Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.

Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre(+) heart and kidney transplants were readily transmitted to MCMV-naïve recipients by primary viremia. In contrast, when a Tie2-cre(+) transplant was infected by primary viremia in an infected recipient, the recombined EC-derived virus poorly spread to recipient tissues. Similarly, in reverse direction, EC-derived virus from infected Tie2-cre(+) recipient tissues poorly spread to the transplant. These data contradict any privileged role of EC in CMV dissemination and challenge an indiscriminate applicability of the primary and secondary viremia concept of virus dissemination

Recipient Morbidity After Living and Deceased Donor Liver Transplantation: Findings from the A2ALL Retrospective Cohort Study †

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72284/1/j.1600-6143.2008.02440.x.pd

Evolution of laparoscopic left lateral sectionectomy without the Pringle maneuver: through resection of benign and malignant tumors to living liver donation

BACKGROUND: Laparoscopic left lateral sectionectomy (LLS) has gained popularity in its use for benign and malignant tumors. This report describes the evolution of the authors' experience using laparoscopic LLS for different indications including living liver donation. METHODS: Between January 2004 and January 2009, 37 consecutive patients underwent laparoscopic LLS for benign, primary, and metastatic liver diseases, and for one case of living liver donation. Resection of malignant tumors was indicated for 19 (51%) of the 37 patients. RESULTS: All but three patients (deceased due to metastatic cancer disease) are alive and well after a median follow-up period of 20 months (range, 8-46 months). Liver cell adenomas (72%) were the main indication among benign tumors, and colorectal liver metastases (84%) were the first indication of malignancy. One case of live liver donation was performed. Whereas 16 patients (43%) had undergone a previous abdominal surgery, 3 patients (8%) had LLS combined with bowel resection. The median operation time was of 195 min (range, 115-300 min), and the median blood loss was of 50 ml (range, 0-500 ml). Mild to severe steatosis was noted in 7 patients (19%) and aspecific portal inflammation in 11 patients (30%). A median free margin of 5 mm (range, 5-27 mm) was achieved for all cancer patients. The overall recurrence rate for colorectal liver metastases was of 44% (7 patients), but none recurred at the surgical margin. No conversion to laparotomy was recorded, and the overall morbidity rate was 8.1% (1 grade 1 and 2 grade 2 complications). The median hospital stay was 6 days (range, 2-10 days). CONCLUSIONS: Laparoscopic LLS without portal clamping can be performed safely for cases of benign and malignant liver disease with minimal blood loss and overall morbidity, free resection margins, and a favorable outcome. As the ultimate step of the learning curve, laparoscopic LLS could be routinely proposed, potentially increasing the donor pool for living-related liver transplantation

Outcomes of donor evaluation in adult-to-adult living donor liver transplantation

The purpose of donor evaluation for adult-to-adult living donor liver transplantation (LDLT) is to discover medical conditions that could increase the donor postoperative risk of complications and to determine whether the donor can yield a suitable graft for the recipient. We report the outcomes of LDLT donor candidates evaluated in a large multicenter study of LDLT. The records of all donor candidates and their respective recipients between 1998 and 2003 were reviewed as part of the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). The outcomes of the evaluation were recorded along with demographic data on the donors and recipients. Of the 1011 donor candidates evaluated, 405 (40%) were accepted for donation. The donor characteristics associated with acceptance (P < 0.05) were younger age, lower body mass index, and biological or spousal relationship to the recipient. Recipient characteristics associated with donor acceptance were younger age, lower Model for End-stage Liver Disease score, and shorter time from listing to first donor evaluation. Other predictors of donor acceptance included earlier year of evaluation and transplant center

Hybrid Procedure in Living Donor Liver Transplantation

Background We have previously reported a hybrid procedure that uses a combination of laparoscopic mobilization of the liver and subsequent hepatectomy under direct vision in living donor liver transplantation (LDLT). We present the details of this hybrid procedure and the outcomes of the procedure. Methods Between January 1997 and August 2014, 204 LDLTs were performed at Nagasaki University Hospital. Among them, 67 recent donors underwent hybrid donor hepatectomy. Forty-one donors underwent left hemihepatectomy, 25 underwent right hemihepatectomy, and 1 underwent posterior sectionectomy. First, an 8-cm subxiphoid midline incision was made; laparoscopic mobilization of the liver was then achieved with a hand-assist through the midline incision under the pneumoperitoneum. Thereafter, the incision was extended up to 12 cm for the right lobe and posterior sector graft and 10 cm left lobe graft procurement. Under direct vision, parenchymal transection was performed by means of the liver-hanging maneuver. The hybrid procedure for LDLT recipients was indicated only for selected cases with atrophic liver cirrhosis without a history of upper abdominal surgery, significant retroperitoneal collateral vessels, or hypertrophic change of the liver (n = 29). For total hepatectomy and splenectomy, the midline incision was sufficiently extended. Results All of the hybrid donor hepatectomies were completed without an extra subcostal incision. No significant differences were observed in the blood loss or length of the operation compared with conventional open procedures. All of the donors have returned to their preoperative activity level, with fewer wound-related complaints compared with those treated with the use of the conventional open procedure. In recipients treated with the hybrid procedure, no clinically relevant drawbacks were observed compared with the recipients treated with a regular Mercedes-Benz-type incision. Conclusions Our hybrid procedure was safely conducted with the same quality as the conventional open procedure in both LDLT donors and recipients

Donor Morbidity After Living Donation for Liver Transplantation

Reports of complications among adult right hepatic lobe donors have been limited to single centers. The rate and severity of complications in living donors were investigated in the 9-center Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL)

Systemic hematogenous maintenance of memory inflation by MCMV infection.

Several low-grade persistent viral infections induce and sustain very large numbers of virus-specific effector T cells. This was first described as a response to cytomegalovirus (CMV), a herpesvirus that establishes a life-long persistent/latent infection, and sustains the largest known effector T cell populations in healthy people. These T cells remain functional and traffic systemically, which has led to the recent exploration of CMV as a persistent vaccine vector. However, the maintenance of this remarkable response is not understood. Current models propose that reservoirs of viral antigen and/or latently infected cells in lymph nodes stimulate T cell proliferation and effector differentiation, followed by migration of progeny to non-lymphoid tissues where they control CMV reactivation. We tested this model using murine CMV (MCMV), a natural mouse pathogen and homologue of human CMV (HCMV). While T cells within draining lymph nodes divided at a higher rate than cells elsewhere, antigen-dependent proliferation of MCMV-specific effector T cells was observed systemically. Strikingly, inhibition of T cell egress from lymph nodes failed to eliminate systemic T cell division, and did not prevent the maintenance of the inflationary populations. In fact, we found that the vast majority of inflationary cells, including most cells undergoing antigen-driven division, had not migrated into the parenchyma of non-lymphoid tissues but were instead exposed to the blood supply. Indeed, the immunodominance and effector phenotype of inflationary cells, both of which are primary hallmarks of memory inflation, were largely confined to blood-localized T cells. Together these results support a new model of MCMV-driven memory inflation in which most immune surveillance occurs in circulation, and in which most inflationary effector T cells are produced in response to viral antigen presented by cells that are accessible to the blood supply

Buffered memory: a hypothesis for the maintenance of functional, virus-specific CD8(+) T cells during cytomegalovirus infection.

Chronic infections have been a major topic of investigation in recent years, but the mechanisms that dictate whether or not a pathogen is successfully controlled are incompletely understood. Cytomegalovirus (CMV) is a herpesvirus that establishes a persistent infection in the majority of people in the world. Like other herpesviruses, CMV is well controlled by an effective immune response and induces little, if any, pathology in healthy individuals. However, controlling CMV requires continuous immune surveillance, and thus, CMV is a significant cause of morbidity and death in immune-compromised individuals. T cells in particular play an important role in controlling CMV and both CD4(+) and CD8(+) CMV-specific T cells are essential. These virus-specific T cells persist in exceptionally large numbers during the infection, traffic into peripheral tissues and remain functional, making CMV an attractive vaccine vector for driving CMV-like T cell responses against recombinant antigens of choice. However, the mechanisms by which these T cells persist and differentiate while remaining functional are still poorly understood, and we have no means to promote their development in immune-compromised patients at risk for CMV disease. In this review, I will briefly summarize our current knowledge of CMV-specific CD8(+) T cells and propose a mechanism that may explain their maintenance and preservation of function during chronic infection