Bacterial infections after intestine and multivisceral transplantation. The experience of the University of Miami (1994-2001)

BACKGROUND/AIMS

Bacterial infections (BI) are frequent after intestinal transplantation (ITx). Bacteremia, intraabdominal and respiratory infections are the leading forms. The objective of this study is to analyze the occurrence, determinants and outcome of BI.

METHODOLOGY

One hundred and twenty-four patients with ITx (39 isolated, 33 liver-intestine, 63 multivisceral). Only major BI were considered, including bacteremia, pneumonia, intraabdominal infections, severe wound infections.

RESULTS

BI occurred in 92.7% of patients during follow-up, with an average of 2.9 episodes per patient. Bacteremia was the commonest picture (1.7 per patient). More than 80% of patients had a BI before the end of the second month. Multivariate analysis showed that the presence of BI was higher during the first 2 months after Itx in patients hospitalized before Tx [p=0.029, odds ratio (OR) 5.4] and during months 3 to 6 in those treated with Zenapax (p=0.003, OR 6.2). Occurrence of BI was increased with mycophenolate mofetil treatment (p=0.045 OR 4.2). Intraabdominal infection was more frequent when reTx was needed (p=0.0178 OR 15.2), admission before Tx (p=0.034 OR 2.7), IS with MMF (p=0.004 OR 6.2) and Zenapax (p=0.026 OR 3.6). BI was the direct cause of death in 17.8% of patients, and it was present in 76.2% of patients that died. An infectious episode during the first month, a clinically manifested abdominal infection and a positive intraabdominal culture were determinants of shorter patient survival.

CONCLUSIONS

BI continue to be a frequent and dreadful complication after ITx. Pretransplant patient condition, IS used and postoperative complications are crucial on BI onset and outcome.

A computer reconstruction of the entire coronary arterial tree based on detailed morphometric data

A rigorous analysis of blood flow must be based on the branching pattern and vascular geometry of the full vascular circuit of interest. It is experimentally difficult to reconstruct the entire vascular circuit of any organ because of the enormity of the vessels. The objective of the present study was to develop a novel method for the reconstruction of the full coronary vascular tree from partial measurements. Our method includes the use of data on those parts of the tree that are measured to extrapolate the data on those parts that are missing. Specifically, a two-step approach was employed in the reconstruction of the entire coronary arterial tree down to the capillary level. Vessels > 40 microm were reconstructed from cast data while vessels < 40 microm were reconstructed from histological data. The cast data were reconstructed one-bifurcation at a time while histological data were reconstructed one-sub-tree at a time by "cutting" and "pasting" of data from measured to missing vessels. The reconstruction algorithm yielded a full arterial tree down to the first capillary bifurcation with 1.9, 2.04 and 1.15 million vessel segments for the right coronary artery (RCA), left anterior descending (LAD) and left circumflex (LCx) trees, respectively. The node-to-node connectivity along with the diameter and length of every vessel segment was determined. Once the full tree was reconstructed, we automated the assignment of order numbers, according to the diameter-defined Strahler system, to every vessel segment in the tree. Consequently, the diameters, lengths, number of vessels, segments-per-element ratio, connectivity and longitudinal matrices were determined for every order number. The present model establishes a morphological foundation for future analysis of blood flow in the coronary circulation.

Transplantation for the treatment of intra-abdominal fibromatosis

MATERIALS AND METHODS

During the last 9 years we treated 14 patients with a diagnosis of intra-abdominal fibromatosis. The 11 patients who received an intestinal allograft included isolated intestine (n = 6), liver-intestine (n = 1), intestine-kidney (n = 1), multivisceral (n = 1), multivisceral-kidney (n = 1), multivisceral-no liver (n = 1). Three patients received an intestinal autograft after partial abdominal evisceration and ex vivo tumor resection. Three patients additionally underwent an abdominal wall allograft.

RESULTS

At follow-up until August 2004, all autotransplant patients are alive. Four intestinal transplant patients died within the first postoperative month. There were three graft losses. A patient who lost his graft early postoperatively was retransplanted but died of sepsis shortly there after. Two more patients lost their graft due to severe rejection and were retransplanted successfully. Two patients developed desmoid tumor recurrence in their abdominal or thoracic wall. Ten patients are alive 1 to 9 years posttransplantation. Nine have fully functioning grafts and one patient requires TPN supplementation at night due to dysmotility of her autograft.

CONCLUSION

Intestinal allo-, or autotransplantation combined with transplantation of the abdominal wall can be lifesaving for patients suffering from extensive intra-abdominal fibromatosis.

Analysis of blood flow in the entire coronary arterial tree

A hemodynamic analysis of coronary blood flow must be based on the measured branching pattern and vascular geometry of the coronary vasculature. We recently developed a computer reconstruction of the entire coronary arterial tree of the porcine heart based on previously measured morphometric data. In the present study, we carried out an analysis of blood flow distribution through a network of millions of vessels that includes the entire coronary arterial tree down to the first capillary branch. The pressure and flow are computed throughout the coronary arterial tree based on conservation of mass and momentum and appropriate pressure boundary conditions. We found a power law relationship between the diameter and flow of each vessel branch. The exponent is ∼2.2, which deviates from Murray’s prediction of 3.0. Furthermore, we found the total arterial equivalent resistance to be 0.93, 0.77, and 1.28 mmHg·ml−1·s−1·g−1 for the right coronary artery, left anterior descending coronary artery, and left circumflex artery, respectively. The significance of the present study is that it yields a predictive model that incorporates some of the factors controlling coronary blood flow. The model of normal hearts will serve as a physiological reference state. Pathological states can then be studied in relation to changes in model parameters that alter coronary perfusion.

Trends in serum citrulline and acute rejection among recipients of small bowel transplants

A test for detecting acute cellular rejection (ACR) of small intestinal transplants (ITx) would be a major advance. Small preliminary studies suggest that serum citrulline levels correlate with ACR. The results for a group of 26 isolated intestinal and multivisceral transplant recipients are summarized here. Serum citrulline concentrations were determined by ion exchange chromatography and compared to biopsy-based grade of ACR. Other factors considered included patient and donor age and sex, ischemia time, and serum creatinine. Straight-line fits were employed to describe how each patient's citrulline levels changed over time. Estimated times to achieve normal citrulline (>or=30 micromol/L) ranged from 1 to 730 days posttransplant for 21 patients demonstrating increasing citrulline levels over time. Using stepwise linear regression, patients' ranks for time required to achieve normal citrulline levels were the only independent predictors of both maximum ACR (P <.0001) and average ACR (P =.0059) after 14 days posttransplant. The rate and direction of change in citrulline over time may be an indicator of the risk of acute rejection. We plan to further examine the use of citrulline as a marker for rejection in larger prospective studies.

Lymphoplasmacytic hyperplasia (possibly pre-PTLD) has varied expression and appearance in intestinal transplant recipients receiving Campath immunosuppression

Posttransplant lymphoproliferative disorders (PTLD) are a frequent complication in bowel transplant recipients. Histological changes in PTLD range from expansile lymphoplasmacytic (LP) hyperplasia to frank lymphoma. Small bowel allograft biopsies obtained in the first 250 days posttransplant were retrospectively graded after patients had received induction immunosuppression with either anti-CD52 (Campath) or anti-CD25 (Zenapax) monoclonal antibodies. The biopsies were analyzed with respect to the onset intensity of lymphoplasmacytic infiltrates and presence of in situ EBV hybridization (EBER) positivity. We observed that lymphoplasmacytic infiltrates were a frequent change in all bowel transplant patients over the examined period. Campath-treated patients developed earlier LP infiltrates of mild to moderate intensity between day 1 and 100 posttransplant, thereafter decreasing to mild. No EBER positivity was detected in this group. Zenapax-treated patients presented with LP infiltrates later of mild to moderate intensity through day 100 posttransplant. However, more persistent and intense LP infiltrates was observed after day 101 in this group, including a case of lymphoma and two cases of EBER positivity. We conclude that Campath immunosuppression results in an earlier appearance of LP lesions that are generally less intense than those evident with Zenapax. We attribute these findings to the more profound immunodeficiency and cell targeting following Campath treatment.

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.

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.

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.

Intestinal transplantation: advances in immunosuppression and surgical techniques

Campath-1H is being used as induction immunosuppression for intestinal/multivisceral transplantation. Patient and graft survival in this preliminary experience is similar to previous studies but there has been a significant decrease in the incidence and severity of acute rejections without increase of opportunistic infections. Collage of the abdominal wall (transplantation of a composite graft of the abdominal wall) can provide biologic coverage of the newly transplanted abdominal organs if necessary. Partial abdominal exenteration, ex vivo resection, and intestinal autotransplantation may be useful in removing otherwise unresectable lesions of the root of the mesentery.

The clinical spectrum of fibrocalculous pancreatic diabetes in north India

BACKGROUND

Fibrocalculous pancreatic diabetes (FCPD) is a secondary form of diabetes, unique to tropical countries. In earlier reports, patients with FCPD had severe insulin-requiring diabetes, malnutrition and a dismal prognosis. With Improvements in nutrition and medical care, the presentation and prognosis of FCPD may have changed. We report on the clinical profile and prognosis of a cohort of FCPD patients from north India and compare our findings with earlier reports.

METHODS

Eighty consecutive FCPD patients who presented to the Diabetes, Gastroenterology and Surgical Gastroenterology services were evaluated for their nutritional status, clinical presentation, beta-cell function (fasting C-peptide) and exocrine function (faecal chymotrypsin). All patients diagnosed between 1994 and 2000 (n = 32) were followed prospectively for weight gain and glycaemic control.

RESULTS

Only 55% of FCPD patients had a low body mass index (< 18 kg/m2). At the time of diagnosis of diabetes, only 26 (33%) patients presented with severe insulin-requiring diabetes; these patients were younger [23.7 (8.3) years v. 28.7 (10.6) years, p = 0.04], and had higher haemoglobin A1c [9.7 (3.8)% v. 7.3 (2.6)%, p = 0.005] than those requiring diet control or oral hypoglycaemic agents. FCPD patients had a wide range of fasting serum C-peptide (0.03-0.76 nmol/L). C-peptide was negatively associated with increasing duration of diabetes (r = -0.48, p = 0.001), but there was no correlation with faecal chymotrypsin. On prospective follow up (mean 2.3 years), there was significant improvement in body mass index [19.4 (2.9) kg/m2 v. 17.0 (3.7) kg/m2, p < 0.01] and haemoglobin A,c [6.4 (1.6)% v. 8.0 (3.0)%, p < 0.001].

CONCLUSION

FCPD patients differed from those described in earlier reports in many respects, Including improved nutritional status, a wide range of 3cell function and a more favourable prognosis.