Search

Transplantation of immediately vascularized grafts across species barriers in which preformed cytotoxic antibodies exist, otherwise known as discordant combinations, has uniformly resulted in hyperacute rejection. We studied how well plasma exchange and perfusion through organs removes preformed immunoglobulin M cytotoxic antibodies and prolongs survival of a porcine heart heterotopically transplanted into a rhesus monkey. With the use of plasma exchange or absorption of antibodies by porcine kidney perfusion with or without immunosuppression, graft survival was prolonged, although antibody-mediated rejection ultimately occurred. In one case in which plasma exchange, kidney perfusion, and immunosuppression were combined, a functioning pig heart survived in a rhesus monkey for 8 days without evidence of rejection. The animal was killed on day 8 according to protocol because of a wound dehiscence. With this animal we were able to demonstrate that circulating antibodies against graft endothelium had bound to the graft endothelium without inducing rejection, a process referred to as accommodation. In this case, despite the presence of antiendothelial antibodies, complement did not appear to be activated, and fibrin thrombi did not form. Although we have achieved this rejection-free survival only in one animal, this case suggests that it may be possible to maintain xenotransplants in discordant species without rejection if preformed antibodies are appropriately lowered or altered during the initial period of graft implantation.

The immunogenicity of major histocompatibility complex (MHC) class I+ class II- hepatocytes is controversial. We studied the effect of pretransplant donor-specific sensitization with either purified hepatocytes (HC) or splenocytes (Spl) on subsequent skin allograft survival. Five million Percoll-purified DBA HC or 10 x 10(6) DBA Spl were injected into C57BL/6 recipients either intraperitoneally (ip) or into a sponge matrix allograft. Twelve days later, sensitized mice received a DBA skin graft. On the same day, allogeneic (DBA) and syngeneic (BL/6) skin grafts were placed on naive BL/6 mice. In naive BL/6 mice, allogeneic skin graft survival was 7.8 +/- 0.5 days (n = 4), and syngeneic survival was indefinite (n = 5). Skin graft survival (mean +/- SD in days) in recipients sensitized with hepatocytes ip was 6.0 +/- 1.2 days (n = 5) compared with 5.6 +/- 0.5 days in recipients sensitized with splenocytes ip. Similarly, graft survival in recipients that received hepatocytes into a sponge matrix allograft was 5.67 +/- 1 days (n = 6) compared with 5.2 +/- 1.1 days (n = 8) in those that received splenocytes into the sponge. There was no difference in graft survival between mice sensitized with HC vs Spl, nor between mice injected ip vs with the sponge. All sensitized mice experienced accelerated graft rejection compared with naive controls (P less than 0.000). These results demonstrate that purified MHC class I+, class II- murine HCs are immunogenic in vivo. Sensitization with donor-specific HCs led to accelerated rejection of subsequent skin grafts, similar to the accelerated rejection seen after sensitization with MHC class I+ and class II+ splenocytes.

Preventing hyperacute rejection (HAR) is a difficult and unsolved problem in xenotransplantation. This may be due, in part, to a lack of therapies that can suppress production of natural antibodies (NA), which are thought to be critical mediators of HAR. This study examined the effect of 15-deoxyspergualin (DSPG) and splenectomy (Spx) on NA production and return of NA after plasma exchange (PE) in a discordant species combination (strain 2 guinea pig to Lewis rat). A dose of 5 mg/kg/day DSPG + Spx significantly reduced Lewis rat anti-guinea pig NA titer after one week of therapy. Antibody titer was not significantly reduced in rats treated with splenectomy alone. PE alone acutely depleted NA titers; however, complete rebound was seen in 48 hr. When PE was performed in rats treated with DSPG + Spx, an additional significant NA reduction occurred; no rebound 24-48 hr after PE was seen. Except for a 20% reduction in body weight, no serious complications occurred in DSPG + Spx recipients. Despite a profound NA titer reduction, treatment with DSPG, Spx, and PE did not prolong guinea pig cardiac xenograft survival in a clinically significant fashion. Immunopathological study of rejected cardiac xenografts revealed no antibody deposition but persistent complement deposition on vascular endothelium. We conclude that DSPG + Spx effectively inhibits synthesis of rat anti-guinea pig NA, that further NA titer reduction can be achieved with the addition of PE, and that DSPG + Spx prevents post-PE antibody rebound. We also conclude that the limited prolongation in cardiac xenograft survival achieved, despite marked suppression of NA, supports a complement-mediated mechanism of HAR in our animal model.

We prospectively studied the use of prophylactic Minnesota antilymphocyte globulin vs. OKT3 in kidney transplant recipients. Between 7/1/87 and 9/1/90, 138 adult kidney and 35 kidney-pancreas recipients were randomized after stratification for age (18-49 vs. greater than or equal to 50), diabetes (diabetic vs. nondiabetic), transplant number (1 vs. greater than 1) and, for retransplants, the length of survival of the first graft (less than 1 year vs. greater than or equal to 1 year), and then randomized to receive 7 days of either MALG (20 mg/kg/day) or OKT3 (5 mg/day). Immunosuppression was otherwise identical in both groups; prednisone and azathioprine started on the day of surgery, and cyclosporine started on postoperative day 6. Minimum follow-up was 9 months. There was no difference in one- and two-year actuarial patient or graft survival rates, incidence of rejection, or serum creatinine level. MALG was associated with a higher incidence of cytomegalovirus; it was statistically significant in the subgroup of CMV seronegative recipients of kidneys from seropositive donors (P less than .05). OKT3 was more expensive and was associated with significantly more side effects: fever (P less than .0001), dyspnea (P = .04), and acute respiratory distress syndrome (ARDS) (P = .02).

The treatment of choice for end-stage renal failure within the first year of life is controversial. Between September 1970 and February 1991, we performed 28 kidney transplants (27 primary, 1 retransplant, 23 living donor, 5 cadaver) in infants less than 1 yr of age (mean, 7 +/- 2 months; range, 6 wk to 12 months). The 1-yr patient survival rate for living donor recipients was 100% versus 20% for cadaver recipients (P = 0.0001). The 1-yr graft survival rate for living donor recipients was 96% versus 20% for cadaver recipients (P = 0.001). The 1-yr patient survival rate for cyclosporin A (CSA) recipients (N = 12) was 100% versus 75% for non-CSA recipients (P = 0.03). The 1-yr graft survival rate for CSA recipients was 92% versus 75% for non-CSA recipients (P = 0.08). There was no difference in the number of rejection episodes or serum creatinine levels in CSA versus non-CSA recipients. Compared with pretransplant values, the mean posttransplant standard deviation scores (SDS) for height (N = 18), weight (N = 22), and head circumference (N = 8) improved: height SDS from -1.9 to -1.5 (not significant); weight SDS from -2.5 to 0.6 (P less than 0.0005); head circumference SDS from -2.0 to -0.7 (P = 0.01). Because no other renal replacement therapy can match these results, we conclude that renal transplantation is the treatment of choice for infants with end-stage renal failure.

The natural history of focal segmental glomerulosclerosis in patients retransplanted after loss of a primary allograft is not well established. We studied 14 patients with FSGS who were retransplanted between April 1964 and September 1990 to determine if recurrence in a second or subsequent allograft could be predicted. In this group, 8 of the primary allografts were lost to recurrent disease and 6 to rejection. None of the 6 patients who lost their primary allograft to rejection without evidence of recurrent FSGS suffered recurrent disease after retransplantation. In contrast, 3 of the 8 patients who lost their primary allograft rapidly to FSGS suffered recurrent disease and loss of function in all subsequent allografts. The remaining 5 patients had prolonged function of the primary allograft ranging between 4 and 10.5 years, despite recurrence of FSGS. Of these 5 patients, 2 have excellent renal function after retransplantation without recurrence of FSGS in the secondary allograft at 9 and 10.5 years posttransplant; 2 have lost their secondary allograft to recurrent FSGS, but are free of recurrence in the third allograft at 0.5 and 5.8 years postoperatively; 1 maintains a serum creatinine level of 1.9 mg% despite recurrence of FSGS in the secondary allograft at 1 year postoperatively. Our data show that, without recurrence of FSGS in the primary allograft, further renal transplants will be free of recurrent disease. Based on this finding, we advocate use of living-related donors for second transplants in these patients. With rapid recurrence of FSGS and subsequent accelerated loss of the primary allograft, further renal transplants carry a high likelihood of recurrent FSGS and graft loss. A substantial proportion of patients with recurrent FSGS in the primary allograft will have prolonged renal function, and are likely to have excellent results with subsequent allografts.

The purpose of this study was to determine the role of L3T4+, Ly2- T cells in the development of allospecific cytolytic T cells in response to purified allogeneic MHC class I+, class II- hepatocytes in vivo in hepatocyte-sponge matrix allografts (HC-SMA). In previous studies we have shown that 99% pure murine hepatocytes stimulate the development of allospecific cytolytic T cells in vitro in mixed lymphocyte-hepatocyte culture (MLHC) and in vivo in HC-SMA. Furthermore, depletion of L3T4+, Ly2- T cells from responder splenocytes inhibits the development of allo-CTLs in response to purified hepatocytes in mixed lymphocyte-hepatocyte culture. Here, using an anti-L3T4 monoclonal antibody, we tested the effect of in vivo immunodepletion of L3T4+, Ly2- T cells on the subsequent development of allo-CTLs in HC-SMA. Sponge cells were harvested on day 4 and day 12 after grafting from control and treated groups and phenotypically analyzed by FACS and immunofluorescent labelling. Splenocytes from the same animals were similarly analyzed to assess for completeness of immunodepletion. Allospecific cytotoxicity was assessed on day 12 after grafting. We found that immunotherapy with anti-L3T4 mAb was effective in depleting L3T4+, Ly2- T cells from the spleen; however, a similar number of L3T4+ cells was isolated from the sponge between control and treated groups. Furthermore, the development of allo-CTLs in response to hepatocytes in HC-SMA was completely abrogated by both local and systemic immunotherapy with anti-L3T4 mAb. We conclude from these and previous data that host or responder L3T4+, Ly2- T cells and responder accessory cells in MLHC or host macrophages in HC-SMA may participate in "indirect" recognition of hepatocyte class I antigen both in vitro and in vivo.

The decision for simultaneous pancreas-kidney (SPK) versus kidney transplant alone (KTA) in diabetic patients with renal failure depends on the potential risks and benefits for each procedure. The purpose of this study was to compare the morbidity, mortality, and renal allograft survival in diabetic patients who underwent SPK versus KTA, and to discern the added risks associated with pancreas transplantation. Between 7/1/86 and 9/30/90, 69 primary cadaver SPK and 59 primary cadaver KTA were performed in type I diabetic patients with chronic renal failure. Antilymphocyte globulin or OKT3 was used for induction therapy, followed by standard triple therapy (prednisone, azathioprine, and cyclosporine). Patient and graft survivals were retrospectively analyzed. In addition, a detailed comparison of morbidity in those patients treated after 7/1/87 was performed (53 SPK, 49 KTA). For those less than 45 years of age (65 SPK, 42 KTA), there were no significant differences (P greater than 0.6) in the actuarial patient survival at one year (SPK 92%, KTA 95%), or two years (SPK 89%, KTA 92%), or actuarial renal allograft survival at one year (SPK 82%, KTA 83%) or two years (SPK 77%, KTA 83%). However, for those greater than 45 years old, actuarial renal allograft survival was significantly higher (P less than 0.03) in the KTA group. The mean serum creatinine levels were similar at one year (SPK 1.8, KTA 1.9 mg/d).(ABSTRACT TRUNCATED AT 250 WORDS)

Purified hepatocytes stimulate the development of L3T4-, Ly2+ allospecific cytolytic T cells from naive splenocytes after 5 days in primary mixed lymphocyte-hepatocyte culture (MLHC). Previous studies indicate that the immunogenicity of purified hepatocytes relates to the expression of MHC class I antigen. The purpose of the following experiments was to identify the cell subsets that specifically recognize hepatocyte MHC class I antigen. We employed primed lymphocyte testing (PLT) in order to test for a "second set" response. Cells from primary MLHC reverted to a functionally quiescent state when they were grown in culture for an additional 7-9 days. The cells were then tested for cytotoxicity or rechallenged with allogeneic, syngeneic, or "third party" hepatocytes and tested for proliferation. Allocytotoxicity was low on day 12 in MLHC, but the sensitized cell population demonstrated peak proliferation in response to allogeneic hepatocytes 48 hr after restimulation. When bulk PLT cells were immunodepleted, both L3T4+, Ly2- and L3T4-, Ly2+ T cell subsets demonstrated a "second set" response to allogeneic hepatocytes consistent with specific recognition of and retention of "memory" for hepatocyte MHC class I alloantigen.

To improve our understanding of posttransplant infections, we analyzed bacterial, viral, fungal, parasitic, and other infections in 604 consecutive recipients of kidney (n = 518), kidney-pancreas (n = 82), kidney-liver (n = 3), or kidney-islet (n = 1) allografts (355 cadaveric, 14 living-unrelated, 235 living-related donors) who also received cyclosporine, azathioprine, and prednisone immunosuppression. Recipients of cadaveric grafts received additional induction immunosuppression (antilymphocyte globulin or murine monoclonal antibody OKT3). Rejection episodes were treated with high-dose steroids, and either antilymphocyte globulin or OKT3 was administered when clinically indicated. Perioperative antibiotics and posttransplant prophylactic acyclovir sodium or ganciclovir sodium, trimethoprim-sulfamethoxazole, and clotrimazole or nystatin (Mycostatin) were administered to all recipients. Two hundred thirteen patients (35.3%) were found to have had no identifiable infections, while 391 (64.7%) had either isolated bacterial (97 [16.1%]), viral (53 [8.8%]), or fungal (34 [5.6%]) infections or combination (concurrent or sequential) infections with bacterial plus viral (46 [7.6%]), bacterial plus fungal (66 [10.9%]), viral plus fungal (20 [3.3%]), bacterial plus viral plus fungal (64 [10.6%]), or bacterial plus viral plus fungal plus parasitic (11 [1.8%]) pathogens in the posttransplantation period. Renal allograft survival (percentage, actuarial method) was diminished in patients with infections at both 1 year (91% vs 83%) and 3 years (81% vs 76%) after transplantation, as was actuarial patient survival (1 year, 97% vs 92%; 3 years, 93% vs 88%). We conclude that infection remains a major cause of both patient demise and allograft loss following successful solid-organ transplantation.

We utilized a canine renal transplant model to estimate the first-pass extraction of mizoribine (MZB) during renal artery infusion and to compare the efficacy and toxicity of continuous intraarterial (i.a.) versus intravenous (i.v.) MZB delivery, with and without a background of oral cyclosporine. Five autotransplanted mongrel dogs with programmable, implantable pump/catheter systems were given MZB by both i.v. bolus (5 mg/kg) and i.a. infusion (5.0 mg/kg/day). Mean +/- SD elimination half-life was 3.02 +/- 0.81 hr, and the transplanted kidney removed as much as 47-59% (mean 56%) of locally infused MZB. With increasing local and systemic MZB delivery in a single autografted dog undergoing both i.a. and i.v. pump/catheter placement, renal extraction decreased from at least 47% (5.0 mg/kg/day) to 33% (7.5 mg/kg/day), finally to 18% (10.0 mg/kg/day). A dose of 3.0 mg/kg/day MZB did not significantly prolong survival of renal allograft recipients over that of untreated controls (median survival time [MST] = 8 days) when administered either locally (MST = 9 days) or systemically (MST = 12 days). All dogs receiving 4.0 mg/kg/day MZB i.a. died from rejection, and a survival advantage was still not realized (MST = 7 days). In contrast, 4.0 mg/kg/day i.v. prolonged survival over controls (MST = 14 days; P = 0.03) but not when directly compared with the i.a. group (P = 0.30), and produced death from severe debility in five of seven animals with significantly higher mean systemic MZB levels (P = 0.02). Four of six dogs receiving 5.0 mg/kg/day MZB i.a. (MST = 14 days) and two of four dogs receiving 5.0 mg/kg/day i.v. (MST = 14 days) died from severe debility, though survival in both groups was prolonged over control values (P = 0.01 and P = 0.05, respectively). Coadministration of a subtherapeutic dose of oral CsA (5 mg/kg/day) significantly prolonged the overall survival of dogs receiving MZB 4.0 mg/kg/day i.a. (MST = 23; P = 0.01) but not i.v. (MST = 11; P = 1.00), so that a significant difference in overall survival between the combined MZB i.a. + CSA and MZB i.v. + CSA groups was now realized in favor of the former (P = 0.04). We conclude that at local doses required to achieve immunosuppression, the transplanted kidney was not able to extract enough MZB to prevent death from systemic toxicity, presumably as a result of saturation of renal elimination mechanisms, so that an overall survival benefit was not realized.(ABSTRACT TRUNCATED AT 400 WORDS)

Cyclosporine has improved the results of renal transplantation. In 1984, we began using it as part of a sequential immunosuppression protocol (MALG, AZA, P, and delayed administration of CsA) in our pediatric renal transplant recipients. We studied the outcome of the 131 pediatric renal transplants (less than or equal to 18 years of age at transplant) performed at our institution between June 1984 and March 1991. We compared these results with the 144 similar transplants performed since January 1980 that did not involve CsA immunosuppression. In the sequential immunosuppression group, there were 97 primary (74%) (26 [27%] cadaver, 71 [73%] living donor [LD]) and 34 (26%) retransplant (23 [68%] CAD, 11 [32%]) recipients. Age at transplant (mean +/- SD) was 7.4 +/- 5.5. Overall, 1-year actuarial graft survival was 93%; 1-year patient survival was 100%. The mean number of hospital readmissions was 3.0 +/- 3.5; 26 (20%) were readmission-free. The mean number of rejection episodes was .87 +/- 1.3 per patient; 73 (56%) were rejection-free. Importantly, LD (vs. CAD) recipients had fewer rejection episodes (P = 0.06). In the first post-transplant year, the serum creatinine level was significantly lower in primary (vs. retransplant) recipients and in LD (vs. CAD) recipients (P less than 0.05). In the 144 patients not receiving CsA, there were 129 (90%) primary (27 CAD, 102 LD) and 15 (10%) retransplant (7 CAD, 8 LD) recipients. Age at transplant was 6.9 +/- 5.3 years. The 1-year actuarial graft survival rate was 82%; the 1-year patient survival rate was 94%. The mean number of hospital readmissions was 3.3 +/- 2.3; 5 (8%) were readmission-free. The mean number of rejection episodes was 1.2 +/- 1.5; 27 (45%) were rejection-free. There was no difference in the serum creatinine level based on donor source or transplant number. Sequential immunosuppression has significantly improved patient (P = 0.003) and graft survival (P = 0.004) rates. Comparing sequential vs. non-CsA immunosuppression, there was no difference in the number of readmissions (P = 0.47), number of rejection episodes (P = 0.17), or serum creatinine level. The number of rejection-free patients was significantly lower in LD (vs. CAD) recipients (P less than 0.05). There was no evidence of progressive deterioration in renal function in the sequential (vs. non-CsA) recipients.

With current immunosuppressive protocols, 1- and 6-year graft survival is similar in diabetic and nondiabetic kidney transplant recipients. Living-donor transplant recipients have significantly better outcome. Death with function and chronic rejection remain the 2 predominant causes of graft loss for diabetic recipients. Compared with national statistics on diabetic patient survival on dialysis, our data suggest that transplantation is the treatment of choice for diabetic patients with end-stage renal disease.

A variety of refinements in the care of kidney transplant recipients have been instituted over the past decade. The authors studied the overall impact of these refinements on kidney allograft losses at a single institution. To do this they compared the causes and rates of graft loss for primary kidney transplants in the 1970s (January 1, 1970 to December 31, 1979; n = 1012; 657 nondiabetics, 355 diabetics; 617 living donors, 395 cadaver donors) versus the 1980s (January 1, 1980 to December 31, 1989; n = 1,384; 756 nondiabetics, 628 diabetics; 740 living donors, 644 cadaver donors). Overall patient survival improved significantly, with rates at 1, 5, and 10 years of 94%, 84%, and 68% for the 1980s, compared with 86%, 69%, and 57% for the 1970s (p less than 0.001). Actuarial graft survival also improved significantly, with rates at 1, 5, and 10 years of 86%, 71%, and 52% for the 1980s, compared with 73%, 58%, and 43% for the 1970s (p less than 0.001). This improvement occurred even though there were proportionately more cadaver donors and diabetic recipients in the 1980s. For both decades combined, 24% of the lost grafts were due to chronic rejection, 18% to cardiovascular causes of death with function, 13% to infectious causes of death with function, and 11% to acute rejection. The overall gain in graft survival rates in the 1980s was principally due to fewer cases of acute rejection and fewer infectious deaths. Improvement in graft survival due to the two leading causes--chronic rejection and cardiovascular causes of death--was relatively small, if any. These data indicate that future kidney transplantation research should emphasize prevention of chronic rejection and cardiovascular death.

Second renal allograft survival rates are lower than those of primary allografts. For recipients immunosuppressed with azathioprine, prednisone, and Minnesota ALG (conventional immunosuppression), risk factors associated with decreased second graft survival have been identified: age greater than 40, cadaver donor, less than 6 months between primary graft loss and retransplantation, duration of primary graft function (6 months or 1 year, depending on the study), high peak panel-reactive antibody, number of human leukocyte antigen mismatches, and delayed graft function. In this study, we used a multivariate analysis to identify risk factors associated with decreased second graft survival in patients who did or did not receive cyclosporine. Results were compared with primary graft survival rates. Risk factors for patients receiving conventional immunosuppression were: (a) primary graft loss caused by rejection greater than or equal to 6 months (P = 0.01 vs. either rejection less than 6 months or nonimmunologic loss); (b) cadaver donor (P = 0.005 vs. living related); and (c) interval between primary graft loss and retransplantation of greater than or equal to 6 months (P = 0.05 vs. less than 6 months). For CsA, risk factors that most decreased second graft survival were: (a) primary graft loss caused by rejection less than 6 months (P = 0.11 vs. nonimmunologic loss); (b) conventional immunosuppression for the primary graft (P = 0.08 vs. CsA immunosuppression); and (c) a peak PRA of greater than or equal to 21 (P = 0.14 vs. peak PRA of 1-20). For second graft recipients immunosuppressed with CsA, primary graft loss to either rejection greater than 6 months posttransplant or nonimmunologic causes was not a risk factor for second graft survival. These data extend the recent reports of other investigators by identifying risk factors for retransplant recipients treated with CsA and by demonstrating that subgroups of patients in the retransplant population can be retransplanted without additional risk (i.e., their second graft survival rates are similar to primary graft survival rates). This may become more important if, in the future, organ distribution is based on graft survival data. If so, our data would support retransplantation in patients who are immunosuppressed with CsA, especially those who lost their primary graft to either rejection greater than or equal to 6 months posttransplant or nonimmunologic causes; who receive living related grafts; and who have a peak PRA of 1-20.

The rate of progression of renal insufficiency was quantitated from reciprocal of serum creatinine versus time plots in patients with clinical and histologic evidence of chronic renal transplant rejection. The plots were evaluated by the breakpoint test. This method identifies breakpoints in a linear plot and compares the statistical significance of the fit provided by two intersecting lines with that of a single straight line. The breakpoint test when applied to the 22 patients with a significant linear correlation between the reciprocal of serum creatinine versus time detected a change in the slope in 20 cases (90.9%) indicating the presence of a breakpoint. The average diastolic, systolic, and mean arterial pressures before the breakpoint were significantly correlated with the value of the serum creatinine at the time of the change of the slope (r = 0.45, P less than 0.05; r = 0.58, P less than 0.01; r = 0.56, P less than 0.05, respectively) demonstrating more severe hypertension in those patients with the more severe renal dysfunction. The slope after the breakpoint was significantly correlated with the mean diastolic blood pressure values after the breakpoint (r = 0.48, P less than 0.05) with higher pressures being found in those patients with faster rates of decline in renal function. Both before and after the breakpoint occurred, the rate of progression of the renal disease, as estimated by the reciprocal of serum creatinine versus time plot, was greater when the mean diastolic blood pressure was higher than 90 mmHg. In conclusion, the vast majority of patients with proven chronic rejection progress linearly although a change in the rate of progression was frequent. Higher levels of blood pressure correlate with greater rates of progression of renal insufficiency, and a faster progression associates with a diastolic blood pressure greater than 90 mmHg.

Hyperacute rejection is the inevitable consequence of the transplantation of vascularized organs between phylogenetically distant species. The nature of the incompatibility and the pathogenetic mechanisms that lead to hyperacute xenograft rejection are incompletely understood. We investigated these issues by the immunopathological analysis of tissues from swine renal and cardiac xenografts placed in rhesus monkeys. Hyperacute rejection was associated with deposition of recipient IgM and classic but not alternative complement pathway components along endothelial surfaces, the formation of platelet and fibrin thrombi, and the infiltration of neutrophils. In animals from which natural antibody was temporarily depleted by organ perfusion, rejection was observed at 3 days to 5 days posttransplant. The immunopathology of rejection in these tissues revealed focal vascular changes similar to those observed in hyperacute rejection. A xenograft functioning for a prolonged period in a recipient temporarily depleted of circulating natural antibody contained recipient IgM along endothelial surfaces but no evidence for significant deposition of complement, formation of platelet and fibrin thrombi, or infiltration of neutrophils. These results suggest that rhesus IgM contributes significantly to the development of hyperacute rejection in the swine to Rhesus model and that the fixation of complement is a critical factor in the recruitment of the coagulation cascade and platelet aggregation--and possibly in the adherence and infiltration of PMN.

Transplantation is the treatment of choice for children with end-stage renal disease. However, the long-term quality of life and socioprofessional outcome for those with successful transplants have not previously been reported. We studied these factors in patients transplanted when less than 18 years old who currently have greater than or equal to 10 years of graft function. A total of 57 questionnaires were sent out; 57 (100%) responded [24 female and 33 male patients; average (+/- SD) age at tx = 10 +/- 5 years (0.9-17.7); average f/u = 15.6 +/- 3 years (10-26); current age = 26 +/- 5 years (12-38); 26 had greater than 1 transplant]. Of the 57 respondents, 9 are less than 18 (all are in school); 48 are greater than or equal to 18 (7 in school, 37 employed, 4 unemployed); 12 are married, 1 engaged, and 2 divorced; and 9 have children. While in school, 43 (75%) had participated in sports, 37 (65%) in other extracurricular activities; 7 (12%) were A and 33 (58%) B students; 15 (26%) received awards or scholarships. For those working, the range of occupations is broad (average work week = 41 +/- 5 hr). Health-related absence from work has been nonexistent for 93%. Health is rated as good to excellent by 91% and fair by 9%. The future is regarded as hopeful or promising by 80%. Similarly, 89% are satisfied with life in general; 95% said health never or seldom interferes with family life; 95% feel health and drug side effects are of no or minor concern in sexual relationships. Only 3% feel health is a problem in maintaining a sexual relationship (41% are not sexually active). Only 4% stated that health often interferes with social life; 98% meet with friends on a regular basis; 76% are satisfied with personal relationships and 8% dissatisfied; 91% are satisfied with their ability to perform at work or school and 5% dissatisfied. Of note, 32% are dissatisfied with body appearance. Major concerns are short stature and brittle bones. Major suggestions include education/support groups to deal with teasing at school and peer problems. We conclude that transplanted children with long-term graft function have a favorable social and professional outcome. Overall, quality of life seems excellent.

The ability of an on-line, rapid plasma exchange (PE) system to remove circulating antibodies in preparation for xenogeneic heart transplantation was studied. Plasma exchanges were performed 27 times on 13 rhesus monkeys weighing from 6.5 to 12.0 kg, using systemic heparinization, without untoward effects. Blood flow rates of 22-72 ml/min resulted in plasma collection rates of 7-22.5 ml/min. Serum immunoglobulin levels were decreased by more than 90%, and specific antiendothelial xenoreactive IgM was completely removed after two plasma exchanges. Transferrin levels were decreased 85-95%, and complement levels fell by greater than 80%. Platelets were partially conserved, with removal rates of 18-60%. All factors returned to normal ranges within 48 hours and no bleeding complications were encountered. When antiendothelial antibodies were removed in this manner, survival of a pig heart transplanted into a rhesus monkey was extended to 12 hours, from a baseline of 2 hours, without treatment.

Pigs appear to be a suitable biological and logistical animal donor of islets for xenotransplantation in human diabetic type I recipients. To improve the islet isolation technique in this species, to evaluate the islet function in vivo, and to assess the toxic effects of various immunosuppressive regiments on transplanted islets will necessitate a model of the pancreatectomized pig suitable for islet autotransplantation. We describe three techniques of total pancreatectomy in pigs. The first removed the pancreas in order to study postoperative management and pig survival; no attempt was made to preserve the pancreas for islet isolation. The second consisted of a pancreatectomy in a surviving pig, with careful preservation of the whole pancreas for subsequent islet isolation. The third was rapid en bloc procurement of the pancreas and duodenum, to obtain a pancreas solely for the purpose of islet isolation. We conclude that pigs tolerate and survive a total pancreatectomy--they are suitable animals for islet isolation and possible autotransplantation. The result of islet isolation does not appear related to the pancreas procurement technique; however, the islet yield must be improved before autotransplantation can be functionally successful.

The long-term kidney function (KF) in the three categories of diabetic type 1 pancreas (P) transplant recipients (simultaneous P and kidney [SPK]; P after K [PAK]; PTx alone [PTA] was studied sequentially over a 2-year period in 62 patients who received a bladder-drained allograft that functioned for at least 1 year. Fifty-three (85%) patients were analyzed at 1 month, 42 (68%) at 1 year, and 16 (26%) at 2 years posttransplant. Comparison of KF was made within each recipient category and between categories. In addition, the KF in the SPK and PAK patients was compared to a matched group of diabetic type 1 recipients of KTx alone (functioning at least 1 year). In the SPK group, KF was stable over time: the mean +/- SD serum creatinine (mg/dl) was 1.5 +/- 0.5 at 1 month, 1.8 +/- 1.0 at 1 year, and 1.7 +/- 0.5 at 2 years. In the PAK category, the pre-PTx serum creatinine value was 1.4 +/- 0.5, and then remained stable after the PTx (1.3 +/- 0.2 at 1 month, 1.3 +/- 0.4 at 1 year, and 1.2 +/- 0.4 at 2 years). In the recipients of a PTA, the values at 1 month (1.1 +/- 0.4), 1 year (1.4 +/- 0.5), and 2 years (1.3 +/- 0.5) were significantly higher (P less than or equal to 0.03) than the pre-PTx value (0.9 +/- 0.2); and results at 1 month and 2 years were lower than those at 1 year, a significant difference compared to the 1-month value (P = 0.01). Comparisons between the categories of PTx recipients demonstrated that the pre-PTx value in the PTA group (0.9 +/- 0.2) was significantly lower (P = 0.01) than in the PAK group (1.4 +/- 0.5). At 1 month the serum creatinine value in the PTA category (1.1 +/- 0.4) was significantly lower (P = 0.02) than in the SPK category (1.5 +/- 0.5), but thereafter (1 and 2 years) the difference was not significant (P greater than 0.1). KF in recipients of KTx alone was similar at each post-Tx time point when compared to the SPK and PAK categories. We concluded that a PTx can be performed in diabetics without a detrimental effect on a simultaneously or a previously transplanted kidney and that a statistically significant, albeit minimal to moderate, initial but not progressive deterioration in native KF occurs in recipients of a PTx alone.

To determine the effect of fluconazole on cyclosporine concentrations, we used a randomized, double-blind, placebo-controlled study design to evaluate 16 stable renal transplant recipients receiving a constant cyclosporine dose. The two groups of patients were given identical capsules of either placebo or fluconazole 200 mg daily for 14 days. Compliance with the protocol was ensured by watching each patient take all the drug doses. Frequent whole-blood cyclosporine trough concentrations, measured by high-performance liquid chromatography, and two area under the blood concentration time curves were determined before and after 14 days of fluconazole or placebo. The results show that cyclosporine trough concentrations, in patients given fluconazole, increased from a mean +/- SD of 27 +/- 16 to 58 +/- 28 ng/ml (P = 0.001) while patients given placebo did not change--35 +/- 26 vs. 37 +/- 35 ng/ml (P = 0.7). Mean cyclosporine AUC increased in the fluconazole patients from 2167 +/- 1039 to 3989 +/- 1675 ng.hr/ml (P = 0.02) while the placebo patients did not change, 3089 +/- 2439 vs. 2954 +/- 2216 ng.hr/ml (P = 0.9). The pre- and post-treatment cyclosporine AUC difference (day 16 minus day 2) for fluconazole vs. placebo was 1822 +/- 1083 vs. -134 +/- 831 ng.hr/ml (P = 0.001). Mean cyclosporine clearance decreased an average of 55% in the fluconazole patients from 1.2 +/- 0.5 to 0.7 +/- 0.4 ml/hr.kg (P = 0.03); the placebo patients did not change--1.4 +/- 1.1 vs. 1.7 +/- 2.3 ml/hr.kg (P = 0.07). During the study period, serum creatinine concentrations did not increase after fluconazole vs. placebo treatment; they were 1.4 +/- 0.3 vs. 1.3 +/- 0.3 mg% (P = 0.8) initially, and 1.4 +/- 0.2 vs. 1.3 +/- 0.3 mg% (P = 0.5) after 14 days. This study indicates that fluconazole 200 mg daily can slowly increase cyclosporine concentrations over two weeks of therapy, approximately doubling the cyclosporine trough concentrations. The management of this interaction requires prospective planning for adjustments in the cyclosporine dosage, guided by cyclosporine concentrations, while transplant recipients are receiving fluconazole.