Small intestinal transplantation using cyclosporine. Report of a case

History of clinical intestinal transplantation

The intestines have been considered the "forbidden organ" for years, and intestinal failure became the last organ failure recognized as such in the medical field. The impossibility of providing adequate nutritional support, turned these patients into recipients of just palliative comfort. In the 1960's, parenteral nutrition appeared as the most reasonable replacement therapy, but the initial success obtained with clinical kidney, heart, liver, lung and pancreas transplantation served as background to explore intestinal transplantation. The first clinical report of an isolated intestinal transplant was done by Richard Lillihei in 1967; in 1983, Thomas Starzl, performed the first multi visceral transplant, and in 1990, David Grant performed the first combined liver-intestinal transplant in an adult recipient in Canada. Since then, advances in immunosuppressive therapies and surgical innovations have allowed not only a continuous increase in indications, but also a worldwide application of all procedures, bringing clinical intestinal transplantation to reality. In this historical account, the most important contributions have been summarized, thus describing the steady progress, expansion and novelties developed over the last 56 years, since the first attempt. Clinical intestinal transplantation remains a complex and evolving field; ongoing research and technological advancements will continue shaping its future.

Transplant-associated thrombotic microangiopathy and immune haematological complications following intestine-containing organ transplantation: experience from over 100 consecutive cases

Descriptions of passenger lymphocyte syndrome (PLS), immune cytopenias and transplant-associated thrombotic microangiopathy (TA-TMA) after intestine-containing transplants remain scarce. We describe our centre's experience of these complications from 2007 to 2019. Ninety-six patients received 103 transplants. PLS occurred in 9 (9%) patients (median 12 days post-transplant); all due to ABO antibodies. There were 31 minor ABO mismatch transplants. No patient required change in immunosuppression. Immune cytopenias (excluding PLS) occurred in six patients at an incidence of 1·7/100 patient years; three immune haemolysis, one immune thrombocytopenia, one acquired Glanzmann's and one immune neutropenia; 50% occurred with other cytopenias. All cases eventually responded to treatment, with a median of four treatments (range 1-8) and 5/6 were treated with rituximab. One patient with immune haemolysis required bortezomib. Complications were common in patients with immune cytopenias; 4/6 with infection needing intravenous antibiotics and 3/6 with venous thromboembolism. In 3/6 cases, a secondary cause for the immune cytopenia was evident. Switching from tacrolimus to ciclosporin was not necessary. There were five cases of transplant-associated thrombotic microangiopathy (TA-TMA; 1·5/100 patient years) requiring calcineurin inhibitor withdrawal; two cases associated with acute rejection. Two cases were managed with plasma exchange, one with plasma infusions and one with eculizumab. Further research in this patient group is required.

India's first successful intestinal transplant: the road traveled and the lessons learnt

Intestinal transplant is a therapeutic challenge not just surgically but also logistically because of the multidisciplinary expertise and resources required. A large proportion of patients who undergo massive bowel resection and develop intestinal failure have poor outcome, because of inability to sustain long-term parenteral nutrition and limited availability of intestinal and multi-visceral transplantation facilities. We report the first successful isolated intestinal transplant from India.

A radiologist's guide to small bowel and multivisceral transplantation

This review will describe the indications for the various small bowel containing transplants. The importance of early referral will be highlighted. Radiologists play a central role in assessing these complex patients prior to transplantation. Furthermore, in the postoperative period, radiologists play an important part in diagnosing and treating complications.

Intestinal transplantation: current status

Intestine transplant is indicated for patients with intestinal failure who are unable to be weaned from parenteral nutrition (PN). Long-term PN, although life sustaining in many patients, can be associated with life-threatening complications including PN-associated liver disease (PNALD). Most patients are not considered for intestine transplant until they have developed severe PNALD and also need a liver transplant. Overall outcomes with intestinal transplantation are steadily improving, and current 1-year patient survivals for intestine-only transplants are now similar to those for liver transplant. Intestinal transplantation should be considered earlier in intestinal failure patients who are at high risk for developing PNALD and other life-threatening complications.

Induction of antigraft and antirecipient antibody responses after fully allogeneic and semiallogeneic rat small bowel transplantation

BACKGROUND

Given the potential influence of alloantibodies on organ graft outcome, this study investigated the induction of antigraft and antirecipient antibodies after allogeneic and semiallogeneic rat small bowel transplantation.

METHODS

Fully allogeneic, unidirectional rejection and unidirectional graft-versus-host disease (GvHD) heterotopic small bowel transplantation was performed using DA, PVG, and (PVGxDA)F1 donor-recipient combinations. Serum was obtained before and at time points after transplantation and incubated with blood from untransplanted DA and PVG rats. Antibody binding to T cells was detected by whole blood flow cytometry using FITC-conjugated anti-rat IgM murine monoclonal antibody. Antibody levels were determined by reference to a standard curve of fluorescent intensity generated using a serum sample with known anti-target cell IgM activity. Data are presented as arbitrary units/ml (AU/ml).

RESULTS

In the PVG-->DA combination, five of six DA recipients had detectable anti-graft (PVG) antibodies by day 4 after transplantation (mean 72 AU/ml) and all animals were positive by day 6 (976 AU/ml). Antirecipient (DA) antibodies were also induced, however, they were only apparent after 6 days in five of eight animals (90 AU/ml). Antigraft (DA) antibody responses were also induced in the DA-->PVG combination (day 6-218 AU/ml), however no antirecipient (PVG) response was apparent. Transplantation induced antirecipient (DA) antibodies in the unidirectional GvHD model (day 6-90 AU/ml) and an anti-graft (PVG) response in the unidirectional rejection model (day 6-60 AU/ml). However, the latter was quantitatively lower than that generated in the PVG-->DA combination (day 6-976 AU/ml).

CONCLUSIONS

Antigraft and antirecipient antibody responses are simultaneously induced after fully allogeneic small bowel transplantation, despite rejection being the predominant clinical feature. Further studies are required to elucidate their influence on graft outcome.

Desmoid disease in patients with familial adenomatous polyposis

PURPOSE

The aim of this retrospective study was to review the clinical features, and surgical and medical management of patients with familial adenomatous polyposis-associated desmoid tumors.

METHODS

From 1980 to 1997, 97 of 780 patients with familial adenomatous polyposis developed desmoid disease. Clinical and demographic data; operative notes; and histologic, radiologic, and follow-up reports were retrieved from patients' medical records. Risk factors for desmoid disease, such as prior surgery, age at desmoid tumor diagnosis, pregnancy, and family history were sought. The outcome after noncytotoxic and cytotoxic therapy was evaluated with respect to improvement of symptoms.

RESULTS

There were 38 males with a mean age of 32.1 years and 59 females with a mean age of 29.1 years. A family history of desmoid tumors was found in 41 patients (42 percent), and a history of pregnancy was documented in 33 females (56 percent). The most common clinical presentation was small-bowel obstruction (58 percent). One-half of the desmoids were located in the mesentery, and 32 percent were located in the mesentery and the abdominal wall. Desmoids developed after colectomy in 77 cases (80 percent), after a mean time of 4.6 years. Partial resection of desmoid tumor was performed in 46 patients (47 percent), resection of extra-abdominal desmoid tumors was performed in 17 cases (17 percent), and biopsy only was performed in 34 patients (35 percent). Postoperative morbidity was 23 percent after desmoid tumor resection. Eight patients (8 percent) died of their intra-abdominal desmoid. Mean follow-up time was 5.3 years. Sulindac, tamoxifen, or toremifene therapy was able to alleviate symptoms in only 4 of 31 patients. Symptomatic improvement was noted after chemotherapy in six of ten patients with extremely complex desmoids.

CONCLUSION

Desmoid disease was found in 12.4 percent of our patients with familial adenomatous polyposis. In view of the high rate of morbidity, indication for surgery should be limited mainly to acute or chronic small-bowel obstruction, because resection triggers a high recurrence rate. Noncytotoxic therapy was not effective for progressive desmoid tumors, whereas chemotherapy was effective in aggressive cases of intra-abdominal desmoid tumors.

Tolerance induction permits the development of graft-versus-host disease: donor-mediated attack following small bowel transplantation in mixed chimeras

The induction of tolerance to organ allografts would eliminate acute and chronic rejection as well as the need for nonspecific immunosuppression. We have shown that tolerance induced through the creation of mixed allogeneic bone marrow chimeras allows for the long-term engraftment of cardiac and small bowel allografts across strong multiple major histocompatibility barriers. The possibility that tolerance might render the host susceptible to graft-versus-host disease (GVHD) has not been investigated in this or other models of tolerance. To test this possibility chimeras were created by transplantation of T-cell depleted ACI and Lewis bone marrow into lethally irradiated Lewis rats. Chimerism was determined post bone marrow transplant (BMTx) by flow cytometry of lymphocytes from reconstituted animals. ACI/Lew chimeras (ALC), Lewis/ACI F1 (LACF1), and Lewis (LEW) rats all received heterotopic ACI vascularized small bowel grafts. A second group of chimeras received small bowel grafts from ACI rats pretreated with low dose irradiation to eliminate T-cells from the graft. LEW-->LEW small bowel isografts were also performed. Animals were examined for evidence of GVHD by clinical signs and histologic examination of biopsied tissues. GVHD was quantified using the popliteal lymph node enlargement assay. All LACF1 rats developed severe lethal GVHD following ACI small bowel transplant. Bone marrow chimeras, ALC (n = 6), developed fatal GVHD in a similar fashion after receiving a small bowel transplant. LEW-->LEW isografts and chimeras receiving bowel from irradiated ACI rats survived long term without GVHD while ACI-->LEW allogeneic transplants all underwent acute rejection. GVHD or its absence was confirmed histologically. Popliteal lymph node enlargement indices reflected the presence of GVHD in the chimeras (1.87) and LACF1 (5.4) receiving allografts, but not in isografts or chimeras receiving irradiated allogeneic transplants. Analysis of cytokines in the tongues of rats undergoing GVHD showed elaboration of Th1 type proinflammatory cytokines which was not seen in isografted rats or rats receiving preirradiated small bowel. These results demonstrate that tolerance induction through mixed chimerism results in susceptibility to small bowel induced GVHD. Preirradiating the donor bowel prior to SBTx can prevent GVHD.

Length of transplanted small bowel required for adequate weight gain in rats

Progress has been made toward developing a clinically successful small-bowel transplant procedure, but there has been little research concerning the functional aspects of the transplanted small bowel. Using a rat model, our study examined the length of transplanted small bowel required to provide adequate weight gain. The rats were divided into six groups; groups 1 and 2 were considered controls. Group 1 (n = 6) underwent a gastrostomy. Group 2 (n = 3) underwent a jejunoile-ectomy followed by re-establishment of intestinal continuity and anastomosis of the native proximal small bowel to an abdominal stoma and the distal portion to the ascending colon. Groups 3 (n = 5), 4 (n = 4), 5 (n = 5), and 6 (n = 4) underwent small-bowel transplantation, receiving 100%, 50%, 25%, and 15% transplants, respectively. The donor small-bowel anastomoses were the same as the native small-bowel anastomoses in group 2. All of the rats began to produce stool within 4 days of becoming dependent upon the transplanted small bowel. By the end of postoperative week 4, there was no significant difference between the percentages of preoperative body weight in groups 1-4 (range 125.7%-130.0%). Although the weight gain in group 5 was significantly less than that in groups 1-4 (P < 0.05), it was adequate (111.8%); group 6 animals lost weight (94.7%). It is concluded that a 50% or more small-bowel transplant with or without an ileocecal valve provides ample weight gain; minimally adequate weight gain is achieved by a 25% transplant without an ileocecal valve; and the graft begins to function soon after transplantation.

Increased intestinal permeability in rats with graft versus host disease

BACKGROUND/AIMS

The study of graft versus host disease of the intestine has significant clinical relevance and may also be a model for other immune mediated intestinal diseases. There presently is no simple non-invasive test that can be used to evaluate graft versus host disease induced intestinal injury in humans or animal models. This study tested the hypothesis that graft versus host disease leads to an increase in host bowel permeability as assessed by the relative urinary excretion of orally administered lactulose and rhamnose.

METHODS

The urinary excretion ratio of orally administered lactulose and rhamnose was determined daily for two weeks in (Lewis x Brown-Norway) F1 rats with graft versus host disease caused by either the transplantation of parental (Lewis) small bowel or the intraperitoneal injection of parental (Lewis) splenic lymphocytes.

RESULTS

Significant twofold to fourfold increases in the lactulose to rhamnose ratio were seen in both small bowel transplant and splenic lymphocyte transfer animals suffering from graft versus host disease during the second postoperative week. This effect occurred sooner in small bowel transplant than in splenic lymphocyte transfer animals (postoperative day 7 versus 11, respectively). The signs of graft versus host disease, including splenomegaly and altered intestinal mucosal architecture, as well as the increased lactulose to rhamnose ratio were significantly attenuated in small bowel transplant animals treated with cyclosporine A (10 mg/kg/day).

CONCLUSIONS

Graft versus host disease is associated with an increase in the lactulose to rhamnose clearance ratio reflecting an increase in host bowel permeability. This increase, along with the signs of systemic graft versus host disease, can be significantly ameliorated by cyclosporine A. The lactulose to rhamnose clearance ratio is a non-invasive technique that can be used to assess the intestinal effects of graft versus host disease and the associated increase in intestinal permeability.

Combined liver/small bowel transplantation using a blood group compatible but nonidentical donor

A successful liver/small intestinal transplantation with a blood group O donor to a blood type A recipient is described. Mild graft versus host disease developed, manifested by hemolysis, but did not result in graft loss or patient mortality. This suggests that minor ABO incompatibility may be tolerated with intestinal transplantation, despite the transplantation of large amounts of lymphoid tissue.

Small bowel transplantation. A life-saving option for selected patients with intestinal failure

Thirty-seven patients were listed for small bowel transplantation; 16 were transplanted and 15 died while waiting for a donor. Cyclosporine (N = 6) or tacrolimus (N = 10) were used for immune suppression. Graft rejection rates were lower in the combined liver/small bowel grafts than the isolated intestinal transplants (1/7 vs 5/7; P < 0.01) All of the cyclosporine group have died; the median survival was 25.7 months with two patients living more than five years. The tacrolimus group had fewer infections and a shorter hospital stay. All but two are alive with a median survival of 13 months. Seven of eight long-term survivors are off intravenous feedings. We conclude that small bowel transplantation is a life-saving option for patients with intestinal failure who cannot be maintained on total parenteral nutrition.

Clinical intestinal transplantation

The advent of tacrolimus allowed clinical intestinal transplantation to become a feasible procedure for patients with irreversible intestinal failure. Over last 5 years, 71 patients underwent intestinal transplantation. Forty-one recipients were children, and 30 recipients were adults. Twenty-five patients received an isolated intestinal graft, 34 patients received a combined liver-intestinal graft, and 12 received a multivisceral graft. The colon was included the intestinal graft in 29 patients. One-year, 2-year, and 4-year actuarial patient survival is 72%, 57%, and 45%, respectively. Our experience has shown that infectious, and immunological problems have caused significant morbidity and mortality. In this paper, we present our clinical experience and overview with intestinal transplantation.

Evidence that orthotopic transposition following rat heterotopic small bowel transplantation corrects overgrowth of potentially pathogenic bacteria

An overgrowth of pathogenic organisms occurs following rat heterotopic small bowel transplantation. This study assessed whether the bacterial microflora return to normal following subsequent orthotopic transposition of the graft. After 14 days the heterotopic graft was placed into continuity following resection of 15 cm of the host midintestinal loop. Quantitative and qualitative analyses of the intraluminal bacteria were performed studying the resected host intestine, the heterotopic graft at 14 days, and the graft 14 days after transposition. A group of normal rats were used as controls. An overgrowth of Staphylococcus epidermidis evident in the heterotopic graft at 14 days returned to a more normal bacterial profile following orthotopic transposition. These findings suggest that early interposition of a small bowel graft into an orthotopic position may prevent an alteration in the small bowel ecology toward potentially pathogenic organisms capable of translocation.

Small bowel transplantation in children: an immunohistochemical study of intestinal grafts

Seven children with short bowel syndrome underwent small bowel allografting. Episodes of early rejection were observed in five patients who received a graft from paediatric or adult donors but not in two patients who received a neonatal graft. This study aimed, firstly, to define immunohistochemical parameters accompanying rejection and, secondly, to compare immunohistochemical parameters in neonatal grafts with those in grafts from older donors. An immunohistochemical analysis was performed on 85 intestinal biopsy specimens taken for monitoring the transplant. Acute histological rejection was associated with pericryptic infiltrates of CD3+TcR alpha beta + T cells containing clusters of CD8+ cells, numerous CD25+ cells, and increased numbers of CD68+ macrophages. These changes were associated with the appearance of major histocompatibility (MHC) class II antigens on crypt enterocytes and with an appreciable increase in the expression of E-selectin on mucosal endothelial cells. Immunohistochemistry was useful in predicting rejection by showing the appearance of pericryptic CD25+ T cells 48 hours before the first histological lesions of crypt necrosis. Comparison of neonatal grafts with grafts from older donors did not show any significant difference in the density of CD68+ macrophages or in the endothelial expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, or E-selectin. In contrast to grafts from older donors, however, neonatal grafts did not express MHC class II antigens on epithelial cells and contained very low numbers of intraepithelial lymphocytes. These data indicate, firstly, that immunohistochemistry is useful for monitoring intestinal transplants and, secondly, that the better clinical tolerance of neonatal allografts may be related to the lower immunogenicity of the neonatal epithelium.

Graft-versus-host disease after small bowel transplantation is associated with host colonic injury

The present studies were undertaken to evaluate the histologic effects of graft-versus-host disease on the host colon after small bowel transplantation. Graft-versus-host disease was produced in six Lewis x Brown Norway F1 rats by performing vascularized, out-of-continuity small bowel transplants from parental Lewis donors. Host proximal and distal colon were sampled 14 days after operation when signs of graft-versus-host disease, including weight loss and splenomegaly, were present. Tissue was assessed histologically by blinded observer and compared to eight sham-operated controls. Three histologic features were noted to be statistically increased in diseased animals: (1) mucin loss; (2) crypt abscesses; and (3) large lymphoid aggregates in the mucosa and submucosa. These features were more commonly noted in the distal rather than the proximal colon. Another group of five grafted animals treated with cyclosporine A (10 mg/kg/day intramuscularly) still lost weight but did not display overt signs of graft-versus-host disease and had normal-sized spleens. There was normal mucin content and no evidence of crypt abscesses in these treated animals, although large lymphoid aggregates were present. It is concluded that mucin loss, crypt abscesses, and large lymphoid aggregates are characteristics of graft-versus-host disease-induced colonic injury in this model and that these changes are most evident in the distal colon. Cyclosporine A therapy does not completely reverse the histological changes of colonic graft-versus-host disease. This model may be useful in studying the mechanisms by which immune mediated colitides preferentially affect the distal colon.

Intestinal transplantation: a clinical update

BACKGROUND

Until very recently the results of clinical small-bowel transplantation were disappointing. The latest developments indicate, however, that significant improvements have been made towards clinical application of this mode of therapy for patients with short-bowel syndrome.

METHODS

Because of better immunosuppression and means to treat rejection, morbidity and mortality after small-bowel transplantation have been reduced and patient and graft survival has increased.

RESULTS

Septic complications and abnormal intestinal motility with functional problems remain pertinent problems. Nevertheless, a significant number of recipients have been able to stop TPN and resume a normal diet.

CONCLUSIONS

Although recent results of intestinal transplantation are encouraging, long-term survival is less than with other solid organ transplants. However, continued improvements in immunosuppression and the diagnosis of rejection as well as better management of functional and infectious problems will certainly improve future results.

Effect of small bowel transplantation, denervation and ischaemia on rat intestinal microflora

The effects of denervation and warm ischaemia on quantitative and qualitative changes in small intestinal microflora following rat heterotopic small-bowel isotransplantation were assessed. Animals with Thiry-Vella fistula, but without transplants, acted as controls. Thirty and 40-fold increases in bacterial colony counts were seen in the isografts compared to controls at 2 and 7 days, respectively (P < 0.05). Aerobic faecal organisms predominated at 2 and 7 days, but an overgrowth of Flavobacterium meningosepticum occurred at 28 days in the transplanted and host bowels. The effect of warm ischaemia on intestinal microflora was assessed by the application of a microvascular clamp to the superior mesenteric artery for 90 min. The effect of denervation was assessed following microsurgical division of all nervous tissue around the superior mesenteric artery. After 7 days, lengths of jejunum and ileum were removed and intraluminal microflora assessed. The number of bacterial colonies isolated from the ileum in the warm ischaemia group was six times greater than the number in the control group, whereas no significant changes were seen in the upper bowel. In contrast, denervation led to a slight, but consistent, decrease in colony counts. These findings suggest that the increase in bacterial numbers in an isografted small bowel primarily results from warm ischaemia rather than from mesenteric denervation, and that physical aspects of the procedure may affect the development of sepsis following small-bowel transplantation.

Induction of chronic graft-versus-host disease in a rat model after transplantation of sensitized small bowel allografts

The recent success in controlling acute rejection in clinical small bowel transplantation has resulted in a number of patients with functioning grafts and an occasional occurrence of graft-versus-host disease (GVHD). To better understand this complication following small bowel transplantation, a model of chronic GVHD was developed, using the Brown Norway-->Lewis rat strain combination. When the Lewis recipients were immunocompromised at the time of transplantation and received a graft specifically sensitized against Lewis, fatal GVHD developed in 3 of 5 animals. Serial histologic evaluation and determination of donor major histocompatibility complex (MHC) class I antigens were used to delineate the course of GVHD. Although the histologic results were inconsistent, with the exception of the animals developing fatal GVHD, the detection of donor MHC antigens correlated well with the development of GVHD. Determination of donor MHC class I antigens may serve as useful indicators for the development of GVHD.

Short bowel syndrome: metabolic and surgical management

The management of short bowel syndrome requires long-term nutritional support and monitoring, medication, and occasionally additional surgical procedures. Constant attention is required to ensure adequate adaptation of the gut. This article reviews the normal function of the small bowel, adaptation following resection, total parenteral and enteral nutrition, and the role of adjunctive surgical procedures in the management of short bowel syndrome.

Small intestinal transplantation in humans with or without the colon

Under FK506-based immunosuppression, 16 cadaveric small bowel transplantations were performed in 15 recipients with (n = 5) or without (n = 11) the large bowel. Twelve (80%) patients are alive after 1.5 to 19 months, 11 bearing their grafts, of which 4 include colon. The actuarial one-year patient and graft survivals are 87.5% and 65.9%, respectively. Five grafts were lost to acute (n = 4) or chronic (n = 1) rejection, and 3 of these patients subsequently died after 376, 440, and 776 days total survival. Six recipients developed severe CMV infection that was strongly associated with seronegative status preoperatively and receipt of grafts from CMV positive donors; 3 died, and the other 3 required prolonged hospitalization. Currently, 9 patients are free from TPN 1-18 months postoperatively, 2 require partial TPN, and one has returned to TPN after graft removal. The results show the feasibility of small bowel transplantation but emphasize the difficulty of managing these recipients not only early but long after their operation.

Method for diagnosing rejection in small bowel transplantation

Diagnosis of rejection in small bowel transplantation by the identification of a host-cell infiltrate is hampered by the physiological trafficking of host lymphocytes to the 'gut-associated lymphoid tissue' of the graft. This study compared physiological host-cell infiltration of small bowel grafts with that occurring in rejection and stable immunosuppression. Physiological host-cell infiltration, where the graft does not present an immune stimulus to the host, was assessed by transplanting bowel from DA to (DA x PVG) F1 hybrid rats. The extent of host-cell infiltration was determined by immunohistochemical analysis. In the lamina propria, considerable infiltration by host cells was seen, although it was significantly less than that in rejection or stable immunosuppression. By contrast, host cells were seen in the intraepithelial compartment only in rejection. Host-cell infiltration in the absence of an allogeneic stimulus suggests that histological identification of host cells in the lamina propria is not necessarily indicative of rejection. However, the presence of host cells in the intraepithelial compartment is specific for rejection in small bowel transplantation.

Donor cell infiltration of recipient tissue as an indicator of small bowel allograft rejection in the rat

This study assessed whether screening of host tissues for graft cells could be used as an effective monitor of rejection following small bowel transplantation. Allogeneic rat small bowel transplantation was performed with or without cyclosporin (CyA) immunosuppression and cellular infiltration of host tissues assessed by immunohistological staining. Without immunosuppression, grafts were completely rejected within 1 week. CyA treatment for 7 days preserved the graft for 28 days although there was histological evidence of mild rejection in some of the animals studied. Continuous CyA treatment preserved the graft for up to 56 days. The peripheral lymph nodes and spleens of untreated animals were transiently infiltrated by low numbers of donor cells that disappeared by day 6. There was a marked donor cell infiltration of the lymph nodes and spleens of 7-day. CyA-treated animals that was maintained during the administration of immunosuppressive therapy but that declined thereafter. Continuous CyA treatment sustained donor cell infiltration up to day 56. These findings suggest the presence of donor cells in recipient lymph nodes and spleen to be indicative of effective control of rejection and their disappearance to be predictive of developing rejection responses. Examination of recipient peripheral tissues for donor cells may provide an improved technique for monitoring clinical small bowel transplantation.

Limited survival of rat small bowel transplants preserved in University of Wisconsin solution for 48 hours

We have previously shown that rat small bowel may successfully be transplanted after preservation for 24 hours. In this study, syngeneic rat small bowel transplants were studied by light microscopy and transmission electron microscopy during and after preservation in University of Wisconsin (UW) solution for 48 hours. A total of 6 transplants were carried out using a previously described, standardized technique. In most cases, the bowel appeared histologically well preserved at the end of the 48 hr storage period (prior to implantation). Upon revascularization, however, reperfusion injury was dramatic, with loss of villi and crypts and inflammatory cells in all layers. The bowel was abnormal grossly as well as microscopically. This injury was irreversible with persistently abnormal histology for up to 1 week in all but 2 cases. We conclude that UW solution alone may allow satisfactory preservation of intestinal grafts for 48 hours only in isolated cases, and is therefore not adequate for predictable, satisfactory 48 hr preservation. Attempts to prevent reperfusion injury with oxygen-free radical scavengers are in progress.

Potential candidates for small bowel transplantation

The number of potential candidates for small bowel transplantation in the UK is unknown. Potential recipients are those with irreversible small intestinal failure, including those treated with permanent parenteral nutrition. This study of one of the largest groups of patients receiving such nutrition identified ten of 25 adult patients as possible recipients. The remaining 15 were considered unsuitable, mainly because of multiple previous abdominal operations or abscesses. Extrapolation of these data to national figures on the incidence of irreversible small intestinal failure suggests that each year up to 20 new adult patients in the UK might benefit from small bowel transplantation.

Persistence of allogeneic cells in graft and host tissues after small bowel transplantation

Small bowel transplantation is associated with a significant risk of graft versus host disease owing to the large amount of organized lymphoid tissue within the graft. This study assessed whether graft lymphoid cells could persist in the long term following fully allogeneic small bowel transplantation when graft rejection was prevented by cyclosporin immunosuppression. Transplantation was carried out between PVG and DA strains of rat. Cyclosporin (15 mg/kg) was given daily from transplantation, and groups of animals were studied at 28 and 56 days after grafting. The proportions of donor- and recipient-derived cells in the graft and in the host gut and lymphoid tissues were assessed using immunohistochemical tissue staining and monoclonal antibodies specific for cells expressing class I antigens from the two strains of rat. Results demonstrated a persisting population of graft-derived T cells which were capable of migration to the host. Therefore, there may be a long-term risk of graft versus host disease after small bowel transplantation under cyclosporin immunosuppression.

Reduction of graft-versus-host reactivity after small bowel transplantation: ex vivo treatment of intestinal allografts with an anti-T cell immunotoxin

A specific T lymphocyte immunotoxin was used to pre-treat small bowel grafts in an attempt to prevent graft-versus-host (GVH) reactivity and GVH disease in a rat transplant model. The immunotoxin used was a conjugate of the anti-CD5 MoAb MRC OX-19 with ricin A chain. The grafts were perfused ex vivo with a standard solution of immunotoxin followed by incubation at 4 degrees C for 1 h before transplantation. In a semi-allogeneic strain combination (parent to F1 hybrid offspring) graft treatment with immunotoxin led to a prolongation of recipient survival compared with groups receiving similar transplants without immunotoxin treatment. An additive effect on survival was observed when the host was treated with cyclosporin. The effect of immunotoxin was greater than that of mesenteric lymphadenectomy in increasing host survival. The effect of graft treatment with the immunotoxin on cellular migration from graft to host lymphoid tissues was assessed in fully allogeneic transplantation (PVG to DA). Host lymphoid tissues were subjected to immunohistochemical analysis using a MoAb specific for donor class I MHC antigens. Graft treatment with the immunotoxin led to a significant decrease in the number of graft cells found in host lymphoid tissues 7 days after transplantation. However, this effect was less marked than that achieved by graft mesenteric lymphadenectomy. With our current protocol graft treatment with a specific T cell immunotoxin can significantly reduce but not abolish GVH reactivity in rat small bowel transplantation.

From a historical outline of transplants to the concept of biological ego

A chronology of the biological preliminaries of human transplantation science is proposed together with a chronological listing of the applications which transplants have had in clinical medicine in general and in pediatrics in particular. The most significantly immunological elements which surface from this assortment of experiences (in which those of pediatric interest have a considerable role) contribute easily to a more deeply perceived culture of man's biological individuality.

Graft versus host disease in small bowel transplantation

Quantities of organized lymphoid tissue in small bowel allografts may cause graft versus host disease (GVHD) following transplantation. This study examines the effect of graft mesenteric lymphadenectomy on development of GVHD following small bowel transplantation in rats. GVH reactivity was assessed by measuring the degree of graft cell emigration to the host. In the PVG to DA strain combination, graft mesenteric lymphadenectomy led to a significant reduction in graft cell colonization of host lymphoid tissues from 40-50 per cent to 25-35 per cent. Transplantation from PVG to (PVG x DA)F1 hybrids caused fatal GVHD within 21 days whereas when DA donors were used survival was over 30 days. When mesenteric lymphadenectomy was performed on PVG donors, host survival increased by only 3-4 days. Mesenteric lymphadenectomy in DA donors led to long-term recipient survival with no GVHD. Intensity of GVHD following rat small bowel transplantation is a strain-dependent phenomenon and graft mesenteric lymphadenectomy does not always prevent GVHD. The mucosa may have an important immunological role.

Quantitative effects of allogeneic small-bowel transplantation on nutrient digestion and on body protein balance as determined in vivo in rats

Heterotopic and orthotopic small-bowel allotransplantation was carried out in Wistar rats using grafts reduced to one-half of the original length. Portocaval venous anastomoses and intestinal end-to-end anastomoses were performed. Animals either with complete or with partially reduced native small-bowel served as control. In a total of 51 rats, 88 quantitative in vivo measurements of apparent digestion and absorption of dietary dry matter, organic matter, energy, protein, fat, total ash, and glucose were carried out. Body protein retention was calculated from intake and losses with feces and urine. The digestion trials comprised 8 days of adaptation and 10 days of continual recording of nutrient balance data. In experiments 1 and 2, digestibility coefficients were obtained before and after transplantation within the same animals, untreated or initially treated with cyclosporine A after surgery. Similar groups of rats untreated, with partial resection and with transplantation of the small-bowel, followed by temporary cyclosporine treatment, were used in experiment 3. In experiment 4, rats with transplanted intestines from experiments 1 and 2 were subjected to a further digestion trial 4 to 6 months after the respective first trial. With transplantation of the small intestine, apparent digestion and absorption of nutrients, as well as protein retention, tended to be lower. Significant depression occurred in the digestion of fat and ash. In long-term survivors all parameters decreased further. The adverse effects on fat and ash digestion seemed to be pronounced when rejection occurred. Fecal fat excretion might therefore be an indication of dysfunction of small-bowel grafts. Digestion was less imparied if cyclosporine was applied, and part of the effects on digestion and protein balance could be attributed to the shortened bowel.