Lymphatics Keep Flowing Along . . .
by Lowell A. Goldsmith, MD, MPH
Lymphatics were a challenge to me and my fellow medical students during our gross anatomy class a half century ago. We could find arteries and veins galore, but where were the elusive lymphatics? Even the two larger connections between the venous and lymphatic systems were elusive.
Lymphatic biology has progressed exponentially since then. For two days in May, 2013 the world’s lymphatic gurus gathered at Yale to fete the rich molecular biology and physiology of the lymphatics, as summarized recently in Science (Simons and Eichmann, 2013). As of August 17, 2013, lymphedema was a feature of almost 70 genetic diseases and syndromes in OMIM, and many common conditions are transmitted by -- or alter -- lymphatics. Vascular endothelial growth factors and their receptors are major players in lymphatic development, and an RNA binding protein antigen, R(huR), and other molecules are important VEGF modulators. Lymphatics continue to be the subject of many narratives, with implications for cutaneous biology and cutaneous diseases, both inflammatory and neoplastic. The key role of lymphatic endothelial cells during the transit of dendritic cells from the periphery to lymph nodes is highlighted in the September issue of JID, underscoring the importance of lymphatics in cutaneous inflammatory biology. (Teijeira et al, 2013)
I started with history and end on a historical theme. Dermatology and Yale have a rich history in lymphatic and vascular biology, and Irwin Braverman, currently a Professor of Dermatology at Yale, published a masterful review in 1983 on the role of blood vessels and lymphatics in skin diseases containing many of his seminal original studies.(Braverman, 1983) I suspect he is pleased that skin and lymphatics are still closely intertwined and that Yale was the setting for this vascular biology meeting.