Immune Cells Key to Abdominal Drainage

Armine Hareyan's picture

Gou Young Koh and colleagues at the Korea Advanced Institute of Science and Technology in Daejeon, Korea have discovered that macrophages, a type of immune cell, impair fluid drainage during peritoneal inflammation. They present these findings in the October 2009 issue of the American Journal of Pathology.

Lymphatic vessels in the diaphragm are responsible for draining excess peritoneal fluid, which lubricates most of the organs in the abdomen. During peritoneal inflammation, however, these vessels have altered structure and function.

To characterize changes in lymphatic vessels during peritoneal inflammation, Kim et al injected the inflammatory molecule LPS into mice to induce peritonitis. LPS injection induced changes in lymphatic vessel structure and function that were reversible upon discontinuation of LPS-induced inflammation. Macrophage migration to these sites of lymphangiogenesis contributed to lymphatic remodeling, and both macrophage attachment to the lymphatic vessels and inflammatory fibrosis resulted in impaired peritoneal fluid drainage. These data highlight the key role of macrophages in inflammation-induced lymphangiogenesis and lymphatic vessel dysfunction in the diaphragm.

This study by Kim et al "reveal[s] that CD11b+ macrophages play an important role in intraperitoneal LPS-induced aberrant lymphangiogenesis and lymphatic dysfunction in the diaphragm." They suggest that "it is possible that human patients with Gram-negative bacterial peritonitis may also have dysfunctional lymphangiogenesis and lymphatic remodeling in the diaphragm."

By American Journal of Pathology

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