14 DAY TRIAL // LAM is a rare but serious lung disease that can even be fatal sometimes. Researchers at the University of Cincinnati (UC) and Cincinnati Children's Hospital Medical Center have found that a certain blood test can successfully identify this illness. This is a big progress for the non-invasive diagnosis, because a surgical lung biopsy is no longer necessary.
Lymphangioleiomyomatosis is an idiopathic disease affecting women that was first described by von Stossel in 1937. It results from proliferation in the lung, kidney and axial lymphatics of a neoplastic cell having a smooth muscle cell phenotype (LAM cell). Cystic destruction of the lung with progressive pulmonary dysfunction and the presence of abdominal tumors characterize the disease. Because this condition typically occurs in premenopausal women, involvement of the female hormones in disease pathogenesis is a current hypothesis.
Lisa Young, MD, lead author and researcher at UC and Cincinnati Children's, says that these findings will not only help diagnosing LAM but might also be useful in screening for the disease in women with Tuberous Sclerosis Complex (TSC), a genetic disorder that causes tumors to form in many different organs, and a major risk factor in the development of LAM.
The test consisted in analyzing the amount of a specific protein (vascular endothelial growth factor-D, or VEGF-D) in patients' blood. This protein helps the lymphatic vessels and the blood vessels' growth and can be involved in the spread of cancer. 195 women took part at this blood test. Results showed that VEGF-D levels were significantly bigger in women with LAM than in healthy women, or women with other lung diseases. When the test's precision was evaluated without knowing in advance the women's diagnosis, it proved to be reliable.
Dr. Young says that even if a level of VEGF-D higher than 800 pg/ml is specific for LAM, a negative result do not exclude it.