Acute thrombosis of the renal transplant artery after a single dose of OKT3

We present the case of an 18-year-old male who 8 months after a living-related donor, one-haplotype-matched renal transplantation developed acute thrombosis of the renal allograft artery, within 10 h of the first dose of OKT3. The antibody therapy had followed five daily doses of intravenous pulse methylprednisolone for a Banff class 1B acute tubulointerstitial rejection, on a ciclosporin-based immunosuppression protocol. We briefly review the literature on the incidence of vascular thrombosis after transplantation and the procoagulant effects of OKT3, pulse methylprednisolone, and ciclosporin therapy.

Impact of cyclosporine withdrawal on living related renal transplants: a single-center experience

High treatment costs force the discontinuation of cyclosporine (CSA) in a vast majority of renal transplant recipients in India. The impact of CSA withdrawal among 108 living related renal transplant recipients 12.54 +/- 4.2 months after transplantation was studied retrospectively. In 83 patients, CSA was withdrawn over a 12-week period (group I). Azathioprine dosage was increased to 2 to 2.5 mg/kg/d, and prednisolone, to 30 mg/d 2 weeks and 1 week before starting CSA withdrawal, respectively. In the other 25 patients, CSA had to be withdrawn faster (mean, 28.52 +/- 14.18 days; group II). Twenty-nine rejection episodes (26.9%) were noted in 22 patients (20.4%; 19% in group I and 52% in group II; P: = 0.008). Fifteen group-I patients (18%) and 11 group-II patients (44%) died or lost their grafts (P: = 0.017). There was no difference in age, donor source, HLA matches, pretransplantation cross-match positivity, delayed graft function, immunosuppressive drug doses, rejection episodes, or prewithdrawal serum creatinine levels between the patients who did or did not develop acute rejection after CSA withdrawal. On follow-up, 10 patients (50%) died or returned to dialysis among the rejection group compared with 16 patients (18%) in the nonrejection group (P: = 0.007). The mean creatinine level at last follow-up was greater in the rejection group (3.97 +/- 2.54 versus 1.65 +/- 1.1 mg/dL; P: < 0.001). CSA withdrawal because of economic constraints carries a significant risk for acute rejection and death and/or graft loss in Indian living donor renal transplant recipients, even after 12 months.

Neonatal (cord blood) T cells can competently raise type 1 and 2 immune responses upon polyclonal activation

In the neonate, cellular immunity has generally been hypothesized as being incompetent. Accumulating evidence from several recent studies, together with our present report, contradicts this hypothesis. T-helper cell and T cytotoxic type 1 and 2 (Th1/Th2 and Tc1/Tc2, respectively) cytokine responses to polyclonal T cell receptor (TCR) activation were assessed in medium-term cultures of human cord blood T cells using intracellular cytokine staining, which could measure the frequencies of cytokine-producing cells. In this study, we examined the responses of cord blood CD4(+) and CD8(+) T cells in regard to the production of interferon (IFN)-gamma and interleukin (IL)-4 and compared the responses with those obtained from T cells of healthy adults. We found that the responses in cord blood T cells activated with TCR stimulation were comparable to those of their adult counterparts. Moreover, the Th/Tc cells that developed in cord blood were as competent as adult cells for both IFN-gamma and IL-4 secretion. In addition, IL-12 production, which is critical for both Th1 and Tc1 responses, was equally comparable in the two groups. The production of two major cross-regulatory cytokines, tumor necrosis factor-alpha and IL-10, was similarly comparable and not significantly different between the two groups. Taken together, these results indicate that, though naive, the neonatal T cell is competent to respond to TCR-mediated stimulation and to produce both type 1 and type 2 cytokines.

Single doses of FK506 and OKT3 reduce severity in early experimental acute pancreatitis

OBJECTIVE

To find out if two immunomodulatory drugs used in organ transplantation (FK506 (tacrolimus) and OKT3 (Orthoclone) would reduce early inflammatory complications in experimental acute pancreatitis.

DESIGN

Laboratory study.

SETTING

University hospital, Germany.

ANIMALS

36 Balb/c mice.

INTERVENTIONS

Pancreatitis induced by 7 intraperitoneal injections of cerulein 50 microg/kg at hourly intervals followed by FK506 0.32 mg/kg, OKT3 0.6 mg/kg, or 0.9% sodium chloride (controls) (n = 12 in each group). 12 hours after induction of pancreatitis the animals were killed.

MAIN OUTCOME MEASURES

Serum amylase activity and interleukin-6 (IL-6) concentrations; histological damage to pancreas and lungs, apoptotic cells in pancreas; and myeloperoxidase activity in lungs.

RESULTS

No animal died during the experiment. At 12h serum amylase activity and IL-6 concentrations were increased in all 3 groups, but highest in the OKT3 group. The pancreatic histological score, apoptosis, and inflammatory infiltration were lower in the two experimental groups than controls, but the degree of vacuolisation of acinar cells was similar. Packed cell volume was higher in the control than the experimental groups, and pulmonary damage and myeloperoxidase activity were less in the experimental groups than the controls.

CONCLUSION

Single therapeutic doses of FK506 and OKT3 reduced the early severity of pancreatitis, pulmonary damage, and haemoconcentration in mice. Single doses of FK506 or OKT3 may therefore be effective in preventing the early complications of pancreatitis.

A randomized prospective trial of low-dose OKT3 induction therapy to prevent rejection and minimize side effects in recipients of kidney transplants

BACKGROUND

We attempted to minimize the undesired side effects and maximize the benefit of OKT3 induction therapy in renal transplantation.

METHODS

One hundred and one recipients of kidney-only transplants were randomized to three groups. Each received low-dose 2.5-mg OKT3 induction for 7-14 days, but different premedication on days 0, 1, and 2. Group I was given 250 mg i.v. methylprednisolone at 1 and 6 hr, and group II received another 500 mg at 1 hr before initial OKT3. Group III received Atgam 15 mg/kg on day 0 and began OKT3 on day 1. A CD3+ T-cell cut-off of 50/mm3 was used to guide therapy. Maintenance therapy included cyclosporine and steroids for each patient. However, groups I and II were also given mycophenolate mofetil, and group III received azathioprine as a third agent. All rejections were biopsy confirmed and Banff scored.

RESULTS

No differences in demographic or transplant characteristics were noted between groups I, II, and III, and mean follow-up was 25.7 (1-38) months. There was no significant difference in actuarial patient (90%, 91%, 94%) or graft survival (83%, 88%, 84%) at 3 years between the respective groups. Mean creatinine values and infectious complications were similar for each group. No patient experienced acute rejection during induction, and eight patients required dose escalation to sustain suppression of CD3 counts. The incidence of acute rejection at 6 and 12 months was significantly (P=0.004) greater in group III (38.2, 44.1%) than in either group I (15.1, 18.1%) or group II (14.7, 17.6%); relative risk 1.988 (95% CI 1.012-3.906). Formation of anti-OKT3 antibody was significantly (P=0.006) greater in group III (26.5%) than in group I (6%) or group II (2.9%). Group I recipients enjoyed significantly (P=0.001) fewer (2.17) OKT3 side effects on days 0, 1, and 2 than group II (3.03) or group III (2.49), and contained the largest number (61%) of recipients who experienced no side effects. Group I also exhibited the most suppressed profile of OKT3-induced release of tumor necrosis factor-alpha (P=0.006), interferon-gamma (P=NS), and interleukin-6 (P=0.01) on days 0 and 1.

CONCLUSIONS

Low-dose 2.5-mg OKT3 with pretreatment of split-dose steroids on days 0, 1, and 2 provides the most effective method for OKT3 induction, which minimizes side effects for most patients. Subsequent maintenance therapy with cyclosporine, mycophenolate mofetil, and steroids provides effective rejection prophylaxis without increased complications for up to 3 years. Predepletion of T cells before exposure to OKT3 does not prevent cytokine release.

Postpericardiotomy syndrome during intensive immunosuppression after cardiac transplantation

A 15-year-old man with end-stage heart failure due to dilated cardiomyopathy, underwent heart transplantation. In the second postoperative week, while being treated with monoclonal antibodies (OKT3), cyclosporine and azathioprine, he developed a postpericardiotomy syndrome and cardiac tamponade, which necessitated emergency pericardiocentesis. Corticosteroids, administered according to the immunosuppression protocol, resulted in the prompt subsidence of the syndrome. This is the first report of a large pericardial effusion and cardiac tamponade due to a postpericardiotomy syndrome in an adult cardiac recipient.

Efficacy of tacrolimus in patients with steroid-resistant cardiac allograft cellular rejection

BACKGROUND

Tacrolimus is an immunosuppressive agent that is gaining widespread use in solid organ transplantation. This study was undertaken to evaluate the efficacy of tacrolimus in treating steroid-resistant cellular myocardial rejection.

METHODS

We retrospectively analyzed the incidence of rejection and clinical outcome of 21 heart transplant recipients who were electively converted from cyclosporine to tacrolimus for recurrent episodes of steroid-resistant cellular rejection. These were compared to a historic group of 6 hemodynamically stable patients who were treated electively with Orthoclone OKT3 (Muromonab/CD3) for recurrent rejection.

RESULTS

Eighty five percent (56/66) of the episodes of rejection occurred within the first 3 months after heart transplantation. Tacrolimus was started 2. 4 +/- 2.0 months post-transplant, and the mean follow-up duration on tacrolimus was 11.0 +/- 7.0 months. After conversion, a significant decline was noted in both the number of episodes of acute rejection per patient (3.14 +/- 0.85-0.57 +/- 0.87, p < 0.0001), and the incidence of acute rejection per 100 patient-days (6.39 +/- 3.96-0. 25 +/- 0.47, p < 0.0001). In comparison, OKT3 was started 5.25 +/- 9. 20 months post-transplant. Similarly, there was a significant decrease in the incidence of acute rejection per 100 patient-days (8. 69 +/- 5.65-0.20 +/- 0.23, p < 0.0001). The average hospital charges per patient for the OKT3-treated group was $33,339 +/- $10,511. There was no significant difference in the actuarial 1-year survival between the tacrolimus and OKT3-treated groups (93% vs 80%, p = 0.5).

CONCLUSIONS

Outpatient conversion to tacrolimus is safe, well tolerated, and an effective therapeutic strategy for the treatment of steroid-resistant cellular rejection in heart transplant recipients. It is more cost-effective than OKT3 in the hemodynamically stable patient and outcomes are similar.

Predicting factors of long-term results of OKT3 therapy for steroid resistant acute rejection following cadaveric renal transplantation

In this retrospective study, we evaluated the histological and biological predictors of long-term response of renal transplant (RT) patients treated with orthoclone OKT3 for steroid resistant acute rejection (AR). Seventy-three patients, aged 37 +/- 12 years, were included in this study between March 1987 and December 1996. All the patients but one had received sequential quadruple immunosuppression (polyclonal antilymphocyte globulins; steroids; azathioprine, and cyclosporin A). OKT3 (5 mg/day for 10 days) was administered for biopsy-proven steroid resistant AR i.e., after 3 consecutive pulses of methylprednisolone (10 mg/kg each). This was the first AR in 46 cases, the second AR in 22 cases and the third AR in 4 cases. Renal histology (Banff) showed borderline (BL) changes in 18 patients, grade I AR in 28 patients; grade II AR in 22 patients, and grade III AR in 5 patients. When treatment with OKT3 commenced (107 +/- 18 days post-transplantation) the mean serum creatinine (SCr) level was 325 +/- 195 micromol/l; this had decreased to 191 +/- 106 micromol/l by the end of OKT3 therapy. The immediate response to OKT3 therapy i. e., within the first month, was not dependent on the histological score. Twenty-six patients (35%) subsequently experienced at least one more AR episode of whom 4 were retreated with OKT3. The overall patient's survival was 94.5% at last follow-up. The overall cumulative graft survival was 64.5% at 2 years, 52.5% at 5 years, and 40.5% at 8 years. The graft survival (5 years) tended to depend on the initial histological score, i.e. BL 30%; grade I 66%; grades II and III 55.5% (p = 0.08). In a multiple logistic regression analysis we tried to identify independent factors that would predict that a graft would still be functioning at least 2 years after OKT3 therapy. We therefore analyzed the following parameters: donor and recipient's age; gender; cold ischemia time; HLA matching; panel reactive antibodies (PRA) prior to grafting; previous transplantation(s); total number of AR episodes; the time of onset of the AR treated by OKT3 compared to the other AR; the time of onset of the AR treated by OKT3; SCr levels at days 0, 10 and 30 after OKT3 therapy; histological score (Banff) i.e., the magnitude of AR and the presence or absence of chronic lesions. The only independent factors which would predict that a graft was still functioning 2 years after OKT3 therapy were: PRA <25% (Odds ratio (OR) 7.68 (1.15-51.3); p = 0.035); a grade I AR (OR 10.52 (1.18-93. 5); p = 0.035); SCr level 1 month after OKT3 therapy (OR 0.935 (0. 87-1.002); p = 0.05). HLA matching and the presence of histological chronic lesions were nearly significant (p = 0.06 and 0.09 respectively). In conclusion, this retrospective study shows that independent predictors of the long-term response to OKT3 therapy for AR in RT patients are the magnitude of pre-transplant PRA, the histological score, and the SCr level one month after OKT3 therapy.

Immuno-activation with anti-CD3 and recombinant human IL-2 in HIV-1-infected patients on potent antiretroviral therapy

BACKGROUND

A stable reservoir of latently infected, resting CD4 T cells has been demonstrated in HIV-1-infected patients despite prolonged antiretroviral treatment. This is a major barrier for the eradication of HIV by antiretroviral agents alone. Activation of these cells in the presence of antiretroviral therapy might be a strategy to increase the turnover rate of this reservoir.

METHODS

Three HIV-1-positive patients on potent antiretroviral therapy, in whom plasma viremia had been suppressed to below 5 copies/ml for at least 26 weeks, were treated with a combination of OKT3 (days 1-5) and recombinant human IL-2 (days 2 6).

RESULTS

The side-effects were fever, headache, nausea, diarrhea, and in one of the patients transient renal failure and seizures. The regimen resulted in profound T cell activation. In one patient plasma HIV-1 RNA transiently increased with a peak at 1500 copies/ml. In the other two patients plasma HIV-1 RNA levels remained below the detection limit, but HIV-1 RNA levels in the lymph nodes increased two- to threefold. All patients developed antibodies against OKT3.

CONCLUSION

OKT3/IL-2 resulted in T cell activation and proliferation, and could stimulate HIV replication in patients having achieved prolonged suppression of plasma viremia. OKT3/IL-2 therapy was toxic and rapidly induced antibodies against OKT3.

Phase I trial of a humanized, Fc receptor nonbinding OKT3 antibody, huOKT3gamma1(Ala-Ala) in the treatment of acute renal allograft rejection

BACKGROUND

HuOKT3gamma1(Ala-Ala) is a genetically-engineered derivative of the parental murine OKT3 monoclonal antibody, in which the six complementarity-determining regions have been grafted within a human IgG1 mAb, and whose C(H)2 region has been altered by site-directed mutagenesis to alter FcR-binding activity, thereby eliminating T cell activation properties. This report describes the results of a phase I trial of huOKT3gamma1(Ala-Ala) treatment of acute renal allograft rejection.

METHODS

Acute renal allograft rejection in kidney and kidney-pancreas transplant recipients was treated with huOKT3gamma1(Ala-Ala). huOKT3gamma1(Ala-Ala) dosing consisted of daily 5- or 10-mg doses adjusted initially to achieve target levels of 1000 ng/ml.

RESULTS

A total of seven patients, five kidney transplant and two kidney-pancreas transplant recipients, were treated with the monoclonal antibody for first rejection episodes. Corticosteroids (500 mg i.v. Solumedrol) were given 2 hr before the first huOKT3gamma1(Ala-Ala) dose only. Banff classification of treated rejections were the following: grade I, 1 patient, grade IIA, 1 patient, grade IIB, 4 patients, and grade III, 1 patient. Median time from transplant to rejection was 15 days, and median follow up 12 months (range 10-17 months). HuOKT3gamma1(Ala-Ala) therapy was given for 10.1+/-2.5 days, and mean total dose was 76+/-27 mg. Rejection was reversed in five of seven patients, and recurrent rejection was observed in one patient. Serum creatinine values peaked on day 1 of huOKT3gamma1(Ala-Ala) therapy, and thereafter demonstrated a progressive decline. Rejection reversal (return of creatinine to baseline) occurred at a median of 4 days and a mean of 4.1+/-2 days. Renal allograft biopsies obtained during huOKT3gamma1(Ala-Ala) therapy provided evidence of rapid rejection reversal. Patient and graft survival were both 100%. First dose reactions were minimal, and anti-OKT3 antibodies were not detected. Elevations in serum IL-10, but not IL-2 levels were observed after the first huOKT3gamma1(Ala-Ala) dose. Marked reductions in circulating CD2+, CD4+, and CD8+ T cells were observed after the first huOKT3gamma1(Ala-Ala) dose, followed by a slow progressive return of cell counts toward pretreatment values. Pharmacokinetic analysis revealed a half-life of 142+/-32 hr.

CONCLUSIONS

HuOKT3gamma1(Ala-Ala) possesses the ability to reverse vigorous rejection episodes in kidney and kidney-pancreas transplant recipients, and in comparison to murine OKT3, possesses minimal first dose reactions and does not seem to induce antibodies that bind the OKT3 idiotype. These results support the conduct of additional clinical trials with the huOKT3gamma1(Ala-Ala) antibody.

Mycophenolate mofetil, together with cyclosporin A, prevents anti-OKT3 antibody response in kidney transplant recipients

OKT3 monoclonal antibody, a murine IgG2a monoclonal antibody targeting the T cell CD3 antigen, elicits a neutralizing humoral response in 20 to 50% of kidney transplant recipients when the concomitant immunosuppression consists of CsA-Sandimmun (SAND) and azathioprine (AZA). In the present study, we investigated the impact of the newer agents, CsA-Neoral (NEO) and mycophenolate mofetil (MMF) on OKT3 sensitization. Sixty-two consecutive kidney transplant recipients received prophylactic OKT3 (5 mg/d) from days 0 to 13, together with steroids. Concomitant immunosuppression consisted of either AZA + SAND (n=20), AZA + NEO (n=31), or MMF + NEO (n=11). The following doses were used: AZA, 2 mg/kg per d from days 0 to 13, then 1 mg/kg per d; MMF, 2 g/d starting on day 1; and CsA, either SAND or NEO, 6 mg/kg per d from day 6. At least two serum samples per month were available during the initial 3 mo for each patient. IgG anti-OKT3 antibodies were first evaluated by enzyme-linked immunosorbent assay. Patients were considered sensitized if their serum scored positive at a dilution > or = 1/1000. Peak titers of IgG anti-OKT3 antibodies and the incidence of patients harboring neutralizing anti-idiotypic antibodies were also determined. A first reduction in OKT3 sensitization was seen in patients receiving Neoral instead of Sandimmun (AZA + SAND: 10 of 20 [50%] patients sensitized versus 6 of 31 [19%] in the AZA + NEO group; P=0.03). This was probably related to the achievement of higher mean CsA trough blood levels in the NEO group during the first month (253+/-44 versus 186+/-49 ng/ml in SAND patients). Peak antibody titers and the proportion of patients with anti-idiotypic antibodies were similar in the AZA + SAND and AZA + NEO groups. A further reduction in the sensitization rate was observed with the replacement of AZA by MMF (MMF + NEO: 0% sensitized patients; P=0.0013). It is concluded that the combination of CsA-Neoral and MMF efficiently prevents sensitization against OKT3.

Two low-dose OKT3 induction regimens following renal transplantation--clinical experience at a single center

Experience with quadruple-drug induction therapy with two regimens of low-dose OKT3 in renal transplant patients was evaluated. Group I received 5.0 mg OKT3 in the operating room and on day 1, followed by 2.5 mg/d for a total dose and duration of 40 mg and 14 d, respectively, and group II received 14 d of OKT3 2.5 mg/d (a total dose of 35 mg). Rejection episodes developed in 21% of patients: 29% of group I vs. 17% of group II. In groups I and II, the mean number of days until first rejection was 134 and 119 d, respectively, and delayed graft function was observed in 24 vs. 13% of patients, respectively. Cytokine release syndrome was noted in 95% of group I patients and in 78% of group II patients. The overall incidence of infections did not differ significantly between the two groups; however, the incidence of oral candidiasis was higher in group II (30 vs. 11% in group I, p = 0.021) and the incidence of herpes simplex virus infection was higher in group I (13 vs. 1% in group II, p = 0.015). The average length of hospital stay was 6.7 d in group I and 6.2 d in group II. The current pharmacy charge for a 2.5-mg vial of OKT3 is 28% lower for a 5.0-mg vial. Our study suggests that by using either low-dose OKT3 regimen renal transplant patients can be safely treated with shortened hospital stays, lower pharmacy costs, and without increased incidence of graft loss or patient morbidity.

A randomized prospective study comparing low-dose OKT3 to low-dose ATG for the treatment of acute steroid-resistant rejection episodes in kidney transplant recipients

Acute steroid-resistant rejection episodes in kidney allograft recipients require treatment with antilymphocyte antibodies. Monoclonal anti-CD3 and polyclonal antilymphocyte antibodies have been widely used but seldom compared. Recent data have suggested that these antibodies could be used at reduced doses without jeopardizing their efficacy. In this study, we randomized renal transplant recipients who encountered a first acute steroid-resistant rejection episode to low-dose ATG or low-dose OKT3 treatment. Sixty patients were enrolled in the study. They received prophylactic immunosuppression with cyclosporin, azathioprine, and prednisolone. Treatment of biopsy-proven rejection consisted of a 10-day course of either ATG (n = 31) or OKT3 (n = 29). The total ATG dose was 484 +/- 110 mg, i.e., 0.75 mg/kg per day. The total OKT3 dose was 32 +/- 4 mg, i.e., 0.05 mg/kg per day. We compared reversion of rejection, side effects, immunodepression, and graft function. Reversion of rejection was similar in the two groups, although we noted a trend in favor of ATG. Results were 3% vs 10% early graft failures, 13% vs 23% overall graft failures, 28% vs 38% 3-month actuarial incidence of rebound rejection, and 89% vs 81% 1-year graft survival rate in the ATG and OKT3 groups, respectively. Tolerance was worse in the OKT3 group due to the first-dose syndrome. Infections and cancers occurred with the same frequency. ATG resulted in a deeper and longer decrease in peripheral lymphocyte subsets. Graft function was similar in the two groups. We conclude that low-dose ATG and low-dose OKT3 are equally effective in reversing steroid-resistant acute rejection. Tolerance was better with ATG, which also gave a more potent and longlasting immunodepression. The use of reduced doses of ATG and OKT3 did not appear to lessen their efficacy.

OKT3 monitoring in the treatment of steroid-resistant acute rejection of hepatotransplant recipients

OKT3 is a monoclonal antibody used as T-specific immunosuppressor agent in the treatment of acute rejection of hepato- or renal-transplanted patients. The immunosuppressor effect is related to the elimination and modulation of T-cells after the binding between OKT3 and the specific antigen CD3+. This drug has been used in the treatment of acute rejection. The more frequent side effects is the immunogenic reaction Human Antibody Mouse Antibody (HAMA). The aim of this study is the evaluation of the dose and the administration route of the OKT3. The results of the antibody monitoring in the plasma of the treated patients and the analysis of the clinical data were evaluated to focus a valid therapeutic protocol as well as a more rational time sampling of the circulating drug to achieve a correct monitoring. The results show a gradual increase of the hematic concentration of the drug, positively correlating the clinical data of hepatic biopsy and lymphocytic screening. These results have permitted to modify the therapeutic protocol previously performed. It has been defined the administration route choosing i.v. infusion (5 mg/die/2 h), moreover it the therapy has been shortened to 6 days. The HAMA were also evaluated and the analysis of the data showed a negative results, suggesting the possibility of the OKT3 retreatment in the cases of rescue.

[Kidney-pancreas transplantation. Clinical results in 23 consecutive patients]

Immunosuppressive approaches to combined kidney-pancreas tx include quadruple therapy with either antilymphocyte globulin (ATG) or OKT3 for a short period (7-14 days) immediately after transplantation. Maintenance therapy with prednisone, azathioprine and cyclosporin is then used to ensure the long-term survival of the graft. This study reports 23 cases of combined kidney-pancreas tx under ATG induction (n = 7) and OKT3 induction (n = 16). Both groups had maintenance therapy with azathioprine, prednisone and cyclosporin. The follow-up was 12 months. Graft loss was 3 out of 7 vs 1 out of 16 (p < 0.05) for the kidney and 3 out of 7 vs 3 out of 16 for the pancreas in ATG treated vs OKT3 treated patients respectively. There were two deaths in the ATG group and one in the OKT3 group; two patients died with functioning graft, one in each group. The one year actuarial survival was 87% for graft and patient, 83% for kidney and 77% for pancreas. Combined kidney-pancreas tx with ATG or OKT3 have a similar outcome. OKT3 allows a longer period before the onset of rejection. There is a trend in survivals which suggests a better survival in OKT3 treated recipients. Infections and other complications were similar in ATG and OKT3 patients.

Use of low-dose OKT3 as induction therapy in liver transplantation

BACKGROUND

A pilot study was performed to prospectively evaluate the safety and efficacy of "low-dose" OKT3 induction after liver transplantation.

METHODS

Sixteen patients received a 5- to 10-day course of OKT3 (2.5 mg i.v. daily) along with azathioprine, prednisone, and the delayed introduction of cyclosporine (Neoral).

RESULTS

Patient and graft survival rates at 1 year were 88% and 82%. Five patients (31%) had biopsy-proven rejection; all five were treated successfully with steroids. There were 15 infections in 12 patients, including 5 cytomegalovirus infections. Adverse events attributed to OKT3 consisted of low-grade fever (five patients), transient hypoxemia (three patients), and transient hypotension (two patients). Pharmacy acquisition costs for OKT3 averaged $2,139 less as compared to a group of historical controls receiving full-dose therapy.

CONCLUSIONS

Low-dose OKT3 induction appears to be a safe and useful method of postoperative immunosuppression after liver transplantation. Its ultimate clinical, immunologic, and economic efficacy awaits determination by randomized trial.

Administration of OKT3 as a two-hour infusion attenuates first-dose side effects

BACKGROUND

Use of the murine CD3 monoclonal antibody OKT3 is limited by first-dose side effects, which are thought to be caused by the release of inflammatory mediators. Because these processes might be influenced by the speed of administration, we compared a 2-hr OKT3 infusion with the bolus infusion usually applied nowadays.

METHODS

Eighteen renal allograft recipients were prophylactically treated with OKT3 and randomized to receive the first dose either as a 2-hr infusion or as an intravenous bolus infusion. Clinical side effects score and the occurrence of complement activation, cytokine release, and activation of neutrophils were determined.

RESULTS

Two-hour infusion of OKT3 completely prevented the occurrence of dyspnea, reduced the incidence of other side effects, and attenuated complement activation. Cytokine release and depletion of peripheral blood lymphocytes were similar in both groups.

CONCLUSIONS

Thus, complement activation seems to play an additional role in the development of side effects after the first OKT3 dose.

[Treatment of transfusion-associated graft-versus-host disease]

Transfusion-associated graft-versus-host disease (TA-GVHD) in immunocompetent patients is mediated by activated lymphocytes derived from the donor directed against host allogeneic HLA antigens. When considering this pathogenesis, the target of TA -GVHD treatment should be focused on the cytotoxic T cells (CTL) directed against host HLA. The combination therapy of anti-CD3 monoclonal antibody, OKT3, cyclosporin A, and corticosteroid may be effective to inhibit the cytotoxic activity of CTL. In addition to these immunosuppressive agents, monoclonal antibodies against functional cell surface molecules, such as LFA-1, ICAM-1, Fas, and Fas ligand, must be effective for treatment of TA-GVHD. Since the effective standard therapy of TA -GVHD has not been established, the prevention by gamma irradiation of cellular blood components is most important.

Induction immunotherapy in heart transplantation with T10B9.1A-31: a phase I study

Cytolytic induction therapy of heart transplantation with OKT3 (immunoglobulin G2a isotype, anti CD3 idiotype) or T10B9.1A-31 (immunoglobulin MK isotype, anti-T-cell receptor alpha beta idiotype) was done in an open-label trial to determine the safety and efficacy of the latter monoclonal antibody. A total of nine patients undergoing orthotopic heart transplantation received a 10-day course of either T10B9.1A-31 (T10B9) (n = 4) 18 mg on bypass and 6 mg intravenously every 12 hours or OKT3 (n = 5) 10 mg on cardiopulmonary bypass and 5 mg intravenously daily. Endomyocardial biopsy surveillance revealed no rejection during induction therapy with T10B9, and one OKT3 induction failure was successfully treated with T10B9, all without significant side effects. T10B9 effectively prevented the onset of early acute rejection in heart transplantation with minimal side effects. T10B9 reversed rejection in one patient whose OKT3 induction failed. Results are encouraging and warrant further investigation.

Induction immunosuppressive therapy is associated with a low rejection rate after liver transplantation

Despite advances in immunosuppression, allograft rejection occurs frequently after liver transplantation. The use of induction therapy with cytolytic antibodies may decrease the frequency of rejection in liver transplant recipients, but may also increase the rate of cytomegalovirus (CMV) infection. It has been our center's strategy to use induction therapy in our liver transplant recipients. To determine the outcome of our strategy, we retrospectively reviewed all liver transplants performed in the first 5 yr of our liver transplant program. The frequency of acute rejection in the first year after liver transplantation was only 34% in patients who received induction therapy. The type of induction therapy antibody did not affect the rejection rate. Clinically significant CMV infection (requiring treatment) occurred in 22% of patients. These results suggest that use of induction therapy with cytolytic antibodies does not lead to a high incidence of CMV infection and decreases the incidence of rejection after liver transplantation.