Seven years' experience with antilymphoblast globulin for renal transplantation from cadaver donors

Continuous function of 80 primary renal allografts for 30-47 years with maintenance prednisone and azathioprine/mycophenolate mofetil therapy: A clinical mosaic of long-term successes

Eighty primary renal allograft recipients, 61 living-related and 19 deceased donor, transplanted from 1963 through 1984 had continuous graft function for 30-47 years. They were treated with three different early immunosuppression programs (1963-1970: thymectomy, splenectomy, high oral prednisone; 1971-1979: divided-dose intravenous methylprednisolone; and 1980-1984: antilymphocyte globulin) each with maintenance prednisone and azathioprine, and no calcineurin inhibitor. Long-term treatment often included the anti-platelet medication, dipyridamole. Although both recipient and donor ages were young (27.2 ± 9.5 and 33.1 ± 12.0 years, respectively), six recipients with a parent donor had >40-year success. At 35 years, death-censored graft survival was 85.3% and death with a functioning graft 84.2%; overall graft survival was 69.5% (Kaplan-Meier estimate). Biopsy-documented early acute cellular and highly probable antibody-mediated rejections were reversed with divided-dose intravenous methylprednisolone. Complications are detailed in an integrated timeline. Hypogammaglobulinemia identified after 20 years doubled the infection rate. An association between a monoclonal gammopathy of undetermined significance and non-plasma-cell malignancies was identified. Twenty-seven azathioprine-treated patients tested after 37 years had extremely low levels of T1/T2 B lymphocytes representing a "low immunosuppression state of allograft acceptance (LISAA)". The lifetime achievements of these patients following a single renal allograft and low-dose maintenance immunosuppression are remarkable. Their success evolved as a clinical mosaic.

The role of Thymoglobulin induction in kidney transplantation: an update

The rabbit antithymocyte globulin Thymoglobulin first became available over 25 yr ago and is the most widely used lymphocyte-depleting preparation in solid organ transplantation. Thymoglobulin targets a wide range of T-cell surface antigens as well as natural killer-cell antigens, B-cell antigens, plasma cell antigens, adhesion molecules and chemokine receptors, resulting in profound, long-lasting T-cell depletion. Randomized studies have established the anti-rejection efficacy of Thymoglobulin in kidney transplantation. Experimental and clinical data suggest that Thymoglobulin administration may ameliorate ischemia reperfusion injury, thus reducing the incidence of delayed graft function (DGF). Studies have demonstrated the benefit of using Thymoglobulin to facilitate immunosuppression minimization, both for corticosteroid and calcineurin inhibitor (CNI) withdrawal or avoidance, with potential improvement in cardiovascular and renal outcomes. The optimal cumulative dose for Thymoglobulin induction is 6-7.5 mg/kg, with vigilant short- and long-term monitoring of hematological status. Induction with Thymoglobulin is now indicated in immunologically high-risk patients, in those at increased risk of DGF and to maintain efficacy in low-risk transplant recipients receiving steroid or CNI minimization or avoidance regimens. We suggest that in future trials Thymoglobulin be tested with costimulation signal blockers and other immunosuppressants with the objective of establishing operational tolerance.

Rabbit antithymocyte globulin (thymoglobulin): 25 years and new frontiers in solid organ transplantation and haematology

The more than 25 years of clinical experience with rabbit antithymocyte globulin (rATG), specifically Thymoglobulin, has transformed immunosuppression in solid organ transplantation and haematology. The utility of rATG has evolved from the treatment of allograft rejection and graft-versus-host disease to the prevention of various complications that limit the success of solid organ and stem cell transplantation. Today, rATG is being successfully incorporated into novel therapeutic regimens that seek to reduce overall toxicity and improve long-term outcomes. Clinical trials have demonstrated the efficacy and safety of rATG in recipients of various types of solid organ allografts, recipients of allogeneic stem cell transplants who are conditioned with both conventional and nonconventional regimens, and patients with aplastic anaemia. Over time, clinicians have learnt how to better balance the benefits and risks associated with rATG. Advances in the understanding of the multifaceted mechanism of action will guide research into new therapeutic areas and future applications.

Induction therapy in pediatric renal transplant recipients: an overview

Induction therapy to prevent the acute rejection of mismatched allografts with the ultimate aim of prolonging the life of the allograft has been the cornerstone of immunosuppression since the introduction of renal transplantation. Agents used for induction therapy have changed over time. Their role in transplantation is expanding to include corticosteroid avoidance and immunosuppression minimization. This review provides an overview of induction therapies for renal transplantation including historic therapies such as total lymphoid irradiation and Minnesota antilymphocyte globulin, and current therapies with polyclonal and monoclonal antibodies and chemical agents, with special emphasis on children. Data from adult studies, and pediatric studies whenever available, are summarized. A brief summary of experimental therapies with fingolimod and belatacept is provided. Historically, induction therapies were targeted at T cells. The role of induction therapies targeted at B cells is emerging in select groups of patients that include highly sensitized recipients and those receiving transplants from blood group incompatible donors. With the advent of newer maintenance immunosuppressive medications and with very low rates of acute rejection, induction protocols for renal transplantation need to be targeted so that excessive immunosuppression and infections are avoided. Several single-center and registry data analyses in children suggest that the addition of an interleukin (IL)-2 receptor antagonist may improve graft survival compared with no induction. The safety profile of IL-2 receptor antagonists is indistinguishable from that of placebo, with no apparent difference in the incidence of infection or post-transplant lymphoproliferative disease. IL-2 receptor antagonists and polyclonal lymphocyte-depleting antibodies offer equivalent efficacy in standard-risk populations. However, in high-risk patients, acute rejection rates and graft outcomes may be improved with the use of lymphocyte-depleting agents such as Thymoglobulin. However, cytomegalovirus infection and other infections may be more common with this therapy. Therefore, in patients at high risk of graft loss, Thymoglobulin may be the preferred choice for induction therapy, while for all other patients, IL-2 receptor antagonists should be considered the first-line choice for induction therapy. Newer lymphocyte-depleting agents such as alemtuzumab may be better utilized in minimization regimens involving one or two oral maintenance immunosuppressive agents.

B-cell activity of polyclonal antithymocyte globulins

Polyclonal antithymocyte globulins (AThG) are a subset of antilymphocyte antibody preparations derived from the sera of rabbits or horses immunized with unfractionated cells isolated from pediatric human thymi. In vivo, AThG preparations have been used to successfully treat antibody mediated rejection in kidney transplant recipients. In vitro, AThG can induce apoptosis of naïve and memory B cells and terminally differentiated plasma cells. The presence of B-cell reactive antibodies in AThG results from a thymic inoculum containing a significant percentage of CD20(+) B cells and CD138(+) plasma cells. In this paper, the experimental and clinical evidence supporting the B-cell activity of AThG preparations, and their mechanisms of action, are reviewed.

Evolution of immunosuppression at the University of Minnesota

Immunosuppressive protocols at the University of Minnesota have evolved from identical immunosuppression for all recipients (prednisone, azathioprine, and antilymphocyte globulin) to differing protocols for living (triple therapy) and cadaver (sequential therapy) donor recipients, and then to our current protocol in which all recipients receive induction therapy with rapid discontinuation of prednisone. At the same time, progress has been made in the prevention and treatment of cytomegalovirus infection along with numerous parallel improvements in patient care, including in anesthesia, dialysis, and intensive care unit care. The net result has been an incremental improvement in recipient and graft survival.

The impact of cyclosporine on the development of immunosuppressive therapy

The first immunosuppressive regimens based on glucocorticoids and azathioprine were introduced in the early 1960s. However, many patients developed acute rejection, which required treatment with high doses of prednisolone. Leading to a high mortality due to opportunistic infection. Prior to 1985, our center used a regimen of prednisolone and azathioprine for 352 renal transplantations with 1-year graft and patient survival rates of 63.9% and 82.4%, respectively. Cyclosporine was introduced into clinical practice in 1978, enabling more effective control of acute rejection. In 1985, our center adopted a protocol consisting of prednisolone, azathioprine, and cyclosporine producing significantly increased 1-, 3-, and 5-year patient and graft survival rates for living-related and cadaveric renal transplants. Newer drug combinations, which are less toxic and more potent than cyclosporine based protocols, have further decreased acute rejection rates from 60% to approximately 10%. Still, graft loss continues to be a problem. We believe that the most recent strategy of combining monoclonal antibodies with less toxic agents, such as sirolimus and mycophenolate mofetil, may eventually replace calcineurin inhibitors. Such protocols would eliminate the side effects of calcineurin inhibitors, and possibly permit steroid-free maintenance therapy. The immunosuppressive therapy that is currently available is not ideal; the ability to convert patients to a state of permanent immunologic tolerance would minimize the need for these drugs. The new generation of agents that includes FTY 20, anti-sense oligonucleotides, and agents capable of blocking the costimulatory pathway of allorecognition may improve host tolerance.

CD32-mediated platelet aggregation in vitro by anti-thymocyte globulin: implication of therapy-induced in vivo thrombocytopenia

Induction therapy with polyclonal antithymocyte-globulin (ATG) is widely used in the prophylaxis and treatment of acute cardiac-allograft rejection. Thrombocytopenia, however, is a major side-effect of ATG therapy and its mechanisms are poorly understood. The influence of ATG on platelet aggregation was studied aggregometrically, expression of platelet surface activation antigens CD62P and CD63 was determined by flow cytometry analysis, and electron microscopy was utilized to determine thrombocyte morphology. Treatment of platelets with ATG markedly induced aggregation, whereas OKT3 or anti-IL-2R antibodies did not. Furthermore, platelets incubated with ATG featured an up-regulation of the surface activation markers CD62P and CD63, secretion of platelet-bound sCD40L (CD154) and increased signs of aggregation in electron microscopy analysis. The capacity of ATG to induce platelet aggregation was completely blocked by antibodies against the low-affinity Fc IgG receptor (CD32). Since blocking of CD32 abrogates platelet aggregation, we suggest that CD32 plays a crucial role in ATG-induced thrombocytopenia.

Lessons learned from more than 1,000 pancreas transplants at a single institution

OBJECTIVE

To determine outcome in diabetic pancreas transplant recipients according to risk factors and the surgical techniques and immunosuppressive protocols that evolved during a 33-year period at a single institution.

SUMMARY BACKGROUND DATA

Insulin-dependent diabetes mellitus is associated with a high incidence of management problems and secondary complications. Clinical pancreas transplantation began at the University of Minnesota in 1966, initially with a high failure rate, but outcome improved in parallel with other organ transplants. The authors retrospectively analyzed the factors associated with the increased success rate of pancreas transplants.

METHODS

From December 16, 1966, to March 31, 2000, the authors performed 1,194 pancreas transplants (111 from living donors; 191 retransplants): 498 simultaneous pancreas-kidney (SPK) and 1 simultaneous pancreas-liver transplant; 404 pancreas after kidney (PAK) transplants; and 291 pancreas transplants alone (PTA). The analyses were divided into five eras: era 0, 1966 to 1973 (n = 14), historical; era 1, 1978 to 1986 (n = 148), transition to cyclosporine for immunosuppression, multiple duct management techniques, and only solitary (PAK and PTA) transplants; era 2, 1986 to 1994 (n = 461), all categories (SPK, PAK, and PTA), predominantly bladder drainage for graft duct management, and primarily triple therapy (cyclosporine, azathioprine, and prednisone) for maintenance immunosuppression; era 3, 1994 to 1998 (n = 286), tacrolimus and mycophenolate mofetil used; and era 4, 1998 to 2000 (n = 275), use of daclizumab for induction immunosuppression, primarily enteric drainage for SPK transplants, pretransplant immunosuppression in candidates awaiting PTA.

RESULTS

Patient and primary cadaver pancreas graft functional (insulin-independence) survival rates at 1 year by category and era were as follows: SPK, era 2 (n = 214) versus eras 3 and 4 combined (n = 212), 85% and 64% versus 92% and 79%, respectively; PAK, era 1 (n = 36) versus 2 (n = 61) versus 3 (n = 84) versus 4 (n = 92), 86% and 17%, 98% and 59%, 98% and 76%, and 98% and 81%, respectively; in PTA, era 1 (n = 36) versus 2 (n = 72) versus 3 (n = 30) versus 4 (n = 40), 77% and 31%, 99% and 50%, 90% and 67%, and 100% and 88%, respectively. In eras 3 and 4 combined for primary cadaver SPK transplants, pancreas graft survival rates were significantly higher with bladder drainage (n = 136) than enteric drainage (n = 70), 82% versus 74% at 1 year (P =.03). Increasing recipient age had an adverse effect on outcome only in SPK recipients. Vascular disease was common (in eras 3 and 4, 27% of SPK recipients had a pretransplant myocardial infarction and 40% had a coronary artery bypass); those with no vascular disease had significantly higher patient and graft survival rates in the SPK and PAK categories. Living donor segmental pancreas transplants were associated with higher technically successful graft survival rates in each era, predominately solitary (PAK and PTA) in eras 1 and 2 and SPK in eras 3 and 4. Diabetic secondary complications were ameliorated in some recipients, and quality of life studies showed significant gains after the transplant in all recipient categories.

CONCLUSIONS

Patient and graft survival rates have significantly improved over time as surgical techniques and immunosuppressive protocols have evolved. Eventually, islet transplants will replace pancreas transplants for suitable candidates, but currently pancreas transplants can be applied and should be an option at all stages of diabetes. Early transplants are preferable for labile diabetes, but even patients with advanced complications can benefit.

Immunosuppressive agents in transplantation: mechanisms of action and current anti-rejection strategies

Over the past century, the concept of interfering with the immune response at various sites by blocking the formation, stimulation, proliferation, and differentiation of lymphocytes has led to relentless development of new immunosuppressive drugs. These agents are associated with reduced risk of short- and long-term toxicity and have dramatically improved allograft and patient survival, especially in recipients of solid organ transplants. Current protocols in such patients are nearly all calcineurin-inhibitor based, using cyclosporine or tacrolimus, as part of dual, triple, or sequential therapy. This review focuses on agents currently in clinical use at transplant centers in United States. The drugs are described in terms of their basic mechanisms of action, therapeutic uses, clinical studies, and adverse effects. In addition, the efficacy and toxicity of a few promising new therapeutic approaches are examined. Finally, important challenges regarding pharmacological immunosuppression as it relates to solid organ and composite tissue allotransplantation are discussed.

Quadruple tacrolimus-based induction therapy including azathioprine and ALG does not significantly improve outcome after liver transplantation when compared with standard induction with tacrolimus and steroids: results of a prospective, randomized trial

BACKGROUND

Tacrolimus in combination with prednisolone has been proven to be a safe and effective immunosuppressive induction therapy in solid organ transplantation. However, it remains unclear whether a tacrolimus-based quadruple induction regimen with azathioprine and an antilymphocytic preparation could further improve the results after orthotopic liver transplantation. Therefore, we designed a prospective, randomized study to compare the immunosuppressive efficacy of dual (tacrolimus and prednisolone) and quadruple (tacrolimus, azathioprine, ALG Merieux and prednisolone) induction after liver transplantation.

METHODS

After randomization, 120 consecutive patients of primary liver transplants were divided into the dual group (n=59) and the quadruple group (n=61) and followed for a minimum of 3 years.

RESULTS

Patient survival at 3 years was 88.2% in the dual versus 94.9% in the quadruple group. Overall 25 patients in each group (41 and 42%, respectively) developed acute rejection. There was no difference in the number and severity of rejections. In each group only four patients required OKT3-therapy, however, although three of four patients in the quadruple group responded to OKT3 and cleared rejection, none of the four patients in the dual group were treated successfully with OKT3 (P<0.02). Rejection in these patients resolved only after additional treatment with mycophenolate mofetil. Adverse events and infections were equally distributed in both groups. Asymptomatic Cytomegalovirus infections were more common in the quadruple group (P<0.02). As of today, only one patient developed posttransplant lymphoproliferative disease (dual group).

CONCLUSIONS

The data from our single-center study indicate that both tacrolimus-based dual and quadruple immunosuppressive induction regimens yield similar safety and effectiveness after liver transplantation.

Low dose antithymocyte globulins in renal transplantation: daily versus intermittent administration based on T-cell monitoring

BACKGROUND

Despite the long history of use of antithymocyte globulins (ATG) in renal transplantation, ideal doses and duration of ATG administration based on the monitoring of T lymphocytes have yet to be defined.

METHODS

Two immunosuppressive regimens based on low-dose rabbit ATG (Thymoglobuline; Imtix-Sang-stat, Lyon, France) were assessed during the first year after transplantation: daily ATG (DATG; n=23) where 50 mg of ATG was given every day and intermittent ATG (IATG; n=16) where similar doses of ATG were given for the first 3 days and then intermittently only if CD3+ T lymphocytes (measured by flow cytometry) were > 10/mm3. Both groups received steroids, azathioprine, and cyclosporine.

RESULTS

ATG-induced depletion was similar for peripheral blood lymphocytes and T cells in both groups: it began at day 1 after transplantation, was submaximal at day 3, and reached maximum intensity between days 6 and 8, from which time cell counts progressively increased. However, T-cell depletion was still present at day 20. The total ATG dose per patient (381.5+/-121 vs. 564+/-135 mg/patient) and the mean cumulative daily dose of ATG (0.60+/-0.17 vs. 0.80+/-0.14 mg/kg/day) were significantly lower in the IATG group (P=0.0001 and 0.0006, respectively). The overlap of ATG and cyclosporine treatment was 6.7+/-3 vs. 7.4+/-4.3 days (P=NS), and the mean duration of ATG therapy was 11.3+/-3.2 vs. 11.6+/-2.7 days in the IATG and DATG groups, respectively (P=NS). ATG was given in an average of one dose every 1.6 days in the IATG group compared with one dose daily in the DATG group (P=7 x 10(-7)). There was no significant difference in renal graft function, the number of acute graft rejections, or ATG-related side effects and complications. Despite the daily immunological follow-up, there was a net saving of $760/patient in the cost of treatment in the IATG group.

CONCLUSION

IATG had the advantage of a reduction in the dose of ATG and in the cost of treatment, while offering similar T-cell depletion and effective immunosuppression. This approach could be proposed as an induction protocol, particularly for patients with poor graft function in whom cyclosporine introduction has to be delayed or those with increased risk of cytomegalovirus infections or secondary malignancies.

Cadaveric kidney transplantation under prophylactic polyclonal antibody immunosuppression with anti-lymphoblast globulin versus anti-thymocyte globulin

OBJECTIVES

This retrospective study was undertaken to evaluate and compare the clinical and immunologic outcomes following prophylactic induction treatment with Minnesota anti-lymphoblast globulin (MALG) and Upjohn anti-thymocyte globulin (ATGAM) in cadaver renal transplantation.

METHODS

From 1990 to 1994, 63 patients with renal transplants from cadavers received MALG and 77 patients received ATGAM for induction treatment. Most pretransplant parameters were equivalent in both groups. There was no significant difference in the total dose and mean duration of MALG/ATGAM administration. The post-transplant outcome in these groups was compared.

RESULTS

There was no difference between the MALG and ATGAM groups with respect to the overall number of rejection episodes, median days to rejection, or the number of steroid-resistant rejection episodes. However, MALG-treated patients experienced a greater number of rejections in the first 60 days postoperatively (P = 0.06). There was no difference in the nadir serum creatinine level in the first 20 postoperative days in the two groups; however, it took fewer days to reach the nadir in the ATGAM group (P = 0.03). The incidence of delayed graft function was higher in the MALG group than in the ATGAM group (38% versus 31%) but not statistically significant. Graft survival at 12 and 24 months was comparable in both groups. However, patient survival was superior at 12 and 24 months in ATGAM-treated transplant recipients (P = 0.03). The mean serum creatinine at 6, 12, and 24 months was similar in both the MALG and ATGAM groups. The mean fall and recovery of CD3, CD4, and CD8 T-lymphocyte subsets while on MALG/ATGAM were similar in both groups. The incidence of infectious complications was greater in the MALG group.

CONCLUSIONS

MALG and ATGAM have comparable clinical immunosuppressive effects. Patients receiving ATGAM experienced fewer rejections in the first 2 months, fewer infections, and better survival.

Evolution of kidney, pancreas, and islet transplantation for patients with diabetes at the University of Minnesota

Transplantation began at the University of Minnesota in 1963. Treatment of diabetes and its complications has been emphasized since 1966, when the first pancreas-kidney transplant was done. Of 3,640 kidneys transplanted by 1992, 1,373 were for diabetic recipients, including 658 from living donors and 715 from cadaver donors. The results progressively improved; since 1984, survival rates of kidney grafts have been similar for diabetic and nondiabetic recipients, with three fourths of the grafts functioning at 4 years. As of 1992, 501 pancreas transplants had been done, including 170 simultaneous with a kidney, 142 after a kidney, and 188 alone for nonuremic diabetic patients; again, the results have improved: by the 1990s, graft survival rates were similar in the 3 recipient categories. Successful pancreas transplants have been shown by our coworkers to stabilize or improve neuropathy and prevent recurrence of diabetic nephropathy in kidney grafts. In an attempt to simplify endocrine replacement therapy, we have done 63 human islet transplants, 34 as allografts for patients with type I diabetes and 29 as autografts after total pancreatectomy to treat chronic pancreatitis. Insulin independence occurs for about 50% of islet autograft recipients. Two recent islet allograft recipients treated with 15-deoxyspergualin have had sustained insulin independence. We anticipate that endocrine replacement therapy by transplantation will become routine for diabetic patients as methods to prevent rejection are refined.

Clinical, biochemical, and hematologic evaluation of normal dogs after administration of rabbit anti-dog thymocyte serum

Renal allografting is the only long-term alternative to euthanasia in dogs with end-stage kidney disease. The purpose of this study was to determine the clinical, biochemical, and hematologic effects of rabbit anti-dog thymocyte serum (RADTS) in normal dogs and to develop a safe and practical route of administration before its use in an allograft immunosuppressive protocol. Thirteen mongrel dogs were divided into three groups; each received RADTS subcutaneously, intramuscularly, or intravenously. The inflammation and pain associated with subcutaneous administration was unacceptable. A significant (p < or = .05) leukopenia and lymphopenia developed in all dogs, regardless of the route of administration of RADTS. Thrombocytopenia was a consistent finding after intravenous administration and with high doses given intramuscularly. Both the intravenous and intramuscular routes were well tolerated by all dogs with minimal or no discomfort. Serum creatinine was unchanged, whereas serum alanine aminotransferase activity increased in one dog. There were no histologic changes in any of the kidneys examined.

Symptomatic cytomegalovirus infection in renal transplant recipients given either Minnesota antilymphoblast globulin (MALG) or OKT3 for rejection prophylaxis

To compare the impact of using Minnesota antilymphoblast globulin (MALG) versus the monoclonal antibody, OKT3, on the development of symptomatic cytomegalovirus (CMV) infection, we reviewed a cohort of 130 cadaveric renal transplant recipients enrolled in a prospective comparison of MALG versus OKT3 for rejection prophylaxis. Among the 112 patients at risk for CMV, prophylactic MALG was associated with an increased risk of symptomatic infection (relative hazard [rh] = 3.31; 95% confidence interval CI], 1.50 to 7.30; P = 0.003). Transplantation of kidneys from CMV-seropositive donors into CMV-seronegative recipients (rh = 5.22; 95% CI, 2.34 to 11.63; P = 0.00004), first transplantation (rh = 4.76; 95% CI, 1.06 to 21.3; P = 0.039), and acute rejection therapy (rh = 2.03; 95% CI, 0.98 to 4.21; P = 0.055) were also associated with an increased risk. Prophylactic MALG followed by treatment with any agent for acute rejection was strongly correlated with symptomatic CMV infection (rh = 4.46; 95% CI, 3.71 to 5.21; P = 0.00006). Symptomatic CMV infection was not only more frequent, but more severe in recipients of prophylactic MALG, and more MALG recipients were treated with ganciclovir. There was no difference in rejection rate for the two rejection prophylaxis regimens (P = 0.625). Prophylactic OKT3 results in less risk of symptomatic CMV infection than prophylactic MALG in cadaveric renal transplant recipients who are seropositive for CMV or whose donors are seropositive for CMV.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibodies in renal transplantation: a review

OKT3 is the first anti-CD3 monoclonal antibody available for treatment in humans. Over the last few years it has proven to be a very powerful immunosuppressive agent in renal transplantation. Clinical studies have shown that OKT3 is superior to high-dose steroids as first-line treatment for acute renal allograft rejection. Furthermore, it is comparable to antithymocyte globulin (ATG) in treating steroid-resistant rejection and is also effective as rescue treatment in ATG- and antilymphocyte globulin-(ALG-) resistant rejection. Despite its excellent rejection-reversal rate, OKT3 treatment is followed by a substantial percentage of re-rejections, most of which respond well to steroids. In the early post-transplantation period, a prophylactic course of OKT3 is very effective in preventing acute rejections, and in this respect it is probably equivalent to ATG. Indirect evidence exists that a prophylactic course of OKT3 may be beneficial in immunologically high-risk patients and in patients with delayed graft function. However, more clinical studies are required to answer the question whether OKT3 should be given as induction treatment, as first-line treatment, or as rescue treatment. To answer this question, the side effects of OKT3 should also be taken into account. First-dose-related side effects, although frequent and disturbing, are usually transient and seldom life-threatening, provided overhydration has been corrected and steroids have been given before the first administration. These side effects are attributed to the release of cytokines as a result of T-cell activation or lysis. After exposure of patients to OKT3 an increased incidence of infections and malignancies has been reported. However, it is not yet clear whether this is due to OKT3 as such, or whether it merely reflects the total burden of immunosuppression. Xeno-sensitization represents an important limitation to OKT3 treatment, although a second or third course can still be effective in patients with low antibody titers. The precise immunosuppressive mechanism of anti-CD3 monoclonal antibodies is yet unknown. Monitoring of patients treated with OKT3 revealed CD3 and/or T-cell antigen receptor depletion and immunological incompetence of remaining T cells. More clinical data are required to establish the correct dose and duration of OKT3 treatment. In conclusion, OKT3 is a powerful immunosuppressive agent but its real value in renal transplantation remains to be determined. A practical approach may be to reserve it for the treatment of steroid-resistant rejections.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibition of CD25 (IL-2R alpha) expression and T-cell proliferation by polyclonal anti-thymocyte globulins

Anti-lymphocyte and anti-thymocyte globulins (ATG) are currently used as immunosuppressive agents in organ transplantation. Their administration in vivo may induce not only lymphocyte depletion but also functional effects which were investigated in the present study. In vitro ATG inhibited T-cell proliferation induced by monocyte-dependent T-cell mitogens, like CD3 antibodies, phytohaemagglutinin (PHA) and concanavalin A (Con A), by monocyte-independent mitogens, like CD2 antibodies, or by protein kinase C activators (phorbol esters) associated with a calcium ionophore. The inhibitory effect of ATG was therefore not solely accounted for by a suppression of co-stimulatory signals delivered by monocytes, but rather implied a direct action on T cells. Addition of recombinant human interleukin-2 (rIL-2) did not overcome the inhibition. Suppression of T-cell proliferation by ATG was characterized by normal RNA synthesis and IL-2 secretion contrasting with markedly reduced expression of the CD25 protein [p55, the alpha-chain of interleukin-2 receptor (IL-2R)] both in cytoplasm and on T-cell membrane, as well as a decreased secretion of interferon-gamma (IFN-gamma). Northern blot analysis revealed increased levels of CD25 and IFN-gamma mRNA, suggesting a post-transcriptional inhibition of these molecules, whereas IL-2 mRNA levels were unchanged. These data demonstrate that inhibition of T-cell proliferation by ATG can be attributed primarily to a post-transcriptional defect of CD25 expression, implying a novel mechanism different from those described with other immunosuppressive agents. Blocking of T-cell proliferation in the late G1 phase of the cell cycle may contribute to the immunosuppressive activity of ATG in prophylactic treatment of allograft rejection.

Monocyte-independent T-cell activation by polyclonal antithymocyte globulins

The in vitro mitogenic properties of polyclonal antithymocyte and antilymphocyte globulins (ATG) on peripheral blood mononuclear cells were investigated. The ATG were mitogenic in a dose-dependent manner with maximal proliferation observed at 250 or 500 micrograms/ml. ATG activated blastogenesis of CD4+, CD8+, and CD57+ (NK cells) lymphocytes. The ATG induced interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) gene expression and lymphokine secretion in cell culture supernatant and IL-2 receptor (CD25) expression. At submitogenic concentrations ATG potentialized the effect of phorbol esters on T cell proliferation, but not that of calcium ionophore. The mitogenic effect of ATG was not abrogated by monocyte depletion indicating that like CD2 monoclonal antibodies (mAbs) ATG activate T cells via a monocyte-independent pathway. CD3 and CD2 mAbs which activate T cells without binding to B surface determinants stimulated the proliferation of B cells and their differentiation into immunoglobulin (Ig)-secreting cells. In contrast, ATG induced only a transient B cell activation, but failed to support B cell differentiation into Ig-secreting cells despite the secretion of IL-2. These properties shared by ATG obtained in horses or rabbits by immunization with different cell types appear to differ from those of other T cell mitogens.

Causes of renal allograft loss. Progress in the 1980s, challenges for the 1990s

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.

Influence of early function on long-term pediatric cadaveric renal allograft survival

The significance of early renal graft function on long-term transplant survival is controversial. From our pediatric renal transplant population we studied 151 children who had an initial cadaveric renal transplant, were dependent on dialysis before transplantation and were 5 to 19 years old at transplantation. We used dependence upon dialysis as the parameter for early graft function. There was a statistically significant difference in long-term graft survival between patients who were independent of and dependent on dialysis at 1 week and 1 month postoperatively. Our results show that early renal graft function is important for long-term graft survival. All efforts should be directed to obtaining early renal graft function by proper organ procurement, storage, operative technique and aggressive postoperative management.

Long-term immunoregulatory effects of therapy with corticosteroids and anti-thymocyte globulin

Corticosteroids and anti-thymocyte globulin (ATG) have been extensively used in the treatment of autoimmune diseases, aplastic anemia and organ graft rejection; nonetheless, the precise mechanisms of action of these agents are unknown. Studies of their long term immunoregulatory effects, particularly in humans, have been limited. We examined the long term effects of therapy with ATG given for 2-4 weeks and prednisone for 2 months in 4 patients with newly diagnosed insulin dependent diabetes (IDD). Three matched newly-diagnosed untreated IDD patients and 17 healthy volunteers served as controls. No differences in total lymphocyte count, percentage of B cells, percentage of total T cells (CD3), helper-inducer T cells (CD4) or cytotoxic-suppressor cells (CD8), lymphocyte blastogenesis assays, or pokeweed mitogen-induced IgG secretion in T & B cell co-cultures were detected before therapy. A transient lymphopenia following ATG administration was the only immunological defect found in the first month of therapy. At 2 months, however, patients treated with ATG and prednisone had diminished immunoregulatory T cell function demonstrated by production of only 28 +/- 3% IgG expected in T & B co-culture, compared to 205 +/- 35% for untreated IDD patients and 107 +/- 13% for normals (p less than 0.01). This diminished IgG production resulted from excessive suppressor function, since co-cultures of T cells from treated patients with T and B cells from normal volunteers suppressed the latter's IgG production by 76 +/- 9%. This enhanced suppressor activity persisted for 3-6 months following therapy. Other immunological functions were not statistically different from those present at the inception of the study. Thus, treatment with corticosteroids and ATG produces long-term enhanced suppressor activity, a finding which suggests that treatment with combination ATG and Prednisone is a rational form of immunomodulation in conditions associated with decreased suppressor function.

Factors influencing patient and graft survival in 300 cadaveric pediatric renal transplants

We reviewed the results of 300 cadaveric pediatric renal transplantations performed at our institution. The procedures provided significant survival and improvement of the quality of life in the majority of children. Recipient and graft survival was better in patients more than 5 years old than in younger children. Early nontechnical thrombosis was a major specific problem in young recipients. The original disease did affect graft survival. Uncorrected congenital bladder storage and micturition inefficiency adversely affected graft survival.

Induction in human allograft recipients of unresponsiveness to anti-lymphocyte globulin

The observations presented here confirm previous reports that polyclonal ALG prepared at the University of Minnesota or ATGAM of The Upjohn Co., administered as described, rarely induced sensitization of patients to the horse gamma globulin. In addition, the phenomena of transient antibody production prior to the onset of unresponsiveness and the induction of unresponsiveness in individuals with preexisting antibodies were observed.

Use of OKT3 with cyclosporin and steroids for reversal of acute kidney and liver allograft rejection

OKT3 monoclonal antibody therapy was added to preexisting baseline immunosuppressive treatment with ciclosporin and steroids to treat rejection in 52 recipients of cadaveric livers and 10 recipients of cadaveric kidneys. Rejection was controlled in 75% of patients treated, often after high-dose steroid therapy had failed. Rejection recurred during the 17-month follow-up period, after completion of OKT3, in only 25% of the patients who had responded. The safety and effectiveness of this monoclonal therapy, added to ciclosporin and steroids, has been established in this study.

Results of the Minnesota randomized prospective trial of cyclosporine versus azathioprine-antilymphocyte globulin for immunosuppression in renal allograft recipients

Between September 26, 1980 and June 8, 1984, 246 splenectomized, transfused renal allograft recipients were randomized to treatment with either cyclosporine (CsA)-prednisone (n = 131) or azathioprine (Aza)-prednisone-antilymphocyte globulin (n = 115). On December 31, 1984, actuarial patient survival rates at three years were 89% in the CsA group and 90% in the Aza group, and the corresponding graft survival rates were 82% and 79% (statistically insignificant differences). The results were also compared separately in diabetic and nondiabetic patients and in recipients of related and cadaver donor grafts; only in the subgroup of diabetic recipients of cadaver kidneys were the differences in graft survival rates significantly different between CsA- and Aza-treated patients. The incidence of posttransplant acute tubular necrosis was similar in CsA- and Aza-treated patients (33% v 27%), but the duration was significantly longer in CsA- than in Aza-treated recipients (15.7 +/- 18.4 v 7.7 +/- 3.0 days). Rejection episodes and infections (particularly CMV) occurred significantly less frequently in CsA- than in Aza-treated patients. Mean serum creatinine levels were significantly higher in CsA- than in Aza-treated recipients (2.0 +/- 0.6 v 1.5 +/- 0.5 mg/dl). Treatment of hypertension and hyperkalemia was required significantly more frequently in the CsA-treated patients than in the Aza-treated patients. Initial mean hospitalization time was significantly shorter in the CsA group than in the Aza group (15.6 +/- 9.5 v 19.8 +/- 10.7 days). In the CsA group, 19% of the patients were switched to Aza and 35% had Aza added to their regimen with a concomitant lowering of the CsA dose because of nephrotoxicity. The results of our randomized trial are at variance with those of others in that the graft survival rates in our trial were not different between CsA and Aza-treated patients, primarily because our conventionally-treated patients had a higher graft survival rate than in the other trials. The advantages of CsA (fewer rejection episodes, fewer infections, shorter hospitalization) outweigh the disadvantages (higher serum creatinine, more hypertension), and thus we believe it should be used in most renal allograft recipients, perhaps in combination with Aza so that a lower dose of CsA can be used and the side effects minimized--a regimen that we are currently evaluating.

A single institution, randomized, prospective trial of cyclosporin versus azathioprine-antilymphocyte globulin for immunosuppression in renal allograft recipients

Between September 26, 1980 and December 31, 1983, 230 splenectomized, transfused renal allograft recipients were randomized to treatment with either cyclosporin-prednisone (N = 121, 68 diabetic and 53 nondiabetic recipients; 73 cadaver and 48 related donor grafts) or azathioprine-prednisone-antilymphocyte globulin (N = 109, 61 diabetic and 48 nondiabetic recipients; 69 cadaver and 40 related donor grafts). The results were analyzed on March 31, 1984. Actuarial patient survival rates at 2 years were 88% in the cyclosporin and 91% in the azathioprine groups (p = 0.649). Graft survival rates at 2 years were 82% in all cyclosporin and 77% in all azathioprine-treated recipients (p = 0.150); the corresponding figures in the recipients of related donor grafts were 87% vs. 83% (p = 0.656), and in the recipients of cadaver donor grafts were 78% vs. 73% (p = 0.178). The 2-year graft survival rates were 81% in cyclosporin and 74% in azathioprine-treated diabetic recipients (p = 0.150) and 83% in cyclosporin and 81% in azathioprine-treated nondiabetic recipients (p = 0.604). Within the cyclosporin and azathioprine treatment groups, the differences in graft survival rates between diabetic and nondiabetic recipients were not significant (p = 0.822 and 0.423, respectively). Although there were no significant differences in graft survival rates, the cumulative incidence of rejection episodes within the first post-transplant year was significantly lower in the cyclosporin (34%) than in the azathioprine (60%) treated recipients (p = 0.001). In recipients of technically successful cadaver kidney grafts, the incidence of acute tubular necrosis (ATN) was 31% in cyclosporin and 30% in azathioprine-treated recipients (p = 0.822). Graft survival rates in azathioprine- and cyclosporin-treated recipients who did or did not undergo ATN were 72% vs. 89% (p = 0.011). The mean (+/- S.D.) serum creatinine levels (mg/dl) at 1 year were higher in cyclosporin (2.0 +/- 0.6) than in azathioprine (1.5 +/- 0.5) treated recipients (p = less than 0.001). A reduction in cyclosporin dose because of nephrotoxicity was required in 96 of the cyclosporin-treated patients (70%), and 25 were switched to treatment with azathioprine (21%). The incidence of all infections in cyclosporin-treated patients was approximately half of that in azathioprine-treated patients, and only nine per cent of the cyclosporin-treated patients were diagnosed to have cytomegalovirus infections during the first post-transplant year vs. 28% in azathioprine-treated patients (p = 0.002).(ABSTRACT TRUNCATED AT 400 WORDS)

Sonography of abdominal posttransplant lymphoma

Five patients developed abdominal lymphoma an average of 89 months after successful renal transplantation. Sonographically, the lymphomas presented as bulky intraperitoneal masses or focal deposits in the liver. These lesions exhibited good sound transmission and intrinsic patterns ranging from sparse, soft echoes to coarse trabeculations. Prompt diagnosis of this serious late complication of renal transplantation is crucial.

Prevention of cytomegalovirus infection by prophylaxis with an intravenous, hyperimmune, native, unmodified cytomegalovirus globulin. Randomized trial in bone marrow transplant recipients

We have completed a randomized trial to evaluate the safety and effectiveness of hyperimmune cytomegalovirus intravenous human globulin in prevention of cytomegalovirus infection and related problems in bone marrow transplant recipients. Prophylactic intravenous administration of this native, intact, hyperimmune, cytomegalovirus IgG, at a dose of 200 mg/kg 25, 50, and 75 days following transplant resulted in complete protection against cytomegalovirus infection during the 120 days covered by the treatment (p = 0.009). There was no interstitial pneumonia or mortality in the group receiving the hyperimmune IgG. This is significant at the p = 0.014 when compared with the supporting treatment control group. In bone marrow transplant recipients, prophylaxis with a total dosage of 0.6 g/kg of an intravenous hyperimmune cytomegalovirus globulin was safe and afforded effective protection against cytomegalovirus infection and interstitial pneumonia in this high-risk population.

Improved results of cadaver renal transplantation in the diabetic patient

The results of 54 renal transplants performed on 48 patients with end stage renal disease and insulin-dependent diabetes mellitus are reported. Pre-transplant screening with coronary angiography was done to determine the presence and severity of coronary artery disease and left ventricular dysfunction. There were 12 living related donor (group 1) and 42 cadaver renal transplants. The cadaver transplant recipients were grouped further into those who received additional prophylactic immunosuppression with antilymphoblast globulin (group 2, 18 patients) and those who received standard immunosuppression with azathioprine and prednisone (group 3, 18 patients). The 2-year patient and graft survival rates in groups 1 to 3 were 81 and 67, 88 and 69, and 61 and 32 per cent, respectively. The use of prophylactic antilymphoblast globulin for adjunctive immunosuppression resulted in significantly improved graft survival among cadaver recipients (p less than 0.003). Selection of patients for transplantation on the basis of preliminary screening with coronary angiography was found to have a major impact on patient survival.

Antithymocyte globulin treatment of severe aplastic anaemia

Nineteen patients with severe aplastic anaemia were treated with antithymocyte globulin. Ten patients obtained remissions (transfusion independent, at least 45000 platelets and 2000 PMN/mm3) within 2-3 months and continue in remission 5-35 months after antithymocyte globulin. Ages of responders ranged from 17 to 71. Complications of antithymocyte globulin included arthralgias, rash, serum sickness, angioedema and fever. Two patients died during, two shortly after, and one 10 months after therapy. One patient with a previous remission following antithymocyte globulin relapsed and achieved a second remission with retreatment. Previous androgen therapy did not affect outcome since two of four patients with and eight of 15 patients without previous androgen therapy achieved remission with ATG. Treatment with antithymocyte globulin is a promising alternative to bone marrow transplantation in the treatment of severe aplastic anaemia.

Factors contributing for improved graft survival in recipients of kidney transplants

We analyzed the survival results of 300 consecutive kidney transplants (TXs) performed at Hennepin County Medical Center, Minneapolis, Minnesota, between March 1965 and April 1980. The graft survival result were compared between three sequential time periods, each comprising 100 renal TXs. The proportion of live donor TXs decreased from 27% in period 1 to 16% in period 2 and 5% in period 3, while the number of older patients, diabetic and multiple TX patients increased steadily. A comprehensive patient care scheme utilizing clinical protocols was developed in period 2 and carried out effectively in period 3. The Cox multivariate regression models used in this analysis allowed us to assess the influence of each variable on the graft survival results, while the effects of all others were held constant. Among the nondiabetic patients who received antilymphocyte globulin, the 1 and 5 year graft survival rates were 59.7 and 38.8% in period 1, 85.3 and 74.3% in period 2, 90.4 and 83.1% in period 3 (periods 1 versus 2: P = 0.008, periods 1 versus 3: P less than 0.0001). This improvement in graft survival was independent of the effects of the following variables, that is, the recipient's age, donor source, prior dialysis, co-existing medical problems, splenectomy, previous TXs, blood transfusions, cytotoxic antibodies, cold ischemia time, HLA mismatches, and post-TX acute tubular necrosis. Our observations indicate that reduced immunosuppression, frequent use of biopsy specimens and comprehensive patient care, played an important role in minimizing the loss of renal transplants in the later time periods and contributed indirectly for the improved graft survival results of our institution.

The value of needle renal allograft biopsy. I. A retrospective study of biopsies performed during putative rejection episodes

Following renal transplantation, immunosuppression is usually increased to treat presumed rejection episodes. However, a) many conditions mimic rejection in the post-transplant period, and b) many rejection episodes are irreversible. As increased immunosuppressive therapy is associated with an increased risk of infection, it would be ideal to limit antirejection therapy to only the rejection episodes that are reversible. The role of percutaneous allograft biopsy was studied as an aid to decide which patients to treat for rejection, to limit unnecessary immunosuppression and to predict allograft survival. One hundred thirty-five patients with suspected rejection underwent 206 allograft biopsies without complication. Two hundred four biopsies were available for study. Biopsies were coded on a 1-4 scale (minimal, mild, moderate, severe) for acute and chronic tubulointerstitial infiltrate and vascular rejection, as well as no rejection (e.g., recurrence of original disease). Treatment decisions were made on the basis of the biopsy combined with clinical data. All patients have been followed two years and outcome correlated with biopsy findings (death, nephrectomy, and return to dialysis defined as kidney loss). The results were the following: 1) biopsies represented changes within the kidney. Of 16 kidneys removed within one month of biopsy, no nephrectomy specimen showed less rejection than that seen on biopsy. 2) Eighty-one biopsies (39.7%) led to tapering or not increasing immunosuppression (either no rejection, minimal rejection, or irreversible changes). 3) Kidneys having either severe acute or chronic vascular rejection (less than 30% function at three months) had significantly (p less than 0.05) decreased survival three to 24 months postbiopsy than those with minimal or mild vascular rejection or tubulointerstitial infiltrate (83% function at three months). 4) Kidneys with moderate chronic vascular rejection and those with severe acute tubulointerstitial infiltrate had significantly (p less than 0.05) decreased survival at six to 24 months. 5) Kidneys with moderate chronic vascular rejection (MCV) without an acute infiltrate (ATI) had significantly better survival than those having both MCV and ATI. 6) Similarly, kidneys having severe ATI alone had better survival than those with ATI plus vascular rejection. It was concluded that a) percutaneous allograft biopsy can be done without graft loss or infection; b) biopsy represents changes throughout the kidney; c) biopsy aids in deciding when to treat for rejection and in deciding when to withhold increased immunosuppression, and d) allograft biopsy predicts the outcome of treatment of a rejection episode.

Thyroid dysfunction among long-term survivors of bone marrow transplantation

Thyroid function studies were followed serially in 27 long-term survivors (median 33 months) of bone marrow transplantation. There were 15 men and 12 women (median age 13 1/12 years, range 11/12 to 22 6/12 years). Aplastic anemia (14 patients) and acute nonlymphocytic leukemia (eight patients) were the major reasons for bone marrow transplantation. Pretransplant conditioning consisted of single-dose irradiation combined with high-dose, short-term chemotherapy in 23 patients, while four patients received a bone marrow transplantation without any radiation therapy. Thyroid dysfunction occurred in 10 of 23 (43 percent) irradiated patients; compensated hypothyroidism (elevated thyroid-stimulating hormone levels only) developed in eight subjects, and two patients had primary thyroid failure (elevated thyroid-stimulating hormone levels and low T4 index). The abnormal thyroid studies were detected a median of 13 months after bone marrow transplantation. The four subjects who underwent transplantation without radiation therapy have remained euthyroid (median follow-up two years). The only variable that appeared to correlate with the subsequent development of impaired thyroid function was the type of graft-versus-host disease prophylaxis employed; the irradiated subjects treated with methotrexate alone had a higher incidence of thyroid dysfunction compared to those treated with methotrexate combined with antithymocyte globulin and prednisone (eight of 12 versus two of 11, p less than 0.05). The high incidence and subtle nature of impaired thyroid function following single-dose irradiation for bone marrow transplantation are discussed.

Clinical experience with antilymphocyte serum

Many different antilymphocytic antisera have been used clinically, and the properties of any particular type of ALS are not necessarily identical to those of any other type. Nevertheless, it is possible to draw certain general conclusions about the effects of ALS in human subjects. ALS administration has often been shown to reduce the number of circulating E-rosette-positive lymphocytes, although the precise mechanisms by which this reduction occurs are not known. Using a combined technique of E-rosette formation and immunofluorescence, heterologous immunoglobulin has been demonstrated on T and non-T lymphocytes from patients receiving non-selective ALS. Fifteen years' experience has failed to provide convincing support for the view that ALS (including immunoglobulin prepared from the whole antiserum) prolongs human renal allograft survival. It is not yet known whether ALS is a useful immunosuppressive agent in cardiac transplantation. One observation of possible clinical interest is that bone marrow regeneration has occurred in a number of patients with aplastic anemia who have been treated with ALS. No satisfactory method has been developed for monitoring the dose of ALS in human subjects. Appropriate studies may determine whether monoclonal antilymphocytic antibodies are clinically useful, for example in prolonging the survival of transplanted organs, in preventing or treating graft-versus-host disease, or in treating lymphoma, leukemia, or aplastic anemia.

Comparison of standard immunosuppression with adjuvant antilymphoblast globulin in primary cadaver kidney transplant survival

Adjuvant, prophylactic, antilymphoblast globulin and standard immunosuppression have produced comparable long-term cadaver kidney graft survivals at separate institutions. A comparison was made of 35 primary cadaver kidney grafts into recipients treated with prophylactic, adjuvant antilymphoblast globulin to 55 recipients of primary cadaver kidney grafts treated with standard immunosuppression. Antilymphoblast globulin delayed early rejection episodes (P under 0.05), making early post-transplant management simpler. There were no significant differences between the two groups with respect to graft losses due to rejection at any interval beyond one month.