Epithelial and hematopoietic cell chimerism in intestinal allografts

BACKGROUND

In intestinal transplantation recipient lymphocytes infiltrate the allograft soon after reperfusion. Recently, it has been demonstrated that long-surviving small bowel transplants bear enterocytes of recipient origin. We investigated whether epithelial cells (enterocytes) persisted in long-term allografts based on studies of biopsies.

METHODS

The biopsies of four male intestinal transplant recipients of female grafts with a previous graft biopsy positive for recipient enterocytes were examined at least 6 months after previous positive assessment. Using the FISH technique, we searched for Y-chromosome-positive enterocytes in the female allograft.

RESULTS

Recipient male enterocytes were identified in all biopsies at low percentages ranging from 0.18 to 0.26. The lymphocytes within the graft were of both recipient (male) and donor (female) origin.

CONCLUSION

The four types of cells-enterocytes and lymphocytes of recipient and donor origin-coexist in long-term graft biopsies.

Sclerosing mesenteritis in small bowel transplantation: possible manifestation of acute vascular rejection

BACKGROUND

Acute rejection of human small bowel allografts is characterized by clinical symptoms combined with characteristic morphologic alterations. The typical geographic distribution of acute rejection in the bowel is involvement of the intestinal parenchyma, which can be transmural, particularly when the rejection is more severe. However, little is known concerning the potential for donor-derived soft tissue adjacent to the bowel to become involved by the host alloimmune response.

METHODS

We describe a male patient who, several weeks after combined small bowel and liver transplantation, demonstrated sclerosing mesenteritis with vasculitis and acute rejection of the bowel.

RESULTS

The vascular lesions in the mesentery demonstrated increased IgG deposition and the patient developed an alloantibody to the donor.

CONCLUSIONS

The changes described herein may represent a novel presentation of acute vascular rejection.

Use of donor aorta for arterial reconstruction in paediatric liver and multivisceral transplantation

BACKGROUND

Arterial reconstruction remains the most important technical issue in paediatric transplantation. The arteries of paediatric donors as well as recipients are small and friable. The aim of this study was to assess the use of the donor aorta as a conduit for arterial reconstruction in paediatric liver and multivisceral transplantation.

METHODS

Between June 1994 and January 2002, 284 paediatric transplants, including 197 cadaveric liver and multivisceral transplants, were performed in children at this centre. Of these, 41 (20.8 per cent), including nine cadaveric liver transplants and 32 multivisceral transplants, were revascularized by donor aortic reconstruction. Patient demographics, types of donor arterial reconstruction, technical complications and incidence of hepatic artery thrombosis were reviewed.

RESULTS

None of the 41 donor aortic reconstructions used in revascularization of paediatric liver and multivisceral transplants thrombosed. There were no bleeding complications and no pseudoaneurysms developed.

CONCLUSION

Arterial reconstruction using donor aorta is a useful option with a low incidence of thrombosis in paediatric transplantation.

Liver transplant for the septuagenarians: importance of patient selection

With the increasing success of liver transplantation (OLT), more patients above 70 years of age are being considered for OLT. There is not enough data about the predictors for survival in this patient population. We retrospectively analyzed the medical records of 33 patients at least 70 years of age who received 34 OLT from July 1995 to July 2002. There were 16 women and 17 men of mean age 73.7 years. Etiologies of end-stage liver disease (ESLD) were: HCV (17/33, 52%), cryptogenic cirrhosis (8/33, 24%), PBC (3/33, 9%), Laennec's cirrhosis (2/33, 6%), and others (3/33, 9%). According to the UNOS classification, 15/34 (44%) were status 3, 16/34 (47%) status 2, and 3/34 (9%) status 1. Among 13/33 patients who died (39%), 1-year and 3-year survival rates were 78.79% and 71.43%, respectively. Based on UNOS criteria, 4/15 (26%) were status 3; 6/16 (37%), status 2; and 3/3 (100%), status 1 (P value = .04 for status 1 patients). There was no statistical differences between the scores using the Model for End-Stage Liver Disease (MELD) among those who died (MELD (19) versus MELD (17.35) respectively (P = .50). There was a statistically significant difference in cold ischemia time (CIT) and warm ischemia time (WIT) between those who died (P = .024 and.010, respectively). These results suggest that in this group of patients UNOS status classification, CIT and WIT correlate with survival. The sample size was too small to derive a conclusion about the association with the MELD score.

Rat enterocyte cultures on human amniotic membranes

BACKGROUND

Rat enterocytes were cultured on human amniotic membranes.

METHODS

Intestine of neonatal DA rats was digested using collagenase and dispase according to the technique developed by Evans. The harvested enterocytes were cultured on human amniotic membranes using standard cell culture techniques.

RESULTS

After the second day of culture, some intestinal epithelial units started to gradually detach from the membrane, dispersing as single cells and disappearing within a few days. On the contrary, other units showed signs of cell proliferation. The cultured cells underwent morphologic changes, survived, and remained attached to the amniotic membrane for 3 weeks. Paraffin sections of the membrane showed cultured cytokeratin-positive cells attached to the membrane as a monolayer.

CONCLUSIONS

Human amniotic cell membranes help to maintain rat enterocytes in culture for a long time period (3 weeks), possibly via secretion of trophic factors. This technique may provide a valuable tool to study the development and the properties of these epithelial cells in a culture environment.

Immunoenzymatic and morphological detection of epithelial cell apoptotic stages in gastrointestinal allografts from multivisceral transplant patients

Acute allograft rejection (AR) is a major contributor to morbidity and mortality among patients who undergo multivisceral transplantation. Critical to the assessment of AR is detection of apoptosis in the glandular epithelium of the gastrointestinal allograft. We utilized the TUNEL stain (TdT-mediated biotin 16-dUTP nick-end labeling) to test whether this method improved detection of apoptosis compared to standard slide evaluation. TUNEL and H&E stains were performed on paraffin-embedded tissue sections to estimate the number of apoptotic bodies per 10 high power fields, as determined by independent pathologists in blinded fashion. Both methodologies showed similar numbers and distributions of apoptotic foci present among the epithelial cells. There was a correlation between the number of apoptosis and the grade of rejection (P <.001). This is the first use of the TUNEL stain in gastrointestinal allograft biopsies to our knowledge. The similarity in pattern and sensitivity of TUNEL with standard morphology confirms that biopsy assessment with routine H&E staining allows an accurate appraisal of epithelial cell apoptosis. Therefore, current staining protocols for endoscopically derived mucosal biopsies of gastrointestinal allografts are sufficiently accurate to enumerate the critical feature of epithelial apoptosis as a determinant of the grade of acute rejection.

Multivisceral transplantation for pediatric intestinal pseudo-obstruction: single center's experience of 16 cases

Chronic intestinal pseudo-obstruction (CIPO) in children may be life-threatening due to the complications of parenteral nutrition (PN) or catheter-related sepsis. Multivisceral transplantation (MVTx) is a lifesaving option but limited experience is available. We report our experience with MVTx in pediatric CIPO patients. Sixteen children with CIPO underwent MVTx at median age of 4 years. Indications for MVTx were liver failure (n = 10), loss of venous access (n = 3), or sepsis (n = 3). Modified MVTx without the liver was performed in six patients. Induction immunosuppression included tacrolimus, steroid with adjunctive agent in period I (April 1996 to December 2000), namely, OKT3 (n = 1), mycophenolate mofetil (n = 4), or daclizumab (n = 2); and in period II (January 2001 to present), Campath 1H (n = 4) or daclizumab (n = 5). The grade of rejection was severe in 12.5% and mild to moderate in 87.5% of cases. Isolated rejection of the transplanted stomach or pancreas was not diagnosed during clinical course or on autopsy. Actuarial patient survival for 1 year/2 years for period, I and II were 57.1%/42.9% and 88.9%/77.8%. None of the long-term survivors is on PN and all tolerate enteral feedings. Pancreatic enzyme supplementation or insulin therapy is not needed in survivors. Gastric emptying was substantially affected in one case. Bladder function did not improve in those with urinary retention problems. MVTx for CIPO offers a lifesaving option with excellent function of the transplanted pancreas and stomach among survivors.

Neurodevelopmental outcomes of infant intestinal transplant recipients

Little is known about the impact of intestinal transplantation on development of the infant brain. In this study we report four neurodevelopmental studies on children receiving either liver or intestinal/multivisceral transplants. Our preliminary investigation examined the pretransplant status of 27 infants, who were either liver or intestinal/multivisceral candidates, using the Bayley Scales of Infant Development. A second study examined 23 infants after liver or intestinal/multivisceral transplant. A third study included pre- and posttransplant evaluations on 5 multivisceral infant transplants. In the fourth study, 10 children were tested several years after intestinal/multivisceral transplantation. Some children are able to achieve a normal development. However, even several years posttransplant most children can still experience significant cognitive delays. Children receiving a transplant during infancy may also suffer severe motor delays. Infants undergoing intestinal/multivisceral transplantation show significantly more cognitive delays than those undergoing single-organ liver transplantation. In addition, multivisceral transplanted infants are more likely to continue to be severely developmentally delayed at the time of hospital discharge. With improved survival rates for infant transplants, both cognitive and motor development must be evaluated to determine the need for early intervention. In addition, educating families on the importance of compliance with intervention services outside the hospital is essential to maximize long-term neurodevelopmental outcomes for these infants.

Campath-1H immunosuppressive therapy reduces incidence and intensity of acute rejection in intestinal and multivisceral transplantation

Campath-1H, an anti-CD52 antibody, is being used at our institution as immunosuppression in multivisceral and intestinal transplantation. We reviewed the pathologic findings of 1696 small bowel allograft biopsies obtained in the first 250 days posttransplant from 78 patients who underwent isolated intestinal or multivisceral transplantation and received induction immunosuppression with Campath (n = 30) or Zenapax (n = 57). We found an overall reduced incidence of acute cellular rejection (ACR) in patients receiving Campath (19.1%) compared with those on Zenapax (32.8%). The majority of Campath patients showed no rejection or was indeterminate for rejection over the period of measurement. The frequencies of mild and moderate ACR were approximately twice and three times more common, respectively, in Zenapax-treated patients. The mean grade of ACR in Campath patients compared with Zenapax patients was significantly lower (P <.01) during the first 6 weeks posttransplant. Thereafter, the grade of rejection in both patient groups showed fluctuation, with Zenapax patients sometimes having lower values (eg, at 2 to 4 months) than Campath patients. Patient and graft survival was not significantly different between the two groups. These data suggest that the incidence of ACR is significantly reduced with Campath during the first 2 months posttransplant, when compared with Zenapax. However, the incidence and intensity of ACR following this initial time period shows vacillation with both types of immunosuppression.

Study of the development and evolution of neointestine in a rat model

The implantation of fragmented rat intestinal epithelium into the omentum of syngeneic animals results in the formation of a cyst containing neointestine. The purpose of our project was to study the evolution of this neointestine-containing cyst over time. Harvested jejunum and ileum of neonatal DA rats (6 to 8 days old) was digested with collagenase type XI and dispase at room temperature. The resulting organoid units, containing clusters of intestinal epithelium with stem cells were seeded onto a polyglactin polymer mesh (100000 units per mesh). The absorbable mesh was implanted in the omentum or peritoneal wall of an adult syngeneic animal. Animals were sacrificed at weekly intervals to harvest the neointestinal cysts. The lumen of the neointestine cysts was full of mucous while the wall of the cyst was covered by intestinal mucosa. H&E staining of the cyst demonstrated the morphology of intestinal epithelium; PAS staining identified goblet cells. The size of the cyst was maximal between 4 and 8 weeks postimplantation tending to regress thereafter. Neointestinal cysts are a consistent finding after implantation of intestinal epithelium organoids into the omentum or peritoneal wall in the rat model. The cysts reach a maximal size at 4 to 8 weeks postimplantation, tending to regress thereafter.

Bacterial infections after intestine and multivisceral transplantation

BACKGROUND

The frequency of bacterial infections (BI) in intestinal transplant (IT) patients is high with sepsis being the leading cause of death after this procedure. We herein report our experience with major BI to ascertain the incidence, microbiological and clinical factors, risk factors and outcome.

MATERIALS AND METHODS

124 patients (72 children and 52 adults) received 135 grafts: namely, 39 isolated intestine, 33 liver-intestine and 63 multivisceral. Only major BI were considered, namely, those associated with serious morbidity/mortality requiring specific therapy. Patient data were retrieved from computerized databases, flow-charts, and medical records.

RESULTS

92.7% patients showed BI. There were 327 episodes, representing 2.6 episodes/patient (2.8/patients with infection): 193 episodes of bacteremia (1.7/patient with BI) including 29.5% due to catheter related sepsis, 16.5% from abdominal source, 5.7% from respiratory origin and 4.1% from the wound. The organ locations includes 46 respiratory infections, 33 intraabdominal abscesses or infected fluid collections, 8 diffuse peritonitis, 34 wound infections and other miscellaneous sites: empyema, soft tissue infections, cholangitis em leader etc. Median time of infection was nine days after surgery (mean 22+/-3 days), with 67.7% patients having at least one BI before the end of the first month. Infection was present in 76.2% of the 63 deceased patients. An infectious episode during month 1, a clinically manifest abdominal infection and a positive intraabdominal culture had negative impacts on patient survival.

CONCLUSIONS

BI are common and early complications after IT. The high rate of bacteremia, line sepsis and abdominal and respiratory infections reflect the recipient's condition, with chronic deterioration superimposed with the effects of prolonged abdominal visceral surgery.

Herpes simplex colitis in a child with combined liver and small bowel transplant

Herpes simplex virus (HSV) has been a rare cause of gastrointestinal (GI) infection, especially in immunocompromised patients. A variety of GI sites may be involved; however, only three reported cases of HSV colitis have been documented in the literature. To our knowledge, this is the first report of HSV colitis in a small bowel transplant recipient.

Portosystemic shunt for the treatment of portal vein thrombosis following orthotopic liver transplantation

The efficacy of the portosystemic shunt operation for the treatment of portal vein thrombosis following orthotopic liver transplantation was demonstrated. From 1 July 1988 to 31 December 1991 42 portosystemic shunt operations were performed at our centre. In six of these cases portal vein thrombosis after orthotopic liver transplantation (OLT) was the indication for the procedure. All the patients retained adequate liver function but they demonstrated manifestations of significant portal hypertension, mainly variceal rebleeding. Two of the patients were children. Three patients underwent distal splenorenal shunt (DSRS), one mesocaval and one side-to-side splenorenal shunt and the last one side-to-side splenorenal shunt which was converted to DSRS 2 weeks later. All these patients were doing well after 30 months mean follow-up time without rebleeding or other signs of portal hypertension and none had so far required retransplantation.