Different kinetics of donor cell populations after isolated liver and combined liver/small bowel transplantation

Graft-versus-host disease after intestinal and multivisceral transplantation

BACKGROUND

Graft-versus-host-disease (GVHD) is a rare complication but carries a high mortality after transplantation. We retrospectively evaluated the incidence, risk factors and impact of this complication on the survival outcome of intestinal transplantation at a single center.

METHODS

241 patients who underwent intestinal transplantation between March 1994 and July 2007 were analyzed for evidence of GVHD. A diagnosis of GVHD was based on clinical presentations and confirmed by histological findings.

RESULTS

Of the 241 patients, 22 (9.1%) were diagnosed as GVHD. The median time of GVHD onset was 75 days (range, 14-1,408). The incidence of GVHD was significantly higher in young children than in adults (13.2 versus 4.4%, P = 0.05). The multivisceral graft recipients were more likely to develop GVHD compared with those of isolated small bowel (12.4% versus 4.6%, P = 0.05). The presence of recipient splenectomy was significantly associated with the incidence of GVHD (P = 0.03). The inclusion of the spleen in the multivisceral grafts tended to be at an increased risk of GVHD compared with the group without the spleen transplant (12.3% versus 7.9%, P = 0.43). A total of 16 patients with GVHD died during the entire follow-up. Infection was the leading cause of death in 55% patients.

CONCLUSIONS

GVHD is a fatal and progressive complication of small bowel transplantation. Younger children, multivisceral graft recipients, and particularly those with splenectomy are at high risk of developing GVHD after transplantation.

Graft-vs-host disease after small bowel transplantation in children

PURPOSE

Graft-vs-host disease (GVHD) is a rare complication of transplantation of organs rich in immunocompetent cells. The goal of this study was to report the features of GVHD after small bowel transplantation (SBTx) in children.

METHODS

The study involved a retrospective review of patients undergoing SBTx between 1999 and 2009 who had GVHD.

RESULTS

Of 46 children receiving 52 intestinal grafts (2 liver-intestine and 3 multivisceral), 5 (10%) developed GVHD. Median age at transplant was 42 (19-204) months. Baseline immunosupression consisted of tacrolimus and steroids supplemented with thymoglobulin (n = 2) or basiliximab (n = 3) for induction. Median time between transplantation and GVHD was 47 (16-333) days. All patients had generalized rash, 2 had diarrhea, and 2 had respiratory symptoms. Other symptoms were glomerulonephritis (n = 1) and conjunctivitis (n = 1). Four developed severe hematologic disorders. The diagnosis was confirmed by skin biopsy in 4 patients and supported by chimerism studies in two. Colonoscopy and opthalmoscopic findings were also suggestive in one. Treatment consisted of steroids and decrease of tacrolimus, with partial response in four. Other immunosuppressants were used in refractory or recurrent cases. Three patients died within 4 months after diagnosis.

CONCLUSION

Graft-vs-host disease is a devastating complication of SBTx, with high mortality probably associated with severe immunologic dysregulation.

Combined heart-kidney transplantation: a review of recipient selection and patient outcomes

Elevated serum creatinine is a common finding among patients awaiting heart transplantation because of reduced renal perfusion in the setting of severe heart failure as well as overlapping risk factors for chronic kidney disease and heart disease. Patients with significant renal dysfunction preoperatively have worse outcomes with heart transplantation alone compared with those with normal renal function or those with renal dysfunction who undergo combined heart-kidney transplantation. Optimizing organ distribution and patient outcomes after cardiac transplantation requires appropriate recipient selection, including deciding which patients will benefit from combined heart-kidney transplantation. This review focuses on the evaluation of patients with chronic kidney disease awaiting heart transplantation and the outcomes of combined heart-kidney transplantation.

The combined organ effect: protection against rejection?

OBJECTIVES

To further our understanding of the potential protective effects of one organ allograft for another in combined organ transplants by comparing rejection-free survival and the 1-year rejection rate of each type of combined organ transplant.

SUMMARY BACKGROUND DATA

Liver allografts have been thought to be immunoprotective of other donor-specific allografts. Recent observations have extended this property to other organs.

METHODS

Analysis of data from the United Network of Organ Sharing included recipients 18 years or older (except those receiving intestinal transplants) transplanted between January 1, 1994, and October 6, 2005, and excluded those with a previous transplant (n = 45,306), live-donor transplant (n = 80,850), or insufficient follow-up (n = 4304). Patients were followed from transplant until death (n = 41,524), retransplantation (n = 4649), or last follow-up (n = 87,243).

RESULTS

A total of 133,416 patients were analyzed. Rejection rates for allografts co-transplanted with donor-specific primary liver, kidney, and heart allografts are significantly lower than rejection rates for allografts transplanted alone. Allografts accompanying primary intestinal or pancreatic allografts did not have reduced rejection rates. A decreased rate of rejection was seen in interval kidney-heart transplants when allografts shared partial antigenic identity. Decreased rates of rejection were also seen in transplants of 2 donor-specific organs of the same type.

CONCLUSIONS

In combined simultaneous transplants, heart, liver, and kidney allografts are themselves protected and protect the other organ from rejection. Analysis of interval heart-kidney allografts suggests the need for partial antigenic identity between organs for the immunoprotection to take effect. This was not demonstrated in interval liver-kidney transplants. Increased antigen load of identical antigens, as seen in double-lung and double-kidney transplants, also offers immunologic protection against rejection.

Evolution of the immunosuppressive strategies for the intestinal and multivisceral recipients with special reference to allograft immunity and achievement of partial tolerance

Introduction of new innovative immunosuppressive strategies has been the milestone of the recent evolution of intestinal and multivisceral transplantation. With new insights into the mechanisms of organ engraftment and acquired tolerance, the Pittsburgh tolerogenic protocol was recently introduced and consisted of two main therapeutic principles: recipient pretreatment with lymphoid ablating antibodies and minimal post-transplant immunosuppression with tacrolimus monotherapy. The reported herein improved survival and the striking ability to wean immunosuppression among the intestinal and multivisceral recipients pretreated with a single-dose of Thymoglobulin (rATG) or Campath-1H (alemtuzumab) supports our working hypothesis with successful induction of variable tolerance. It is important, however, that careful monitoring of subtle histologic changes in serial endoscopic-guided mucosal biopsies be carried out for early diagnosis of allograft immune activation with prompt restoration of the baseline immunosuppressive therapy. Future scientific discoveries with better understanding of the mechanisms of immune tolerance and clinical introduction of reliable assays will increase the chance and safety of achieving complete tolerance among the intestinal and other solid organ recipients. This review will focus on the historic evolution of the immunosuppressive and other management strategies utilized for the intestinal and multivisceral recipients at the University of Pittsburgh with special reference to allograft immunity and the successful achievement of partial tolerance.

The establishment of a new en bloc combined liver-small bowel transplantation model in rats

In order to facilitate preclinical research, we established a new combined liver-small bowel transplantation rat model. Male inbred Wistar rats were chosen as donors and recipients. An en bloc liver-small bowel graft was harvested. During the donor operation, the inferior vena cava in the chest was removed to be used as an interpositional venous graft to anastomose to the portal vein. In the recipient operation the portal veins of donor and recipient were quickly anastomosed using a cuff technique instead of the traditional suture method. Rearterialization was achieved by anastomosing the superior mesenteric artery of graft to the right renal artery of the recipient. The recipient small bowel was resected and intestinal continuity restored simultaneously by two end-to-end anastomoses. The postoperative 5-day survival rate was 77.5% (31/40) and 60-day survival rate, 72.5% (29/40). Recipient rats that tolerated the operation remained healthy. Liver and renal function was normal. The liver and intestinal grafts showed normal histological architecture in all rats surviving for 2 months postoperatively. Our results demonstrated that the present model is feasible, allowing preclinical experimental research on combined liver-small bowel transplantation.

Intestinal transplantation under tacrolimus monotherapy after perioperative lymphoid depletion with rabbit anti-thymocyte globulin (thymoglobulin)

Modifications in the timing and dosage of immunosuppression can ameliorate the morbidity and mortality that has prevented widespread use of intestinal transplantation (ITx) in children. Thirty-six patients receiving ITx, aged 5 months to 20 years were given 2-3 mg(kg of rabbit anti-thymocyte globulin (rATG, thymoglobulin) just before ITx, and 2-3 mg(kg postoperatively (total 5 mg(kg). Twice daily doses of tacrolimus (TAC) were begun enterally within 24 h after graft reperfusion with reduction of dose quantity or frequency after 3 months. Prednisone or other agents were given to treat breakthrough rejection. After 8-28 months follow-up (mean 15.8 +/- 5.3), 1- and 2-year patient and graft survival is 100% and 94%, respectively. Despite a 44% incidence of acute rejection in the first month, 16 of the 34 (47%) survivors are on TAC (n = 14) or sirolimus (n = 2) monotherapy; 15 receive TAC plus low dose prednisone; one each receive TAC plus sirolimus, TAC plus azathioprine and TAC plus sirolimus and prednisone. There was a low incidence of immunosuppression-related complications. This strategy of immunosuppression minimized maintenance TAC exposure, facilitated the long-term control of rejection, decreased the incidence of opportunistic infections, and resulted in a high rate of patient and graft survival.

Intestinal transplantation: an update

PURPOSE OF REVIEW

As outcomes with intestinal transplantation continue to improve, its role in the management of intestinal failure patients becomes clearer. Some intestinal failure patients do well with long-term total parenteral nutrition (TPN), while others develop life-threatening complications and need to be evaluated for intestinal transplants (ITs). The purpose of this review is to update the current status of intestinal transplantation and its role in the management of intestinal failure patients.

RECENT FINDINGS

Current outcomes indicate that intestinal transplants should be considered earlier in intestinal failure patients that develop liver injury, to prevent irreversible liver disease that would mandate a simultaneous liver transplant. Due to the small bowel (SB) graft's unique immunobiologic features, it is especially challenging to transplant successfully. Although new immunosuppressive strategies have been developed that appear to improve short-term results, their impact on long-term outcomes has yet to be shown. A better understanding of the interactions that occur between the SB's inherent immune system and its luminal flora may be required to devise strategies that will significantly curtail the SB graft's immunogenicity.

SUMMARY

Intestinal transplantation remains a significant challenge. Ongoing efforts to better define the parameters that best predict total parenteral nutrition failure and the unique mechanisms that influence small bowel allograft outcomes are necessary before a broader application of small bowel transplantation can be indicated.

Combined small bowel and reduced auxiliary liver transplantation: Case report

AIM: To present a case of combined small bowel and reduced auxiliary liver transplantation.

METHODS: A 55-year-old patient with short bowel syndrome and TPN-related liver dysfunction received small bowel transplantation combined with a reduced auxiliary liver graft. A liver was added to restore the patient's liver function and to protect the intestinal allograft from rejection. His own liver was not removed.

RESULTS: Without donor pretreatment and by conventional immunosuppresive therapy following transplantation, the patient experienced had only one episode of mild intestinal rejection, which was easily reversed by treatment with Methylprednisolone. No liver rejection occurred. Unfortunately, the patient died of heart and lung failure 30 d after transplantation, despite successful graft replacement. Histopathologic examination of specimens after death demonstrated normal structure in both intestinal and liver grafts.

CONCLUSION: The auxiliary liver graft might play a role in preventing intestinal allograft rejection. However, the observation period in this case is short. Further study is needed to determine the risks, effect on the protecting the small-bowel from rejection, and feasibility of general application of this procedure.

Small bowel transplantation: selection criteria, operative techniques, advances in specific immunosuppression, prognosis

Intestinal transplantation is now an accepted therapy for intestinal failure when parenteral nutrition therapy cannot be tolerated. During the past year, evidence has been provided indicating that neither stomach nor colon need to be included in the transplant, even if a primary motility disorder is the indication for surgery. The liver should be included in the composite allograft when there are clinical indications of portal hypertension resulting from parenteral nutrition associated cholestasis. When liver disease develops, operations intended to improve gut function should be avoided in preference of early listing for transplantation. During the past year, initial attempts at adult to child intestinal transplantation were carried out with some success; reduction in the diameter of the adult donor bowel may not be uniformly necessary. New immunosuppressive therapies have been employed recently, but few have been subjected to peer review. Experimental models have clarified the pathology, if not the immunobiology, of chronic intestinal allograft rejection and the ability of the liver to promote tolerance of a cotransplanted intestinal allograft. Treatment of posttransplant lymphoproliferative disease has been augmented by the use of anti-CD 20 antibody that targets Epstein-Barr virus infected B-cells for destruction with high specificity.