Effect of cyclosporin therapy in controlling the rejection of ileal versus jejunal allografts

Experimental evidence suggests that jejunal allografts are rejected as rapidly as are ileal grafts, despite their lesser content of lymphoid tissue as an immunologic stimulus. However, it may be possible to postpone the rejection of jejunal grafts more readily than that of ileal grafts by means of immunosuppressive therapy with cyclosporin (CyA). To test this, we used the rat model (BN-LEW) of orthotopic small-bowel transplantation. The proximal third of the small-bowel with one-third of the mesenteric lymph nodes (n=20), or the distal ileal third with all of the mesenteric lymph nodes (n=22), or the entire small-bowel (n=23) was interposed after resection of an equivalent type and length of recipient bowel. CyA (15 mg/kg) was given to all of these rats for 5 days. Three additional control groups were not given CyA. The difference in graft/recipient survival among the groups receiving CyA and among those not on CyA therapy was not statistically significant. Antidonor hemagglutinin titers, the mixed lymphocyte culture (MLC) assay, and histologic examination of the allograft failed to show a mitigated rejection reaction for the recipients of jejunal grafts. The data show that short-term treatment with CyA prolongs graft survival. Equal doses of CyA, however, did not lead to prolonged survival of jejunal grafts or alter the course of rejection in comparison with that for ileal or whole-bowel transplants.Presented at the 1988 Tripartite Meeting of the Society of University Surgeons (SUS), the Surgical Research Society of Great Britain (SRS), and the European Society for Surgical Research (ESSR) Bristol, UK     

Rejection of ileal versus jejunal allografts

Small-bowel allografts are replete with lymphocytes, which may be the main stimulus for the recipient's immune system, thereby inducing rejection. Since most of the lymphoid tissue is located in the ileum, one would expect ileal grafts to be rejected more rapidly than are jejunal grafts. To test this theory, we transplanted a jejunal (n = 13) or an ileal segment (n = 9) or the entire small bowel (n = 6) orthotopically in the BN----LEW rat strain combination. Jejunal grafts included a short segment of the mesentery, whereas ileal and whole small-bowel grafts included the entire mesentery with its lymph nodes. Segmental as well as entire-bowel grafts induced peak anti-BN titers on the 6th to 7th postoperative day. In rats with entire-bowel grafts, rejection culminated in the recipient's death after an average of 9.5 +/- 1 days from graft necrosis and peritonitis; the rejection of jejunal (13.1 +/- 2.1 days) and ileal grafts (12.9 +/- 1.3 days) was less rapid. Segmental grafts were often encapsulated, and the causes of death were inanition and intestinal obstruction. Thus, despite their high lymphocyte content, ileal grafts were not rejected more quickly than were jejunal grafts; they should, therefore, be preferred because of their greater specialized absorptive capacity. Histologically, entire-bowel grafts were found to be rejected as rapidly as were segmental grafts; however, the toxic effects of the larger grafts that are undergoing rejection lead to earlier death of the recipient.     

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.     

Causes of long-term graft failure in renal transplantation

Summary A single-center experience of 980 consecutive renal transplant recipients treated with cyclosporine (CyA) was reviewed to analyze the causes of renal allograft loss and the factors affecting long-term renal survival in CyA-treated kidney transplants. In all, 217 grafts were lost during the observation period, with the most common causes of graft loss being chronic rejection (96 cases, 44%), death with a functioning graft (52 cases, 24%), glomerulonephritis (28 cases, 13%), and acute rejection (20 cases, 8%). The actuarial 10-year survival of patients with living and cadaveric grafts was 93% and 91%, respectively. The actuarial 10-year survival of living and cadaveric grafts was 70% and 63%, respectively. Patients were divided into two groups, namely a graft-survival group (n=763) and a graft-loss group (n=217). There was no significant difference between the two groups in terms of sex, donor source, donor age, recipient age, duration of hemodialysis, retransplants, transfusions, presensitization, of HLA match. There was no difference between the graft-survival group and the graft-loss group in the mean CyA dose given or the mean CyA trough level measured at any time following transplantation. Acute rejection episodes occurred in patients from the graft-survival group (55%) as compared with those from the graft-loss group (83%; P<0.00001). These data suggest that long-term graft survival in CyA-treated kidney transplant patients is primarily influenced by the occurrence of rejection episodes rather than by the drug dose or the duration of CyA administration. CyA nephrotoxicity was not the major risk factor for long-term graft survival in CyA-treated renal transplants.     

Jejunal versus ileal segmental allografts in the dog: comparison of immunologic and functional results.

Segmental small-bowel grafts have been advocated as a means of reducing the incidence of rejection and graft-versus-host disease in small-bowel transplant recipients. This study compared the results achieved with heterotopic segmental allografts of the jejunum and the ileum that used 120 cm Thiry-Vella loops in a dog model. Immunosuppressive therapy consisted of 25 mg cyclosporine/kg/day. Results were monitored by histologic examinations, function tests (maltose and xylose absorption), and brush-border enzyme assays. Thirty-three dogs were randomized for use as a donor (n = 11) or recipient of a jejunal allograft (n = 11) or an ileal allograft (n = 11). Eight allografts were technical failures and were excluded from analysis. Fourteen allografts were successful (eight ileal, six jejunal). No case of graft-versus-host disease was observed. Six allografts (42.5%, three jejunal [50%] and three ileal [37.5%]) were rejected during the first 3 months (not statistically significant). Eight allografts (five ileal, three jejunal) were tolerated for up to 3 months and were removed. Two ileal and two jejunal allografts appeared grossly normal at surgical removal, but two ileal and one jejunal allografts exhibited signs of chronic rejection, and one ileal allograft showed advanced rejection. The jejunal and ileal allografts had similar clinical courses, as were revealed by immunologic reactions and functional parameters. We conclude that there is no major difference between jejunal allografts and ileal allografts in the dog.     

Intestinal allograft survival in the rat following pretreatment with donor-specific UV-B-irradiated leukocytes and peritransplant immunosuppression with cyclosporine

Previous studies from our laboratory showed that pretreatment with ultraviolet-B-irradiated donor leukocytes (UV-B DL) combined with brief peritransplant cyclosporine (CyA) resulted in indefinite survival of Wistar/Furth rat cardiac allografts in Lewis recipients. This study was designed to examine the effect of pretransplant UV-B DL with or without peritransplant CyA on orthotopic intestinal allografts in the same rat strain combination. The results showed that while low-dose CyA treatment alone (10 mg/kg i.m. on days 0, +1, and +2) had no effect on intestinal allograft rejection, 20 mg/kg (on days 0, +1, and +2) CyA significantly (P0.001) prolonged graft survival, with 33% of the hosts surviving indenfinitely. The highest dose of CyA (30 mg on days 0, +1, and +2) abrogated rejection, but most transplant recipients succumbed to infection and functional ileus due to a toxic side effect of CyA. Pretreatment with UV-B DL on days -14 and-7 alone did not prolong intestinal allograft survival. Combination of a subtherapeutic CyA dose (20 or 10 mg/kg) given on days 0, +1, and +2 with pretransplant UV-B DL on days-14 and -7 did not alter the survival of intestinal allografts compared to treatment with CyA alone. This suggests that pretreatment with UV-B DL with or without peritransplant administration of CyA has no effect on intestinal allograft survival, in contrast to the effect of such combined treatment on cardiac allograft survival, where indefinite graft survival is observed. This difference in the effect of pretransplant UV-B DL on intestinal and cardiac allograft survival is most likely due to organ-specific immunogenicity, particularly to the relative density of class I and II histocompatibility antigens present in heart or intestine.     

Effects of donor pretreatment with antilymphocyte serum and cyclosporin on rejection and graft-versus-host disease after small bowel transplantation in immunosuppressed and nonimmunosuppressed rats

After fully allogeneic small bowel transplantation, both graft-versus-host disease (GVHD) and rejection may occur. Donor pretreatment may prevent GVHD, but this sometimes leads to accelerated graft rejection. To study a possible balance between GVHD and rejection, fully allogeneic total orthotopic small bowel transplantation was performed in rats using the WAG-to-BN donorhost combination. Untreated control grafts were rejected in 16.6±2.7 days (mean ±SEM), and 35% of the animals had mild, transient GVHD. Pretreatment of the donor with antilymphocyte serum on days-2 and-1 before grafting, either intravenously or intraperitoneally, completely eliminated the occurrence of clinical GVHD but led to significantly shortened survival times (12.3±0.8 and 10.3±0.9 days, respectively). Donor pretreatment with 50 mg/kg cyclosporin (CyA) on days-2 and-1 prolonged graft survival significantly to 22.1 days but had no significant effect on the incidence of GVHD. Administration of 25 mg/kg CyA on days 0, 1, 2, 4, and 6 after grafting prolonged survival to 38.3 days with no evidence of GVHD. Pretreatment of the donor with antilymphocyte serum (ALS), combined with the same postoperative, short-term CyA regimen, increased survival to more than 50 days, again with no evidence of GVHD. When CyA was used as both donor pretreatment and postoperative therapy, there was no survival advantage compared to the use of postoperative CyA alone. These results show that an in vivo balance between GVHD and rejection exists and that abrogation of GVHD leads to accelerated rejection. Immunosuppression of the recipient may overrule this accelerated rejection while preserving the beneficial effect of donor pretreatment: elimination of clinical GVHD.     

The beneficial effects of oral nifedipine on cyclosporin-treated renal transplant recipients — a randomised prospective study

The aim of this study was to test the hypothesis that nifedipine will improve graft survival in cyclosporin A (CyA)-treated renal transplant recipients. One hundred and forty-seven patients were randomised to one of three regimens. Group A received CyA, 7 mg/kg per day, and prednisolone; group B followed the same regimen as group A plus oral nifedipine and group C received CyA, 4 mg/kg per day, prednisolone and azathioprine. Calcium channel blockers were avoided in groups A and C. The crude 2-year (P=0.0223) and 4-year (P=0.0181) graft survival was significantly better in group B (86% and 81%, respectively) than in group A (75% and 63%, respectively). Delayed initial function was seen least frequently in group B (10.2%) compared to groups A (31%) and C (28%; P<0.01). Group B also experienced fewer rejection episodes than groups A and C (P<0.05). We conclude that the combination of oral nifedipine and CyA significantly improves initial graft function, rejection frequency and long term graft survival.     

Rescue therapy with tacrolimus (FK 506) in renal transplant recipients —a Scandinavian multicenter analysis

All renal allograft recipients (n = 32) in Sweden and Norway who were converted from cyclosporin(CyA)-based immunosuppression to FK 506 (tacrolimus) between October 1992 and June 1995 were analyzed retrospectively. The reasons for conversion were acute refractory rejection (n = 21), chronic rejection (n = 4), and suspected CyA toxicity (n = 6); one patient was converted for psychological reasons. The mean time from transplantation to conversion was 29 (range 1–243) weeks and there was a mean follow-up of 46 (2–143) weeks. Overall graft survival was 59%, with graft survival 52% in patients converted because of acute rejection, 50% in patients converted because of chronic rejection, and 83% in patients converted because of CyA toxicity. There was no significant correlation between preconversion serum creatinine and outcome. Seventy-two percent of the patients had significant side effects during FK 506 treatment, the most frequent ones being neurological and gastrointestinal symptoms. These improved after dose reduction. Two patients became overimmunosuppressed and developed lymphoma. One patient died of the primary kidney disease, hemolytic uraemic syndrome. We conclude that FK 506 therapy is able to salvage kidneys with acute refractory rejection and that it is an alternative in patients with CyA toxicity. However, the risk of overimmunosuppression must be considered.     

A randomized multicenter trial of cyclosporin and prednisolone versus cyclosporin,azathioprine, and prednisolone following primary living donor renal transplantation

A total of 195 consecutive recipients of primary living donor renal transplants were randomized to receive either cyclosporin (CyA) and prednisolone (double therapy) or CyA, prednisolone, and azathioprine (triple therapy). There was no significant difference in patient or graft survival, incidence of acute rejection episodes, or major complications between the groups. The graft survival at 5 years was 71.5% in patients receiving double therapy and 71.6% in patients receiving triple therapy. In a Cox regression analysis, recipient age and occurrence of acute rejection were the only independently significant variables affecting graft survival, whereas treatment schedule did not. Renal function was stable throughout the observation period and did not differ between the double and triple therapy groups. A linear regression analysis showed that recipient age, donor age, gender, and occurrence of acute rejection significantly influenced the serum creatinine level. This and previous similar prospective studies in cadaveric renal transplantation indicate that there is no advantage of routinely adding azathioprine to a double drug regimen.     

Unrelated living donor kidney transplantation

Since 1966, we have performed 41 renal transplants from unrelated living donors (ULD), 39 of which were emotionally related. All donor-recipient pairs included in the present series were AB0-compatible. Recipients included 37 with primary and 4 with secondary transplants; 2 of the latter were diabetics. We compared these results to those of 41 recipients of cadaver donor kidneys matched for age, sex, immunosuppressive regimen, rank, and year of transplant, focusing our attention of the subgroups of patients under cyclosporin A (CyA) therapy (n=24). We found that ULD transplantation was as successful as cadaver transplantation with good HLA matching: at 3 years, graft survival rates were 81% in ULD versus 86% in the control group under CyA. Moreover, grafts from ULD functioned more rapidly (no post-transplant dialysis and 70% of the patients with serum creatinine below 2 mg/dl within 3 days post-transplant). Graft tolerance was equivalent in both groups (50% of the patients experienced no rejection). We conclude that despite poor HLA matching, ULD transplantation with CyA as the basic immunosuppressive agent offers good results: benefiting from the quality of living donor kidney grafts, it helps to alleviate the persistent shortage of cadaver donors.     

Renal allograft immunosuppression

A prospective randomized study was conducted to evaluate the impact of four different conversion protocols on graft outcome in long-term follow-up. Between January 1986 and May 1987, 128 patients with first cadaveric kidnery allografts were randomized at the time of transplantation to four treatment groups of 32 patients each, to be assigned 10 weeks post-transplantation. During the first 10 weeks, all patients received triple therapy with low-dose azathioprine (Aza), cyclosporin (CyA), and methylprednisolone (MP). After 10 weeks, one group continued with triple therapy (group A) while the three other groups received different combinations of two drugs, namely, Aza and CyA (group B), Aza and MP (group C), or CyA and MP (group D). Withdrawal of MP (group B) or especially of CyA (group C) was associated with 4/29 (14%) and 10/28 (36%) acute rejection episodes, respectively, for 60 days after conversion. All rejections were mild and reversible. There were no rejections after Aza withdrawal or in the group that continued on triple therapy during the corresponding time period. The most common reason for dropping out after withdrawal, for those patients who could not continue on the originally randomized medication, was azathioprine intolerance (n=12). Five patients were switched back to triple therapy after CyA withdrawal due to rejection. Steroid intolerance was rare and CyA in low doses was very well tolerated. At 1 year there were no statistically significant differences in graft survival between groups A, B, C, and D-81%, 88%, 88%, and 88%, respecively-or in patient survival-88%, 88%, 88%, and 97%, respectively. For those patients continuing with the originally randomized treatment protocol, there were no differences in patient or graft survival either, the means being 91% and 89%, respectively. The most common cause of death after withdrawal was cardiovascular in nature, and there were no more fatal infections under triple drug treatment than with double drug regimens. There were no statistically significant differences in mean serum creatinine values at 1 year. The median serum creatinine values for groups A, B, C, and D were 112, 132, 133, and 133 mol/l, respectively. At 1 year the mean CyA dose in the groups that continued with CyA was 3.5–4.2 mg/kg per day and CyA concentrations were equal.     

The quality of function of renal allografts is associated with donor age

The quality of renal allograft function was assessed by prospective measurement of creatinine clearance at 1 year (n=197) and at 3 years (n=115) after cadaveric renal transplantation in a cohort of 268 patients treated with triple therapy immunosuppression. Donor age (P<0.0012) and recipient age (P<0.01) were independently associated with creatinine clearance both at 1 and at 3 years. In patients with donor age above 50 years and recipient age above 45 years, the mean creatinine clearance was 32.7 (SD 10.4) ml/min (n=27). When the donor age was below 30 years and recipient age below 45 years, the mean creatinine clearance was 55.6 (SD 14.4) ml/min (n=47, P<0.001). However, in these patients there was no significant association between graft function and many of the factors known to influence graft survival, such as HLA matching, sensitisation of the recipient, and the occurrence of rejection. In conclusion, the quality of renal allograft function declined with increasing donor and recipient age in our patients, whilst immunological factors were not significantly associated with function in surviving grafts.     

Sirolimus improves the two-year outcome of renal allografts in African-American patients

The present study evaluated whether the addition of sirolimus to a cyclosporine (CyA)/prednisone (Pred) regimen mitigated the greater proclivity to acute rejection episodes and graft loss characteristic of African-American renal transplant recipients. Using Kaplan-Meier and log-rank tests, African-American renal transplant recipients treated with either CyA/Pred (n = 90) or sirolimus/CyA/Pred (n = 47) were compared with 120 Caucasian patients treated with sirolimus/CyA/Pred for 2-year rates of patient and graft survival as well as acute rejection episodes. Mean laboratory values were compared using analysis of variance and F-tests. Addition of sirolimus to the CyA/Pred regimen reduced the incidence of acute rejection episodes in African-Americans from 43.3 % to 19.2 % (P = 0.004), a value similar to Caucasian patients. The 97.9 % 2-year graft survival rate among 47 African-American patients treated with sirolimus/CyA/Pred was significantly higher than the 85.6 % rate shown among the 90 CyA/Pred-treated African-American transplant recipients (P = 0.0479) and similar to that in Caucasians. The 95.7 % patient survival rate among the African-American sirolimus/CyA/Pred group was similar to the 97.8 % rate in the African-American CyA/Pred cohort. Interestingly, there was no evident toxicity from the addition of sirolimus. The addition of sirolimus to a CyA-based regimen reduced acute rejection episodes and graft loss experienced by African-American renal transplant recipients. Received: 15 February 2000 Revised: 5 October 2000 Accepted: 3 April 2001     

Renal allograft immunosuppression: II. A randomized trial of withdrawal of one drug in triple drug immunosuppression

Abstract. A prospective randomized study was conducted to evaluate the impact of four different conversion protocols on graft outcome in long-term follow-up. Between January 1986 and May 1987, 128 patients with first cadaveric kidney allografts were randomized at the time of transplantation to four treatment groups of 32 patients each, to be assigned 10 weeks post-transplantation. During the first 10 weeks, all patients received triple therapy with low-dose azathioprine (Aza), cyclosporin (CyA), and methylprednisolone (MP). After 10 weeks, one group continued with triple therapy (group A) while the three other groups received different combinations of two drugs, namely, Aza and CyA (group B), Aza and MP (group C), or CyA and MP (group D). Withdrawal of MP (group B) or especially of CyA (group C) was associated with 4/29 (14%) and 10/28 (36%) acute rejection episodes, respectively, for 60 days after conversion. All rejections were mild and reversible. There were no rejections after Aza withdrawal or in the group that continued on triple therapy during the corresponding time period. The most common reason for dropping out after withdrawal, for those patients who could not continue on the originally randomized medication, was azathioprine intolerance (n= 12). Five patients were switched back to triple therapy after CyA withdrawal due to rejection. Steroid intolerance was rare and CyA in low doses was very well tolerated. At 1 year there were no statistically significant differences in graft survival between groups A, B, C, and D-81 %, 88%, 88%, and 88%, respectively-or in patient survival-88%, 88%, 88%, and 97%, respectively. For those patients continuing with the originally randomized treatment protocol, there were no differences in patient or graft survival either, the means being 91% and 89%, respectively. The most common cause of death after withdrawal was cardiovascular in nature, and there were no more fatal infections under triple drug treatment than with double drug regimens. There were no statistically significant differences in mean serum creatinine values at 1 year. The median serum creatinine values for groups A, B, C, and D were 112, 132, 133, and 133 μmol/l, respectively. At 1 year the mean CyA dose in the groups that continued with CyA was 3. 5–4. 2 mg/kg per day and CyA concentrations were equal.     

The use of FK506 and RS61443 for reversal of small-bowel rejection

Successful clinical small-bowel transplantation is still difficult to achieve [3, 6]. Two features render the small intestine unique among vascularised solid organ grafts. First, the bowel contains a large amount of lymphoid tissue within the Peyer's patches, mesenteric lymph nodes, and intraepithelial lymphocytes, which are thought to mediate graft-versus-host disease and provide a major stimulus for the recipient's immune system [10]. Unfortunately, mere surgical reduction of these tissues, by using segmental allografts, does not furnish any immunological advantage [12]. Second, the small bowel lacks specific serum markers such as blood urea nitrogen (BUN) in the kidney or bilirubin in liver transplantation. Clinical signs such as fever, pain, or tenderness of the abdomen may indicate an already advanced destruction of the graft. Therefore, very potent immunosuppressive regimens are necessary to avoid small-bowel allograft rejection or even to reverse an ongoing rejection process. Cyclosporin was shown in small and large animal models to control rejection reactions sufficiently [4, 13]. However, there are two even more promising immunosuppressive agents currently under investigation. FK506, a macrolide lactone isolated from Streptomyces tsukubaensis, leads to long-term survival of small-bowel allografts in a rodent model and has already been used in a few clinical small-bowel transplantations [11, 14]. RS61443, a mycophenolic acid morpholinoethylester, selectively inhibits T- and B-cell proliferation [9]. We have investigated the use of FK506 and RS61443 for the reversal of small-bowel allograft rejection in a small animal model.     

Studies on the participation of different T cell subsets in rat liver allograft rejection

In this study, we investigated which subsets of rat T cells (CD8 + vs. CD4 + ) are involved in the rejection of liver allografts by the in vivo administration of monoclonal antibody (OX-8 or OX-38, and W3/25 MAb) into thymectomized recipient Lewis (RTI¹) rats prior to DA (RTI^a) liver transplantation. We also compared the results of allograft survival of liver and heart transplants under the same experimental conditions. In order to deplete either CD8 + T cells or CD4 + T cells from recipient animals, 0.4 ml of OX-8 (ascitic form) or a 0.8 ml cocktail of MAb W3/25 and OX-38 (0.4 ml each) was injected into thymectomized recipient rats, respectively. Untreated Lewis rats consistently rejected donor DA liver grafts between 9 and 11 days (n = 7, 9.8 days ± 1.1 days). In contrast, anti-CD8 MAb pretreatment extended the survival times of DA liver grafts for up to 40 days (n = 5, 26.8 days ± 8.4 days). Furthermore, survival of DA liver grafts was significantly prolonged in Lewis rats that had been pretreated with anti-CD4 MAb (n = 7,35.6 days ± 17.9 days). Two out of seven recipient animals survived for more than 60 days. For heart transplantation, untreated Lewis rats rejected DA heart grafts between 6 and 8 days after operation (n = 6, 6.5 days ± 1.2 days). Anti-CD4 MAb treatment prolonged heart graft survival for more than 60 days in all cases (n = 3, > 60 days). However, there was virtually no effect of anti-CD8 MAb treatment on heart graft survival (n = 4, 7.0 days ± 0.9 days). These results suggested that when whole MHC disparity prevailed between donor and recipient, both subsets of T cells were required for the rejection of liver allografts and that class II reactive T cells predominantly mediated liver graft rejection. Furthermore, CD8 + T cells played a differential role in the rejection of rat liver and heart allograft.     

Randomized trial of tacrolimus versus cyclosporin microemulsion in renal transplantation

This study was undertaken to compare the efficacy and safety of tacrolimus (Tac) with the microemulsion formulation of cyclosporin (CyA) in children undergoing renal transplantation. A 6-month, randomized, prospective, open, parallel group study with an open extension phase was conducted in 18 centers from nine European countries. In total, 196 pediatric patients (<18 years) were randomly assigned (1:1) to receive either Tac (n=103) or CyA microemulsion (n=93) administered concomitantly with azathioprine and corticosteroids. The primary endpoint was incidence and time to first acute rejection. Baselinecharacteristics were comparable between treatment groups. Tac therapy resulted in a significantly lower incidence of acute re-jection (36.9%) compared with CyA therapy (59.1%) (P=0.003). The incidence of corticosteroid-resistant rejection was also significantly lower in the Tac group compared with the CyA group (7.8% vs. 25.8%, P=0.001). The differences were also significant for biopsy-confirmed acute rejection (16.5% vs. 39.8%, P<0.001). At 1 year, patient survival was similar (96.1% vs. 96.6%), while 10 grafts were lost in the Tac group compared with 17 graft losses in the CyA group (P=0.06). At 1 year, mean glomerular filtration rate (Schwartz estimate) was significantly higher in the Tac group (62±20 ml/min per 1.73 m², n=84) than in the CyA group (56±21 ml/min per 1.73 m², n=74, P=0.03). The most frequent adverse events during the first 6 months were hypertension (68.9% vs. 61.3%), hypomagnesemia (34.0% vs. 12.9%, P=0.001), and urinary tract infection (29.1% vs. 33.3%). Statistically significant differences (P<0.05) were observed for diarrhea (13.6% vs. 3.2%), hypertrichosis (0.0% vs. 7.5%), flu syndrome (0.0% vs. 5.4%), and gum hyperplasia (0.0% vs. 5.4%). In previously non-diabetic children, the incidence of long-term (>30 days) insulin use was 3.0% (Tac) and 2.2% (CyA). Post-transplant lymphoproliferative disease was observed in 1 patient in the Tac group and 2 patients in the CyA group. In conclusion, Tac was significantly more effective than CyA microemulsion in preventing acute rejection after renal transplantation in a pediatric population. The overall safety profiles of the two regimens were comparable. Received: 1 October 2001 / Revised: 25 October 2001 / Accepted: 15 November 2001     

Changes in blood ketone body ratio with reference to graft viability after liver transplantation in rats

Arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate; KBR), which reflects hepatic mitochondrial redox potential, was measured during a 2-week period after orthotopic liver transplantation in three groups of rats: group 1, the isogenic combination of LEW (RT1¹) graft to LEW recipient as control; group 2, the allogenic combination of ACI (RT1^a) graft to LEW recipient without immunosuppressive treatment; and group 3, the allogenic combination of ACI to LEW with immunosuppressive treatment using cyclosporin (CyA). Isogenic recipients survived indefinitely. Allogenic recipients in group 2 had severe rejection with a mean survival of 10.3±0.54 days, while 77.8% of the allogenic recipients in group 3 survived more than 30 days. KBR of rats surviving more than 2 weeks in groups 1 and 3 gradually increased post-transplantation and was maintained at a high level. By contrast, though KBR in group 2 was restored at 3 days, it gradually fell and remained at a significantly low level (P<0.001). It is suggested that KBR provides an accurate indicator for evaluating metabolic viability of the critically deteriorating liver graft accompanied by severe rejection.     

Anatomical variations of donor portal vein in right lobe living donor liver transplantation: the safe use of variant portal veins

In right lobe (RL) living donor liver transplantation (LDLT), portal vein (PV) variations are of immense clinical significance. In this study, we describe in detail our PV reconstruction techniques in RL grafts with variant PV anatomy and evaluate the impact of accompanying biliary variations on the recipient outcomes. In a total of 386 RL LDLTs performed between July 2004 and July 2012, the clinical data on 52 (13%) transplants using RL grafts with variant PV anatomy were retrospectively analyzed. Portal vein anatomy was classified as type 2 in 20 patients, type 3 in 24 patients, and type 4 in eight patients. The PV reconstruction techniques utilized included back‐wall plasty (n = 21), back‐wall plasty with saphenous vein graft interposition (n = 6), saphenous vein graft interposition (n = 5), cryopreserved iliac vein Y‐graft interposition (n = 6), and quiltplasty (n = 3). There was no donor mortality. In a median follow‐up of 29 months, none of the recipients had vascular complications. Anomalous PV anatomy was associated with a high (54%) incidence of biliary variations; however, these variations did not result in increased biliary complication rate. Overall, the 1‐ and 3‐year patient survival rates of recipients were 91% and 81%, respectively. Vascular and biliary variations in RL grafts render LDLT technically more challenging. By employing appropriate reconstruction techniques, it is possible to successfully use RL grafts with PV variations without endangering recipient and donor safety.