Is Your LAM Being Misdiagnosed as Asthma?
Often, patients with the rare lung disease LAM are misdiagnosed with asthma or even emphysema. But getting the right diagnosis matters, because definitive LAM treatment is now available.
When a young woman comes to a doctor complaining of shortness of breath, the first suspect is typically asthma.
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But in rare cases, the cause could be lymphangioleiomyomatosis — LAM for short. LAM is a lung disease that strikes women in their childbearing years.
“LAM is usually diagnosed between age 20 and 40, and it’s exclusive to women,” says Robert Kotloff, MD.
Below, Dr. Kotloff and Joseph Parambil, MD — both leaders at Cleveland Clinic’s LAM Clinic — talk about why getting the right diagnosis is so important for patients.
With LAM, smooth muscle cells grow out of control in the lungs and obstruct small airways. Unfortunately, this leads to symptoms that seem like more common lung conditions.
To make matters more confusing, a radiologist can see the cysts that come with LAM on a CT scan. But it’s easy to confuse them with emphysema damage. Someone with LAM is also likely to test positive for asthma in a lung function test.
“Most people start without a CT scan,” Dr. Parambil says. “They start with a breathing test, and it really does look like asthma. So a doctor naturally says, ‘You have asthma. Take these inhalers and see how you respond.’”
What comes next is where patients should pay attention. Do your symptoms improve with treatments such as inhalers? That’s important, because inhalers won’t have any effect on LAM.
“If asthma treatment doesn’t improve your shortness of breath, that’s a reason to dig deeper and look for other explanations,” Dr. Kotloff says.
Doctors sometimes misdiagnose LAM as emphysema, too. But that happens less frequently because emphysema is rare among women of this age.
“Still, an emphysema diagnosis in a healthy young woman — especially a nonsmoker — is a red flag,” Dr. Kotloff says. If you’re in this situation, it’s worth asking if something else might be to blame.
Dr. Parambil says patients and doctors often don’t ask these questions early enough.
“Unfortunately, a lot of times we don’t see patients until their lungs have collapsed,” he says. “That’s part of why we’re pushing for early diagnosis.”
Early diagnosis matters because treatment is better than ever before. “There is now a definitive treatment for LAM,” Dr. Kotloff says.
In recent years, researchers have unlocked the genetics of LAM. If you have a certain genetic mutation, a gene called mTOR gets switched on. When that happens, LAM cells grow and spread.
A drug called rapamycin (sirolimus) — now approved by the FDA — can switch mTOR off and slow the disease. And it’s available to treat patients now.
A clinical study called the MILES Trial confirmed this benefit by comparing lung function in women with LAM who took rapamycin and those who took a placebo. “At the end of one year, lung function was better preserved in the rapamycin group,” Dr. Kotloff says.
Getting the word out to patients is critical, Dr. Parambil says. “I have to tell people, ‘Stop reading the Internet,’” he says. “The message out there now is that the only proper treatment is proceeding toward transplant. But this medication really is effective.”
Both doctors say the story of LAM isn’t over yet. They and other researchers are building on MILES to study several other concepts. Can they treat LAM patients even earlier to preserve lung function? Could even more targeted drugs work for patients?
“There is real treatment available for this disease now,” Dr. Parambil says, “and we may be able to make treatment even better.”