Laparoscopic or open cholecystectomy in cirrhosis: a systematic review of outcomes and meta-analysis of randomized trials.

BACKGROUND: Cholecystectomy is associated with increased risks in patients with cirrhosis. The well-established advantages of laparoscopic surgery may be offset by the increased risk for complications relating particularly to portal hypertension and coagulopathy. METHODS: A systematic search was undertaken to identify studies comparing open cholecystectomy (OC) and laparoscopic cholecystectomy (LC) in patients with cirrhosis. A meta-analysis was performed of the available randomized controlled trials (RCTs). RESULTS: Forty-four studies were analysed. These included a total of 2005 patients with cirrhosis who underwent laparoscopic (n= 1756) or open (n= 249) cholecystectomy, with mortality rates of 0.74% and 2.00%, respectively. A meta-analysis of three RCTs involving a total of 220 patients was conducted. There was a reduction in the overall incidences of postoperative complications and infectious complications and a shorter length of hospital stay in LC. However, frequencies of postoperative hepatic insufficiency did not differ significantly. CONCLUSIONS: There are few RCTs comparing OC and LC in patients with cirrhosis. These studies are small, heterogeneous in design and include almost exclusively patients with Child-Pugh class A and B disease. However, LC appears to be associated with shorter operative time, reduced complication rates and reduced length of hospital stay.

Porcine cells express more than one functional ligand for the human lymphocyte activating receptor NKG2D.

BACKGROUND: Xenotransplantation could ameliorate the severe shortage of donor organs. The initial results of transplantation from genetically-modified pig donors to primate recipients suggest that hyperacute rejection can be overcome, but thrombotic microangiopathy and the human anti-pig cellular immune response remain as significant impediments to successful clinical xenotransplantation. NKG2D is an activating immunoreceptor found on human natural killer (HuNK) cells, CD8(+) and gammadelta T cells. Signaling through NKG2D mediates cytotoxicity and cytokine secretion by NK cells and co-stimulation of T cells. METHODS: Chinese hamster ovary P (CHOP) cells were transfected with human NKG2D and used in cell-cell binding studies with porcine epithelial, and endothelial cell lines. Soluble recombinant NKG2D-Fc was used to stain various porcine cells and tissues to indicate ligand expression. Porcine cells were used as targets in cytotoxicity assays with the HuNK cell lines NKL and YT, with and without enzymatic removal of pULBP1 and antibody blockade of NKG2D signaling. RESULTS AND CONCLUSIONS: In this study, we demonstrate the expression of ligands for human NKG2D on porcine cell lines of endothelial and epithelial origin, islet cell clusters and rejecting kidney. HuNK cells were activated to kill pig cells expressing NKG2D ligands, and cytotoxicity was inhibited by antibody blockade of NKG2D. A previous study identified pULBP1 as the principal ligand for human NKG2D on pig aortic endothelial cells. In the current study, renal epithelial and intestinal endothelial cells each expressed high surface levels of pULBP1, but binding of soluble recombinant NKG2D and NKG2D-dependent cytotoxicity against these cells persisted after the enzymatic removal of pULBP1, strongly suggesting the presence of at least one additional functional ligand for human NKG2D in these cell types.