Opposite effects of testosterone and estrogens on chronic allograft nephropathy

In the present study we investigated whether donor gender or the effects of sex hormones play the greater role in the development of chronic allograft nephropathy. Kidneys of male and female Fisher rats were orthotopically transplanted into castrated male Lewis recipients. Animals were treated with testosterone, estradiol, or vehicle and the kidneys were harvested 20 weeks after transplantation for histological, immunohistological, and molecular analysis. Testosterone treatment resulted in increased proteinuria and profound glomerulosclerosis, irrespective of donor gender. In addition, mRNA levels of transforming growth factor-beta1 (TGF-beta1) and platelet-derived growth factor-A and B (PDGF-A and B) chains were enhanced in these allografts. Estradiol reduced glomerulosclerosis and mononuclear cell infiltration in allografts of both genders that paralleled a decreased mRNA expression of TGF-beta1, PDGF-A and B. No donor gender-related differences were noted in vehicle-treated animals. Our findings demonstrate that sex hormones rather than donor gender have a significant impact on chronic allograft nephropathy.     

Effects of sex steroid hormones on sex-associated differences in the survival time of allogeneic skin grafts in rats. Evidence that testosterone enhances and estradiol reverses the immunosuppressive activity of cyclosporine

Three-week-old DA (RT1a) male and female rats were pretreated with either orchiectomy or ovariectomy and administration of the opposite-sex steroid hormones, estradiol or testosterone. Skin from same-sex AO (RT1a) rats was then grafted when these pretreated rats reached 14 weeks of age, with a short course of immunosuppressive treatment of cyclosporine. The survival times of the grafts were reversed in that the male recipients pretreated to be like females acutely rejected the graft within 10 days as do normal adult female recipients. On the other hand, the female recipients pretreated to be like males accepted the graft as do normal adult male recipients. In addition, the synergistic effects of either testosterone or estradiol with CsA on the survival time of the graft were examined. Testosterone successfully prolonged graft survival on normal adult female and young male recipients, but negligible prolongation was observed on young females. In contrast, estradiol abrogated the immunosuppressive activity of CsA and accelerated graft rejection in both male and female recipients.     

The effect of donor gender on graft survival

Differences in actuarial graft survival according to donor gender have been reported for renal allografts and for cardiac and hepatic allografts, but for the latter in small series with limited biostatistical power. Using the large database of the Collaborative Transplant Study (CTS), this study is an evaluation of graft survival according to donor and recipient gender for renal (n = 124,911), cardiac (n = 25,432), and hepatic (n = 16,410) transplants. Confounders, such as calendar year, geographical area, race, donor and recipient age, HLA mismatch, cold ischemia time, and others, as well as interaction terms were taken into consideration. Death-censored actuarial renal allograft survival from female compared with male donors was less in female recipients and even more so in male recipients. The donor gender-associated risk ratio for graft loss was 1.15 in female recipients and 1.22 in male recipients. The age-gender interaction term was statistically significant, the gender effect being more pronounced for younger (16 to 45 yr) compared with older (>45 yr) donors. Serum creatinine concentrations 1 yr after transplantation were also higher for recipients with kidney grafts coming from female donors irrespective of recipient gender. For first cardiac transplants, graft survival was inferior when the donor was female and the recipient male, but no statistical difference according to donor gender was demonstrable in female recipients. For first hepatic transplants overall, no significant differences according to donor gender were noted. The proportion of recipients who had treatment for rejection crisis during the first year was higher for male recipients of kidneys from female donors compared with male donors. No difference according to donor gender was demonstrable in female recipients. For cardiac and hepatic grafts, no significant effect of donor gender on the proportion of patients treated for rejection episodes was noted. The data show that adverse effects of female donor gender for different organs is much less uniform than reported in the past. An important confounder is donor age. A gender effect on graft survival is also observed for cardiac allografts. Therefore, in addition to potential "nephron underdosing," further pathomechanisms must play a role, possibly differences in immunogenicity according to donor gender.     

Living donor kidney transplantation: the effects of donor age and gender on short- and long-term outcomes

BACKGROUND: The influence of donor age and sex on acute rejection episodes and short- and long-term graft survival in living donor (LD) kidney transplantation has not been well characterized. METHODS: This prospective cohort study includes 739 first time LD transplantations with median follow-up time of 55.1 months. Death censored graft survival according to donor age and sex was compared with Kaplan-Meier plots. Cox regression was performed to estimate the association between different risk factors and graft survival and acute rejection episodes. RESULTS: Graft survival was not affected by donor age above 50 years as long as these recipients did not experience an early acute rejection episode. Acute rejection episodes increased in recipients of grafts from donors > or =65 years (P=0.009). Donor age > or =65, recipient age less than 50 years, human leukocyte antigen (HLA)-DR matching, and female donor gender were risk factors for early acute rejection episodes. In multivariate analysis donor age > or =65 years was a risk factor for graft loss in all time periods after transplantation. During the first 5 years after transplantation a steroid resistant rejection episode was an additional risk factor. More than 5 years after transplantation male donor gender was the only additional risk factor for graft loss. CONCLUSION: These results support the continued use of older male and female living donors who meet carefully constructed medical criteria and who are highly motivated to donate. Furthermore, donor age seems to be a more important predictor of graft loss than donor sex.     

The impact of sex and age matching for long-term graft survival in living donor renal transplantation

BACKGROUND: Deficient functional renal mass leads to progressive renal injury owing to the detrimental effects of glomerular hyperfiltration. Therefore, renal transplant mass is an important determinant of outcome. MATERIALS AND METHODS: We retrospectively analyzed 614 living donor renal transplantations performed from 1979 to 2002. Patients were divided into 4 groups according to donor-recipient gender differences: group 1 (male to male), group 2 (male to female), group 3 (female to male), and group 4 (female to female). We analyzed the clinical and immunological data to compare the 4 groups with respect to long-term graft survival, age gender, acute rejection episodes an HLA matching. We used the Kaplan-Meier method with the log-rank test to assess graft survival. RESULTS: The actuarial graft survival rate was 86.24% at 5 years for donors younger than 50 years of age compared with 73.15% for those older than 50 years (P = .0000). The graft survival from younger donors than recipients was 85.23% at 5 years compared with 80.35% for older donors (P = .0213). The graft survival of group 3 (female donor to male recipient) was 75.12% at 5 years compared with 85.72%, 85.33%, and 83.16% for groups 1, 2, and 4, respectively (P = .0165). The main parameters significantly associated with graft survival were donor age (P = .0000), acute rejection episode (P = .0000), donor gender (P = .0215). HLA-DR matching (P = .0516), and donor and recipient age matching (P = .0213). CONCLUSIONS: The results suggest that the sex and age matching between donors and recipients should be considered as a criterion in the choice of donor and recipient pairs for living donor renal transplantation.     

Male recipients of kidneys from female donors are at increased risk of graft loss from both rejection and technical failure

The aim of the present retrospective study was to uncover the factor(s) responsible for the poor outcome of cadaver kidney grafts from female donors in male recipients. The 741 transplantations performed at our center from August 1983 to September 1997 were distributed into four groups according to recipient and donor gender: female donor to female recipient (F to F: n = 117), male donor to female recipient (M to F: n = 172), female donor to male recipient (F to M: n = 170), and male donor to male recipient (M to M: n = 282). All the patients received immunosuppressive therapy based on corticosteroids and cyclosporine, associated or not with either azathioprine or prophylactic anti-lymphocyte globulin. Overall graft survival was lower in the F to M group than in the three other groups (p = 0.009). Failures due to rejection were more frequent during the 1st post-transplant trimester in female than in male donor grafts, irrespective of recipient gender (p = 0.025). All failures due to technical problems occurred during the first 3 months post-transplantation: they were more frequent in the F to M group than in the three other groups (p = 0.040): this could be related to the older age of the donors in the former group. After the first post-transplant year, failures due to causes other than rejection remained low in the F to F group but increased steadily in the three other groups (p = 0.007). Specific survival rates were not correlated with the time-evolution of mean serum creatinine values, daily doses and trough levels of cyclosporine in the four groups of grafts. In conclusion, the poor outcome of F to M grafts results from combined immunologic and technical factors exerting their effects early in the course of transplantation.     

The impact of gender and age matching for long-term graft survival in living donor renal transplantation

In renal transplantation, donor age and allograft size are known to have an important influence on the outcome of the graft reflecting functional renal mass. Women tend to have smaller kidneys with 17% fewer nephrons than male kidneys. The number of glomeruli per kidney as well as the mean glomerular volume closely correlate with kidney weight and negatively correlate with subject age. We evaluated the impact of gender and age matching in living-donor renal transplantation on long-term graft survival. MATERIALS AND METHODS: Four groups were discerned among 614 renal transplants, according to donor and recipient gender: Group 1 was male donor to male recipient; Group 2 was male donor to female recipient; Group 3 was female donor to male recipient; and Group 4 was female donor to female recipient. We analyzed long-term graft survival and risk factors between the four groups as well as according to age matching. Statistical significance was determined by the Kaplan-Meier method and log rank test (P < .05). RESULT: The graft survival rates at 1, 3, 5, and 10 years were 92.62%, 88.13%, 82.37%, and 76.07%, respectively. The risk factors affecting long-term graft survival were donor age, donor gender, acute rejection rate, and HLA-DR matching. Among the four groups, the graft survival rates of Group 3 (female donor to male recipient) were significantly different from the other groups (P = .0165). Also, the long-term graft survival rates according to age differences were significantly different between older donors than recipients and younger donors than recipients in each group (P = .0213). CONCLUSION: The importance of inadequate renal mass is magnified in high-risk recipients. Age matching could perhaps improve the results of transplantation, particularly when kidneys from older donors are used. Consideration of age and gender as criteria for the choice of donors and recipients may be considered in organ allocation.     

雌激素预防大鼠同种肾移植慢性排斥反应的实验研究

目的 探讨雌激素对移植肾慢性排斥反应的影响。方法 以Fisher大鼠作供者,雌性Lewis大鼠作受者进行同种肾移植,为排除排卵周期及相应的内源性性激素变化的影响,肾移植均在非排卵期进行,后治疗组大鼠隔日给予25μg/kg雌二醇皮下注射。移植后16周作肾功能、移植肾组织学及免疫组化检测,测定肾组织中转化生长因子及β－机动蛋白mRNA的表达。结果 与对照组比较,移植后治疗组24d尿蛋白持续保持较低的水平（P＜0.01）,血清肌酐水平降低（P＜0.01）,肌酐清除率升高（P＜0.01）,移植肾组织管内膜增厚、肾小球硬化和间质纤维化程度减轻（P均＜0.01）,淋巴细胞和单核／巨噬细胞浸润减少（P＜0.01）,细胞间粘附分子（ICAM－1）、转化生长因子（TGF－β1）的mRNA表达减少（P均＜0.01）。结论 雌激素对移植肾功能有保护作用,其机理与影响上述细胞因子在移植肾的表达有关,提示雌激素可能为一类潜在的抗慢性排斥反应药物。     

Immunohistochemical analysis of extracellular components in the glomerular sclerosis of patients with glomerulonephritis

Immunofluorescence and immunoperoxidase staining was carried out to determine correlations between the progression of glomerular sclerosis and changes in the amount or distribution of glomerular extracellular components, including type I, III, IV, and VI collagens, laminin and fibronectin, in patients with IgA nephropathy, membranoproliferative glomerulonephritis and rapidly progressive glomerulonephritis. Staining of type I and III collagens was not observed in glomeruli from normal individuals or patients with mild glomerulonephritis. In the advanced stages of glomerulonephritis, the staining of type IV and VI collagens, laminin and fibronectin was marked in the glomerular mesangium, and the distribution of fibronectin extended to the glomerular capillary walls in the sclerotic lesions of glomeruli. However, the staining intensity of type IV collagen, laminin and fibronectin was gradually decreased during the progression of glomerular sclerosis. On the other hand, the staining of type I and III collagens was observed focally in sclerotic or hyalinotic glomeruli and around such glomeruli in those patients. Light microscopic examination revealed that patients who showed marked staining of type I and III collagens by immunofluorescence had severe damage of Bowman's capsules. These results suggest that the hyperproduction and/or invasion of interstitial collagens, i.e., types I and III, are closely linked to the progression of glomerular sclerosis and hyalinosis in patients with various types of glomerulonephritis.     

Contribution of androgens to chronic allograft nephropathy is mediated by dihydrotestosterone.

BACKGROUND: Donor and recipient gender influence long-term allograft outcome after kidney transplantation. Sex hormones are likely to contribute to these gender-related differences. The present study investigated the role of androgens and their inhibition on the development of chronic allograft nephropathy. METHODS: Male or female Fisher (F344) kidneys were orthotopically transplanted into intact male Lewis recipients. Animals were treated either with testosterone, the antiandrogen flutamide, the 5alpha-reductase inhibitor finasteride, or vehicle. Twenty weeks after transplantation animals were harvested for histology, immunohistology, and molecular analysis. RESULTS: Testosterone treatment resulted in an increased proteinuria as well as profound glomerulosclerosis, tubulointerstitial fibrosis, and mononuclear cell infiltration that paralleled enhanced intragraft mRNA levels of transforming growth factor-beta (TGF-beta) and platelet-derived growth factor-A and -B chain (PDGF-A and -B). In contrast, flutamide and finasteride reduced glomerulosclerosis as well as the inflammatory cell infiltration associated with decreased TGF-beta, PDGF-A, and -B chain mRNA expression. No gender-related donor differences were noted between the groups. CONCLUSIONS: Our data suggest that dihydrotestosterone mediates the adverse effects of androgens on chronic allograft nephropathy. The inhibition of androgens improves long-term allograft outcome after kidney transplantation.     

ICAM-1 deficiency suppresses host allosensitization and rejection of MHC-disparate corneal transplants

BACKGROUND: We used a murine model of orthotopic corneal transplantation to determine whether host deficiency in ICAM-1 promotes survival of corneal grafts with different degrees of allodisparity. METHODS: ICAM-1-/- and wild-type C57BL/6 (ICAM-1+/+) received corneal grafts from the following strains of mice: BALB/c (fully mismatched), BALB.b (mismatched at multiple minor H only), or B10.D2 [including major histocompatibility complex (MHC) mismatch]. Graft rejection, induction of allospecific delayed-type hypersensitivity (DTH) responses, and leukocytic infiltration of grafts were measured. RESULTS: There were no differences in long-term survival of allografts that were either fully mismatched or had only minor H disparity in ICAM-1+/+ vs. ICAM-1-/-hosts. However, whereas B10.D2 grafts were accepted in only 58% of the ICAM-1+/+ hosts, graft survival in ICAM-1-/- recipients was 100% (P=0.006). Moreover, none of the ICAM-1-/- mice receiving B10.D2 grafts developed allospecific DTH. CONCLUSIONS: Prolonged survival seen in MHC-mismatched grafts in ICAM-1-/- mice, along with a suppressed DTH response to donor alloantigens after transplantation, suggest that ICAM-1 is associated with recipient sensitization to MHC alloantigens.     

Kombinierte Nieren-Pankreas-Transplantation

BACKGROUND: Differences in graft survival due to gender have been reported after transplantation of the kidney, liver, and heart. However, little is known about the role of donor and recipient gender in simultaneous pancreas-kidney transplantation. METHODS: Single-centre analysis was performed of first simultaneous pancreas-kidney transplantations performed between 1994 and 2005 at the Bochum Transplant Center in Germany (n=218). RESULTS: Recipients of female donor organs exhibited acute organ rejections earlier and more frequently (P<0.05). Male recipients of organs from male donors had a lower risk of acute rejection than recipients of female donor organs (P<0.05). In addition to female donor gender, higher donor age and early kidney dysfunction were risk factors for perioperative rejection (P<0.05). Long-term kidney and pancreas function was best in male-donor-to-female-recipient transplants over the time periods of 7 and 3 years, respectively (P<0.05). Risk factors of long-term organ failure were: the need of revision laparotomy, organ rejection, and early postoperative organ dysfunction (P<0.05). CONCLUSION: This is the first report of graft function after simultaneous pancreas-kidney transplantation looking specifically at gender differences with respect to donor and recipient. There was an increased risk of organ rejection of female donor organs.     

The importance of glomerular deposits of von Willebrand factor in human renal allografts

OBJECTIVE: The aim of this study was to evaluate the importance of glomerular expression of von Willebrand factor (vWF) in human renal allografts. METHODS: We investigated graft biopsies from 72 renal transplant recipients, 40 with acute rejection (AR) and 32 with chronic allograft nephropathy (CAN). All biopsy specimens were immunostained with vWF and CD68 and graded using 3-tiered scales. The follow-up biopsies of patients with AR were reevaluated for development of glomerular sclerosis. RESULTS: A significant difference was found between type 1 and type 2 AR with regard to glomerular vWF expression (P < 0.01). None of the patients with type 1 AR showed mesangial vWF expression, but 36.4% of patients with type 2 AR showed segmental mesangial vWF expression. In follow-up biopsies, 18 of 40 patients developed significant glomerular sclerosis, and patients with mesangial vWF expression (grade 3 GvWF) showed glomerular sclerosis earlier than did others (P < 0.01). In addition, the outcome for grafts that showed grade 3 glomerular vWF was significantly worse than was the outcome noted for grafts that showed grade 1 or grade 2 glomerular vWF (P < 0.001). Half of the biopsy specimens in the CAN group showed global mesangial vWF expression. Glomerular macrophage infiltration was correlated with degree of glomerular vWF expression both in the AR and in the CAN groups (P < 0.05, P= 0.001, respectively). CONCLUSION: We hypothesized that the increasing amount of glomerular vWF may be used as a marker of acute vascular rejection and may help for the evaluation of renal allograft biopsies without sufficient arteries. In addition, it can also be a marker for development of early glomerular sclerosis and may help us determine which patients are in need of further treatment.     

Chronic renal allograft rejection: the significance of non-MHC alloantigens

We studied the role of polymorphic endothelial antigens other than MHC in antibody-mediated chronic renal allograft rejection in two models. In the first model, donor Lewis rat kidneys were transplanted into BN recipients that had been made tolerant for donor class I antigens at the B cell (antibody) level. In this setting Lewis kidney grafts were chronically rejected with stable renal function but increasing proteinuria (> 100 mg/24 h). Rejected graft tissue showed mononuclear cell infiltration and the presence of glomerular vasculonecrotic lesions with fibrinoid material, associated with IgG and IgM deposition, but with absent or weak C3 binding. Graft endothelium showed no expression of MHC class II antigens. Serum antibodies were not reactive with donor class I antigens, but did react with endothelial non-MHC alloantigens. In the second model, more direct information on the role of endothelial non-MHC alloantigens in renal allograft rejection was obtained by transplanting Lewis 1 N kidneys into unmodified BN recipients (MHC-matched transplants). Here, similar to the first model, the animals developed severe proteinuria with stable renal function. Histopathological examination showed mononuclear cell infiltration and deposition of IgM and IgG along the glomerular vasculature, but this time in the presence of strong C3 reactivity. However, glomerular vasculonecrotic lesions with intense fibrin deposition were not observed. The data showed that although clinically the two kidney transplantation models used gave similar chronic rejection phenomena, histopathologically some striking differences were observed in the glomeruli. The precise mechanisms effecting chronic rejection of the grafts is still a puzzle. However, immune reactivity against graft (endothelial) non-MHC antigens may play a significant role.     

C5 Blockade with Conventional Immunosuppression Induces Long-Term Graft Survival in Presensitized Recipients

We explored whether a functionally blocking anti-C5 monoclonal antibody (mAb) combined with T- and B-cell immunosuppression can successfully prevent antibody-mediated (AMR) and cell-mediated rejection (CMR) in presensitized murine recipients of life-supporting kidney allografts. To mimic the urgent clinical features of AMR experienced by presensitized patients, we designed a murine model in which BALB/c recipients were presensitized with fully MHC-mismatched C3H donor skin grafts one week prior to C3H kidney transplantation. Presensitized recipients demonstrated high levels of circulating and intragraft antidonor antibodies and terminal complement activity, rejecting grafts within 8.5 ± 1.3 days. Graft rejection was predominantly by AMR, characterized by interstitial hemorrhage, edema and glomerular/tubular necrosis, but also demonstrated moderate cellular infiltration, suggesting CMR involvement. Subtherapeutic treatment with cyclosporine (CsA) and LF15–0195 (LF) did not significantly delay rejection. Significantly, however, the addition of anti-C5 mAb to this CsA/LF regimen prevented terminal complement activity and inhibited both AMR and CMR, enabling indefinite (>100 days) kidney graft survival despite the persistence of antidonor antibodies. Long-term surviving kidney grafts expressed the protective proteins Bcl-x_S/L and A-20 and demonstrated normal histology, suggestive of graft accommodation or tolerance. Thus, C5 blockade combined with routine immunosuppression offers a promising approach to prevent graft loss in presensitized patients.     

Differentiation between chronic rejection and chronic cyclosporine toxicity by analysis of renal cortical mRNA

BACKGROUND: In kidney transplantation, chronic allograft nephropathy (CAN) is the major cause of graft loss. Causes of CAN include chronic rejection and chronic cyclosporine A (CsA) nephrotoxicity. It is necessary to differentiate between these two entities in order to apply the appropriate therapeutic regimen for the individual patient, but this is hampered by the lack of discriminating functional and morphologic parameters. We investigated whether renal cortical mRNA levels for several matrix proteins can serve as discriminating parameters. METHODS: Patients with chronic rejection (N= 19) and chronic CsA toxicity (N= 17) were selected by clinical and histologic criteria. Protocol biopsies without histologic abnormalities, taken at 6 months after transplantation from patients receiving CsA, were used as controls (N= 6). Total RNA was extracted from the renal biopsy tissue, and mRNA levels of transforming growth factor-beta (TGF-beta) and the extracellular matrix (ECM) molecules collagen Ialpha1, IIIalpha1, IValpha3, decorin, fibronectin, and laminin beta2 were measured by real-time polymerase chain reaction (PCR). RESULTS: In both patient groups, the mean collagen IValpha3 and fibronectin mRNA levels were significantly elevated compared to those in controls, whereas only in CsA toxicity were the laminin beta2 and TGF-beta mRNA levels significantly increased. The increase of laminin beta2 and TGF-beta mRNA levels was significantly higher in the CsA toxicity group than in the chronic rejection group (P < 0.001 and P= 0.004, respectively). Receiver-operating characteristic (ROC) curve analysis showed that with a 15.6-fold increase in laminin beta2 mRNA expression as cut-off point, the presence of CsA toxicity could be predicted with an 87% sensitivity and an 88% specificity. CONCLUSION: Renal laminin beta2 and TGF-beta mRNA levels can be used to differentiate between chronic rejection and chronic CsA toxicity in renal transplants. The method of mRNA quantification might be applicable as an additional diagnostic tool in clinical practice.     

Histological alterations in implant and one-year protocol biopsy specimens of renal allografts

BACKGROUND: The natural course of histological changes and their correlations with clinical parameters have not been studied in large numbers in renal allograft specimens. The aim of this study was to determine whether any histological alterations developed during the first posttransplantation year. Immunological and nonimmunological factors possibly associated with subsequent histopathological changes and development of chronic rejection were also assessed. METHODS: We studied 102 cadaveric kidney allografts for which both implant and 1-year protocol biopsy specimens were available. The chronic allograft damage index (CADI) was used to quantify the extent of histological changes that developed during the first year. RESULTS: Overall, an increase in histological alterations were seen during the first posttransplantation year, and the CADI increased significantly. The mean CADI was 0.7 in relation to implant biopsy samples and 2.9 in relation to 1-year biopsy samples (P<0.05). Although the degree of changes increased during the first posttransplantation year, they were seldom severe. Significant increases in incidences of interstitial inflammation and fibrosis, tubular atrophy, and basement-membrane thickening were seen. Vascular intimal proliferation and glomerular mesangial matrix increase and glomerular sclerosis were also noted. In contrast, anisometric vacuolization in the tubular epithelium decreased significantly in incidence during the first year. CADI values 1 year after transplantation were significantly affected by donor age, occurrence of acute rejection episodes, and prevalence of HLA-DR mismatches. CADIs were also significantly higher in grafts with decreased function. CONCLUSIONS: Histopathological alterations increased in almost every graft, even well-functioning grafts, during the first year. The CADIs relating to alterations seen in cases of chronic rejection increased significantly and were strongly affected by both immunological and nonimmunological factors.     

Chronic rejection of mouse kidney allografts

BACKGROUND: Chronic renal allograft rejection is the leading cause of late graft failure. However, its pathogenesis has not been defined. METHODS: To explore the pathogenesis of chronic rejection, we studied a mouse model of kidney transplantation and examined the effects of altering the expression of donor major histocompatibility complex (MHC) antigens on the development of chronic rejection. RESULTS: We found that long-surviving mouse kidney allografts develop pathological abnormalities that resemble chronic rejection in humans. Furthermore, the absence of MHC class I or class II antigens did not prevent the loss of graft function nor alter the pathological characteristics of chronic rejection. Expression of transforming growth factor-beta (TGF-beta), a pleiotropic cytokine suggested to play a role in chronic rejection, was markedly enhanced in control allografts compared with isografts. However, TGF-beta up-regulation was significantly blunted in MHC-deficient grafts. Nonetheless, these differences in TGF-beta expression did not affect the character of chronic rejection, including intrarenal accumulation of collagens. CONCLUSIONS: Reduced expression of either class I or II direct allorecognition pathways is insufficient to prevent the development of chronic rejection, despite a reduction in the levels of TGF-beta expressed in the allograft. This suggests that the severity of chronic rejection is independent of the level of MHC disparity between donor and recipient and the level of TGF-beta expression within the allograft.     

猕猴预致敏后肾移植加速性排斥反应的免疫学及病理学特点

目的 观察猕猴预致敏后肾移植加速性排斥反应的免疫学及病理学变化特点.方法 建立猕猴皮肤预致敏后肾移植加速性排斥反应模型(供、受者各3只).检测3只受者皮肤移植预致敏前、后及肾移植后血清内供者特异性抗体的变化.并在发生排斥反应时对移植肾进行免疫组织化学(测定补体、抗体的沉积及各类型淋巴细胞浸润情况)及病理学分析.结果 3只受者均发生了加速性排斥反应.其中2只受者在预致敏后血清中供者特异性抗体明显增加,对供者的淋巴毒反应明显升高;肾移植后受者血清中供者特异性抗体及针对供者的淋巴毒进一步升高.苏木精-伊红染色显示排斥反应的移植肾内有明显的动脉坏死、血栓形成、间质出血、中性粒细胞浸润;免疫组织化学及荧光染色显示移植肾内有大量的补体、抗体沉积(主要为IgG),而各种类型的淋巴细胞浸润少见.另1只受者体内的供者特异性抗体及对供者淋巴毒反应的升高程度不如前2只明显,病理学变化以肾小管损伤为主.结论 皮肤移植预致敏可以诱导受者产生程度不等的预存抗体,导致大多数移植肾在术后早期发牛主要南抗体和补体介导的严重的急性体液性排斥反应.     

Adult dual kidney transplantations obtained from marginal donors: two case reports

Organ shortage has led us to use grafts from expanded criteria donors (ECD). Dual kidney transplantation (DKT) using organs from an ECD, which are not acceptable for single kidney transplantation (KT), may overcome the insufficient functioning nephron mass. We performed DKTs in two recipients, the first DKT to be reported from Korea. In case 1, the donor was a 36-year-old man with hypertension. The cause of his brain death was intracranial hemorrhage. He had no known underlying renal disease; his serum creatinine level was 4.2 mg/dL. Despite the relatively young age of the donor, a biopsy revealed mild interstitial fibrosis and tubular atrophy with moderate arteriolar narrowing. The recipient's postoperative course was uneventful over the 69-month follow-up; her last serum creatinine was 1.3 mg/dL. In case 2, the 80-year-old male donor with a history of hypertension had a normal creatinine. The donor biopsy revealed mild glomerular sclerosis, tubular atrophy, and interstitial fibrosis with moderate arteriolar narrowing. The recipient had undergone a previous KT 14 years previously on the right side of the abdomen, but had resumed dialysis 2 years previously due to chronic allograft nephropathy. There was no delayed graft function. At month 4 posttransplantation, lymphoceles were treated by fenestration. At 6-month follow-up, her creatinine was 1.0 mg/dL. In our experience with these two cases, DKT with ECD kidney grafts seemed to be a successful strategy to avoid poor graft outcomes and overcome the donor organ shortage. Further studies including histological criteria for DKT, should be performed to determine the safest means to utilize ECD grafts.