When you are asked if you are aware of any conditions associated with the lungs, what comes to your mind? You may think of asthma, pneumonia or lung cancer. Most of you would not have thought about Lymphangioleiomyomatosis or as it is called, LAM. Lymphangioleiomyomatosis (lim-fan je-o li- o- mi o - ma- to sis) is a rare disease of the lungs and lymphatics, which can occur sporadically or in association with tuberous sclerosis. In people who have LAM (mostly women of childbearing age), abnormal muscle-like cells begin to grow out of control in certain organs or tissues, especially the lungs, lymph nodes, and kidneys. Over time, these LAM cells can destroy healthy lung tissue. As a result, cysts may develop in the lungs, preventing air from moving freely in and out of the lungs. This may prevent the delivery of oxygen to the rest of the body. The curious aspect is that it's not cancer, but it spreads to other organs and the LAM cells are tumour-like cells but are not malignant. Theoretically, it should be easier to fix than cancer. But, unfortunately, it isn't.
There is no cure for LAM.
This rare disease is known to cause complications like pneumothorax (a collapsed lung), chylous collections (a collection of yellowish-white, milky fluid that results from obstruction of lymph flow) and extrapulmonary manifestations. Even though there is no cure for this progressive disease, there is hope. Treatment can help ease symptoms, prevent complications and disease progression. Definitive treatment is a lung transplant but this also carries its own form of problems, like rejection. The life expectancy is a grim 8-10 years after diagnosis. Treatment helps in relieving the symptoms and giving people an extra year or two, but a cure is better. To work on the cure, we must understand the cause of this disease, the root of the problem.
LAM is caused by mutations in the Tuberous Sclerosis (TSC) 1 or TSC2 genes. Abnormal TSC genes make proteins that cannot regulate cell growth and the movement of cells in the body. As a result, abnormal cells that behave like muscle cells appear and grow uncontrollably. What is interesting is that researchers believe that the hormone estrogen plays a role, because the condition affects mostly women of childbearing age. The condition also worsens in a pattern that matches up with the menstrual cycle, during pregnancy, and after the use of medicines such as birth control that contain estrogen. After menopause, LAM has also been known to stop progressing in severity. The reason why estrogen affects only some women this way and not others is unknown and a topic of research.
Reading about this rare disease, we do not picture this as real and cannot understand the impact. However, even though it is rare, it is not impossible. A research study done to understand patient perceptions of people living with LAM makes this a tangible disease. Along with the plethora of physical symptoms like shortness of breath, low energy, cough, sensations in the chest, difficulty sleeping and gastrointestinal issues, there are added psychological issues as well. The common psychological experiences participants reported included frustration, worry, loss of identity, embarrassment, and in some participants, healthy defiance against the disease. Patients feel as though the disease has trapped them and are waiting for the other shoe to drop. The burden of this diagnosis allows us to understand the severity of this disease and intensifies the urgency for effective treatments and a cure.
So what are the treatments available?
For many years, treatment of LAM has been mostly supportive, including bronchodilators, supplemental oxygen (if needed), management of complications (especially pneumothorax) and lung transplantation. Sirolimus therapy has also been used to stabilize lung function and prevent respiratory failure. Sirolimus therapy is effective at improving or stabilizing pulmonary function, oxygen levels, exercise capacity, and quality of life in patients with LAM for up to 4 years. Sirolimus or rapamycin belongs to a class of drugs known as immunosuppressants. It exhibited efficacy in an open-label study published in 2008 and since then has been used to ease symptoms.
There have been efforts to study this mysterious disease and find ways to cure it. A team led by a physician-scientist identified the genetic mutation at its core and developed a model allowing researchers to study it. Scientists like Elizabeth Henske, director of a LAM centre in Brigham, have devoted their lives to study this disease and avoid 20-year-olds, whose lives are just starting, having their life cut short. Hopefully, with advancements in medicine and technology, the prospect of a
the cure is nearer than we think.
Written by: Svasti Tewari
Edited by: Sakshi Deshpande and Subhagata Mandal
Bibliography
コメント