Lymphangioleiomyomatosis (lim-FAN-je-o-LI-o-MI-o-ma-TO-sis), better known as LAM, is a rare lung disease that usually strikes women during the prime of their lives. Known as LAM for short, this disease is characterized by an abnormal growth of smooth muscle cells, especially in the lungs, lymphatic system and kidneys. Unregulated growth of these cells can lead to loss of lung function, accumulation of lymph rich-fluid in the chest and abdomen and growth of tumors in the kidneys.
How LAM Affects the Lungs
When you breathe, oxygen passes through the airways to tiny airsacks (alveoli) in the lungs where oxygen transfers into the blood through a network of tiny blood vessels called capillaries. The abnormal smooth muscle cells of LAM cause blockage of the small airways and release factors causing damage to the lung tissues, resulting in compromise of airflow and oxygen transfer to the blood. Changes to the airways and the lung tissues results in symptoms of shortness of breath, and in some individuals low oxygen levels.
Cysts in the lungs can rupture, allowing air to leak from the lung and into the chest cavity. This condition is called a pneumothorax, and is a common occurrence in women with LAM. As the lung leaks and deflates, it often causes discomfort and shortness of breath. Some women with LAM will also develop blockage of lymphatic channels from LAM cells, resulting in abnormal fluid collections in the chest and abdomen.
The Course of LAM
LAM is a progressive disease but its progression is usually slow. In some women, however, the disease progresses at a rapid rate. Doctors are working to find indicators (biomarkers) that will help determine who will have a more rapid rate of progression and who will progress more slowly. Whether disease progression is slow or rapid, lung function tends to decrease over time. Many LAM patients will, at some point, require oxygen therapy.
The Treatment of LAM
Although great strides have been made in researching the disease, there is no cure for LAM. However, treatment with the drug sirolimus (also known as rapamycin or Rapamune) as well as everolimus (also known as Afinitor) may improve lung function in some women with LAM. Oxygen therapy is required for women with advanced lung disease. Lung transplantation is often considered for very advanced disease. While many women with LAM add several years to their lives through lung transplantation, it is not a cure.