Tolerability of mycophenolate mofetil in elderly kidney transplant recipients: A retrospective cohort study

Assessment of Antimetabolite Intolerance in Older Lung Transplant Recipients

Introduction: Adverse effects from antimetabolites often lead to therapy adjustments; older patients may be more susceptible to these effects. Project Aims: Compare the intolerance of antimetabolites between older and younger lung transplant recipients. Design: A single-center, retrospective analysis of adult lung transplant recipients transplanted between January 1, 2019 and October 31, 2021 was conducted. Patients were stratified by age at the time of transplant (≥60 or <60 years) and assessed for the first year posttransplant. The primary outcome was the incidence of antimetabolite intolerance (defined as dose adjustment, agent/formulation change, or holding/discontinuation of agent). Secondary outcomes included reason for intolerance, safety (infection and leukopenia), and efficacy (rejection and patient/graft survival). Results: One hundred and nine recipients were included; 54 in the older (≥60 years) and 55 in the younger (<60 years) cohort. Most were initiated on azathioprine (74%) posttransplant. Antimetabolite intolerance occurred in 61% of older and 53% of younger recipients (P = 0.377). The most common reasons for intolerance were leukopenia followed by gastrointestinal side effects. Biopsy-proven acute rejection occurred more often in the older cohort (39% vs 18%, P = 0.017); this no longer remained significant when controlling for induction, indication, transplant type, gender, and antimetabolite intolerance (OR 0.36, 95% CI 0.11 to 1.15). There was no difference in the incidence of leukopenia, bacterial infection, or graft/patient survival within 1 year posttransplant. Conclusion: Antimetabolite intolerance between older and younger lung transplant recipients was similar. Most required modification to the initial antimetabolite regimen due to leukopenia and gastrointestinal side effects.

An integrated sampling strategy for therapeutic mycophenolic acid monitoring in lung transplant recipients

BACKGROUND

Mycophenolic Acid (MPA) is the most used anti-proliferative in lung transplantation, but its pharmacokinetic (PK) variability has precluded therapeutic drug monitoring. Both genetic and clinical factors have been implicated in MPA variability. This study aimed to integrate genetic and clinical factors with PK measurements to quantify MPA exposure.

METHODS

We performed 12-hour pharmacokinetic analysis on 60 adult lung transplant recipients maintained on MPA for immunosuppression. We genotyped a SLCO1B3 polymorphisms previously associated MPA metabolism and collected relevant clinical data. We calculated area under the curve (AUC0-12) and performed univariate linear regression analysis to evaluate its association with genetic, clinical, and pharmacokinetic variables. We performed lasso regression analysis to create final AUC estimation tools.

RESULTS

PK-only measurements obtained 2, 3, and 8 hours after MPA administration (C2, C3, and C8) were strongly associated with MPA AUC0-12 (R267%, 67% and 68% respectively). Clinical and genetic factors associated with MPA AUC0-12 included the MPA dose (p = 0.001), transplant diagnosis (p = 0.015), SLCO1B3 genotype (p = 0.049), and body surface area (p = 0.050). The best integrated single-sampling strategy included C2 and achieved an R2 value of 80%. The best integrated limited-sampling strategy included C0, C0.25, and C2 and achieved an R2 value of 90%.

CONCLUSIONS

An integrated limited sampling strategy (LSS) for MPA allows increased accuracy in prediction of MPA AUC0-12 compared to PK-only modeling. Validation of this model will allow for clinically feasible MPA therapeutic drug monitoring and help advance precision management of MPA.

Nail lichen planus treatment safety

AREAS COVERED

Topical therapies for nail lichen planus (clobetasol propionate, topical tacrolimus, bath-PUVA), intralesional treatment (triamcinolone), and systemic treatment (corticosteroids, retinoids, small molecule inhibitors (jak/stat inhibitors)), TNF-alpha inhibitors (etanercept), systemic immunomodulators (oral calcineurin inhibitors, mycophenolate mophetil), and antimalarials (chloroquine), each with unique safety profiles and considerations. Herein, we discuss common and uncommon adverse events, as well as utilization for special populations, including pregnant and pediatric patients.

Individualization of Mycophenolic Acid Therapy through Pharmacogenetic, Pharmacokinetic and Pharmacodynamic Testing

Mycophenolic acid (MPA) is a widely used immunosuppressive agent and exerts its effect by inhibiting inosine 5'-monophosphate dehydrogenase (IMPDH), the main regulating enzyme of purine metabolism. However, significant unexplained differences in the efficacy and tolerability of MPA therapy pose a clinical challenge. Therefore, broad pharmacogenetic, pharmacokinetic, and pharmacodynamic approaches are needed to individualize MPA therapy. In this prospective cohort study including 277 renal transplant recipients, IMPDH2 rs11706052 SNP status was assessed by genetic sequencing, and plasma MPA trough levels were determined by HPLC and IMPDH enzyme activity in peripheral blood mononuclear cells (PBMCs) by liquid chromatography-mass spectrometry. Among the 277 patients, 84 were identified with episodes of biopsy-proven rejection (BPR). No association was found between rs11706052 SNP status and graft rejection (OR 1.808, and 95% CI, 0.939 to 3.479; p = 0.076). Furthermore, there was no association between MPA plasma levels and BPR (p = 0.69). However, the patients with graft rejection had a significantly higher predose IMPDH activity in PBMCs compared to the controls without rejection at the time of biopsy (110.1 ± 50.2 vs. 95.2 ± 45.4 pmol/h; p = 0.001), and relative to the baseline IMPDH activity before transplantation (p = 0.042). Our results suggest that individualization of MPA therapy, particularly through pharmacodynamic monitoring of IMPDH activity in PBMCs, has the potential to improve the clinical outcomes of transplant patients.