What is LAM?
Lymphangioleiomyomatosis (LAM) is a rare, progressive and often fatal lung disease that strikes young women in the prime of their lives causing symptoms which include shortness of breath, chest pain, cough and lung collapse.
Significant strides have been made in understanding, diagnosing and treating symptoms and complications of LAM in the last 10 years. Still, there is an urgent need to:
- Increase awareness about LAM in the medical and lay communities;
- Ensure that women get a timely diagnosis;
- Dedicate research funding to find a safe and effective treatment for LAM and ultimately, a cure.
5 Facts About LAM:
- LAM is a progressive fatal lung disease.
- LAM strikes women of all races at the prime of their lives.
- LAM is characterised by the insidious growth of abnormal smooth muscle cells that infiltrate all lung structures including airways, blood vessels and lymph channels.
- LAM is caused by a sporadic genetic mutation.
- THERE IS NO KNOWN CURE FOR LAM.
Facts about LAM
LAM is not a new disease; it was first described in medical literature by Von Stossel in 1937 and affects only women, usually between the onset of puberty and menopause.
- Symptoms may include shortness of breath, collapsed lung, chest pain, cough, or fatigue
- Up to 50% of women with LAM have a benign kidney tumor called angiomyolipoma
- LAM usually does not appear on an x-ray. A high-resolution CT scan of the chest, and often the abdominal area, is required for accurate diagnosis
- LAM results in progressive destruction of healthy lung tissue caused by cyst formation and abnormal growth of smooth muscle cells, not usually found in the lungs
- Lung capacity progressively declines, resulting in the need for oxygen therapy
- Women often go undiagnosed for years, and are frequently misdiagnosed with asthma, bronchitis, or emphysema
- The discovery of a genetic link between LAM and tuberous sclerosis (TS) leads scientists to estimate that more than 250,000 women worldwide are unaware they have LAM
- Since LAM occurs almost exclusively in women, the disease is thought to be hormonally-related
- Many doctors think pregnancy accelerates the disease
- There is no cure and no treatment that has proven to be effective, but treatment trials are underway.
The disease is characterized by an unusual type of muscle cell that invades the tissue of the lungs, including the airways and blood and lymph vessels. Over time, these muscle cells form into bundles and grow into the walls of the airways, and blood and lymph vessels, causing them to become obstructed.
These cells grow without the usual controls within the lungs. Over time, the muscle cells block the flow of air, blood and lymph vessels to and from the lungs, preventing the lungs from providing oxygen to the rest of the body.
As delivery of oxygen to the body is progressively impaired this results in the need for oxygen therapy and, as a last resort, lung transplantation.
Common signs and symptoms of lymphangioleiomyomatosis (LAM) may include shortness of breath, especially following exertion.
In the early stages of disease, women with LAM may experience shortness of breath only during strenuous exercise, but as the disease advances, this may occur even while at rest.
- Chest pain, often caused by a collapsed lung(s)
- Frequent cough, occasionally expelling small amounts of blood
- Build up of fluid in the lung
- Enlarged lymph nodes
These symptoms are common to other conditions such as asthma, emphysema and chronic bronchitis. Women with LAM are frequently misdiagnosed with one of these conditions. If these symptoms don’t improve with treatment or if lung collapse reoccurs, this may suggest that there is damage to healthy lung tissue. With LAM, healthy lung tissue is destroyed by the abnormal growth of an unusual type of muscle cell that invades the tissues of the lungs.
Patients who have any of the above signs or symptoms who don’t improve should consult their health care provider, as they may indicate LAM or other serious diseases or complications.
Other Things to Watch For
Forty percent of patients with LAM will develop benign kidney tumors called angiomyolipomas, commonly associated with another rare disease, tuberous sclerosis.
Because many of the early signs and symptoms of lymphangioleiomyomatosis (LAM) are similar to those of other lung diseases, including asthma, emphysema and bronchitis, LAM can be difficult to diagnose. In fact, many women have LAM and don’t know it.
Often a woman with LAM first goes to her physician complaining of chest pain and shortness of breath that was caused by a lung collapse. Some patients first consult their physician because of shortness of breath with physical activity. There are a number of tests the physician can run to confirm or rule out the existence of LAM, assess the spread of the disease or determine the extent of lung damage:
Chest X-ray – takes a picture of your heart, lungs and surrounding tissue. It can show whether you have a collapsed lung or a build up of fluid around the lungs. The X-ray may show cysts or clusters of cells on the lungs, which are suggestive of LAM; however, this is not the optimal way to diagnose the disease.
High-resolution CT scan – provides a more detailed (two-dimensional) image of the inside of your lungs and chest. It is the most accurate imaging test for diagnosing LAM. A computed tomography, or CT scan, can reveal cysts or abnormal clusters of cells in your lungs, a collapsed lung or enlarged lymph nodes. It can also show the extent to which the cysts have spread. An abdominal CT scan is also recommended, as benign kidney tumors, known as angiomyolipomas, are found in 40 percent of women with LAM.
Lung biopsy – involves removing samples of lung tissue, which are examined under a microscope to look for abnormalities that may indicate LAM. There are several ways physicians can remove lung tissue.
Thoracoscopy, also called video-assisted thorascopic surgery (VATS), is used to insert a small lighted tube (endoscope) into tiny incisions in your chest wall so that the interior of the lung can be viewed, and small pieces of tissue are removed. This procedure must be done in the hospital under general anesthesia.
Open biopsy should only be performed as a last resort to diagnose LAM; recovery is longer than other, less invasive methods. In this procedure, a few small pieces of lung tissue are removed through an incision made in the chest wall between the ribs. This procedure also takes place in the hospital under general anesthesia.
Transbronchial biopsy may also be used to obtain a small amount of lung tissue. A long, narrow, flexible, lighted tube (bronchoscope) is inserted down the windpipe (trachea) and into the lungs. Pieces of lung tissue are sampled using a tiny forceps. This procedure is usually done in a hospital on an outpatient basis under local anesthesia. However, the amount of tissue that can be sampled is usually not adequate to definitively diagnose LAM.
Lung function test – evaluates how well your lungs are working by measuring the amount (volume) of air inhaled or exhaled, and how much time each breath takes (rate). The patient breathes through a mouthpiece into a machine called a spirometer. The spirometer records the movement of air into and out of the lungs. Although these tests are used to determine the effect LAM has on lung function, they are not typically used for diagnosis.
Blood Tests – a sample of blood is analyzed to determine whether your lungs are providing enough oxygen to the bloodstream, but cannot diagnose LAM.
Much investigation into the cause of LAM has been done and work continues in a growing number of countries around the world including a team of LAM investigators led by Assoc Professor Merv Merrilees from the University of Auckland’s School of Medical and Health Sciences. Scientists are involved in new and exciting studies; treatments have varied in effectiveness from patient to patient and there are some examples of the progress of LAM being slowed.
The New Zealand Trust has been involved with collaborative research, and in May 2003 enrollment for a treatment trial to test the effectiveness of a drug called rapamycin got underway at the University of Cincinnati. This is the first ever treatment trial and many LAM patients and their families, along with researchers, clinicians and physicians feel that a pivotal point in LAM research may have been reached.
In this first phase of the treatment trial, investigations measured the effect of rapamycin on angiomyolipomas, (Amls) which are benign kidney tumours commonly found in patients with LAM and also in some patients suffering from the condition, tuberous sclerosis. The second phase of the trial will be conducted through the Rare Lung Diseases Consortium in the USA and will focus on the effect of rapamycin on lung function.
Phase Two of this double blind, randomised placebo based trial began in 2005 and over the past four years, enrollment centres have spread across the USA and in Japan. LAM patients and their clinicians in New Zealand are watching the results of the US rapamycin trial with interest. In the meantime small trials involving other drug possibilities have begun around the world in countries including England, Australia and Brazil and women with LAM in New Zealand are talking to their specialists about current options.