Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (lim-FAN-je-o-LI-o-MI-o-ma-TO-sis), or LAM, is a rare cystic lung disease that mostly affects women in their mid-forties. In LAM, an unusual type of cell begins to grow out of control throughout the body, including in the lungs, lymph nodes and vessels, and kidneys. Over time, these LAM cells form cysts and clusters of cells, which grow throughout the lungs and slowly block the airways. They also destroy the normal lung tissue and replace it with cysts. As a result, air cannot move freely in and out of the lungs, and the lungs cannot supply enough oxygen to the body’s other organs. Some people also develop growths called angiomyolipomas (AMLs) in the kidneys. There are two forms of LAM - a sporadic form, which occurs for unknown reasons, and a form that occurs in people with a rare, inherited disease called tuberous sclerosis complex.^[1]

LAM may be difficult to diagnosis in the early stages because symptoms may be similar to other lung diseases. A high resolution CT scan is the most accurate imaging test for diagnosing LAM. Additional testing may include an abdominal CT scan or ultrasound, a VEGF-D blood test (measuring the VEGF-D hormone, which would typically be high), and a lung biopsy.^[2] There are several management options for LAM, but the best course of treatment may vary from person to person. Treatment options may include therapy with an mTOR inhibitor (such as sirolimus), and supportive measures such as oxygen therapy or the use of bronchodilators. Some people may need a lung transplant when lung function is considerably impaired.^[3]

While there is currently no cure for LAM, research has led to major progress in the treatment of symptoms. Treatment options may vary from person to person depending on the severity of the disease. People with LAM should speak with their doctor about whether certain options are right for them, as well as the benefits and risks of treatment options.

Treatment for LAM may involve:^[3]

• Sirolimus (also called rapamycin) - this medicine works to stabilize lung function, treat chylothorax (abnormal fluid buildup in the lung), and shrink abnormal kidney and lymph node growths. Sirolimus has been shown to improve quality of life in patients with moderate to severe LAM.
• Oxygen therapy - this may be recommended if the level of oxygen in the blood is low, and may become necessary as lung function worsens.
• Bronchodilators - these medicines relax muscles around the airways and may make it easier to breathe. They may be prescribed for people with LAM who are wheezing or have difficulty breathing.
• Procedures that remove air or fluid from the chest or abdomen - these may help with shortness of breath and relieving discomfort.
• Procedures or surgeries that remove or shrink kidney tumors, which may cause pain or bleeding.
• Lung transplant - people with LAM who have severe symptoms and/or severe lung damage may be eligible for a lung transplant.

Of note, doxycycline and hormone-based therapy, which have previously been used in the treatment LAM, are no longer recommended treatments.

The American Thoracic Society and Japanese Respiratory Society have made available their latest clinical practice guidelines for LAM which include the current treatment recommendations.

The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies To learn more about how you can become involved in clinical research, please see the Research section of this webpage.

The LAM Foundation supports past an ongoing research for the causes and treatment of LAM. The LAM Foundation continues to support clinical trials to search for safe and effective treatments.^[2]

The National Institutes of Health (NIH) established the Rare Diseases Clinical Research Network (RDCRN) to facilitate collaboration among experts in many different types of rare diseases. The goal of the network is to contribute to the research and treatment of rare diseases by working together to identify biomarkers for disease risk, disease severity and activity, and clinical outcome, while also encouraging development of new approaches to diagnosis, prevention, and treatment. The RDCRN consists of ten consortia and a Data and Technology Coordinating Center (DTCC). One of these consortia is the Rare Lung Diseases Consortium (RLDC), a network of cooperating clinical centers and patient support organizations that are working with the National Institutes of Health (NIH) in a collaborative network whose novel structure is designed to accelerate clinical research and improve the delivery of medical care to individuals affected by rare lung diseases. To join the Contact Registry for LAM, click here.