The addition of sirolimus to cyclosporine and steroids inhibits the anti-equine antibody response in renal transplant recipients treated with antithymocyte globulin.

Polyclonal antibodies, such as equine antithymocyte globulin (ATGAM), are known to induce antibody formation. This study evaluated the in vivo effect of sirolimus on antibody formation associated with the use of equine antithymocyte globulin in renal transplant recipients. Recipients of either a living-related donor or cadaveric renal allograft received azathioprine (AZA) (n = 15), mycophenolate mofetil (MMF) (n = 12), or sirolimus (n = 15) in addition to baseline immunosuppression with corticosteroids, cyclosporine, and equine antithymocyte globulin. Immediately before transplantation and weekly for at least 1 month, sequential serum specimens were tested for the presence of human anti-equine antibody using an enzyme-linked immunosorbent assay (ELISA). Anti-equine antibody formation was significantly different among the three treatment groups. Fewer patients receiving MMF (17%, p = 0.007 vs. AZA) and sirolimus (13%, p = 0.003 vs. AZA) developed anti-equine antibody compared with AZA (66%). There was no significant difference (p = 0.81) in the sensitization to equine antithymocyte globulin when comparing the patients receiving MMF or sirolimus. In the sensitized patients, high anti-equine antibody titers (>1 : 500) were more common in those receiving AZA (n = 3) than MMF (n = 0) or sirolimus (n = 1). Compared to AZA, sirolimus, when given in combination with cyclosporine A, significantly reduced anti-equine antibody formation to a degree similar to MMF.

Tacrolimus (FK506)-induced mutism after liver transplant.

Tacrolimus (FK506), an immunosuppressant, has been associated with mutism in adults after liver transplant. Speech arrest, agitation, tremor, ataxia, and downward gaze deviation in a 5-year-old female 13 days after orthotopic liver transplant are reported. FK506, which began to be administered 12 days earlier, rose to a level of 44 ng/mL (normal range, 10-20 ng/mL) 1 day before neurologic abnormalities began. FK506 dose level was maintained and then reduced. Three days later the patient could say a few single words and extra-ocular movement returned to normal. Four months later, she continued to exhibit decreased fluency and dysarthria with ataxia. One year later, decreased fluency and mild ataxia persists. Rapid identification of speech loss linked to FK506 may be important because reduction or cessation of the drug may be associated with reverse of speech loss.

Creatinine reduction ratio and 24-hour creatinine excretion on posttransplant day two: simple and objective tools to define graft function.

To devise objective criteria for early diagnosis of delayed graft function (DGF), 59 adult living donor kidney transplants with immediate graft function (IGF) and 51 cadaveric kidney transplants were investigated for creatinine reduction ratio (CRR2) from posttransplant day 1 to day 2 and 24-h urine creatinine excretion (UC2) on day 2. The mean CRR2 in living donor transplants was 53% (SD +/- 11); the distribution of CRR2 was gaussian, and all of them had UC2 >1000 mg. Criteria for DGF were developed on the basis of living donor transplant: CRR2 < or =30% (2SD below 53%) +/- UC2 < or =1000 mg. Overall, 24 cadaver transplant recipients (47%) developed DGF (CRR2 < or =30%); 13 patients (25%) had mild DGF (UC2 >1000 mg), and the remaining 11 (22%) had severe DGF (UC2 < or =1000 mg). All the patients with severe DGF had a measured creatinine clearance <25 ml/min on day 7, and 8 of 11 were dialyzed within the first week of transplantation. Patients with IGF and mild DGF had a creatinine clearance of > or =25 ml/min on or before day 7, and none of them were dialyzed. Calcineurin inhibitors were avoided or delayed in five patients with mild DGF and all patients with severe DGF. In conclusion, diagnosing DGF within 48-h after transplantation is simple and may be valuable in the management of these patients.

A long-term comparison of tacrolimus (FK506) and cyclosporine in kidney transplantation: evidence for improved allograft survival at five years.

BACKGROUND: The 1-year results of the Phase III U.S. Multicenter Trial comparing tacrolimus (FK506)- and cyclosporine (CsA)-based immunosuppressive therapy in kidney transplantation revealed a significant reduction in the incidence and severity of acute rejection episodes among patients maintained on tacrolimus. The present report at 5 years of follow-up focuses on the long-term impact of tacrolimus treatment on kidney allograft outcome. METHODS: The study protocol permitted crossover of patients to the alternate treatment arm under stringent conditions. The effect of crossover on graft survival was analyzed. Cardiovascular risk factors and serious adverse events were also monitored over 5 years. RESULTS: Intent-to-treat analysis revealed equivalent patient and graft survival between treatment arms at 5 years of follow-up (79.1% vs. 81.4%; P=0.472 and 64.3% vs. 61.6%; P=0.558 among tacrolimus and CsA-treated patients, respectively). However, the rate of crossover was significantly higher among patients randomized to receive CsA-based therapy (27.5% vs. 9.3%; P<0.001). The incidence of treatment failure (43.8% vs. 56.3%; P=0.008) was significantly lower among tacrolimus-treated patients. Graft survival was significantly improved in the tacrolimus treatment arm when crossover due to rejection was counted as graft failure (63.8% vs. 53.8%; P=0.014). Tacrolimus therapy was also associated with a significantly reduced requirement for medications to control hypertension and hyperlipidemia. There was a substantial rate of reversal of tacrolimus-associated insulin dependence. CONCLUSION: Tacrolimus-based therapy resulted in significantly reduced risk of graft failure, without an increase in the incidence of adverse events associated with long-term immunosuppression.