Infrared imaging of lymphatic function in the upper extremity of normal controls and hand transplant recipients via subcutaneous indocyanine green injection.

OBJECTIVES: The goal of this study was to define the parameters of movement of indocyanine green in the upper extremity of normal control and hand transplant recipients. The purpose was to establish a non-invasive method of determining the level of lymphatic function in hand transplant recipients. In hand transplantation (and replantation), the deep lymphatic vessels are rarely repaired, resulting in altered lymphatic connections. In most cases, the relatively rapid inosculation of superficial lymphatic networks and drainage via the venous systems results in sufficient interstitial fluid and lymph drainage of the graft to prevent edema. However, our group and others have determined that some transplant recipients demonstrate chronic edema which is associated with lymphatic stasis. In one case, a patient with chronic edema has developed chronic rejection characterized by thinning of the skin, loss of adnexal structures, and fibrosis and contracture of the hand. METHODS: Lymphatic function was evaluated by intradermal administration of near-infrared fluorescent dye, indocyanine green, and dynamic imaging with an infrared camera system (LUNA). To date, the assessment of lymphatic drainage in the upper extremity by clearance of indocyanine green dye has been studied primarily in oncology patients with abnormal lymphatic function, making assessment of normal drainage problematic. To establish normal parameters, indocyanine green lymphatic clearance functional tests were performed in a series of normal controls, and subsequently compared with indocyanine green clearance in hand transplant recipients. RESULTS: The results demonstrate varied patterns of lymphatic drainage in the hand transplant patients that partially mimic normal hand lymphatic drainage, but also share characteristics of lymphedema patients defined in other studies. The study revealed significant deceleration of the dye drainage in the allograft of a patient with suspected chronic rejection and edema of the graft. Analysis of other hand transplant recipients revealed differing levels of dye deceleration, often localized at the level of surgical anastomosis. CONCLUSION: These studies suggest intradermal injection of indocyanine green and near-infrared imaging may be a useful clinical tool to assess adequacy of lymphatic function in hand transplant recipients.

Stanniocalcin-1 regulates endothelial gene expression and modulates transendothelial migration of leukocytes.

The mammalian counterpart of the fish calcium-regulating hormone stanniocalcin-1 (STC1) inhibits monocyte chemotactic protein-1- and stromal-derived factor-1alpha (SDF-1alpha)-mediated chemotaxis and diminishes chemokinesis in macrophage-like RAW264.7 and U937 cells in a manner that may involve attenuation of the intracellular calcium signal. STC1 is strongly induced in the kidney following obstructive injury. We hypothesized that STC1 may serve to attenuate the influx of inflammatory cells to the site of tissue injury. In this study, we examined the effect of STC1 on the migration of freshly isolated human macrophages, neutrophils, and T and B lymphocytes through quiescent or IL-1beta-treated human umbilical vein endothelial cell (HUVEC) monolayers. STC1 inhibited transmigration of macrophages and T lymphocytes through quiescent or IL-1beta-activated HUVECs but did not attenuate the transmigration of neutrophils and B lymphocytes. STC1 regulates gene expression in cultured endothelial cells and is detected on the apical surface of endothelial cells in vivo. The data suggest that STC1 plays a critical role in transendothelial migration of inflammatory cells and is involved in the regulation of numerous aspects of endothelial function.