Sequential antilymphocyte globulin/cyclosporine immunosuppression in cadaveric renal transplantation. Effect of duration of ALG therapy

ATGAM Associated Coagulopathy in Renal Transplant Patients: A Report of Two Unusual Cases

Polyclonal antibodies, used for both induction and rejection therapy in renal transplant recipients, are associated with such side effects as chills and fever. We describe two patients who developed a coagulopathy during antithymocyte globulin (ATGAM) therapy, a previously unknown complication. The laboratory tests revealed prolonged prothrombin and partial thromboplastin times and thrombocytopenia. Discontinuation of ATGAM therapy resulted in correction of these abnormalities.

Could prophylactic monoclonal antibody improve kidney graft survival?

OBJECTIVES

This study was designed to evaluate the impact of daclizumab monoclonal antibody on early and late kidney graft survival.

MATERIALS AND METHODS

From 2007 to 2008, 57 kidney transplant recipients were followed for a mean of 9.3 months. Twenty-three patients received 1 mg/kg daclizumab 24 hours before and 14 days after transplantation. In contrast, 34 patients (controls) did not receive daclizumab. The same immunosuppressive protocol was administered to all participants: oral prednisolone, mycophenolate mofetil, and cyclosporine. Delayed graft function (DGF), acute rejection, prednisolone pulses and/or antithymoglobulin (ATG), cytomegalovirus (CMV) infection, urinary tract infection (UTI), as well as early and late graft function were compared between the two groups.

RESULTS

The mean age in cases and controls was 39.7 and 37.1 years, respectively. The occurrence of DGF was 4% versus 3%; reversible acute rejection, 16% versus 14.5%, and irreversible acute rejection 0% versus 9% (P < .05) for treated versus control groups, respectively. ATG was used in 21% versus 23%, and pulse prednisolone 26% versus 20%, respectively. In case and control groups, the mean creatinine levels were 1.4 mg/dL versus 1.35 mg/dL at discharge. At last follow-up, it was 1.35 mg/dL versus 1.2 mg/dL, respectively. CMV infection occurred in 30% versus 35%, and UTI in 17% versus 19% of treated versus controls, respectively.

CONCLUSION

The prophylactic administration of daclizumab improved early graft survival and prevented irreversible acute rejection.

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.

Sequential protocols using basiliximab versus antithymocyte globulins in renal-transplant patients receiving mycophenolate mofetil and steroids

BACKGROUND

Sequential anti-thymocyte globulins (ATG)/cyclosporine immunosuppression has two main advantages: delayed introduction of the nephrotoxic drug cyclosporine and prevention of acute rejection. Basiliximab, a recently developed chimeric monoclonal antibody that selectively depletes the minor subpopulation of activated T lymphocytes, has been shown to reduce the incidence of acute rejection when used with cyclosporine introduced on day 1.

METHODS

This open, randomized, multicenter study was undertaken to compare the safety and efficacy of ATG versus basiliximab induction therapy (IT) with delayed introduction of cyclosporine for microemulsion (Neoral) in 105 low immunologic risk renal-transplant patients receiving mycophenolate mofetil and steroids.

RESULTS

One-year patient and graft survival rates were 98.1% and 94.2%, respectively, in the basiliximab group (n = 52), and 98.1% and 96.2% in the ATG group (n = 53). The incidence of biopsy-confirmed acute rejection was comparable (basiliximab 9.6%, ATG 9.4%), as were key parameters of renal function, notably serum creatinine levels, time-to-nadir serum creatinine, and the number of patients requiring posttransplantation dialysis (basiliximab 28.8%, ATG 30.2%). However, significantly fewer patients in the basiliximab group experienced cytomegalovirus (CMV) infection, leukopenia, and thrombocytopenia, and this without any significant difference in any other key safety parameters (including the incidences of serum sickness, fever, lymphoma, and infections in general).

CONCLUSIONS

Both ATG and basiliximab, when used for IT in a sequential protocol, are equally effective in terms of graft and patient survival as well as at preventing acute rejection. However, basiliximab is associated with a lower incidence of certain key adverse events, namely CMV infection, leukopenia, and thrombocytopenia.

Association of antibody induction with short- and long-term cause-specific mortality in renal transplant recipients

A total of 73,707 primary renal transplants reported to the USRDS between 1988 and 1997 were examined to investigate the cause-specific risk for patient death associated with anti-lymphocyte antibody induction therapy (ABI). Cox proportional hazard models were used to estimate the relative risk of the use of ABI and patient death. All Cox models were corrected for potential confounding variables, such as age, gender, race, HLA mismatch, panel reactive antibody, delayed graft function, cold ischemia time, time since start of dialysis, etiology of end-stage renal disease, cytomegalovirus risk group, donor source (living or cadaveric), era effect, and immunosuppressive therapy. Primary study end points were patient death with functioning graft (DWFG) and overall patient death, including death after graft loss. Early patient death (deaths within the first 6 mo after renal transplantation) and late death (deaths after 6 mo post-renal transplantation) were investigated separately. Additionally, specific causes of death were investigated. ABI was associated with a significant risk for late death after renal transplantation (relative risk [RR] = 1.1; P < 0.001) but not for DWFG (RR = 0.94; P = 0.10). ABI conferred the highest RR for late malignancy-related death (RR = 1.35; P < 0.001). ABI was significantly associated with early deaths due to infection and cardiovascular causes (RR = 1.32 [P < 0.001] and RR = 1.27 [P < 0.001], respectively). Kaplan Meier plots confirmed that the risk of ABI for patient death secondary to infectious complications was increased predominately early after transplantation as opposed to late for malignancy-related death. ABI was associated with a significant relative risk for patient death secondary to cardiovascular causes and infectious complications early in the posttransplant period. In addition, ABI was associated with a significant risk for long-term malignancy-related death. The risk of ABI should be taken in context with potential benefits of this therapy.

Induction versus noninduction in renal transplant recipients with tacrolimus-based immunosuppression

BACKGROUND

The aim of this study was to compare the efficacy and safety of induction treatment with antithymocyte globulins (ATG) followed by tacrolimus therapy with immediate tacrolimus therapy in renal transplant recipients.

METHODS

This 12-month, open, prospective study was conducted in 15 centers in France and 1 center in Belgium; 309 patients were randomized to receive either induction therapy with ATG (n=151) followed by initiation of tacrolimus on day 9 or immediate tacrolimus-based triple therapy (n=158). In both study arms, the initial daily tacrolimus dose was 0.2 mg/kg. Steroid boluses were given in the first 2 days and tapered thereafter from 20 mg/day to 5 mg/day. Azathioprine was administered at 1-2 mg/kg per day.

RESULTS

At month 12, biopsy-confirmed acute rejections were reported for 15.2% (induction) and 30.4% (noninduction) of patients (P=0.001). The incidence of steroid-sensitive acute rejections was 7.9% (induction) and 22.2% (noninduction)(P=0.001). Steroid-resistant acute rejections were reported for 8.6% (induction) and 8.9% (noninduction) of patients. A total of nine patients died. Patient survival and graft survival at month 12 was similar in both treatment groups (97.4% vs. 96.8% and 92.1% vs. 91.1%, respectively). Statistically significant differences in the incidence of adverse events were found for cytomegalovirus (CMV) infection (induction, 32.5% vs. noninduction, 19.0%, P=0.009), leukopenia (37.3% vs. 9.5%, P<0.001), fever (25.2% vs. 10.1%, P=0.001), herpes simplex (17.9% vs. 5.7%, P=0.001), and thrombocytopenia (11.3% vs. 3.2%, P=0.007). In the induction group, serum sickness was observed in 10.6% of patients. The incidence of new onset diabetes mellitus was 3.4% (induction) and 4.5% (noninduction).

CONCLUSION

Low incidences of acute rejection were found in both treatment arms. Induction treatment with ATG has the advantage of a lower incidence of acute rejection, but it significantly increases adverse events, particularly CMV infection.

Preventive OKT3 treatment with cyclosporine (Sandimmun) for second kidney transplantation

A total of 793 kidney transplantations (KTx) were performed from November 1073 to March 1993. Two hundred and forty-two patients were treated with conventional immunosuppression (azathioprine + prednisolone) and all the others with cyclosporine (Sandimmun) and prednisolone (SIM + PRED). The survival of the second graft was less good in both therapeutic groups than that of the first ones, so we have started to use preventive immunotherapy with OKT3 (CILAG) in combination with SIM (both before operation) and PRED. We compared 32 SIM-PRED patients with 20 OKT3 + SIM + PRED patients. All underwent a second KTx. The two groups were found to be comparable and homogeneous with regard to 14 of 18 parameters analysed statistically. Statistically significant differences were found between the two groups as regards the frequency of acute rejection within 30 days (46.69% vs 20%), the delta creatinine value on the 1st and 2nd postoperative days (-4.3: -8 vs -8.6: -19.7%), patient survival after 4 years (78.2 vs 100%), and graft survival after 1 and 4 years (-58.9: -42.8 vs -83.5: -83.5%), with better results in the OKT3 group. We conclude that the preventive use of OKT3 simultaneously with SIM + PRED for the second KTx is the method of choice to prevent rejection and improve survival. This treatment results in patient and graft survival following the second KTx being as good as after the first KTx with SIM + PRED.

Mycophenolate mofetil, with cyclosporine and prednisone, reduces early rejection while allowing the use of less antilymphocytic agent induction and cyclosporine in renal recipients with delayed graft function

Antilymphocytic agent induction (ALAI), with antithymocyte globulin or monoclonal antibody, is generally used in renal transplantation (TX) to spare renal allografts with poor initial function from the toxic effects of cyclosporine (CsA) and/or to augment immunosuppression (IS) in the patient at a high risk for early rejection. ALAI, unfortunately, increases the cost of TX and the risk to the patient, having been associated with many adverse side effects. An IS protocol, which results in a low incidence of early rejection while using less CsA and ALAI, is a worthwhile goal. We compare our experience with mycophenolate mofetil (MMF), CsA, and prednisone (MMFCP; n = 62) to our azathioprine (AZA), CsA, and prednisone (AZACP; n = 50) triple-drug IS, with and without ALAI. The patient characteristics for age, race, first TX, cadaveric donor, pediatric recipient, and dialysis in the first post-op week (DGF) were not different for the MMFCP versus AZACP groups. There were more females in the MMFCP group (51.6% versus 30.0%, p = 0.022). We report that rejection-free survival at 6 months (RF6) was better in the MMFCP versus AZACP group (83.9% versus 60.0%, p = 0.005). Less ALAI and CsA were used in the MMFCP patients. At 1 year, actuarial graft survival was 91.9% in the MMFCP group and 81.9% in the AZACP group (p = 0.116). Actuarial 1-year patient survivals were not different in the two patient groups. In the sub-population of patients with DGF, the RF6 in the MMFCP (n = 13) group was 92.3% versus 57.1% in the AZACP (n = 14) group (p = 0.041). The reduction in early rejection episodes in the patients on MMFCP with DGF was accomplished while using half as much ALAI and lower CsA doses and levels. The African-American recipient sub-population on MMFCP also demonstrated an improvement in RF6 while using less ALAI and CsA (78.6% versus 48.0%, p = 0.022). We conclude that the use of MMF-based triple-drug IS results in fewer rejection episodes while allowing for lower CsA levels and less ALAI, even in patients with delayed graft function.

Immunosuppressive therapy

Although several new immunosuppressive medications have been developed in the past decade, many possible avenues are yet to be explored. Although the newer agents have not reflected any clear benefit in patient or graft survival over CsA or tacrolimus, they have been useful in reducing the incidence and severity of rejection, reducing the concomitant use of steroids, and decreasing the doses of CsA or tacrolimus to minimize their toxicity profile. The appearance of these new agents has given more options to clinicians, who can select the one with the least toxicity and most efficacy for individual patients. In the future, combinations of these agents, in conjunction with a strategy to induce tolerance of the donor organ without drug toxicity, will be the goal.

Prevention of transplant rejection: current treatment guidelines and future developments

In the past 2 decades, progressive improvements in the results of organ transplantation as a therapeutic strategy for patients with end-stage organ disease have been achieved due to greater insight into the immunobiology of graft rejection and better measures for surgical and medical management. It is now known that T cells play a central role in the specific immune response of acute allograft rejection. Strategies to prevent T cell activation or effector function are thus all potentially useful for immunosuppression. Standard immunosuppressive therapy in renal transplantation consists of baseline therapy to prevent rejection and short courses of high-dose corticosteroids or monoclonal or polyclonal antibodies as treatment of ongoing rejection episodes. Triple-drug therapy with the combination of cyclosporin, corticosteroids and azathioprine is now the most frequently used immunosuppressive drug regimen in cadaveric kidney recipients. The continuing search for more selective and specific agents has become, in the past decade, one of the priorities for transplant medicine. Some of these compounds are now entering routine clinical practice: among them are tacrolimus (which has a mechanism of action similar to that of cyclosporin), mycophenolate mofetil and mizoribine (which selectively inhibit the enzyme inosine monophosphate dehydrogenase, the rate-limiting enzyme for de novo purine synthesis during cell division), and sirolimus (rapamycin) [which acts on and inhibits kinase homologues required for cell-cycle progression in response to growth factors, like interleukin-2 (IL-2)]. Other new pharmacological strategies and innovative approaches to organ transplantation are also under development. Application of this technology will offer enormous potential not only for the investigation of mechanisms and mediators of graft rejection but also for therapeutic intervention.

A prospective randomized trial comparing interleukin-2 receptor antibody versus antithymocyte globulin as part of a quadruple immunosuppressive induction therapy following orthotopic liver transplantation

BACKGROUND

Quadruple immunosuppressive induction therapy has been shown to markedly reduce the incidence of acute rejection episodes without increasing the incidence of infectious complications after liver transplantation. However, the use of polyclonal antibody preparations (e.g. antithymocyte globulin [ATG]) is associated with side effects such as fever and tachycardia. To evaluate the efficacy and the safety of a monoclonal antibody directed against the interleukin-2 receptor (BT563) in comparison with ATG as part of a quadruple induction regimen, a prospective, randomized study was conducted.

METHODS

Eighty consecutive adult recipients of primary orthotopic liver transplants were randomized to receive either BT563 (10 mg/day; days 0-12; n=39) or ATG (5 mg/kg/day; days 0-6; n=41) in addition to the standard immunosuppressive protocol consisting of cyclosporine, and prednisolone, and azathioprine.

RESULTS

Patients treated with BT563 had a significantly lower incidence of steroid-sensitive rejection episodes (3 vs. 11; P<0.025) and also significantly fewer drug-related side effects (4 vs. 18, P<0.038) when compared with patients treated with ATG. The incidence of infectious complications was not different between the two groups. Patient survival did not differ significantly between the two groups (84.6% at 1, 2, and 3 years in the BT563 group and 90.2% at 1 year and 87.8% at 2 and 3 years for the ATG group). Analysis of graft function showed an advantage for the BT563 group in terms of postoperative bilirubin levels. However, no differences were observed in long-term follow-up between the two groups.

CONCLUSIONS

Our results indicate that treatment with anti-interleukin-2 receptor antibody as part of quadruple induction therapy after orthotopic liver transplantation is safe and effective and shows fewer steroid-sensitive rejection episodes as well as fewer side effects when compared with quadruple induction therapy including ATG.

Radiation therapy for renal transplant rejection refractory to pulse steroids and OKT3

PURPOSE

To determine the response rate and kidney graft survival following local irradiation to the transplanted renal graft undergoing persistent rejection after medical management including pulse steroids and OKT3. The role of radiation for renal transplant rejection after failure of OKT3 has not been previously reported.

METHODS AND MATERIALS

From July 1, 1988 to July 1, 1994, 72 consecutive patients with kidney graft rejection were treated with local irradiation to the transplanted renal graft following failure of medical management. All patients received pulse steroids and OKT3, an anti-CD3 immunosuppressant. Patients who failed to respond to methylprednisolone and OKT3 therapy were referred for radiation therapy. The median time from the diagnosis of rejection to irradiation was 8 days. All kidney grafts received local graft irradiation to a total of 8 Gy delivered in four daily fractions.

RESULTS

Sixty (83%) patients initially responded to radiotherapy at 7 days after completion of radiotherapy, as defined by a decrease in serum creatinine. Thirty-five responding patients have not experienced a second episode of graft rejection. Overall, 43 (60%) patients have renal graft survival, with a median follow-up of 16 months (range of 6-73 months)>

CONCLUSION

It is concluded that there is a subgroup of kidney graft patients undergoing graft rejection who are refractory to pulse steroids and OKT3 therapy where irradiation may be an effective modality with high rates of response and a moderate rate of graft survival. However, a prospective, randomized trial in these medically refractory patients is needed to ascertain whether these results are clinically significant.

Single-shot, high-dose rabbit ATG for rejection prophylaxis after kidney transplantation

We studied the effects of a single intravenous injection of rabbit ATG (RIVM, Bilthoven, The Netherlands) in a dose of 8 mg/kg body weight administered 6 h after kidney transplantation on graft survival, rejection incidence, T-cell subsets, and cost-effectiveness. A total of 58 (37 male/21 female) consecutive renal allograft recipients were entered in this trial. Treatment results were compared with 56 patients treated with intravenous cyclosporin (CyA). In all patients concomitant medication consisted of steroids and azathioprine, followed by oral CyA. Following rabbit ATG, T cells (WT31) quickly disappeared from the peripheral blood and a return to greater than 100/mm3 was observed at a median of 7 (range 3-21) days. Graft survival was the same in both groups, as was the incidence of primary nonfunction. The rate of acute rejection was significantly lower in the rabbit ATG-treated patients (12% vs 50%). We conclude that a single shot of rabbit ATG is an attractive, easy, and cost-effective induction scheme with a low incidence of delayed graft function and acute rejection episodes. A relatively high incidence of vascular thrombosis of the graft, however, warrants further study before this treatment regimen can be generally applied.

Antilymphocyte globulin versus OKT3 induction therapy in cadaveric kidney transplantation: a prospective randomized study

Different induction therapies have been used in renal transplantation to avoid cyclosporine (CsA) nephrotoxicity and early acute graft rejection. This study compares the efficacy of a short course of prophylactic OKT3 to that of antilymphocyte globulin (ALG) in preventing acute renal allograft rejection when administered concomitantly with CsA and steroids. Between March 1988 and December 1990, 140 first-cadaver renal transplant recipients were randomly allocated to two immunosuppression groups--ALG group (n = 68): ALG 15 mg/kg just before transplant surgery, ALG 12 mg/kg the first day after transplant, followed by four doses of 10 mg/kg on alternate days; and OKT3 group (n = 72): OKT3 5 mg just before transplant, followed by four doses of 5 mg/d. Both groups included low-dose CsA and steroids. The incidence of rejection during the first 3 months after transplantation was 15% in the ALG group and 19% in the OKT3 group (NS). Kaplan-Meier estimates of patients free of rejection at 2 years was 85% in the ALG group and 77% in the OKT3 group (NS). The 3-year actuarial graft survival was 82% and 85% (NS), and 3-year patient survival was 97% and 98% (NS), in the ALG and OKT3 groups, respectively. These results indicate that the concomitant association of CsA and ALG or OKT3 constitutes a safe and effective therapeutic strategy that provides a low incidence of rejection and gives good results for patient and graft survival.

Cytomegalovirus infection and disease after liver transplantation. An overview

Cytomegalovirus is the single most important pathogen in clinical transplantation. Although much progress has been made in our understanding of the molecular biology and epidemiology of CMV infection and in our ability to diagnosis and treat CMV disease, it remains a major cause of morbidity but is no longer a major cause of mortality after liver transplantation. Risk factors for CMV disease after liver transplantation include donor and recipient serologic status, the use of antilymphocyte therapy, and retransplantation. CMV disease occurs early after transplantation, and the most frequent site of disease is the hepatic allograft. We have treated 79 patients with intravenous ganciclovir, with ultimate control of disease achieved in 69 patients (87.3%). Preliminary results using intravenous immunoglobulin and oral acyclovir for CMV prophylaxis in high-risk patients have been encouraging. In addition to producing clinical syndromes. CMV may have direct immunologic effects and is a marker of the net state of immunosuppression.

Opportunistic infections in children following renal transplantation

Opportunistic infections following renal transplantation in children are a major cause of severe morbidity and mortality. These infections account for the majority of early post renal-transplant deaths in children. General risk factors which affect the incidence and severity of these infections include: transmission of the infectious agent by the donor organ; history of immunity in the recipient prior to transplantation; type and amount of immunosuppression including treatment for rejection episodes; availability of specific treatment for the infection. Children are at particular risk because of the lack of exposure to certain pathogens prior to transplantation. There have been recent advances in the prevention and treatment of important infections which occur in children following transplantation, including varicella, Pneumocystis carinii pneumonia (PCP) and cytomegalovirus (CMV) disease. Varicella is treatable with acyclovir, often without decreasing immunosuppression and placing the graft at risk. Prophylaxis against PCP may be achieved by provision of alternate-day trimethoprim sulpha, but clear guidelines for determining who should be treated are lacking. Treatment of this disease with high-dose trimethoprim sulfa or pentamidine is usually successful. CMV disease is frequently severe, especially when the donor is seropositive and the recipient seronegative. In these situations, prophylactic CMV immunoglobulin reduces the morbidity and the mortality of the disease and prophylactic oral acyclovir may decrease its incidence. Treatment of severe CMV disease with gancyclovir is promising.

Comparison of 2-drug and 3-drug immunosuppression for cadaveric renal transplantation

We compare the results in recipients of cadaveric renal allografts immunosuppressed with cyclosporine and prednisone to those who received immunosuppression with cyclosporine, azathioprine and prednisone. The 2 groups were compared relative to HLA-ABDR matching, plasma reactive antibodies, cold ischemia time, diabetes as a cause of renal failure and recipient age greater than 50 years. The incidences of clinical allograft rejection and grafts lost to rejection were not significantly different in these 2 groups evaluated at 1 year. In the 2-drug immunosuppressed group the actual 3, 6 and 12-month graft function was 87, 86 and 85%, respectively, compared to 79, 78 and 74%, respectively, in the 3-drug immunosuppressed group. A difference in graft survival was due to graft loss secondary to vascular thrombosis and patient death, and not to immunological events. No advantage was demonstrated for the use of 3-drug immunosuppression for kidney allografts over a 2-drug protocol of cyclosporine and prednisone.