Common Anti-Rejection Drug May Help Treat Patients With Serious Lung Condition
Published February 2008
Not long ago, lymphangioleiomyomatosis—commonly known as LAM—was a lung condition that many doctors didn’t know existed.
Now, researchers at UC and Cincinnati Children’s Hospital Medical Center are on the path to finding new treatment options for patients living with the rare disease.
In LAM, an unusual type of cell begins to grow out of control and spread to restricted areas in the body, including the lungs, lymph nodes and vessels, and kidneys.
The researchers, led by UC’s John Bissler, MD, have found that the transplant drug sirolimus shrunk kidney tumors in LAM patients by 50 percent and improved some measures of lung function by 10 to 15 percent.
The results were published in the Jan. 10, 2008, issue of the New England Journal of Medicine.
“These findings hold promise that targeting cell growth pathways known to be unbalanced in LAM can have an impact on the disease,” says study coauthor Frank McCormack, MD, a professor in the division of pulmonary, critical care and sleep medicine.
“Our next steps are to determine if sirolimus can have an effect on important medical or functional outcomes in patients with LAM, such as exercise tolerance, quality of life and survival.”
He adds that this research could lead to treatments that would shrink tumors in other areas of the body, such as the heart or brain.
The study showed that sirolimus, usually prescribed to prevent the rejection of transplanted organs, shrunk tumors caused by LAM and tuberous sclerosis complex (TSC)—another rare genetic disease—by about half of their size during the course of a year in 20 patients.
In addition, preliminary data in a parallel study indicated a certain protein, called vascular endothelial growth factor D, is elevated in the blood of LAM patients and could eventually be useful in helping diagnose LAM.
“Currently, doctors rely on biopsies and lung scans,” McCormack says. “A blood test for these protein levels would be less invasive and safer for the patient.”
LAM affects mostly women of childbearing age. Arising from an unknown source, LAM cells enter the lung and obstruct airways, blood vessels and lymphatics.
Eventually, the lung becomes completely replaced by 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.
TSC also causes tumors to form in the kidneys, brain, heart and other organs. About 30 to 40 percent of women with TSC also develop some form of LAM.
Treatment options for both diseases are limited to surgery for the tumors, supportive care for symptoms of lung and kidney failure and, in the worst cases, organ transplants.
Bissler, an associate professor of pediatrics and cancer and cell biology, says the findings will hopefully give patients more treatment options and provide better quality of life.
“By manipulating the pathway that controls cell growth of the LAM and angiomyolipoma cells, we have taken a huge step forward,” says Bissler, who also conducts research at Cincinnati Children’s.
Study coauthors included Lisa Young, MD, and David Franz, MD, both of UC.
“We are now conducting further studies to see if we can optimize the drug effect.”