Showing papers by "Edward S. Cole published in 2003"

Clinical outcomes during the first three months posttransplant in renal allograft recipients managed by C2 monitoring of cyclosporine microemulsion.

Abstract: Background. MO2ART (monitoring of 2-hr absorption in renal transplantation) is the first prospective, multicenter trial of cyclosporine (CsA) blood level 2 hr postdose (C 2 ) monitoring in de novo kidney recipients receiving CsA microemulsion (ME) (Neoral; Novartis, Basel, Switzerland). Efficacy and safety results from the first 3 months are presented here. Methods. MO2ART is a 12-month, open-label, randomized study involving 296 patients. In all patients, the dose of CsA-ME was adjusted to achieve protocol-defined C 2 targets of 1.6 to 2.0 μg/mL for the first month, with subsequent tapering. Randomization into two target groups occurred at 3 months. All patients received steroids and mycophenolate mofetil (89%) or azathioprine. For patients with delayed graft function, the protocol permitted reduced C 2 targets and prophylactic administration of antibodies. Results. At 3 months, overall incidence of biopsy-proven acute rejection was 11.5%. Median serum creatinine was 132 μmol/L. Patient and graft survival were 96.6% and 91.2%, respectively. C 2 levels greater than 1.6 μg/mL were achieved within 5 days by 60.6% of patients with immediate graft function and 19.5% of patients with delayed graft function. Prophylactic antibodies were used in 15% of the total population. Twenty-four patients (8.1%) experienced serious adverse events with a suspected relation to CsA, and 26 patients (8.8%) discontinued the study because of adverse events (n=15) or after a switch in immunosuppression after rejection episodes (n=11). Conclusions. Patient management by C 2 monitoring resulted in a low incidence of biopsy-proven acute rejection in standard risk de novo kidney recipients, 85% of whom did not receive prophylactic antibodies. CsA-ME with C 2 monitoring provides excellent short-term efficacy and safety among de novo renal transplant patients.

Clinical benefits of neoral C2 monitoring in the long-term management of renal transplant recipients.

Abstract: BACKGROUND Cyclosporine monitoring using the 2-hr postdose sample, C2, has been shown to have advantages in monitoring de novo renal transplant recipients. The purpose of this study was to assess cyclosporine exposure, using C2, in stable renal transplant patients previously monitored by C0 to determine the effect of dose reduction on patients with C2 more than 10% above target and the course of those with C2 at and more than 10% below target, whose dose was not modified. METHODS One hundred and seventy-five patients, three or more months after transplantation, had C2 assessed. The relationship of C2 to C0 and of both to renal function was analyzed by linear regression. Blood pressure, serum creatinine level, and lipids were followed for a mean of 15+/-2.6 months. RESULTS Eighty-five patients had values more than 10% above target, 42 were within 10% of target, and 48 were more than 10% below target. Cyclosporine dose was reduced in all patients above target. In this group, serum creatinine level was stable overall, but fell significantly in 46 (54%) of 85 from 153+/-55 to 132+/-49 microM. Blood pressure also fell in that group from 135/82 to 131/77. Serum creatinine level was stable in the remaining two groups of patients. CONCLUSIONS These data suggest that dose reduction in many overexposed patients leads to improvements in renal function and blood pressure. Further study is required to confirm the long-term benefits of this strategy.

The effect of posttranslational modifications on the in vitro activity of recombinant human thyroid-stimulating hormone.

Abstract: Posttranslational modification can influence the biologic activity of recombinant proteins. The effects of beta-subunit C-terminal truncation, oligosaccharide heterogeneity, and chemical oxidation on the in vitro activity of recombinant human thyroid-stimulating hormone (rhTSH) were investigated. beta-Subunit C-terminal truncation up to residue 113 did not effect the in vitro activity of the hormone. The relationship between the heterogeneity of oligosaccharide structures on rhTSH and specific activity of the glycoprotein hormone was also examined. Oligosaccharide profiles were generated for preparations of rhTSH containing similar sialic acid levels. A weak correlation was observed between relative levels of monosialylated biantennary, bisialylated biantennary, and trisialylated triantennary oligosaccharide species and in vitro activity of the recombinant hormone (p < 0.05). To examine the effect of chemically induced methionine oxidation on the activity of rhTSH, the hormone was treated with tert-butyl hydroperoxide and then characterized. Using peptide mapping and mass spectrometry, the degree of oxidation of the five methionine residues within rhTSH was measured. Met-71 in the alpha-subunit was the most susceptible to oxidation whereas Met-9 in the beta-subunit was the most resistant. Also, after tert-butyl hydroperoxide treatment, levels of oxidation of Met-32 in the beta-subunit, and Met-29 and Met-47 in the alpha-subunit were less than half of that observed for Met-71. The in vitro activity of rhTSH initially declined with increasing oxidation; however, the loss in activity plateaued at approximately 50% of the control sample activity. In summary, despite the possible effects that posttranslational modifications may have on the bioactivity of a protein, a limited degree of variation in bioactivity was observed for the rhTSH preparations described in this study.