LYVE-1 EXPRESSION ON HIGH ENDOTHELIAL VENULES (HEVs) OF LYMPH NODES

Abstract

LYVE-1 (lymphatic endotheliumhyaluronan receptor) has been identified as apowerful marker for lymphatic endothelium.Apart from lymphatic endothelium, LYVE-1is expressed in normal liver blood sinusoids,spleen endothelium and activated tissuemacrophages. LYVE-1 has not been detectedin blood vascular endothelium with theexception of blood vessels in the lung. Highendothelial venules (HEVs) belong to thevascular compartment of lymph nodes. Theyare the major site of entry for circulatinglymphocytes into the node. HEVs arecharacterized by cuboidal endothelial cells,the existence of discontinuous junctionsbetween these endothelial cells, and thepresence of large numbers of lymphocyteswithin their walls. 40 paraffin-embeddedlymph node biopsy specimens from newlydiagnosed patients with non-Hodgkinlymphoma were evaluated as well as 10 lymphnode biopsy specimens from adult patientswith reactive lymphadenitis, and 10 normal,non-metastatic lymph nodes obtained fromadult patients during cancer surgery served ascontrols. Samples were fixed in 10% bufferedformalin, paraffin embedded, and stained withhematoxylin and eosin for histopathologicalevaluation. Sections were also evaluated withmouse monoclonal antibodies against LYVE-1and CD34, and expression of both LYVE-1and CD34 was demonstrated in HEVs.LYVE-1 expression was also found on theendothelial cells of the lymphatic sinus andin reticular cells in the lymph nodes.