Abstract: FR-PO1218
Beyond Tacrolimus Trough Levels: Area Under the Curve-Based Monitoring in Guatemalan Kidney Transplant Recipients
Session Information
- Transplantation: Clinical - Rejection, Biomarkers, and Pharmacology
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Mendoza, Efrain Antonio, Hospital General San Juan de Dios, Guatemala City, Guatemala Department, Guatemala
- Perez, Elio, Hospital General San Juan de Dios, Guatemala City, Guatemala Department, Guatemala
- Escobar Castro, Karla, Hospital General San Juan de Dios, Guatemala City, Guatemala Department, Guatemala
- Oliva, Alejandra, Hospital General San Juan de Dios, Guatemala City, Guatemala Department, Guatemala
Group or Team Name
- Nefrología HOSPIGEN
Background
Tacrolimus therapeutic drug monitoring remains challenging because trough concentrations (C0) may not adequately reflect systemic exposure. Area under the curve (AUC 0–12) estimation using limited sampling strategies (LSS) represents a practical alternative, particularly in resource-limited settings.
Methods
We conducted an observational longitudinal study in adult kidney transplant recipients followed at Hospital General San Juan de Dios, Guatemala. Patients were ≥ 6 months post-transplant and receiving tacrolimus-based immunosuppression. Tacrolimus exposure was estimated using a limited sampling model based on C0, C2, and C4 concentrations. Clinical, renal, and pharmacokinetic variables were analyzed.
Results
Fifty kidney transplant recipients were included. Mean age was 29.9±10.4 years, and 60% received kidneys from living related donors. Mean tacrolimus trough concentration was 6.2±2.4 ng/mL, while estimated mean AUC 0 – 12 was 109.0±46.3 ng*h/mL. Marked interindividual variability in tacrolimus exposure was observed, with many patients outside the proposed therapeutic AUC range (80–100 ng*h/mL), predominantly showing overexposure. Tacrolimus trough concentrations demonstrated strong positive correlation with estimated AUC (r=0.84, p<0.001).
Conclusion
Tacrolimus exposure demonstrated substantial pharmacokinetic variability among Guatemalan kidney transplant recipients. AUC estimation using the C0–C2–C4 model appears feasible for therapeutic drug monitoring in resource-limited transplant centers and may support individualized tacrolimus dose adjustment.
Acknowledgment
The authors acknowledge the Department of Nephrology and Renal Transplantation at Hospital General San Juan de Dios for institutional support and collaboration in the development of this study. We are especially grateful to the kidney transplant recipients whose participation made this research possible.