Pleural Disease in Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a multisystem disease affecting women characterized by cystic lung destruction, lymphangioleiomyomas (LLM), and angiomyolipomas (AML). LAM occurs sporadically or in association with tuberous sclerosis complex (TSC). LAM is caused by mutations of the TSC1 or TSC2 genes, which encode, respectively, hamartin and tuberin, two proteins that regulate the mechanistic Target Of Rapamycin (mTOR) signaling pathway. LAM presents with dyspnea and pneumothorax and may progress to respiratory failure. Inhibition of mTORC-1 signaling pathway with mTORC1 inhibitors stabilizes lung function and reduces the size of LLM, AML, chylous effusions, and giant-cell astrocytomas.

The number of medical emergencies onboard aircraft is increasing as commercial air traffic increases and the general population ages, becomes more mobile, and includes individuals with serious medical conditions. Travelers with respiratory diseases are at particular risk for in-flight events because exposure to lower atmospheric pressure in a pressurized cabin at cruising altitude may result in not only hypoxemia but also pneumothorax due to gas expansion within enclosed pulmonary parenchymal spaces based on Boyle's law. Risks of pneumothorax during air travel pertain particularly to those patients with cystic lung diseases, recent pneumothorax or thoracic surgery, and chronic pneumothorax. Currently available guidelines are admittedly based on sparse data and include recommendations to delay air travel for 1 to 3 weeks after thoracic surgery or resolution of the pneumothorax. One of these guidelines declares existing pneumothorax to be an absolute contraindication to air travel although there are reports of uneventful air travel for those with chronic stable pneumothorax. In this article, we review the available data regarding pneumothorax and air travel that consist mostly of case reports and retrospective surveys. There is clearly a need for additional data that will inform decisions regarding air travel for patients at risk for pneumothorax, including those with recent thoracic surgery and transthoracic needle biopsy.

La sporadic lymphangioleiomyomatosis (S-LAM, «linfangioleiomiomatosis esporádica») es una enfermedad rara que afecta a la mujer. Se caracteriza por una proliferación anormal de células musculares lisas inmaduras, células LAM, que crecen de una manera aberrante en el pulmón. La enfermedad no tiene tratamiento, evolucionando hacia la insuficiencia respiratoria. El trasplante pulmonar (TP) puede ser una opción terapéutica en este estadio. Nuestro objetivo es el estudio de 7 pacientes sometidas a TP por S-LAM.

Se estudiaron las características clinicodemográficas, de diagnóstico, y los resultados. Se realizó un análisis descriptivo y se estimó la supervivencia mediante el método de Kaplan-Meier.

La edad media de aparición de los síntomas, diagnóstico y TP fue de 35, 37 y 38 años, respectivamente. El síntoma más frecuente fue la disnea. La media del volumen espiratorio forzado en el primer segundo fue del 32,7%, y la de difusión del monóxido de carbono, del 29%. La supervivencia fue del 100, 85,7 y 57,1% a uno, 3 y 5 años, respectivamente. Tres pacientes fallecieron por bronquiolitis obliterante y en 2 necropsias realizadas no se observó recidiva de la enfermedad.

El TP es una opción terapéutica en pacientes con S-LAM en insuficiencia respiratoria avanzada.

Sporadic lymphangioleiomyomatosis (S-LAM) is a rare disease that affects only women. It is characterized by an abnormal proliferation of immature smooth muscle cells (LAM cells) that grow in an aberrant manner in the airway, parenchymal lung lymph and blood vessels, determining the onset of pulmonary cystic lesions. The disease has no treatment, progressing to respiratory failure, and lung transplantation (LT) may be a treatment option at this stage. Our goal was to study 7 patients undergoing LT for S-LAM.

We studied a series of clinical and demographic characteristics, diagnostic modality and post-transplant outcomes. We performed a descriptive analysis of the series. The Kaplan-Meier method was used to estimate survival.

The mean age of onset of symptoms was 35 years, the diagnosis of 37 years and that of LT 38 years. The most common symptom was dyspnea. Four patients had a history of pneumothorax and pleural effusion. The mean forced expiratory volume in one second was 32.7% and the diffusing capacity for carbon monoxide was 29%. All patients were subjected to LT and survival was 100, 85.7 and 57.1% at one, 3 and 5 years, respectively. Three died of bronchiolitis obliterans and 2 necropsies did not show evidence of disease recurrence.

LT is a therapeutic option in patients with S-LAM with an advanced respiratory functional impairment.