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Background: Data on the outcome of renal transplantation in antineutrophil cytoplasmic antibody-associated glomerulonephritis (AAGN) patients are still limited. In particular, how disease recurrence in the renal allograft defines graft outcome is largely unknown. Therefore, we conducted a multicenter observational clinical and histopathological study to establish recurrence rate of AAGN in the allograft and the impact of recurrence on allograft survival., Methods: Using the nationwide Dutch Pathology Registry (PALGA), we retrospectively collected clinical and histopathological data of consecutive AAGN patients who had developed end-stage renal failure and received a kidney allograft in 1 of 6 Dutch university hospitals between 1984 and 2011. Transplant biopsies were scored using the Banff '09 classification. Renal disease recurrence was scored using the histopathological classification of AAGN., Results: The posttransplantation recurrence rate of AAGN was 2.8% per patient year, accumulating to recurrence in a total of 11 of 110 AAGN patients within the first 5 years after transplantation. Four of these 11 patients lost their graft, with 1-year and 5-year graft survival rates of 94.5% and 82.8%, respectively. By multivariate analysis, AAGN recurrence was independently associated with subsequent graft loss., Conclusions: In this study in 110 Dutch patients, the recurrence rate of AAGN within 5 years after kidney transplantation appeared slightly higher than in previous reports. Moreover, recurrence of AAGN contributed independently to kidney allograft loss, emphasizing the importance of clinical vigilance, because early treatment might be critical to rescuing the allograft.

Background: Allogeneic islets of Langerhans transplantation is hampered in its success as a curative treatment of type 1 diabetes by the absence of potent, specific, and nontoxic immunosuppressive drugs. Here, we assessed whether donor bone marrow-derived dexamethasone-treated dendritic cells (dexDCs) could prolong islet allograft survival in a full major histocompatibility complex mismatch rat model., Methods: Rodent allogeneic islet transplantation was performed from DA rats to Lewis rats and vice versa. Permanently immature dendritic cells were generated from the bone marrow of DA and Lewis rats by treatment with dexamethasone. Animals were either vehicle or donor dexDCs pretreated. Serum was used to monitor glucose, C-peptide, and alloreactive antibodies., Results: The transplantation of DA islets into Lewis recipients showed direct graft failure with reduced numbers of β-cells when rats were pretreated with donor dexDCs. In the reverse model (Lewis islets into DA recipients), dexDC-treated DA recipients even showed a significantly accelerated rejection of Lewis islets. Immunohistochemical analysis of allograft tissue of dexDC-treated recipients showed a predominant natural killer cell infiltration and a presence of antibody reactivity in the absence of complement deposition. Alloreactive antibodies were solely found in dexDC-treated recipients., Conclusion: Our study shows that pretreatment with donor-derived dexDCs induces an antibody-mediated rejection in this islet transplantation rodent model.

Endothelial chimerism in transplanted organs is a fascinating phenomenon, indicative of a mechanism by which progenitor recipient cells replace the donor endothelium. It has been hypothesized that this replacement could lead to a decrease in alloreactivity and thus would positively influence graft outcome. However, recent studies have shown that the amount of recipient-derived endothelial cells found in donor organs is relatively small. What effect on graft survival can we expect from this low number of chimeric cells? There are several hypotheses that address this question, but distinguishing the true effect of donor endothelial replacement on outcome from other factors affecting graft survival is difficult. Furthermore, "contamination" of chimeric cells from sources other than the recipient would have to be excluded before the effect of donor endothelial replacement by recipient cells can be accurately assessed. Pregnancies and blood transfusions are the other sources that may induce chimerism. Most of the techniques currently used to detect chimeric cells in donor organs are not specific enough to distinguish chimeric cells that may have been present in the graft before transplantation and recipient-derived chimeric cells that replace the endothelium after transplantation. Also, the sensitivity of these techniques may be questioned: do we really detect all chimeric cells that are present? This review will elaborate on these questions and discuss future perspectives of research into chimerism.

Background: Delayed graft function (DGF) occurs in up to 50% of renal transplants. Hypercalcemia and hyperparathyroidism are associated with impaired renal function. Little is known on the effects of serum calcium levels on DGF. This issue was addressed in the current study., Methods: Patients receiving a cadaveric renal transplant between 1986 and 1996 were studied. Data on calcium metabolism and histologic characteristics of nephrocalcinosis, acute tubular necrosis (ATN), and acute rejection in biopsies taken within the first week were related to the occurrence of DGF., Results: The incidence of DGF in a cohort of 585 cadaveric transplants was 31%. DGF correlated independently with serum calcium levels (odds ratio [OR] 1.14 [95% confidence interval (CI) 1.04-1.26] per 0.1 mmol/L). The use of calcium channel blockers before transplantation protected against DGF (OR 0.5 [95% CI 0.29- 0.87]). In this selected group, we found an association with histologic signs of ATN and DGF. However, most of the biopsies also had features of acute rejection or nephrocalcinosis. Nephrocalcinosis was found in 12 of 71 biopsies and was not associated with serum calcium levels or the occurrence of DGF., Conclusions: In this study, serum calcium levels were independently associated with DGF. This could not be explained by the presence of microscopic nephrocalcinosis. Therefore, DGF is attributed to high intracellular calcium levels. Because calcium supplementation and vitamin D analogues are commonly used in dialysis practice, hypercalcemia influences long-term graft outcome by its effect on DGF. The pretransplant use of calcium channel blockers has a protective effect on the occurrence of DGF.

Background: Acute rejection is a major complication after renal transplantation and the most important risk factor for chronic rejection. We investigated whether the timing of the last treated acute rejection episode (ARE) influences long-term outcome and compared the risk profiles of early versus late ARE., Methods: A cohort of 654 patients who underwent cadaveric renal transplants (1983-1997) that functioned for more than 6 months was studied. In 384 of 654 transplant recipients, one or more treated AREs were documented; the last ARE occurred in 297 of 384 transplant recipients within 3 months and in 87 of 384 after 3 months. Applying multivariate logistic regression analysis, we compared the predictor variables of the two groups with transplants without AREs., Results: Ten-year graft survival rates censored for causes of graft loss other than chronic rejection were 94%, 86%, and 45% for patients without ARE, with early ARE, and with late ARE, respectively. Delayed graft function, odds ratio (OR) 2.37 (1.55-3.62), and major histocompatibility complex (MHC) class II incompatibility, OR 2.28 (1.62-3.20) per human leukocyte antigen (HLA)-DR mismatch, were independent risk factors for early ARE. In contrast, recipient age, OR 0.75 (0.61-0.93) per 10-year increase, donor age, OR 1.28 (1.07-1.53) per 10-year increase, female donor gender, OR 1.74 (1.03-2.94), and MHC class I incompatibility, OR 1.35 (1.07-1.72) per mismatch of cross reactive groups, were associated with late ARE., Conclusions: Late ARE has a detrimental impact on long-term graft survival and is associated with MHC class I incompatibility, whereas early ARE is correlated with HLA-DR mismatches and has a better prognosis. These data are consistent with the role of direct and indirect allorecognition in the pathophysiology of early and late ARE, respectively.

Background: Endothelial chimerism, that is, the replacement of damaged donor endothelium by recipient precursors, has been proposed to reduce the allogeneic stimulus and graft rejection. However, both its mechanism and consequence are poorly understood. In this study, we set up a rat model of renal transplantation to investigate the phenomenon of endothelial chimerism and the relationship among the factors involved in its induction, such as preischemic injury, severity of graft rejections, and the role of cyclosporine A toxicity., Methods: Female Lewis rats received renal transplants from male Brown Norway kidneys. Groups were divided according to ischemia or nonischemia of the donor kidney and cyclosporine treatment or nonimmunosuppression. To investigate the endothelial chimerism, an in situ hybridization by an X-chromosome-specific DNA probe was performed. The severity of allograft rejection was scored according to the Banff '97 classification., Results: In grafts without preischemic injury or without cyclosporine A treatment, a low degree of endothelial chimerism was detected, although severe vascular rejection and tissue necrosis developed. More chimerism was found in recipients receiving an ischemic kidney followed by immunosuppressive treatment, although less severe rejection developed. In recipients receiving an ischemic kidney without cyclosporine A treatment, the highest degree of endothelial chimerism occurred., Conclusions: Endothelial chimerism demonstrated in rats after renal transplantation may be caused by endothelial damage induced by vascular rejection or ischemia. Ischemia had the strongest association with the induction of chimerism, which may function as a synergistic promoter. A low-dose cyclosporine A treatment was shown to inhibit endothelial replacement.

Background: A case-control study was performed to investigate whether mRNA levels of transforming growth factor-beta (TGF-beta) and various extracellular matrix molecules in renal transplant biopsy specimens, taken during acute rejection episodes within 6 months of transplantation, discriminate between patients who show deterioration of graft function and develop chronic rejection (CR+ group), and those who do not develop chronic rejection (CR- group)., Methods: Patients in both the CR+ group (n=10) and the CR- group (n=18) had at least one biopsy-proven acute rejection episode within the first 6 months after transplantation. The two groups were similar with respect to donor-, recipient-, and transplantation-related clinical variables. Histologic changes (Banff classification) and the timing of the acute rejection episodes in the biopsies studied did not differ between groups. Renal cortical mRNA levels of TGF-beta1, collagen alpha1(IV), collagen alpha1(I), decorin, and the household gene glyceraldehyde-3-phosphate dehydrogenase in biopsy specimens taken during acute rejection episodes were quantified by real-time polymerase chain reaction., Results: The mean TGF-beta mRNA level in the CR- group was 3.4 times higher than that in the CR+ group (P<0.04). The mean collagen IV, collagen I, and decorin mRNA levels in the CR- group were 4.2 times (P<0.05), 5.1 times (not significant), and 3.2 times (P<0.05) higher, respectively, than those in the CR+ group. The mean TGF-beta to decorin mRNA ratios between the two patient groups did not differ significantly., Conclusions: In summary, high mRNA levels for TGF-beta, collagen IV, and decorin, but not histopathologic changes, in biopsies taken during acute rejection episodes early after kidney transplantation are associated with absence of chronic rejection. We hypothesize that TGF-beta might have beneficial effects during acute rejection through its known antiinflammatory actions or as an inducer of tissue repair.

Background: After successful kidney transplantation patients may suffer from the adverse effects due to the use of calcineurin inhibitors. Calcium channel blockers are effective in the treatment of hypertension and may ameliorate cyclosporine- (CsA) induced impairment of renal function after kidney transplantation. Calcium channel blockers may also modulate the immune-system which may result in reduction of acute rejection episodes., Patients and Methods: From June 1995 till 1997 the effect of isradipine (Lomir) on renal function, incidence and severity of delayed graft function (DGF), and acute rejection after kidney transplantation, was studied in 210 renal transplant recipients, who were randomized to receive isradipine (n=98) or placebo (n=112) after renal transplantation in a double-blind fashion., Results: In the isradipine group renal function was significantly better at 3 and 12 months (P=0.002 and P=0.021) compared with the placebo group. DGF was present in both groups: isradipine: (28+6)/98 (35%); placebo: (35+9)/112 (40%), P=0.57. Severity of DGF was comparable in both groups (isradipine: 9.1+/-8.7 vs. placebo: 9.3+/-8.1 days). No statistical difference was found in incidence or severity of biopsy-proven acute rejection [isradipine: (42+6)/98 (49%) versus placebo: (46+9)/112 (49%), P=1.00]. Renal vein thrombosis was observed in eight patients. This proved to be associated with the route of administration of the study medication [6/45 (13%) on i.v. medication versus 2/165 (1%) on oral medication, P<0.001]., Conclusions: Addition of isradipine results in a better renal function after kidney transplantation, without effect on incidence or severity of DGF or acute rejection.

Background: Mycophenolic acid, the active metabolite of mycophenolate mofetil, inhibits the glycosylation of cell membrane glycoproteins. We hypothesized that impaired glycosylation of cell adhesion molecules on endothelial cells in vivo results in decreased susceptibility to inflammation or immunogenicity after allogeneic transplantation., Methods: The expression of mannose residues on cultured rat endothelial cells was examined after stimulation with interleukin 1 in the presence or absence of mycophenolic acid using labeled Galanthus nivalis agglutinin. The in vitro adhesion of blood leukocytes to heart tissue was examined using peripheral blood leukocytes of recipient origin and sections of donor heart tissue exposed to ischemia-reperfusion injury after pretreatment with vehicle or mycophenolic mofetil. (LEWxBN)F1 donor rats were treated with 20 or 60 mg/kg/day of mycophenolate mofetil for 1 or 2 weeks followed by transplantation of the heart into Lewis recipients after storage in heparin-containing normal saline for either 10 min at 4 degrees C or 120 min at room temperature., Results: Endothelial cells stimulated in vitro with interleukin 1 showed an increase in a population of strongly mannose-positive cells, which was prevented by the addition of mycophenolic acid during the culture. The in vitro adhesion of peripheral blood leukocytes to cardiac tissue sections exposed to prolonged storage and reperfusion was significantly less if the donor had been treated with mycophenolate mofetil. Treatment of cardiac graft donors with mycophenolate mofetil protected the graft against early graft failure after prolonged storage at room temperature, because the mean graft survival was 9.4+/-0.6 days for grafts that came from donors treated with mycophenolate mofetil versus 1.2+/-0.9 days (P<0.05) for grafts that came from vehicle-treated donors. Donor pretreatment with mycophenolate mofetil did not affect the survival time of heart grafts transplanted after 15 min of standard cold storage or the survival of grafts transplanted into presensitized recipients., Conclusion: Donor treatment with mycophenolate mofetil protects cardiac grafts against primary nonfunction after prolonged tepid storage, which may be related to the inhibition of glycosylation of cell adhesion molecules involved in ischemia-reperfusion injury.

Unlabelled: DNA of the epidermodysplasia-verruciformis associated subgroup of HPV (EV-HPV) is frequently detected in biopsies of premalignant lesions and nonmelanoma skin cancers of renal transplant recipients. The prevalence of EV-HPVs, however, has never been systematically studied in benign keratotic skin lesions of patients with or without a history of skin cancer. This study included 42 renal transplant recipients with and 36 without a history of skin cancer. A total of 176 skin biopsies were tested for the presence of EV-HPV DNA, using a nested polymerase chain reaction (PCR)., Method: EV-HPV typing was done by comparison of the sequence of the amplified PCR products with the sequence of all known EV-HPVs. The natural history of the development of keratotic skin lesions was studied. The number of keratotic skin lesions rapidly increased after transplantation. This increase was most pronounced in patients who developed skin cancer. The prevalence of EV-HPV DNA in benign keratotic skin lesions was equally high in patients with and without a history of skin cancer, i.e., 55 and 53% in the two groups, respectively. A large variety of EV-HPV types was found, but of these none were predominantly present in either patient groups. A higher prevalence of EV-HPV DNA was found in benign skin lesions from sun-exposed sites, but only in patients with a history of skin cancer. The association between the number of keratotic skin lesions and the development of skin cancer strongly supports the hypothesis that EV-HPVs play a role in cutaneous oncogenesis. The equally high prevalence of EV-HPV infection in patients with and without a history of skin cancer, however, may indicate that besides EV-HPV infection, other factors, such as sun exposure may also be important.

Background: There is accumulating evidence that blockade of the costimulatory pathways offers a valid approach for immune suppression after solid organ transplantation. In this study, the efficacy of anti-CD80 and anti-CD86 monoclonal antibodies (mAbs) in combination with cyclosporine (CsA) to prevent renal allograft rejection was tested in non-human primates., Methods: Rhesus monkeys were transplanted with a partly major histocompatibility complex-matched kidney on day 0. Anti-CD80 and anti-CD86 mAbs were administered intravenously daily for 14 days starting at day - 1. CsA was given intramuscularly for 35 days starting just after transplantation. The kidney function was monitored by determining serum creatinine levels., Results: The combination of anti-CD80 and anti-CD86 mAbs completely abrogated the mixed lymphocyte reaction. Untreated rhesus monkeys rejected the kidney allograft in 5-7 days. Treatment with anti-CD80 plus anti-CD86 mAbs resulted in a significantly prolonged graft survival of 28+ 7 days (P=0.025). There were no clinical signs of side effects or rejection during treatment. Kidney graft rejection started after the antibody therapy was stopped. The anti-mouse antibody response was delayed from day 10 to 30 after the first injection. No difference in graft survival was observed between animals treated with CsA alone or in combination with anti-CD80 and anti-CD86 mAbs. However, treatment with anti-CD80 and anti-CD86 mAbs reduced development of vascular rejection., Conclusions: In combination, anti-CD80 and antiCD86 mAbs abrogate T-cell proliferation in vitro, delay the anti-mouse antibody response in vivo, and prevent graft rejection and development of graft vascular disease in a preclinical vascularized transplant model in non-human primates.

Background: We previously reported the successful withdrawal of immunosuppression in kidney-allografted rhesus monkeys. Recipients had received pretransplant blood transfusions and cyclosporine (CsA) immunosuppression for 6 to 12 months. One animal is still alive at more than 15 years after transplantation. Our hypothesis was that the sharing of a single DR antigen between blood donor and recipient, and the sharing of the same DR antigen with the kidney donor, may be beneficial to allograft survival. We now report on the results from a prospective study., Methods: The animals received three pretransplant blood transfusions from a single donor sharing one DR antigen with the recipient. Subsequently, a life-supporting kidney from a donor sharing the same DR antigen was transplanted. CsA was given for at least 6 months after transplantation., Results: Two animals rejected their graft at 5-8 weeks after cessation of CsA treatment. One animal is still alive at 700 days after transplantation. This animal showed MLR nonreactivity to its kidney donor, similar to the animal at more than 15 years after transplantation., Conclusion: These results demonstrate that withdrawal of immunosuppression may be a realistic option in kidney graft patients under careful immunological monitoring of donor-specific immunity.

Background: Recently it has been recognized that apoptosis of target cells may occur during liver and kidney allograft rejection and is probably induced by infiltrating cells. Pancreas rejection is also characterized by a cellular infiltrate, however, the occurrence of apoptosis has not been investigated. We assessed whether pancreas rejection was associated with apoptosis of target cells and an influx of granzyme B (GrB)-positive or CD68-positive cells., Methods: Eighteen pancreas biopsies (10 of 18 with rejection) from 15 patients with a pancreas-kidney transplantation were stained with the in situ end-labeling method for apoptosis, and for CD3, GrB, and CD68., Results: Significantly more apoptotic acinar cells were found in biopsies with rejection when compared with biopsies without rejection. No difference was observed between the groups for GrB+ or CD68+ cells., Conclusion: We conclude that pancreas rejection is associated with apoptosis of acinar cells, but not with an increased influx of GrB+ cells or macrophages.

Background: Rejection after pancreas-kidney transplantation may occur isolated or concurrently in both grafts. To get more insight into the cellular mechanisms underlying these rejection episodes, we compared the functional characteristics of pancreas and kidney graft-infiltrating T cells., Methods: Graft-infiltrating T cell (GIC) lines were cultured from simultaneously taken pancreas and kidney biopsies from eight patients. CD4 to CD8 ratios were determined by fluorescence-activated cell sorter and cytotoxicity toward donor proximal tubular epithelial cells (PTEC) and donor spleen cells (DSC) using a standard cytotoxicity assay. Cytokine production was determined by enzyme-linked immunosorbent assay., Results: CD4 to CD8 ratios were comparable between the pancreas and kidney lines for each patient, but differences were observed in cytotoxicity toward PTEC and DSC. For four of eight patients, the lysis of PTEC by pancreas GIC was less than the lysis induced by kidney GIC. This was also seen in three of five patients for lysis of DSC. The specificity of GIC lines toward mismatched donor antigens was studied for two patients and appeared to be comparable for pancreas and kidney. Most GIC lines produced interferon (IFN)-gamma (75.5+/-22.7 pg/ml), but no IL-10, indicating that the cell lines consisted primarily of Th1 and type 1 CD8+ cells. Mean production of IL-6 was 465.6+/-193.6 pg/ml. No major differences were observed between kidney and pancreas GIC for either cytokine., Conclusions: We conclude that pancreas and kidney GIC lines have the same phenotype, cytokine production, and allospecificity. Differences were, however, seen for lysis of PTEC and DSC, suggesting that tissue-specific antigens might play a role.

Background: Graft rejection is one of the major causes of graft loss after pancreas transplantation. Pancreatitis-associated protein (PAP) is synthesized by the pancreas due to pancreatic inflammation and has shown to be a good serum marker for injury of the pancreas. It may also be potentially useful in the early recognition of rejection and may thus improve pancreas survival., Methods: We retrospectively evaluated PAP as an early serum marker of pancreas graft rejection in a cross-sectional study in which immunohistochemical analysis of pancreas biopsies was undertaken using antibodies against PAP. PAP concentrations were also measured in sera of blood donors and in patients with renal failure, renal replacement therapy, kidney transplantation alone, and simultaneous pancreas-kidney transplantation., Results: All patients had elevated PAP serum levels compared with blood donors (median PAP: 22 ng/ml, range: 5-75 ng/ml; P<0.0001). Patients on renal replacement therapy had higher values than patients with renal failure (median: 420 ng/ml and 150 ng/ml, respectively). There was a strong inverse correlation between PAP levels and creatinine clearance (P<0.001). PAP values in simultaneous pancreas-kidney transplantation patients with histological rejection were significantly higher than values in those who were clinically stable (median: 925 ng/ml and 322 ng/ml, respectively; P=0.006). Rejection was significantly associated with PAP staining of acinar cell surface. There was also a significant correlation between surface positivity of staining and serum PAP levels (P=0.008). No positive PAP staining was observed in concurrently collected biopsies of renal allografts undergoing rejection., Conclusions: Serum PAP levels appear to strongly correlate with creatinine clearance measurements. In patients with a pancreas-kidney transplantation, PAP may prove to be a useful biological and histological marker of pancreatic graft rejection.

Histological and immunohistochemical analyses were made of biopsy specimens from 50 consecutive patients who experienced putative graft rejection. The mean age of the patients was 44.5 years (range, 17-69 years) and 26 were men. There were 67 evaluable allograft specimens, which were grouped according to the histological diagnosis: group 1, acute tubulointerstitial rejection (n = 42); group 2, acute vascular rejection (n = 18); and group 3, diffuse thrombosis (n = 7). Over a follow-up period of 21-57 months, the mean number of rejection episodes was 1.7, 2.8, and 3.3 in groups 1, 2, and 3, respectively. Allograft loss occurred in 7 out of 30, 10 out of 16, and 4 out of 4 patients in groups 1, 2, and 3, respectively. The following histological parameters differed significantly (P < 0.05) among the groups: interstitial edema, congestion of peritubular capillaries, glomerular thrombosis, and glomerular ischemia (group 3 > group 2 > group 1). Interstitial bleeding was seen more often in group 2 and 3 tissues than in group 1 specimens (P < 0.01). Immunohistochemical analyses showed that vascular rejection was associated with WT14 staining for monocytes and macrophages around the tubuli and with interstitial deposition of complement factor 3. With regard to serology, positive anti-endothelial cell antibody-dependent cellular cytotoxicity was associated with vascular rejection and thrombosis of the graft in all patients tested, and with graft loss in 75%. Pre-existent positive anti-IgG immunofluorescence on peritubular capillaries in pretransplant biopsy specimens incubated with patient serum was found in only 3 of the 50 patients, but was associated with graft loss in 2 of the 3. Cytomegalovirus infection was associated with a higher percentage of graft loss. There were significant intergroup differences in panel reactive antibodies before transplantation (P < 0.001), with higher titers in groups 2 and 3. The findings in relation to interstitial rejection are compatible with cellular rejection, while the data on vascular rejection support a humorally mediated pathogenesis.

Chronic rejection of renal allografts is a major cause of late graft loss. However, time of onset, relation with acute early rejection episodes, and risk factors are largely unknown. We undertook a cohort study of 482 consecutive patients from a single center who received a cadaveric renal allograft between January 1983 and April 1991. During the first 3 months after transplantation, 76 (15.8%) patients developed vascular rejection and 115 (23.9%) developed interstitial rejection. One-year graft survival of patients without rejection, with interstitial rejection, and with vascular rejection was 87.8%, 87%, and 48.7%, respectively. Five-year graft survival was 73.5% for the group without rejection, 71.4% for patients with interstitial rejection, and 34.3% for patients with vascular rejection. The adjusted relative risk of graft loss was 4.92 (95% CI 3.25-7.43) for patients with vascular rejection and 1.27 (95% CI 0.80-2.02) for patients with interstitial rejection compared with patients without early rejection, taking the time dependency of the rejection events and prognostic factors into account. The incidence of vascular rejection was increased in patients with primary nonfunction (RR 1.69, 95% CI 1.01-2.84), with 1 HLA-DR mismatch (RR 2.38, 95% CI 1.44-3.93), with 2 HLA-DR mismatches (RR 3.24, 95% CI 1.25-8.42), with a prolonged cold ischemia time (RR 1.03, 95% CI 1.00-1.06 per hr), and with 1 or more previous transplantations (RR 1.76, 95% CI 1.01-3.07). Risk of developing vascular rejection was decreased in patients using CsA as compared with azathioprine (RR 0.41, 95% CI 0.24-0.67). Early vascular rejection, occurring within 3 months after transplantation, is the most important predicting variable of both early and late graft loss. Use of CsA, less HLA-DR mismatching, and a cold ischemia time of short duration possibly prevent the development of vascular rejection.

Serum samples of 64 consecutive patients who underwent renal transplantation in our institution were examined for the presence of antibody-dependent cellular cytotoxicity (ADCC) activity against endothelial cells (EC). From each patient serum samples were obtained immediately before transplantation and 1 week, 1 month and 1 year thereafter. The results were evaluated in the context of tests to measure donor-specific humoral immunity against lymphocytes and monocytes, and related to parameters of presensitization, graft survival, and histology. Sera from 10 patients were positive for ADCC on a panel of HLA-typed endothelial cells. In 8 patients sera were already positive before transplantation and remained positive thereafter. In 4 patients a positive crossmatch with donor T and B cells and monocytes could be observed after transplantation. In only one patient were these crossmatches positive before transplantation. A significant correlation was found between ADCC positivity and vascular rejection (P = 0.015); in addition graft survival was significantly better in the ADCC negative group vs. the positive group (P = 0.0004). These data demonstrate the significance of allospecific anti EC antibodies for the occurrence of vascular rejection and graft loss after renal transplantation.

The role of hydroxyethyl starch (HES), the colloid component of the UW solution, was tested in canine pancreas preservation. Segmental pancreatic autografts were preserved for 48 hr cold storage with UW solution with HES (group 1) or UW solution without HES (group 2). After preservation, the pancreas was transplanted, and survival, serum glucose, serum amylase, intravenous glucose tolerance tests, tissue water content, and histology were compared between groups. In group 1 (with HES), 9/10 dogs were long-term survivors with one dog dying due to causes unrelated to preservation failure. In group 2 (without HES), 3/6 dogs died due to graft loss within one week posttransplant (P = 0.01). No graft failure occurred in group 1 (0/9) versus graft loss in 4/6 dogs in group 2 (P = 0.04). All animals in group 1 (with HES) showed normal serum glucose and amylase concentrations postoperatively, normal tissue water values after preservation, k values comparable to those observed after segmental autotransplantation without preservation, and relatively good histology. In group 2 (without HES), in 4/6 dogs graft failure occurred that led to the death (3 dogs) of the animals or to a diabetic state (1 dog). After 48-hr cold storage without HES, a significant increase in tissue water content, glucose and amylase levels was seen. After transplantation, hyperglycemia, hyperamylasemia, and clinical diabetes were observed in 4/6 dogs. Autopsy and histological evaluation showed evidence of thrombosis and ischemic insult. Two of 6 dogs in group 2 remained normoglycemic during follow-up with borderline k values. The results suggested that for consistently successful 48-hr preservation of the pancreas, HES is an important component of the UW solution. Although a colloid may not be essential for short-term preservation of kidney and liver, it appears to be an important factor in successful pancreas preservation.