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C Troppmann

Publications and source records attributed to C Troppmann.

At least 19 recordsLinked to original sources
PubMed2005

Predictive value of pretransplant inflammatory markers in renal allograft survival and rejection in children.

Pretransplant (pre-Tx) inflammation has been associated with acute rejection (AR) in adult Tx recipients. Our study was performed to determine whether a single pre-Tx serum C-reactive protein (CRP), Neopterin (Neo), and IL-12 determination could predict outcome in pediatric renal Tx recipients. Pre-Tx sera from 51 children transplanted between 1985 and 2000 were analyzed for serum CRP, Neo, and IL-12 for correlation with Tx-related variables. Endpoints were graft loss and AR. Kaplan-Meier and log-rank statistics were used to compare rejection-free and overall graft survival at different quartiles for each marker. Cox regression analysis was performed to determine the independent effects of various pre-Tx variables on the endpoints. The mean age of the children at Tx was 11 years. The mean CRP, Neo, and IL-12 were 1.3 mg/L, 1.78 ng/mL and 123 pg/mL, respectively. At last-follow-up (mean 4.9 years after Tx), 50% of the children had experienced AR and 29% had lost their grafts. The mean CRP, Neo, and IL-12 were not different between the patients with versus without AR or graft loss (P > .4 for all). Neither rejection-free survival nor graft survival was affected by CRP, Neo, or IL-12 quartiles (log-rank test). Cox regression analysis demonstrated no predictive value of any marker on the outcomes. Unlike adults, a single pre-Tx determination of inflammatory markers was not predictive of AR or graft loss in children. The pathogenesis of AR may be different in children with a lesser contribution of alloantigen-independent factors such as chronic infections.

Analysis of Variance↗
PubMed2001

Increased transplantation of kidneys with multiple renal arteries in the laparoscopic live donor nephrectomy era: surgical technique and surgical and nonsurgical donor and recipient outcomes.

BACKGROUND: For anatomical and technical reasons, many transplant centers restrict laparoscopic live donor nephrectomy (in contrast with open live donor nephrectomy) to left kidneys. HYPOTHESIS: This change in surgical practice increases procurement and transplantation rates of live donor kidneys with multiple renal arteries (RAs), without affecting donor and recipient outcomes. DESIGN AND SETTING: Retrospective review at an academic tertiary care referral center comparing laparoscopically procured single vs multiple-RA kidney grafts (April 1997 to October 2000). PATIENTS: Seventy-nine consecutive left laparoscopic live kidney donors and 78 transplant recipients. MAIN OUTCOME MEASURES: Donor and recipient complications and postoperative length of stay; cold and warm ischemia time; operating time; short-term and long-term graft function; and survival. RESULTS: We noted multiple RAs in 21 (27%) of all kidneys. The proportion of donors with 1 or more perioperative complications was 19% in the single-RA group vs 10% in the multiple-RA group (P was not significant). For the recipients, we noted no significant differences between groups with respect to surgical complications, quality of early and late graft function, rejection rates, graft losses (all immunologic), and graft survival. Cold and warm ischemia time and length of stay were similar for donors and recipients in both groups. Median operating times were significantly longer for the multiple-RA vs single-RA group (difference, 41 minutes for donors and 45 minutes for recipients; P<.02). CONCLUSIONS: While the introduction of laparoscopic live donor nephrectomy has significantly increased the number of grafts with multiple RAs (compared with historical open controls), this change in practice is safe for both donors and recipients from a patient outcome-based perspective. However, from an economic perspective, the longer operating time associated with multiple-RA grafts provides strong added rationale for optimization of surgical instruments and techniques to make right-sided laparoscopic nephrectomy a routine intervention.

Adult↗
PubMed1999

[Organ donation by living donors in isolated pancreas and simultaneous pancreas-kidney transplantation].

We studied retrospectively 106 pancreas transplants from living donors. Of these, 83 were solitary pancreas transplants, done between June 1979 and December 1997 (51 pancreas transplants alone for non-uremic recipients as well as 32 pancreas-after-kidney transplants for previously uremic recipients with a functioning kidney graft), and 23 were simultaneous pancreas-kidney transplants (SPK), done between March 1994 and December 1997. In all, 105 (99%) donors were genetically related to the recipients. Perioperative donor mortality was 0%. Donor complications included 9 splenectomies as well as 4 operatively drained and 7 percutaneously managed peripancreatic fluid collections. We noted hyperglycemia in 3 (3%) donors (all among the initial cases in this series). The 1-year survival rate was 50% for solitary pancreas recipients and 78% (pancreas) and 100% (kidney) for SPK recipients. Of the 5 pancreas graft losses which occurred after SPK, 3 were due to thrombosis, 1 to pancreatitis and infection, and 1 to chronic rejection. Currently, all kidney grafts and 18 pancreas grafts are functioning in these 23 dual organ recipients (with 0% recipient mortality). Living donor pancreas and SPK grafting is associated with low donor morbidity and good graft outcome. With stringent donor criteria and appropriate counseling of the prospective donor/recipient pairs, living donor pancreas transplants may become a more widely applied therapeutic alternative for selected non-uremic and uremic patients with Type I diabetes.

Diabetes Mellitus, Type 2↗
PubMed1998

Surgical complications requiring early relaparotomy after pancreas transplantation: a multivariate risk factor and economic impact analysis of the cyclosporine era.

OBJECTIVES: To study significant surgical complications requiring early (< or = 3 months posttransplant) relaparotomy (relap) after pancreas transplants, and to develop clinically relevant surgical and peritransplant decision-making guidelines for preventing and managing such complications. SUMMARY BACKGROUND DATA: Pancreas grafts are still associated with the highest surgical complication rate of all routinely transplanted solid organs. However, the impact of surgical complications on morbidity, hospital costs, and graft and patient survival rates has not been analyzed in detail to date. METHODS: We retrospectively studied surgical complications requiring relap in 441 consecutive cadaver, bladder-drained pancreas transplants (54% simultaneous pancreas and kidney [SPK]; 22% pancreas after kidney [PAK]; 24% pancreas transplant alone [PTA]; 37% retransplant). Outcome and hospital charges were analyzed separately for recipients with versus without reoperation. RESULTS: The overall relap rate was 32% (SPK, 36%; PAK, 25%; PTA, 16%; p = 0.04). The most common causes were intraabdominal infection and graft pancreatitis (38%), pancreas graft thrombosis (27%), and anastomotic leak (15%). Perioperative relap mortality was 9%; transplant pancreatectomy was necessary in 57% of all recipients with one or more relaps. The pancreas graft was lost in 80% of recipients with versus 41% without relap (p < 0.0001). Patient survival rates were significantly lower (p < 0.05) for recipients with versus without relap. By multivariate analysis, significant risk factors for graft loss included older donor age (SPK, PAK), retransplant (PAK), relap for infection (SPK, PAK), and relap for leak or bleeding (PAK). For death, risk factors included older recipient age (SPK, PAK),retransplant (SPK, PAK), relap for thrombosis (PAK), relap for infection or leak (SPK), and relap for bleeding (PTA). CONCLUSIONS: Posttransplant surgical complications requiring relap were frequent, resulted in a high rate of pancreas (SPK, PAK, PTA) and kidney (SPK, PAK) graft loss, and had a major economic impact (p = 0.0001). Complications were associated with substantial perioperative mortality and decreased patient survival rates. The focus must therefore shift from graft salvage to preservation of the recipient's life once a pancreas graft-related complication requiring relap occurs. Thus, the threshold for pancreatectomy should be low. In this context, acceptance of older donors and recipients must be reconsidered.

Adolescent↗
PubMed1997

Recipient preconditioning and donor-specific bone marrow infusion in a pig model of total bowel transplantation.

BACKGROUND: In an outbred pig model of total bowel transplantation, we previously showed that simultaneous donor-specific bone marrow infusion (DSBMI), rather than promoting engraftment, sensitizes recipients and causes rejection; it also aggravates the risk of generalized graft-versus-host disease (GVHD) and infection, and tends to reduce recipient and graft survival. Small and large animal models of bone marrow-induced transplant tolerance suggest that some form of recipient preconditioning (RPC) may facilitate engraftment of co-transplanted bone marrow cells and fully expose their tolerogenic potential. METHODS: In a preclinical model, we prospectively studied the effect of RPC on simultaneous DSBMI and total (i.e., small and large) bowel transplantation. RPC consisted of whole body irradiation with 400 R (day 0); some recipients additionally received horse anti-pig antithymocyte globulin (days -2, -1, and 0). We studied six groups of outbred pigs, all of which underwent at least a total bowel transplant: group 1, nonimmunosuppressed control pigs (n=5); group 2, nonimmunosuppressed DSBMI pigs (n=13); group 3, tacrolimus pigs (n=7); group 4, DSBMI+tacrolimus pigs (n=15); group 5, RPC+nonimmunosuppressed DSBMI pigs (n=11); and group 6, RPC+DSBMI+tacrolimus pigs (n=14). RESULTS: RPC did not prolong overall survival at 7, 14, 21, and 28 days after transplant. Survival rates were 100%, 100%, 86%, and 71% in group 3; 71%, 43%, 29%, and 29% in group 6; 55%, 9%, 0%, and 0% in group 5; and 60%, 0%, 0%, and 0% in Group 1. Moreover, RPC (groups 5 and 6) increased the incidence of death from rejection, GVHD, and infection when compared with group 3. Survival was significantly higher for RPC+DSBMI+tacrolimus pigs (group 6), compared with RPC+nonimmunosuppressed DSBMI pigs (group 5). Survival greater than 28 days was noted only in pigs that received tacrolimus after transplant: 71% in group 3 versus 29% in group 6. With both RPC and DSBMI (groups 5 and 6), rejection, GVHD, and infection were not mutually exclusive events. In groups 5 and 6, at autopsy, the incidence of rejection and GVHD was 17%; rejection and infection, 17%; and GVHD and infection, 45%. A combination of all three immunologic events was noted in 14%. CONCLUSIONS: RPC, combined with DSBMI, and with or without posttransplant immunosuppression, does not prolong survival after total bowel transplantation. Rather, it increases the incidence of death from rejection, GVHD, infection, or a combination of these three immunologic events. According to this preclinical study, RPC and unmodified DSBMI do not improve patient and graft outcome after total bowel transplantation and need to be refined before being applied clinically.

Animals↗
PubMed1997

Combined liver-total bowel transplantation has no immunologic advantage over total bowel transplantation alone. A prospective study in a porcine model.

BACKGROUND: Rejection remains a major obstacle to successful bowel transplantation in humans. It has been suggested that a simultaneous liver transplant would shield the bowel graft from immunologic attack, but the liver shortage would be aggravated. In a preclinical model, we studied the influence of simultaneous liver grafting by comparing the incidence of early bowel rejection after combined liver-total (small- and large-) bowel transplants vs total bowel transplants alone. METHODS: We assessed the incidence of early post-transplant rejection, graft-vs-host disease, and infection after combined liver-total bowel transplants (group 1, n = 10) and total bowel transplants alone (group 2, n = 9) in outbred Yorkshire Landrace pigs. Liver and bowel grafts were transplanted orthotopically with portal vein drainage after recipient hepatectomy (group 1) and total enterectomy (groups 1 and 2). Posttransplant immunosuppression was performed with intravenous tacrolimus (whole blood levels, 15 to 30 ng/mL) and prednisolone. In groups 1 and 2, bowel biopsy specimens from the ileostomy were obtained daily. In group 1, liver biopsy specimens were obtained weekly. Rejection was graded according to a 4-point scoring system (none, mild, moderate, and severe). RESULTS: Overall graft survival at days 7, 14, and 21 was 89%, 44%, and 11%, respectively, in group 1 vs 100%, 100%, and 86%, respectively, in group 2 (P < .001). Death rates owing to (irreversible) rejection at days 7, 14, and 21 were 0% in groups 1 and 2 (P = .48). Grading of bowel rejection episodes, based on the results of daily biopsy specimens, was not significantly different between the groups whether on individual days or overall. In group 1, the incidence of liver rejection episodes was as high as 66% (day 14 and at autopsy). At autopsy, generalized graft-vs-host disease (skin, native intestine, and native liver) was noted in 55% of group 1 and 43% of group 2 pigs (P = .55). Graft-vs-host disease was noted concurrently with rejection episodes of the liver or bowel grafts. CONCLUSIONS: Simultaneous liver grafting did not further reduce the incidence of early bowel rejection or graft-vs-host disease when compared with total bowel transplants alone. Based on the results of this preclinical study, simultaneous liver grafting is not indicated for patients with short-bowel syndrome and normal liver function.

Animals↗
PubMed1997

Duodenal complications in bladder-drained pancreas transplantation.

BACKGROUND: The most common type of pancreas transplantation is whole pancreaticoduodenal (with bladder drainage) from a cadaver donor. Complications can arise not only from the pancreas itself but also from the simultaneously transplanted duodenum. The purpose of this study was to analyze the incidence, diagnosis, and treatment of duodenal complications and their impact on patient and pancreas graft survival rates. METHODS: Our retrospective study is based on 425 pancreaticoduodenal transplantations performed between July 1, 1986, and June 30, 1994. Complications pertaining to the duodenal segment were labeled early if they occurred within the first postoperative month and late otherwise. Mean follow-up was 55 months (range, 13 to 108 months). RESULTS: We noted 85 (20%) duodenal complications: duodenal leaks (n = 42), hematuria (n = 26), recurrent urinary tract infections (n = 9), duodenal ulceration or necrosis (n = 6), and bladder stones (n = 2). Of these complications, 40 (48%) required surgical intervention. In all, duodenal complications resulted in 14 (16%) enteric conversions and eight (9%) pancreas graft losses (six because of duodenal leak and 2 because of hematuria). The mortality rate from duodenal complications was 0%. CONCLUSIONS: Duodenal complications were common, but they were not associated with a high rate of pancreas graft loss (only 9%). With early diagnosis and treatment, morbidity can be reduced and death avoided in pancreas transplant recipients.

Duodenal Diseases↗
PubMed1997

Donor-specific unmodified bone marrow transfusion does not facilitate intestinal engraftment after bowel transplantation in a porcine model.

BACKGROUND: The immunosuppression required to prevent rejection of intestinal transplants causes a high rate of infection and lymphoma. It is crucial that immunomodulatory strategies be developed to facilitate intestinal engraftment. METHODS: We prospectively examined the effect of unpurified donor-specific bone marrow transfusions (DSBMTs) on rejection, infection, graft-versus-host disease (GVHD), and survival after intestinal transplantations in 44 Yorkshire Landrace pigs. Four groups that differed according to presence or abscence of treatment with FK506 and DSBMT were analyzed. RESULTS: In nonimmunosuppressed pigs, DSBMTs had no effect on survival (8 days versus 9 days in controls; p = 0.9). In FK506 pigs, DSBMTs tended to reduce survival (21 days versus 37 days in FK506 controls; p = 0.1); no difference was seen between two bone marrow dosages 5 x 10(7) or 5 x 10(8) bone marrow cells/kg. No difference in the incidence of death caused by rejection was seen between DSBMTs and controls, but there was a marked tendency toward more deaths caused by rejection in DSBMTs + FK506 versus FK506-only pigs (p = 0.09). Daily stomal assessment showed a higher rate of moderate and severe interstitial rejection in DSBMT + FK506 versus FK506-only pigs; DSBMT was also associated with increased vascular rejection. Finally, groupwise comparison showed an order of susceptibility to lethal GVHD and infection as follows: DSBMT + FK506 > FK506 > DSBMT > controls. CONCLUSIONS: Rather than promoting engraftment, DSBMT can sensitize recipients and cause rejection after intestinal transplantation. It aggravates the risks of generalized GVHD and infection and tends to reduce graft and recipient survival. Before being applied clinically, DSBMT needs to be refined to increase its tolerogenic potential without causing GVHD.

Animals↗
PubMed1997

Discordant xenoislets from a large animal donor undergo accelerated graft failure rather than hyperacute rejection: impact of immunosuppression, islet mass, and transplant site on early outcome.

BACKGROUND: It is not known whether discordant, free, nonvascularized xenoislets-akin to discordant, vascularized, solid xenoorgans-are hyperacutely rejected. Quantitative xenoislet requirements and the optimal transplant site also remain to be defined. METHODS: We studied these questions with a discordant dog-to-diabetic Lewis rat xenoislet model, using (1) functional (cure of streptozotocin-induced diabetes) and (2) histologic (biopsies of intraportal grafts) parameters. WF-to-Lewis alloislet recipients served as histologic controls. RESULTS: (1) We found that 5000 xenoislet equivalents (IEs) transplanted into the portal veins of nonimmunosuppressed rats never functioned. Peritransplant combination therapy (rapamycin, cyclosporin A, anti-rat lymphocyte serum) significantly prolonged graft survival of 5000 intraportal IEs (median, 3 days) but not of 2500 intraportal or of 5000 intraperitoneal or renal subcapsular IEs. (2) By means of immunofluorescence (at 1 hour after transplantation), we noted immunoglobulin M (IgM) and IgG binding to islets in xenografts but not allografts; we noted complement and fibrinogen binding in both xenografts and allografts. Insulin-positive islet cells within intact xenoislets were demonstrated in nonimmunosuppressed rats up to 48 hours after transplantation. Cellular xenograft infiltration and inflammation, beginning at 6 hours, were observed even in immunosuppressed rats. (3) Thus, in spite of IgM and IgG binding, intraportal discordant xenoislets were not hyperacutely rejected and destroyed. Nevertheless, universal xenoislet nonfunction in nonimmunosuppressed rats was immune mediated. A large xenoislet mass (more than 10,000 IEs/kg), the intraportal site, and combination therapy were absolute prerequisites for immediate function. But even if the prerequisites were all fulfilled, accelerated xenoislet graft failure occurred. CONCLUSIONS: This outcome suggests that the specific binding of IgM and IgG to xenoislets, in conjunction with the binding of complement and fibrinogen, contributed to accelerated graft failure. Thus distinction between discordant and concordant species combinations is important for free, nonvascularized xenoislet transplants. These findings and the steroid-free combination protocol (rapamycin, cyclosporin A, anti-T-cell therapy) warrant further testing in preclinical discordant xenoislet studies.

Animals↗
PubMed1997

The surgical risk of pancreas transplantation in the cyclosporine era: an overview.

BACKGROUND: Pancreas transplants are still associated with the highest surgical complication rate of all routinely performed solid organ transplants. To date, the impact of serious surgical complications in the cyclosporine era on perioperative patient morbidity, graft and patient survival, and hospital costs has not been analyzed in detail. STUDY DESIGN: We retrospectively studied surgical complications after 445 consecutive pancreas transplants (45% simultaneous pancreas-kidney [SPK], 24% pancreas after kidney [PAK], and 31% pancreas transplant alone [PTA]). Of these, 80% were primary transplants, 20% were retransplants. Cadaver donors were used in 92%, living related donors in 8%. To develop guidelines for their prevention and management, we studied the impact of significant surgical complications (intra-abdominal infections, vascular graft thrombosis, and anastomotic leak) requiring relaparotomy on graft and patient survival. RESULTS: Relaparotomy was required after 32% of all pancreas transplants (SPK: 36%, PAK: 25%, PTA: 16% [p = 0.04]). Perioperative mortality was 9%. Graft and patient survival rates were significantly lower for recipients with (versus without) relaparotomy. The most common procedures were drainage of intra-abdominal abscess with graft necrosectomy (50% of all relaparotomies) and transplant pancreatectomy (34%). The most common causes of relaparotomy were intra-abdominal infection, vascular graft thrombosis, and anastomotic leak. Intra-abdominal infection occurred in 20% (SPK: 18%, PAK: 24%, PTA: 20% [p = NS]). The rate was significantly higher for living related donor (42%) versus cadaver donor (18%) recipients and for those with enteric-drained (39%) versus bladder-drained (18%) transplants. Graft and patient survival rates were significantly lower for recipients with (versus without) intra-abdominal infection. Outcome was better after bacterial (versus fungal) infections. For SPK recipients, those not on dialysis before the transplant had significantly higher graft survival than those on dialysis. Vascular graft thrombosis occurred in 12% of all recipients. The rate was significantly higher for PAK (21%) than for PTA (10%) and SPK (9%) recipients. It was significantly lower for recipients of grafts with donor iliac Y-graft reconstruction (versus all other types of arterial reconstruction) and with right-sided (versus left-sided) graft placement. Of note, patient survival was not different for recipients with versus without vascular graft thrombosis. The incidence of anastomotic or duodenal stump leaks was 10%; of these recipients, 70% required relaparotomy. Patient and graft survival rates were no different for recipients with versus without leaks. CONCLUSIONS: Serious surgical complications occurred in 35% of pancreas recipients and had a significant impact on patient and graft survival. Based on multivariate risk factor analyses, we recommend the following: donors over 45 years and those dying of cerebrocardiovascular disease should not be used; recipients over 45 years and those with a history of cardiac disease should be considered for a kidney transplant alone (KTA); surgical technique for graft procurement, preparation, and implantation should be meticulous; right-sided implantation and arterial Y-graft reconstruction should be performed when possible, since they had the highest success rates; when complications require relaparotomy, the focus must switch from graft salvage to life preservation; and the threshold for pancreatectomy should be low. Diagnosis should be timely, and treatment and relaparotomy expeditious. These cornerstones of success should help decrease the risk of surgical complications and mortality after pancreas transplants.

Abdominal Abscess↗
PubMed1997

Correlation of the arterial resistive index in pancreas transplants of patients with transplant rejection.

OBJECTIVE: This study was undertaken to determine whether arterial resistive indexes (RIs) in pancreas transplants correlate with biopsy-proven transplant rejection. MATERIALS AND METHODS: We retrospectively reviewed arterial RIs in pancreas transplants for all patients who underwent Doppler sonography within 1 week before transcystoscopic or percutaneous biopsy of pancreas transplants. RIs were correlated with type and degree of rejection in the 20 transplants for which biopsies provided sufficient tissue for diagnosis. Three patients were subsequently eliminated from the study because of significant intervening therapy between sonography and biopsy. RESULTS: The nine transplants with no evidence of rejection had a mean arterial RI of 0.64 (range, 0.49-0.80). The six transplants with acute mild or moderate rejection had a mean RI of 0.67 (range, 0.56-0.73). The two transplants with acute severe rejection had a mean RI of 0.85 (range, 0.80-0.90). We found no statistically significant difference between arterial RIs in pancreas transplants of patients with acute mild or acute moderate rejection and those with no evidence of rejection. CONCLUSION: Arterial RIs of pancreas transplants do not differentiate between acute mild or acute moderate rejection and absence of rejection. The higher mean value of arterial RIs in pancreas transplants with acute severe rejection suggests that elevated arterial RIs are sensitive, but not specific, for revealing acute severe rejection of pancreas transplants. However, our study data are limited, and a larger sample size is necessary to draw statistically significant conclusions.

Adult↗
PubMed1997

Venous thrombosis of pancreatic transplants: diagnosis by duplex sonography.

OBJECTIVE: Our objective was to determine whether elevated pancreatic transplant arterial resistive index (RI) and absence of venous flow correlate with pancreatic transplant venous thrombosis. MATERIALS AND METHODS: Thirteen episodes of surgically documented pancreatic venous thrombosis occurred in 175 pancreases that had been transplanted over a 3-year period. Duplex sonography was performed before surgical exploration in 11 cases. We retrospectively reviewed these 11 sonograms to determine whether blood was flowing in the veins and arteries of the graft. The RI was calculated from all pancreatic artery waveforms. We compared these arterial RIs and the presence or absence of venous flow with those of pancreatic grafts without venous thrombosis to determine sensitivity and specificity. RESULTS: In the venous thrombosis group, thrombosis occurred within 12 days of transplantation (mean, 3.5 days) in all 11 cases. Six cases of thrombosis (55%) occurred within 1 day. Arterial flow was detected within the graft in nine cases (82%) and in the stump of the donor artery between the graft and the recipient iliac artery in the two remaining cases. Antegrade diastolic flow was absent in all arterial tracings. Diastolic flow reversal was present in seven (78%) of nine grafts with detectable intrapancreatic arterial flow. Arterial RIs ranged from 1.00 to 2.00 (mean +/- SD, 1.27 +/- 0.29). Intrapancreatic venous flow was absent in all 11 cases. In the control group (43 examinations in 34 patients) RIs ranged from 0.46 to 1.29 (mean +/- SD, 0.72 +/- 0.18). Two of 43 arterial tracings had diastolic flow reversal (RI > 1.0). Venous flow was present in all examinations in the control group. A statistically significant difference existed between the RIs in the thrombosis group and the RIs in the control group (p = .0001). CONCLUSION: Reversal of diastolic flow in pancreatic transplant arteries is highly specific for detection of graft venous thrombosis during the first 12 days after transplantation. Our findings suggest that an RI greater than or equal to 1.00 and absence of venous flow, in combination, are highly sensitive and specific for the diagnosis of pancreatic graft venous thrombosis.

Adult↗
PubMed1996

Combined transplantation of small and large bowel. FK506 versus cyclosporine A in a porcine model.

Clinically, FK506 is superior to CsA after solitary small bowel transplantation (SBTx). Development of diarrhea after SBTx has been the rationale for adding the colon to small bowel grafts. However, the additional lymphoid and bacterial content transferred with total small plus large bowel transplants (TBTx) might aggravate the alloimmune response-rejection and graft-versus-host disease (GVHD)-and increase the risk of infection. We studied the incidence of rejection, GVHD, and infection after TBTx and the impact of CsA versus FK506. We performed orthotopic TBTx with portal drainage after total enterectomy in outbred Yorkshire Landrace pigs, divided into 3 groups: control pigs (n=6) received no immunosuppression; CsA pigs (n= 14) received CsA (5 mg/kg), antilymphocyte globulin (10 mg/kg for 10 days), prednisone (2 mg/kg), and AZA (2.5 mgtkg); and FK506 pigs (n=9) received FK506 (0.2 mg/kg) and prednisone (2 mg/kg). Trough CsA whole blood levels were >400 ng/ml for the first 7 days and >200 ng/ml thereafter. FK506 levels were > 15 ng/ml. We excluded from further analysis 5 early deaths (<3 days) due to anesthesiologic (n=2) or technical reasons (n=3). Median survival of control pigs was 9.5 days (range, 4-13). Cyclosporine did not extend survival: median, 9 days (range, 5-31) (P=0.6). FK506 prolonged survival: median, 37 days (range, 21-49) (P<0.001 vs. control and CsA pigs). Of FK506 pigs, 60% gained weight (+75 g/day), whereas 100% of controls and 75% of CsA pigs lost weight (-550 g/day and -300 g/day, respectively). All control pigs died of rejection within 2 weeks versus none of the FK506 pigs. However, 36% of CsA pigs died of rejection. Groupwise comparison showed less rejection in FK506 versus control pigs (P<0.001) and in FK506 versus CsA pigs (P<0.03), but no difference between CsA and control pigs. None of the control pigs died of GVHD versus 18% of CsA pigs (by day 31) and 37% of FK506 pigs (by day 49). Groupwise comparison showed increased GVHD in FK506 versus control pigs (P<0.001) and a tendency toward increased GVHD in FK506 versus CsA pigs (P=0.08). None of the control pigs died of infection alone versus 22% of CsA pigs (by day 31) and 67% of FK506 pigs (by day 49). Groupwise comparison showed increased infection in FK506 versus control pigs (P<0.001). We detected significant endotoxemia early and late postoperatively. But we saw no specific correlation between endotoxemia, rejection, GVHD, or infection. Based on this study, we have drawn several conclusions: (1) In untreated pigs, TBTx provokes a severe rejection response, but no lethal GVHD. (2) Cyclosporine and particularly FK506 pigs have a high incidence of infection and lethal GVHD, a complication that we had not seen after solitary SBTx. (3) FK506 is superior to CsA in controlling rejection and in prolonging graft and recipient survival; FK506, however, does not reduce GVHD, but rather tends to augment it. (4) TBTx causes endotoxemia. As with solitary SBTx, FK506 is superior to CsA after TBTx. However, longterm survival is difficult to achieve on FK506 recipients because of the development of GVHD and infection.

Animals↗
PubMed1996

Delayed endocrine pancreas graft function after simultaneous pancreas-kidney transplantation. Incidence, risk factors, and impact on long-term outcome.

BACKGROUND: The incidence of delayed endocrine pancreas graft function and its impact on long-term outcome after simultaneous pancreas-kidney transplantation are unknown. METHODS: We studied 54 technically successful adult type I insulin-dependent diabetic recipients of cadaver, whole organ, bladder-drained simultaneous pancreas-kidney transplants (mean age, 37.6 years; 65% male, 35% female; 9% pancreas retransplants; 63% on chronic pretransplant dialysis; mean duration of diabetes, 25.1 years). Insulin was administered during the first 2 weeks after transplantation, as needed, to keep blood glucose < 150 mg/dl. Delayed endocrine pancreas graft function was defined as total, cumulative insulin requirement of > 30 U between day 5 and day 10, and/or > 15 U between day 11 and 15. Quadruple immunosuppression was used for all recipients. RESULTS: The incidence of delayed endocrine pancreas graft function was 69%. By univariate analysis, delayed endocrine graft function was associated with pretransplant recipient weight > 80 kg (P = 0.04), donor age > 45 years (P = 0.02), and cardiocerebrovascular (P = 0.06) and nontraumatic causes of donor death (P = 0.02). The incidence of acute pancreas rejection episodes was similar for recipients without and with delayed endocrine pancreas graft function. Pancreas graft survival at 1 and 3 years was 94% and 82% without versus 76% and 59% with delayed endocrine graft function (P = 0.03). CONCLUSIONS: Increased pancreas graft failure after delayed endocrine function was a consequence of insufficient functional reserve (e.g., older donors) rather than increased immunogenicity. Pretransplant reduction of recipient weight and careful donor selection are therefore crucial in order to decrease the incidence of delayed endocrine pancreas graft function and its negative impact on long-term outcome.

Adult↗
PubMed1996

Delayed graft function in the absence of rejection has no long-term impact. A study of cadaver kidney recipients with good graft function at 1 year after transplantation.

We previously reported that delayed graft function (DGF) in the absence of biopsy-proven acute rejection (Rej) had no effect on outcome of primary cadaver kidney transplantation (TX). By contrast, DGF in combination with Rej strongly predicted poor long-term graft survival. We asked whether this poor long-term outcome was due to early graft loss associated with DGF, or to an ongoing process leading to late graft loss. To answer this question, we studied a subset of 298 cadaver kidney transplant recipients who had not suffered early graft loss and had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX. The incidence of DGF (defined by dialysis during the first week after TX) in this subset was 19%. DGF was associated with cold ischemia time >24 hr (P = 0.0003) and Rej (P = 0.06). For grafts with versus without DGF, the incidence of late acute Rej (>1 year after TX) was similar. Actuarial graft survival was similar for Rej-free recipients with versus without DGF (P = 0.9) and was worse for those with Rej and no DGF (P < 0.02). Importantly, however, in our recipients who all had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX, the worst long-term outcome was noted in the subgroup with both DGF and Rej (P < 0.0001). By multivariate analysis, DGF was also only a risk factor in combination with Rej (P = 0.002, relative risk = 3.7), while a 0-antigen HLA mismatch had no impact. Patient survival decreased for recipients with both DGF and Rej by univariate (P = 0.009) and multivariate (P = 0.02, relative risk = 2.9) analyses. We conclude that DGF without Rej has no impact on long-term survival. However, our data for recipients with both DGF and Rej suggest that a chronic ongoing process leads to late graft failure. Further research is necessary to identify the exact pathophysiology of this process, which appears to be, at least in part, HLA antigen independent.

Acute Disease↗
PubMed1996

Quadruple immunosuppression in a pig model of small bowel transplantation.

Rejection remains a major obstacle to successful small bowel transplantation in humans, irrespective of the immunosuppressants. Previous large animal studies have not used quadruple immunosuppression (with high-dose intravenous cyclosporine A [CSA]) for induction, followed by triple immunosuppression for maintenance therapy. Nor have immunosuppressive doses been comparable to clinical solid organ transplants. We studied, in 78 nonrelated outbred pigs, the effect of quadruple immunosuppression (including horse anti-pig thymocyte globulin [ATG] and high-dose intravenous CSA) on the incidence and severity of rejection in the early, critical posttransplant period. Group A (n = 19) pigs were nonimmunosuppressed. Group B (n = 20) received quadruple immunosuppression: pig ATG (10 mg/kg/day x 10 days), intravenous CSA (3.0 mg/kg/day), prednisolone (2 mg/kg/day), and azathioprine (2.5 mg/kg/day); prednisolone and azathioprine were each reduced by 50% on posttransplant Days 8 and 15. Trough CSA levels were > or = 400 ng/ml for the first 7 days posttransplant, > 200 ng/ml thereafter. Recipient pigs underwent resection of large and small bowel; orthotopic transplants (proximal duodenojejunostomy, distal ileostomy) were done with systemic vein drainage. We developed a scoring system (no, mild, moderate, severe rejection) to grade the extent of both interstitial and vascular rejection: biopsies were obtained daily from the ileostomy. Rejection-free graft survival at posttransplant Days 7, 10, and 14 was 32, 26, and 16% in the nonimmunosuppressed group versus 95, 90, and 85% in the immunosuppressed group (P < 0.0001). Rejection grades were significantly better over the whole observation period in immunosuppressed pigs: interstitial rejection was not present in up to 67% of all daily biopsy specimens. Rejection was present in all specimens of nonimmunosuppressed pigs. Vascular rejection was uncommon (incidence < 10%) in both groups. Isolated vascular rejection without interstitial rejection was not found. Graft-versus-host reaction was noted in both groups in the skin only; liver and native bowel were not involved. We conclude that quadruple immunosuppression with pig ATG and high-dose intravenous CSA for induction effectively prevents moderate and severe rejection in this model. Since clinical transplant complications (rejection, lymphomas) have persisted under FK 506 treatment, our immunosuppressive regimen should be considered an alternative for bowel transplantation in humans to prevent early rejection.

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