Azathioprine monotherapy in HLA-identical live donor kidney transplant recipients.

The high success rate of HLA-identical sibling transplants and our previous experience with steroid-free immunosuppressive regimens and cyclosporine withdrawal prompted us to evaluate the safety and efficacy of monotherapy with azathioprine in 12 HLA-identical kidney transplant recipients with a serum creatinine concentration less than 176.8 mumol/L, a 1-way stimulatory index less than 2.0 in a post-transplant mixed lymphocyte culture, and a demonstrated tolerance of a minimum azathioprine dose of 1.0 mg/kg per day without leukopenia. Eleven of 12 patients were successfully converted to azathioprine monotherapy without a significant change in serum creatinine concentration for as long as 76 months. Benefits of steroid and cyclosporine withdrawal included a significant reduction in mean systolic and diastolic blood pressure, number of blood pressure medications, total serum cholesterol, and glycohemoglobin in diabetic subjects. Our results suggest that azathioprine monotherapy is safe and effective in a select group of HLA-identical sibling transplants, but these benefits must be carefully balanced against an associated risk of precipitating acute allograft rejection.

Renal function following conversion from Sandimmune to Neoral in stable renal transplant recipients.

Conversion of stable renal transplant patients from Sandimmune to Neoral may pose a risk of short-term nephrotoxicity. Serial serum creatinine concentrations were measured in 141 kidney and simultaneous kidney-pancreas transplant recipients converted from Sandimmune to Neoral on a 1:1 dosing basis and followed for up to 11 months. Following conversion, cyclosporine dose was reduced in 74% of patients with a mean dose reduction of 22.6% for the entire cohort. Serum creatinine concentrations transiently increased to more than 30% above baseline in 48% of patients and remained more than 30% above baseline in 16% of patients. Multivariate analyses suggested that acute rejection, maintenance steroid therapy, young age, Sandimmune dose prior to conversion, and an increment in trough cyclosporine levels after conversion were positive predictors of renal insufficiency following conversion. Lower doses of Neoral should be considered at the time of conversion to minimize nephrotoxicity.