4% of 801 LAM patients registered in 2016). Patients in cluster 1 had only dyspnea on exertion, relatively low lung function, the earliest onset age, and the lowest prevalence of tuberous sclerosis complex (TSC). Those in cluster 2 had various manifestations with the highest prevalence of TSC. Patients in cluster 3 had major respiratory symptoms (cough, sputum, or dyspnea on exertion) or fatigue and the lowest lung function. Those in cluster 4 were asymptomatic and had the latest onset age, shortest disease duration, and relatively high prevalence of TSC. Patients in cluster 1 had the highest rate of receiving mechanistic target of rapamycin (mTOR) inhibitor treatment, suggesting that cluster 1 included those with declining lung function for which mTOR inhibitor treatment was required.

CONCLUSIONS

Hierarchical cluster analysis based on manifestations data identified four clusters. The characteristics of cluster 1 are noteworthy in relation to the indication for mTOR inhibitor treatment. A cluster analysis of accumulated and longitudinal data that allows valid clustering and outcome comparisons is required in the future.

YouTube-videos for patient education in lymphangioleiomyomatosis?

BACKGROUND

The Internet is commonly used by patients to acquire health information. To date, no studies have evaluated the quality of information available on YouTube regarding lymphangioleiomyomatosis (LAM). Our aim was to determine the quality and content of YouTube videos regarding LAM and to compare the information provided with current knowledge and guidelines about the disease.

METHODS

The first 200 video hits on YouTube in English for the search term "lymphangioleiomyomatosis" were recorded. All videos suitable for patient education on LAM were included. Video quality was analyzed independently by two investigators utilizing the Health on the Net (HONcode) score, which assesses whether websites provide understandable, accessible, and trustworthy health information; the DISCERN score, which evaluates the quality of information about treatment decisions; and a newly developed LAM-related content score (LRCS) with 31 guideline elements.

RESULTS

The search identified 64 eligible videos. The "engagement rate" of 0.3 was low, with a median number of views of 408 (range 42-73,943), a median of 4 likes (range 0-2082), and the majority (53%) receiving a low HONcode score (≤ 2) and only 10% of videos achieving a high score (> 5). The median DISCERN score was 28 (range 15-61, maximum possible score 80), indicating poor video quality and reliability. The median LRCS was 8 (range 0-29, maximum possible score 31) and videos frequently failed to provide sources of information.

CONCLUSIONS

Online resources could contribute to the limited and often inaccurate information available to patients with LAM, with only a few YouTube videos providing high-quality patient-relevant information.

Lymphangioleiomyomatosis: pathogenesis, clinical features, diagnosis, and management

Lymphangioleiomyomatosis (LAM) is a slowly progressive, low-grade, metastasising neoplasm of women, characterised by infiltration of the lung parenchyma with abnormal smooth muscle-like cells, resulting in cystic lung destruction. The invading cell in LAM arises from an unknown source and harbours mutations in tuberous sclerosis complex (TSC) genes that result in constitutive activation of the mechanistic target of rapamycin (mTOR) pathway, dysregulated cellular proliferation, and a programme of frustrated lymphangiogenesis, culminating in disordered lung remodelling and respiratory failure. Over the past two decades, all facets of LAM basic and clinical science have seen important advances, including improved understanding of molecular mechanisms, novel diagnostic and prognostic biomarkers, effective treatment strategies, and comprehensive clinical practice guidelines. Further research is needed to better understand the natural history of LAM; develop more powerful diagnostic, prognostic, and predictive biomarkers; optimise the use of inhibitors of mTOR complex 1 in the treatment of LAM; and explore novel approaches to the development of remission-inducing therapies.

Tuberous sclerosis complex for the pulmonologist

Tuberous sclerosis complex (TSC) is a rare multisystem genetic disorder affecting almost all organs with no sex predominance. TSC has an autosomal-dominant inheritance and is caused by a heterozygous mutation in either the TSC1 or TSC2 gene leading to hyperactivation of the mammalian target of rapamycin (mTOR). TSC is associated with several pulmonary manifestations including lymphangioleiomyomatosis (LAM), multifocal micronodular pneumocyte hyperplasia (MMPH) and chylous effusions. LAM is a multisystem disorder characterised by cystic destruction of lung parenchyma, and may occur in either the setting of TSC (TSC-LAM) or sporadically (S-LAM). LAM occurs in 30–40% of adult females with TSC at childbearing age and is considered a nonmalignant metastatic neoplasm of unknown origin. TSC-LAM is generally milder and, unlike S-LAM, may occur in males. It manifests as multiple, bilateral, diffuse and thin-walled cysts with normal intervening lung parenchyma on chest computed tomography. LAM is complicated by spontaneous pneumothoraces in up to 70% of patients, with a high recurrence rate. mTOR inhibitors are the treatment of choice for LAM with moderately impaired lung function or chylous effusion. MMPH, manifesting as multiple solid and ground-glass nodules on high-resolution computed tomography, is usually harmless with no need for treatment.

Tuberous sclerosis complex is associated with diverse pulmonary manifestations including LAM, multiple micronodular pneumocyte hyperplasia and chylous effusions. LAM occurs in 30–40% of adult females with tuberous sclerosis complex.https://bit.ly/3iLqZ08

Machine learning can predict disease manifestations and outcomes in lymphangioleiomyomatosis

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease with variable clinical manifestations and differing rates of progression that make management decisions and giving prognostic advice difficult. We used machine learning to identify clusters of associated features which could be used to stratify patients and predict outcomes in individuals.

PATIENTS AND METHODS

Using unsupervised machine learning we generated patient clusters using data from 173 women with LAM from the UK and 186 replication subjects from the US National Heart, Lung, and Blood Institute (NHLBI) LAM registry. Prospective outcomes were associated with cluster results.

RESULTS

Two- and three-cluster models were developed. A three-cluster model separated a large group of subjects presenting with dyspnoea or pneumothorax from a second cluster with a high prevalence of angiomyolipoma symptoms (p=0.0001) and tuberous sclerosis complex (TSC) (p=0.041). Patients in the third cluster were older, never presented with dyspnoea or pneumothorax (p=0.0001) and had better lung function. Similar clusters were reproduced in the NHLBI cohort. Assigning patients to clusters predicted prospective outcomes: in a two-cluster model the future risk of pneumothorax was 3.3 (95% CI 1.7-5.6)-fold greater in cluster 1 than cluster 2 (p=0.0002). Using the three-cluster model, the need for intervention for angiomyolipoma was lower in clusters 2 and 3 than cluster 1 (p<0.00001). In the NHLBI cohort, the incidence of death or lung transplant was much lower in clusters 2 and 3 (p=0.0045).

CONCLUSIONS

Machine learning has identified clinically relevant clusters associated with complications and outcome. Assigning individuals to clusters could improve decision making and prognostic information for patients.

A Retrospective Study of Lung Transplantation in Patients With Lymphangioleiomyomatosis: Challenges and Outcomes

Background: Lymphangioleiomyomatosis (LAM) is a rare systemic disease that generally leads to a progressive decline in pulmonary function. Experience, especially from the Asian population, including combined drug therapy before and after lung transplantation (LT) in LAM, is still limited. This study aimed to summarize the clinical data from patients with pulmonary LAM who underwent LT at centers in China. Methods: A retrospective review of all patients with LAM undergoing LT at the two largest centers in China between 2010 and 2018 was conducted. Pre- and posttransplant data were assessed and analyzed. Results: Overall, 25 patients with LAM underwent bilateral LT. The mean age was 35.0 ± 8.6 years at diagnosis and 36.8 ± 9.3 years at the time of transplant. Before LT, only six patients could complete pulmonary function test; the reachable mean forced expiratory volume in one second (FEV₁) before LT was 15.9 ± 6.9%. Twenty-one patients (84%) had a recurrent pneumothorax, four (16.0%) of which required pleurodesis. Eight patients (32%) were treated with sirolimus pretransplant for 3.9 years (1-9 years). The average intra-surgery bleeding volume was 1,280 ± 730 ml in need of a transfusion of 1,316 ± 874 ml due to moderate-to-severe adhesion and pretransplant pleurodesis. The causes of death of four patients (16%) included primary graft dysfunction, bronchial dehiscence with long-term use of sirolimus, and uncontrollable infections. The median follow-up time from LT was 41.1 ± 25.0 months. Conclusions: LT for LAM patients from the Asian population has been reinforced from the data that we presented. Peri-transplantation use of sirolimus and LAM-related complications should be further defined and under constant surveillance.

A Systematic Review of Lymphangioleiomyomatosis on Diagnosis and Molecular Mechanism

Objective

Lymphangioleiomyomatosis (LAM) is a rare low-grade metastatic tumor; however, LAM patients were always found in young age with difficulty for diagnosis. Our study is aimed at observing the clinical characteristics of patients with lymphangiomatosis, including the clinical manifestations, imaging findings, histopathological features, and immunophenotype.

Methods

We did a systematic review on LAM/PLAM cases, especially on male cases, and collected the clinical features and molecular mechanisms of PLAM based on previous findings.

Results

Diagnosis criteria were summarized by combining CT scans, MRI, immunohistochemistry results, and gene sequencing results for effectively distinguishing between PLAM and similar diseases. Moreover, our study illustrated the molecular mechanism of PLAM as well as the signaling pathway involved in the disease initials. In addition, a male case was reported with differential diagnosis on the clinical manifestations, microscopic features, immunophenotypes, and genotypes.

Conclusion

Our review will definitely improve the understanding of diagnosis and treatment in PLAM cases.

Initial presentation of lymphangioleiomyomatosis in third trimester of pregnancy

Lymphangioleiomyomatosis (LAM) is a progressive cystic lung disease which mostly affects premenopausal women and could be exacerbated by pregnancy. Therefore, it is thought that oestrogen plays an important role in LAM pathogenesis. Here, a case of LAM is described in which the first presentation of symptoms occurred during the third trimester of pregnancy. Symptoms included acute onset dyspnoea and chest pain at gestational age of 39 weeks and 2 days. A CT was performed which showed multiple thin-walled cysts and a small pneumothorax. Serum levels of vascular endothelial growth factor-D (VEGF-D) was 1200 pg/mL. The typical cystic lung changes on chest CT in combination with elevated VEGF-D is diagnostic for LAM. Given the risk of respiratory complications, the decision was made to deliver the baby at a gestational age of 39 weeks and 6 days by a planned caesarean section. Both mother and child were discharged home in good condition.

Lymphangioleiomyomatosis: a clinical review

Lymphangioleiomyomatosis (LAM) is a diffuse cystic lung disease. There are two main types of LAM: sporadic, and LAM associated with the tuberous sclerosis complex (TSC), which is caused by mutations in the TSC1 and TSC2 genes. LAM is characterised by cystic lung disease resulting in progressive dyspnoea, renal angiomyolipomas and lymphatic complications. Pneumothorax occurs frequently (70%) and definitive management with pleurodesis is recommended as the risk of recurrence is high. Characteristic thin-walled cysts are seen on computed tomography and the presence of elevated serum levels of a vascular endothelial growth factor-D has good diagnostic specificity. Currently, no single clinical or serological factor has been shown to predict prognosis. However, over the past decade, significant advances in our understanding of the pathophysiology of LAM has led to improved recognition of this rare disease and identification of treatment options. Mechanistic target of rapamycin inhibitors slow the rate of lung function decline and can resolve chylous effusion and regress angiomyolipomas. Life expectancy in patients with LAM is favourable, with a mean transplant-free survival >20 years from the time of diagnosis. Continued advances in understanding the molecular basis of LAM will lead to improved therapeutic targets and the development of more robust prognostic indicators.

Educational aims

To illustrate the clinical features, common presentations and radiological features of LAMTo outline the diagnostic approach to LAM, including the role of VEGF-DTo review the current prognostic indicators in LAM, and outline the impact of lung function, hormonal status, VEGF-D and clinical presentation on outcomeTo inform clinicians on the management options for LAM both pharmacological and nonpharmacological.

Pregnancy in lymphangioleiomyomatosis: clinical and lung function outcomes in two national cohorts

Pregnancy in women with lymphangioleiomyomatosis (LAM) has been associated with increased complications and worsening lung function although objective data to advise patients are not available. We assessed lung function and CT scans before and after pregnancy in 16 women with LAM. During the pregnancy, pneumothorax was frequent and mean forced expiratory volume in 1 s (FEV₁) fell from 77%±19% prepregnancy to 64%±25% predicted and DL_CO from 66±26 to 57±26 (both p<0.01). After pregnancy, rates of FEV₁ decline were high and 10 patients required sirolimus. Women with LAM, especially with moderate or advanced disease should be counselled regarding adverse events and loss of lung function during the pregnancy.

Possible Novel Therapeutic Targets in Lymphangioleiomyomatosis Treatment

Lymphangioleiomyomatosis (LAM) is a rare systemic neoplastic disease that exclusively happens in women. Studies focusing on LAM and tuberous sclerosis complex (TSC) have made great progress in understanding the pathogenesis and searching for treatment. The inactive mutation of TSC1 or TSC2 is found in patients with LAM to activate the crucial mammalian target of rapamycin (mTOR) signaling pathway and result in enhanced cell proliferation and migration. However, it does not explain every step of tumorigenesis in LAM. Because cessation of rapamycin would break the stabilization of lung function or improved quality of life and lead to disease recurrent, continued studies on the pathogenesis of LAM are necessary to identify novel targets and new treatment. Researchers have found several aberrant regulations that affect the mTOR pathway such as its upstream or downstream molecules and compensatory pathways in LAM. Some therapeutic targets have been under study in clinical trials. New methods like genome-wide association studies have located a novel gene related to LAM. Herein, we review the current knowledge regarding pathogenesis and treatment of LAM and summarize novel targets of therapeutic potential recently.

Ultra-rare cystic disease

Diffuse cystic lung diseases include a group of heterogeneous disorders characterised by the presence of cysts within the lung parenchyma, sometimes showing a characteristic computed tomography scan pattern that allows diagnosis. The pathogenetic mechanisms underlying cyst formation in the lung are still not clear and a number of hypotheses have been postulated according to the different aetiologies: ball-valve effect, ischaemic dilatation of small airways and alveoli related to infiltration and obstruction of small vessels and capillaries that supply the terminal bronchioles and connective tissue degradation by matrix metalloproteases. A wide number of lung cyst diseases have been classified into six diagnostic groups according to the aetiology: neoplastic, congenital/genetic, lymphoproliferative, infective, associated with interstitial lung diseases, and other causes. This article focuses on lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis and Erdheim–Chester disease, Birt–Hogg–Dubé, follicular bronchiolitis and lymphocytic interstitial pneumonia, light-chain deposition disease and amyloidosis, congenital lung disease associated with aberrant lung development and growth, and cystic lung disease associated with neoplastic lesion. These cystic diseases are epidemiologically considered as ultra-rare conditions as they affect fewer than one individual per 50 000 or fewer than 20 individuals per million. Despite the rarity of this group of disorders, the increasing use of high-resolution computed tomography has improved the diagnostic yield, even in asymptomatic patients allowing prompt and correct therapy and management without the need for a biopsy.

Diffuse cystic lung diseases show a characteristic CT scan pattern that often allows for diagnosis, even in asymptomatic patients, allowing prompt correct therapy and management without the needing of a biopsyhttps://bit.ly/2wIUKet

Sphingolipid, fatty acid and phospholipid metabolites are associated with disease severity and mTOR inhibition in lymphangioleiomyomatosis

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease almost exclusively affecting women which causes loss of lung function, lymphatic abnormalities and angiomyolipomas. LAM occurs sporadically and in people with tuberous sclerosis complex (TSC). Loss of TSC gene function leads to dysregulated mechanistic target of rapamycin (mTOR) signalling. As mTOR is a regulator of lipid and nucleotide synthesis, we hypothesised that the serum metabolome would be altered in LAM and related to disease severity and activity.

METHODS

Ultrahigh performance liquid chromatography-tandem mass spectroscopy was used to examine the serum metabolome of 79 closely phenotyped women with LAM, including 29 receiving treatment with an mTOR inhibitor and 43 healthy control women.

RESULTS

Sphingolipid, fatty acid and phospholipid metabolites were associated with FEV₁ in women with LAM (eg, behenoyl sphingomyelin adjusted (adj.) p=8.10 × 10^-3). Those with higher disease-burden scores had abnormalities in fatty acid, phospholipid and lysolipids. Rate of loss of FEV₁ was associated with differences in acyl-carnitine, acyl-glycines, acyl-glutamine, fatty acids, endocanbinoids and sphingolipids (eg, myristoleoylcarnitine adj. p=0.07). In TSC-LAM, rapamycin affected modules of interrelated metabolites which comprised linoleic acid, the tricarboxylic acid cycle, aminoacyl-tRNA biosynthesis, cysteine, methionine, arginine and proline metabolism. Metabolomic pathway analysis within modules reiterated the importance of glycerophospholipid metabolites (adj. p=0.047).

CONCLUSIONS

Women with LAM have altered lipid metabolism. The associations between these metabolites, multiple markers of disease activity and their potential biological roles in cell survival and signalling, suggest that lipid species may be both disease-relevant biomarkers and potential therapeutic targets for LAM.

Evolution of lung pathology in lymphangioleiomyomatosis: associations with disease course and treatment response

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease with a variable clinical course. The lungs are infiltrated by nodules of LAM cells, stromal cells and inflammatory cells, causing lung cysts and respiratory failure. We used immunohistochemical markers in lung biopsy and transplant samples from a national cohort of women with LAM with linked clinical data to understand how LAM nodule cell populations changed with disease progression. Marker distribution was examined qualitatively by dual immunohistochemistry, and markers for LAM cells, fibroblasts, lymphatics, mast cells, proliferation, cathepsin K and mTOR pathway activity were quantitated in LAM nodules and compared with clinical features and prospective lung function loss. The LAM cell marker PNL2 was more extensively expressed in those with higher forced expiratory volume in one second (FEV₁), higher diffusion in the lung for carbon monoxide (DL_CO) and less extensive disease involvement whilst the converse was true for the protease cathepsin K. Each percentage increase in cathepsin K reactivity was associated with a 0.65% decrease in FEV₁ (95% CI −1.11 to −0.18) and a 0.50% decrease in DL_CO (95% CI −0.96 to −0.05). Higher reactivity to the mTOR complex 1 activation marker, phospho‐ribosomal protein S6, was associated with a better lung function response to rapamycin (p = 0.0001). We conclude that LAM nodules evolve with disease progression, with LAM cells becoming outnumbered by fibroblasts. Increasing cathepsin K expression is associated with more severe disease and lung function loss. Markers of mTOR activation predict the response to rapamycin, suggesting that more advanced LAM may be less mTOR responsive and treatments specifically targeted towards LAM associated fibroblasts may have roles as adjuncts to mTOR inhibition.

Unconventional Estrogen Signaling in Health and Disease

Estrogen is a key hormone involved in the development and homeostasis of several tissue types in both males and females. By binding estrogen receptors, estrogen regulates essential functions of gene expression, metabolism, cell growth, and proliferation by acting through cytoplasmic signaling pathways or activating transcription in the nucleus. However, disruption or dysregulation of estrogen activity has been shown to play a key role in the pathogenesis and progression of many diseases. This review will expatiate on some of the unconventional roles of estrogen in homeostasis and disease.

The efficacy and safety of pharmacological treatments for lymphangioleiomyomatosis

Background

Lymphangioleiomyomatosis (LAM) is a rare, low-grade multisystem neoplastic disease. Most LAM patients are at a high risk of losing lung function at an accelerated rate and developing progressive dyspnea. Recently, several studies have reported their experience with pharmacological treatments for LAM. Therefore, we conducted a systematic review and meta-analysis to assess the efficacy and safety of these therapies.

Methods

PubMed (Medline), EMBASE, Cochrane Library, Web of Science and EBSCO Host were searched (until March 31, 2019) for eligible prospective studies regarding LAM patients treated with pharmacological treatments. Random effect models were used for quantitative analysis.

Results

Fourteen prospective studies regarding five pharmacological treatments (including sirolimus, everolimus, doxycycline, triptorelin, and a combination therapy of sirolimus and hydroxychloroquine) were enrolled in our systematic review, and ten of them were used for the meta-analysis. Seven prospective studies reported that sirolimus was effective at improving or stabilizing lung function and alleviating renal angiomyolipoma (AML) in LAM patients. Subsequent quantitative analyses showed that during sirolimus treatment, the pooled values of lung function and 6-min walk distance (6MWD) were not significantly changed (P > 0.05), with the pooled response rate of AML being 0.62 (95% confidence intervals [CIs]: 0.43 to 0.82, I² = 65%). Regarding everolimus, three prospective studies reported similar effects to those of sirolimus with regard to preserving lung function and reducing AMLs. The meta-analysis showed that the changes in lung function during everolimus treatment were not statistically significant (P > 0.05), while the pooled response rate of AML was 0.78 (95% CI: 0.68 to 0.88, I² = 8%). Neither the qualitative nor the quantitative results confirmed the benefits of doxycycline or triptorelin treatment, and the effects of the combination therapy were unclear in LAM patients. Most of the adverse events during pharmacological treatments were low or moderate grade and tolerable.

Conclusions

Overall, sirolimus and everolimus were recommended for the treatment of LAM because they could stabilize lung function and alleviate renal AML. Doxycycline and triptorelin were not recommended for the treatment of LAM because no beneficial outcomes were consistently observed. The efficacy and safety of combination therapy remain to be further explored.

Analysis of the MILES cohort reveals determinants of disease progression and treatment response in lymphangioleiomyomatosis

INTRODUCTION

The Multicenter International Lymphangioleiomyomatosis (LAM) Efficacy of Sirolimus (MILES) trial revealed that sirolimus stabilised lung function in patients with moderately severe LAM. The purpose of this study was to further examine the MILES cohort for the effects of racial, demographic, clinical and physiological patient characteristics on disease progression and treatment response in LAM.

METHODS

MILES subjects were stratified on the basis of menopausal status (pre-menopausal/post-menopausal), race (Asian/Caucasian), bronchodilator responsiveness (present/absent), initial forced expiratory volume in 1 s (FEV₁; 51-70% versus ≤50% predicted) and tuberous sclerosis complex (TSC) association (yes/no). A linear mixed effects model was used to compare slope differences, and nonparametric tests were used to compare medians and proportions between treatment groups in each stratum.

RESULTS

In the MILES placebo group, pre-menopausal patients declined 5-fold faster than post-menopausal patients (mean±se FEV₁ slope -17±3 versus -3±3 mL·month^-1; p=0.003). Upon treatment with sirolimus, both the pre-menopausal (-17±3 versus -1±2 mL·month^-1; p<0.0001) and post-menopausal patients (-3±3 versus 6±3 mL·month^-1; p=0.04) exhibited a beneficial response in mean±se FEV₁ slope compared with the placebo group. Race, LAM subtype, bronchodilator responsiveness or baseline FEV₁ did not impact the rate of disease progression in the placebo group or treatment response in the sirolimus group. Menopausal status and race had differential effects on the adverse event profile of sirolimus. Baseline serum vascular endothelial growth factor (VEGF)-D >600 pg·mL^-1 identified subgroups of patients who were more likely to decline on placebo and respond to treatment with sirolimus.

CONCLUSIONS

In LAM patients, treatment with sirolimus is beneficial regardless of menopausal status, race, bronchodilator responsiveness, baseline FEV₁ or TSC association. Serum VEGF-D and menopausal status can help inform therapeutic decisions.

A Case of Lymphangioleiomyomatosis (LAM) of the Lung in a Patient with a History of Breast Cancer

Patient: Female, 47

Final Diagnosis: Lymphangioleiomyomatosis

Symptoms: Dyspnea

Medication: —

Clinical Procedure: —

Specialty: Pulmonology

The vitamin D binding protein axis modifies disease severity in lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease of women. Decline in lung function is variable, making appropriate targeting of therapy difficult. We used unbiased serum proteomics to identify markers associated with outcome in LAM.101 women with LAM and 22 healthy controls were recruited from the National Centre for LAM in the UK. 152 DNA and serum samples with linked lung function and outcome data were obtained from patients in the National Heart, Lung and Blood Institute LAM Registry in the USA. Proteomic analysis was performed on a discovery cohort of 50 LAM and 20 control serum samples using a SCIEX SWATH mass spectrometric workflow. Protein levels were quantitated by ELISA and single nucleotide polymorphisms in GC (group-specific component) encoding vitamin D binding protein (VTDB) were genotyped.Proteomic analysis showed VTDB was 2.6-fold lower in LAM than controls. Serum VTDB was lower in progressive compared with stable LAM (p=0.001) and correlated with diffusing capacity of the lung for carbon monoxide (p=0.01). Median time to death or lung transplant was reduced by 46 months in those with CC genotypes at rs4588 and 38 months in those with non-A-containing haplotypes at rs7041/4588 (p=0.014 and 0.008, respectively).The VTDB axis is associated with disease severity and outcome, and GC genotype could help predict transplant-free survival in LAM.

The efficacy and adverse events of mTOR inhibitors in lymphangioleiomyomatosis: systematic review and meta-analysis

Background

Lymphangioleiomyomatosis (LAM) is a rare lung disease and the mammalian target of the rapamycin (mTOR) inhibitors has been used as an effective therapy. Here we conducted a systematic review and meta-analysis with the aims to quantify the efficacy and safety of mTOR inhibitors in LAM patients.

Methods

The following databases were searched for clinical trials regarding LAM patients treated with mTOR inhibitors until December 2017: Pubmed, Embase, Cochrane Library and OVID medicine. Random effect models were used for the quantitative analysis.

Results

Nine eligible studies were included in our systematic review, 7 of which were used for the meta-analysis. In LAM patients, mTOR inhibitors improved forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) significantly, with the weighted mean difference (WMD) 0.15 L (95%CI: 0.08 to 0.22, P < 0.01, I² = 0%) and 0.22 L (95%: 0.11 to 0.32, P < 0.01, I² = 0%) respectively. There was no significant change in neither the diffusing capacity for carbon monoxide (WMD: 0.51 ml/mm Hg/min, 95%CI: -0.48 to 1.49, P = 0.31, I² = 0%) nor 6-min walking distance (WMD: 5.29 m, 95%CI: -18.01 to 28.59, P = 0.66, I² = 1%). The weighted partial response rate was 0.68 (95%CI: 0.53 to 0.84, P < 0.01, I² = 72%) for renal angiomylipoma. The cumulative incidence rates of common safety events were 50, 40, 23, 20 and 19% for oral mucositis, hyperlipidemia, headache, bone marrow suppression, and diarrhea, respectively. And most events were low grade and tolerant.

Conclusions

In LAM patients, there are improvements of FEV₁ and FVC after the application of mTOR inhibitors and over a half achieved the shrinkage of renal angiomyolipoma.

Trial registration

PROSPERO registration number: CRD42018085470. Registered 22 January 2018.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0874-7) contains supplementary material, which is available to authorized users.

Pulmonary manifestations in tuberous sclerosis complex

Tuberous sclerosis complex has manifestations in many organ systems, including brain, heart, kidney, skin, and lung. The primary manifestations in the lung are lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH). LAM affects almost exclusively women, and causes cystic lung destruction, pneumothorax, and chylous pleural effusions. LAM can lead to dyspnea, oxygen dependence, and respiratory failure, with more rapid disease progression during the premenopausal years. In contrast, MMPH affects men and women equally, causing small nodular pulmonary deposits of type II pneumocytes that rarely progress to symptomatic disease. Here, we review the clinical features and pathogenesis of LAM and MMPH.

The NHLBI LAM Registry: Prognostic Physiologic and Radiologic Biomarkers Emerge From a 15-Year Prospective Longitudinal Analysis

BACKGROUND

The natural history of lymphangioleiomyomatosis (LAM) is mainly derived from retrospective cohort analyses, and it remains incompletely understood. A National Institutes of Health LAM Registry was established to define the natural history and identify prognostic biomarkers that can help guide management and decision-making in patients with LAM.

METHODS

A linear mixed effects model was used to compute the rate of decline of FEV₁ and to identify variables affecting FEV₁ decline among 217 registry patients who enrolled from 1998 to 2001. Prognostic variables associated with progression to death/lung transplantation were identified by using a Cox proportional hazards model.

RESULTS

Mean annual decline of FEV₁ was 89 ± 53 mL/year and remained remarkably constant regardless of baseline lung function. FEV₁ decline was more rapid in those with greater cyst profusion on CT scanning (P = .02) and in premenopausal subjects (118 mL/year) compared with postmenopausal subjects (74 mL/year) (P = .003). There were 26 deaths and 43 lung transplantations during the evaluation period. The estimated 5-, 10-, 15-, and 20-year transplant-free survival rates were 94%, 85%, 75%, and 64%, respectively. Postmenopausal status (hazard ratio, 0.30; P = .0002) and higher baseline FEV₁ (hazard ratio, 0.97; P = .008) or diffusion capacity of lung for carbon monoxide (hazard ratio, 0.97; P = .001) were independently associated with a lower risk of progression to death or lung transplantation.

CONCLUSIONS

The median transplant-free survival in patients with LAM is > 20 years. Menopausal status, as well as structural and physiologic markers of disease severity, significantly affect the rate of decline of FEV₁ and progression to death or lung transplantation in LAM.

Human renal angiomyolipoma cells of male and female origin can migrate and are influenced by microenvironmental factors

Background

Improving the knowledge of angiomyolipoma physiopathology might help in refining its pharmacological treatment. We investigated if angiomyolipoma cells have migratory properties, how their growth and motility can be influenced by the hormonal milieu, and if this can be related to a specific gender.

Methods

Primary cells were isolated from angiomyolipomas surgically resected for therapeutical reasons in a female and in a male patient. The genetic control demonstrated no TSC2 deletion. Bi- (wound healing) and three-dimensional (transwell assay) migration were analyzed in vitro in basal conditions and under the influence of 17- β-estradiol and SDF-1α.

Results

Treatment up to 72 hours with 17-β-estradiol (0.1–100 nM), tamoxifen (0.2–20 μM) or with both, does not modify angiomyolipoma cells proliferation. On the other hand, SDF-1α and 17-β-estradiol treatment induce a significant motility increase (both bi- and three-dimensional) which becomes evident already after 2 hours of incubation. Angiomyolipoma cells express mRNA coding for SDF-1α and 17-β-estradiol receptors and secrete both the metalloproteases principally involved in malignant phenotype acquisition, i.e. MMP-2 and MMP-9.

Conclusion

Angiomyolipoma cells behave similarly, despite their different source. Primary angiomyolipoma cells migrate in response to hormonal milieu and soluble factors, and produce active metalloproteases, both aspects being consistent with the theory claiming they can migrate to the lungs (and/or other organs) and colonizing them. No main feature, among the aspects we analyzed, seems to be referable to the gender of origin.

Rates of change in FEV1 and DLCO as potential indicators for mTOR inhibitor therapy in premenopausal lymphangioleiomyomatosis patients

The value of rates of change in forced expiratory volume in 1 s (FEV₁) and diffusing capacity of the lung for carbon monoxide (D_LCO) to predict disease progression, and initiation of mTOR (mechanistic target of rapamycin) inhibitor therapy has not been evaluated.In 84 premenopausal lymphangioleiomyomatosis patients, individual rates of change in FEV₁ and D_LCO and their 95% confidence intervals were used to derive subsequent lowest values of FEV₁ and D_LCO that would prompt initiation of sirolimus therapy. These treatment criteria were compared with a criterion based on FEV₁ or D_LCO ≤70% predicted. In 12 patients undergoing sirolimus therapy both methods for determining the optimal point for initiation of therapy were evaluated.27 and 35 patients who experienced greater than expected rates of change in FEV₁ and D_LCO, respectively, would have been excluded from therapy based on an FEV₁ or D_LCO >70% pred. 25 of the 84 patients were eventually treated, but only when FEV₁ or D_LCO were ≤70% pred. Applying such treatment criteria to 12 patients undergoing sirolimus therapy would have delayed treatment for many years.Premenopausal females in whom FEV₁ or D_LCO are declining at rates above the expected based on their individual rates of decline, should be considered for sirolimus therapy before the FEV₁ or D_LCO falls to ≤70% pred.

A Phase II Clinical Trial of an Aromatase Inhibitor for Postmenopausal Women with Lymphangioleiomyomatosis

RATIONALE

Lymphangioleiomyomatosis (LAM) is a progressive cystic lung disease that predominantly affects women and can worsen with pregnancy, estrogen treatment, and the menstrual cycle, suggesting an important role for estrogen in disease pathogenesis.

OBJECTIVES

To assess the efficacy and safety of the aromatase inhibitor letrozole in the treatment of LAM.

METHODS

Seventeen postmenopausal women with LAM were enrolled in this phase II trial and randomized to receive letrozole 2.5 mg daily (n = 9) or placebo (n = 8) for a period of 12 months. Five patients in each group were also taking sirolimus at baseline and remained on the drug throughout the treatment period. Lung function, exercise capacity, quality of life, and serum vascular endothelial growth factor D (VEGF-D) were measured at baseline and at 3-month intervals.

RESULTS

Fifteen patients completed the study. Two patients withdrew. There were no differences in adverse events in the letrozole and placebo groups. The target enrollment of 25 patients per arm was not met, so the efficacy of letrozole could not be assessed as planned. After adjusting for sirolimus use, we found that the rate of change in FEV₁ for all subjects was -3 ± 3 ml/mo (P = 0.4), and for serum VEGF-D, the rate of change was -0.024 ± 0.009 pg/ml/mo (P = 0.015), showing a steeper decline in the letrozole group (-0.029 ± 0.013; P = 0.025). All patients who were taking sirolimus had a reduction in VEGF-D levels from baseline to the last visit, compared with only half of the patients who were not taking sirolimus. In a post hoc analysis, eight matched letrozole-treated-placebo-treated pairs were constructed, six of which demonstrated better FEV₁ improvement for the letrozole-treated patients.

CONCLUSIONS

Letrozole treatment appears to be safe and well tolerated in postmenopausal patients with LAM, including those taking sirolimus. Enrollment in this trial was compromised by the publication of an effective treatment (sirolimus) in the same month as the study opened, resulting in limited power to detect treatment effects. Post hoc matched pairs exploration studies provide tentative support for additional studies of letrozole in LAM. Considering the reduced rate of lung function decline in postmenopausal patients, future studies will likely require enhanced study designs, such as selective enrollment of those with prognostic biomarkers predictive of decline. Clinical trial registered with www.clinicaltrials.gov (NCT01353209).

Efficacy and Safety of Long-Term Sirolimus Therapy for Asian Patients with Lymphangioleiomyomatosis

RATIONALE

Sirolimus has been shown in a randomized, controlled clinical trial to stabilize lung function in patients with lymphangioleiomyomatosis (LAM) treated for a 12-month time period; however the pretreatment decline in lung function after the drug was discontinued indicated that continued exposure is required to suppress disease progression.

OBJECTIVES

To elucidate the durability and tolerability of long-term sirolimus treatment in Asian patients with LAM.

METHODS

We conducted a single-arm, open-label, investigator-initiated safety and efficacy study of sirolimus in 63 women with LAM at 9 sites in Japan. Subjects received sirolimus for 2 years at doses adjusted to maintain a trough blood level of 5-15 ng/ml.

MEASUREMENTS AND MAIN RESULTS

Fifty-two subjects (82.5%) completed the trial with mean drug compliance of more than 80% overall during the study. The number of adverse events was greatest during the initial 6 months of therapy, but they continued to occur with declining frequency throughout the 2-year study period. Of the 1,549 adverse events, 27 were classified as serious, including reversible sirolimus pneumonitis in 3 patients. New hypercholesterolemia occurred in 30 patients (48%); microcytosis in 10 patients; loss of body weight in 33 patients; and increase in blood pressure that required treatment in 5 patients. FEV₁, FVC, and quality-of-life parameters were stable in the overall study cohort during the study period, but baseline to 2-year improvements in lung function occurred in the subset of patients with a prior history of chylothorax.

CONCLUSIONS

Although long-term sirolimus treatment of Asian patients with LAM was associated with a large number of adverse events, including three episodes of pneumonitis, most patients completed the 2-year course of medication with good drug compliance and stable quality of life and lung function.

Lung function response and side effects to rapamycin for lymphangioleiomyomatosis: a prospective national cohort study

Rationale

Mechanistic target of rapamycin inhibitors reduce loss of lung function in lymphangioleiomyomatosis (LAM), although their benefit varies between individuals. We examined lung function response and side effects to rapamycin in a national cohort.

Methods

Subjects were receiving rapamycin for progressive lung disease. Clinical evaluation, detailed phenotyping, serial lung function, rapamycin and safety monitoring were performed according to a clinical protocol. Lung function change, measured as FEV1 slope (ΔFEV1), was reported for those treated for 1 year or longer.

Results

Rapamycin was associated with improved ΔFEV1 in 21 individuals where pretreatment data were available (p<0.0001). In 47 treated for a mean duration of 35.8 months, mean ΔFEV1 was +11 (SD 75) mL/year, although it varied from +254 to −148 mL/year. The quartile with the highest positive ΔFEV1 had greater pretreatment FEV1 (p=0.02) and shorter disease durations (p=0.02) than the lowest quartile. Serum rapamycin level was positively associated with side effects (p=0.02) but not ΔFEV1 over 1 year. Within the first month of therapy, apthous ulcers, nausea and diarrhoea were associated with higher rapamycin levels. Acne, oedema and menstrual irregularities tended to increase over the first year of therapy. At the end of observation, the prevalence of side effects was 5% or less.

Conclusions

Rapamycin reduces lung function loss in LAM, although in some, ΔFEV1 continues to fall at an accelerated rate. Poor response to rapamycin was associated with lower pretreatment lung function and longer disease duration but not serum level. Early intervention with low-dose rapamycin may preserve lung function and reduce side effects.

Efficacy and safety of transbronchial lung biopsy for the diagnosis of lymphangioleiomyomatosis: A report of 24 consecutive patients

BACKGROUND AND OBJECTIVE

Lymphangioleiomyomatosis (LAM) is a diffuse cystic lung disease that occurs in women of childbearing age. LAM can be diagnosed on a clinical basis in patients with typical high-resolution computed tomography (HRCT) patterns and at least one other corroborating disease feature, such as chylothorax, angiomyolipoma, tuberous sclerosis complex or elevated serum vascular endothelial growth factor (VEGF)-D. However, patients who do not meet these criteria require tissue confirmation for a definitive diagnosis, and the utility of methods that are less invasive than surgical lung biopsy, such as transbronchial lung biopsy (TBLB), are not well studied. We retrospectively studied the efficacy and safety of TBLB for the diagnosis of LAM.

METHODS

From January 1991 to August 2015, 131 consecutive LAM patients were prospectively registered in our study, and a TBLB was conducted for 24 patients. We retrospectively studied the yield and safety of TBLB in this cohort.

RESULTS

All 24 patients were women; the median age was 42 years. HRCT showed multiple round thin-walled cysts diffusely scattered throughout the lungs. The median level of serum VEGF-D was 2109 pg/mL. Characteristic pathological findings for LAM were identified in 17 patients (70.8%) by two expert pathologists. The %predicted value for diffusing capacity of carbon monoxide was significantly lower in the 17 TBLB-positive LAM patients compared to the seven TBLB-negative LAM patients (P = 0.046). There were no serious adverse events such as pneumothorax or uncontrollable bleeding due to TBLB.

CONCLUSION

TBLB is a safe and effective method for the pathological diagnosis of LAM.

New insights in lymphangioleiomyomatosis and pulmonary Langerhans cell histiocytosis

Lymphangioleiomyomatosis (LAM) and pulmonary Langerhans cell histiocytosis (PLCH) are rare diseases that lead to progressive cystic destruction of the lungs. Despite their distinctive characteristics, these diseases share several features. Patients affected by LAM or PLCH have similar radiological cystic patterns, a similar age of onset, and the possibility of extrapulmonary involvement. In this review, the recent advances in the understanding of the molecular pathogenesis, as well as the current and most promising biomarkers and therapeutic approaches, are described.

Understanding of LAM/PLCH pathogenesis has improved over the past years, leading to new therapeutic approacheshttp://ow.ly/7wjR30erSJY

Risk factors for stomatitis in patients with lymphangioleiomyomatosis during treatment with sirolimus: A multicenter investigator-initiated prospective study

PURPOSE

Lymphangioleiomyomatosis is a rare lung disease caused by proliferation of abnormal smooth muscle-like cells and typically occurs in premenopausal women. Sirolimus is now the first-line drug for the treatment of lymphangioleiomyomatosis. Sirolimus-induced stomatitis is the most frequent adverse event experienced during treatment. To identify risk factors, we investigated the association of stomatitis incidence with patient background data and treatment parameters, using data from the multicenter long-term sirolimus trial.

METHODS

Subjects received sirolimus for 2 years at doses adjusted to maintain a trough blood level of 5 to 15 ng/mL. The incidence of stomatitis was correlated with baseline demographics, clinical characteristics, and changes in the longitudinal data. Risk factors at baseline were assessed by using univariate and multivariate analyses.

RESULTS

The most frequent adverse event was stomatitis, with the cumulative rate reaching 88.9% by 9 months, higher than that reported in postrenal transplant patients. The repetition, the duration, and the severity of stomatitis events were variable among patients. We found that patients with low hemoglobin (Hb) (<14.5 g/dL) showed significantly higher incidence than those with high Hb (≥14.5 g/dL, P < .01). The cumulative rate for stomatitis incidence was significantly associated with a decrease in the mean corpuscular volume, while the Hb level was constant; thus, red blood cell count in patients increased during the study.

CONCLUSIONS

Baseline Hb levels and a decrease in mean corpuscular volume during treatment were correlated with the incidence of stomatitis.

Official American Thoracic Society/Japanese Respiratory Society Clinical Practice Guidelines: Lymphangioleiomyomatosis Diagnosis and Management

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease that primarily affects women. The purpose of these guidelines is to provide recommendations for the diagnosis and treatment of LAM.

METHODS

Systematic reviews were performed to summarize evidence pertinent to our questions. The evidence was summarized and discussed by a multidisciplinary panel. Evidence-based recommendations were then formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

After considering the panel's confidence in the estimated effects, the balance of desirable (i.e., benefits) and undesirable (i.e., harms and burdens) consequences of treatment, patient values and preferences, cost, and feasibility, recommendations were formulated for or against specific interventions. These included recommendations for sirolimus treatment and vascular endothelial growth factor D testing and recommendations against doxycycline and hormonal therapy.

CONCLUSIONS

Evidence-based recommendations for the diagnosis and treatment of patients with LAM are provided. Frequent reassessment and updating will be needed.

Women's Health and Lung Development and Disease

Although the lung is not traditionally thought of as an organ affected by sex-based differences, emerging literature elucidates major differences between men and women in the development, physiology, and predilection to and outcomes in lung diseases. These differences are driven by both differences in sex hormones and differences in environmental exposures. However, in many cases the underlying etiology of these sex- and gender-based differences is unknown. This article outlines the state-of-the-art knowledge on the etiology of sex differences in lung disease, including differences in lung development and physiology, and reviews therapy recommendations that are sex based.

Lymphangioleiomyomatosis

Lymphangioleiomyomatosis is a rare multisystem disease predominantly affecting women that can occur sporadically or in association with tuberous sclerosis. Lung cysts progressively replace the lung parenchyma, which leads to dyspnea, recurrent pneumothorax, and in some cases respiratory failure. Patients may also have lymphatic disease in the thorax, abdomen, and pelvis, and renal angiomyolipomas. Treatment includes supportive care, bronchodilators, and for those with progressive disease, mammalian target of rapamycin (mTOR) inhibitors.

Minireview: Lymphangioleiomyomatosis (LAM): The "Other" Steroid-Sensitive Cancer

Lymphangioleiomyomatosis (LAM) is a devastating rare lung disease affecting primarily childbearing age women in which tumors consisting of abnormal smooth-muscle-like cells grow within the lungs and progressively lead to loss of pulmonary function. LAM cells metastasize to the lungs, predominantly through the lymphatics; however, the source of the LAM cell is still unknown. LAM cells contain inactivating mutations in genes encoding tuberous sclerosis 1 or 2, proteins that normally limit cell growth through suppression of mammalian target of rapamycin complex 1. As of today, sirolimus (an mammalian target of rapamycin complex 1 inhibitor) is the only treatment, available for LAM patients that is approved by the Food and Drug Administration; however, this drug and others in its class provide stabilization but not remission of LAM. One of the biggest problems in treating LAM is that both the origin of the LAM cells and the mechanism of the sexual dimorphism in LAM are still not understood. LAM cells express estrogen and progesterone receptors, and lung function declines during periods of high circulating estrogen levels. Moreover, numerous basic research studies find that estrogen is a key driving force in LAM cell proliferation, migration, and metastasis. In this review, we highlight recent insights regarding the role of steroid hormones in LAM and discuss possible explanations for the profound female sexual dimorphism of LAM.