Urinary Neutrophil Gelatinase-associated Lipocalin as a Marker for Identification of Acute Kidney Injury and Recovery in Dogs with Gentamicin-induced Nephrotoxicity.

BACKGROUND: Acute kidney injury (AKI) is associated with high mortality rates in dogs, which may be a consequence of late recognition using traditional diagnostic tests. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein-induced during kidney injury that may identify AKI earlier than traditional tests. OBJECTIVES/HYPOTHESIS: To evaluate urinary NGAL (uNGAL) and uNGAL-to-urinary creatinine ratio (UNCR) as early markers of kidney injury and recovery in an AKI model in dogs. It was hypothesized that these markers would document AKI earlier than serum creatinine concentration. ANIMALS: Five purpose-bred dogs. METHODS: Prospective study. Acute kidney injury, defined as a > 50% increase in serum creatinine concentration above baseline, was induced in dogs by gentamicin administration (8-10 mg/kg SC q8h). Blood and urine collected for biochemical analyses and uNGAL and urinary creatinine concentrations, respectively, during AKI induction and recovery. RESULTS: Acute kidney injury was diagnosed significantly earlier based on a 7-fold increase in UNCR compared to a > 50% increase in serum creatinine concentration (day 8; range, 2-10 mg/dl vs day 16; range, 14-19 mg/dl; P = .009). During recovery, the initial decrease in UNCR preceded the decrease in serum creatinine concentration by a median of 2 days. The uNGAL changes paralleled UNCR changes, but the increase in uNGAL was triphasic; the initial peak occurred earlier than UNCR (median, day 11 versus median, day 19). CONCLUSIONS AND CLINICAL IMPORTANCE: The UNCR was early marker of gentamicin-induced AKI and its decrease documented onset of renal recovery. Additional studies are needed to validate this marker in dogs with naturally occurring renal injury.

Ex vivo generation of dendritic cells from CD34+ cells in gas-permeable containers under serum-free conditions.

Dendritic cells (DC) are efficient and potent APCs that can be generated ex vivo. For them to be used clinically, however, a closed culture system using serum-free medium should be used. Our goal was to differentiate DC from human blood CD34+ cells in serum-free media in a new gas-permeable culture container, PL2417. Apheresis products were collected from healthy G-CSF-mobilized donors, and CD34+ cells were selected using the Isolex immunomagnetic cell selection system. Cells were cultured in the presence of GM-CSF and tumor necrosis factor-alpha (TNF-alpha) in various serum-free media and compared with serum-containing medium in 4-well plates. One of the serum-free media was then selected and used in PL2417 containers and compared with serum-containing medium in standard flasks. The cells were evaluated at days 0, 7, and 14 for the presence of DC, which were identified morphologically after Wright-Giemsa staining by cytoplasmic processes extending from the surface of the cell. The cultures were evaluated phenotypically by flow cytometry and immunohistochemistry. The stimulatory capacity was examined in MLR. Overall, results from serum-free media and PL2417 containers were comparable results obtained under the other conditions. These data indicate that culture-deriving DC from CD34+ cells in PL2417 closed system containers using serum-free media is as effective as using standard flasks and serum-supplemented media.