Risk Factors for the Adverse Events after Conversion from Twice-Daily to Once-Daily Tacrolimus in Stable Liver Transplantation Patients

Safety and Efficacy of Conversion to Once-Daily Tacrolimus from Twice-Daily Tacrolimus in Pediatric Liver Transplant Recipients

BACKGROUND

Nonadherence to immunosuppression is the most common cause of late acute rejection in pediatric liver transplant (LT) recipients. A prolonged-release once-daily tacrolimus formulation was developed to improve adherence and long-term allograft survival.

METHODS

We screened 179 pediatric LT recipients who converted from twice-daily tacrolimus (TD-TAC) to once-daily tacrolimus (OD-TAC) between February 2011 and September 2019.

RESULTS

One hundred seventy-nine recipients converted to OD-TAC and were followed for 18 months. 152 OD-TAC-converted recipients (84.9%) experienced uneventful follow-up, while 21 recipients showed LFT elevation. Four recipients had biopsy-proven acute rejection within six months of conversion, all of which were successfully treated with steroid pulse. 166 recipients (92.7%) remain on OD-TAC and 13 (7.3%) were switched back to TD-TAC. The mean tacrolimus trough level significantly decreased three months following conversion (3.14 ± 1.9 ng/mL) compared with pre-conversion levels (3.69 ± 1.98 ng/mL). Mean tacrolimus trough levels remained unchanged from 3 months to 12 months following conversion. Percent coefficient of variation of tacrolimus trough levels decreased significantly from 32.5 ± 16.4 ng/mL to 27.5 ± 15.6 ng/mL after conversion to OD-TAC, reflecting a decrease in variation of tacrolimus trough levels following conversion.

CONCLUSIONS

Conversion to OD-TAC in pediatric LT recipients with stable graft function is safe and effective.

LEVEL OF EVIDENCE

Level IV.

Impact of single-nucleotide polymorphisms on tacrolimus pharmacokinetics in liver transplant patients after switching to once-daily dosing

BACKGROUND

The effects of multidrug resistance-1 (MDR1), ABCC2, and P450 oxidoreductase (POR)*28 gene polymorphisms on tacrolimus metabolism following a switch to once-daily dosing have not been elucidated. We investigated the effects of recipient and donor CYP3A5, MDR1, ABCC2, and POR*28 polymorphisms on tacrolimus pharmacokinetics following a switch to once-daily tacrolimus dosing.

METHODS

Eighty-seven liver transplant recipients who were switched from twice- to once-daily tacrolimus dosing following living-donor liver transplantation and 81 matched donors were genotyped for CYP3A5, MDR1 (1236C>T, 2677G>T/A, and 3435C>T), ABCC2 (-24C>T, 1249G>A, and 3972C>T), and POR*28. Tacrolimus dose-adjusted trough levels (C0/dose) before and after the switch were determined and calculated based on past medical records. Recipients were divided into two groups, one group constituted of 38 patients with a C0/dose decrease of less than 30% following conversion (group 1) and the other constituted of 49 patients with a C0/dose decrease of ≥ 30% (group 2).

RESULTS

CYP3A5 *1/*3 and *3/*3 were more frequent in recipients in group 1 (60.5% vs. 36.8%), while CYP3A5 *1/*1 was more frequent in group 2 (59.2% vs. 32.7%) (p = 0.016). The proportions of donor ABCC2 1249G>A genotypes AA and AG were higher in group 2 than in group 1 (20.4% vs. 5.3%; p = 0.042).

CONCLUSION

Recipient CYP3A5 polymorphism and donor ABCC2 1249G>A polymorphism affected tacrolimus pharmacokinetics following the switch to once-daily dosing. Dose adjustment to maintain therapeutic tacrolimus levels following the switch to once-daily dosing should be considered based on polymorphisms in both the recipient and donor.

Network pharmacology-based analysis of the role of tacrolimus in liver transplantation

Background

Tacrolimus is a powerful immunosuppressant and has been widely used in organ transplantation. In order to further explore the role of tacrolimus in liver transplantation, we conducted network pharmacology analysis.

Methods

GSE100155 was obtained from the GEO database, and the DEGs of liver transplantation were analyzed. The 2D structure of tacrolimus was obtained from the National Library of Medicine, and the pharmacophore model of tacrolimus was predicted using the online tool pharmmapper. Then a network of tacrolimus and target genes was constructed through network pharmacology, and visualization and GO enrichment analysis was performed through Cytoscape. In addition, we also analyzed the correlation between key genes and immune infiltrating cells. The data of GSE84908 was used to verify the changes of key gene expression levels after tacrolimus treatment.

Results

The results of network pharmacological analysis showed that tacrolimus had 43 target genes, and the GO enrichment results showed many potential functions. Further analysis found that there were 5 key target genes in DEGs, and these 5 genes were significantly down-regulated in liver transplant patients. Another important finding was that 5 genes were significantly related to some immune infiltrating cells. The results of the GSE84908 data analysis showed that after tacrolimus treatment, the expression of DAAM1 was significantly increased (p = 0.015).

Conclusion

Tacrolimus may inhibit the human immune response by affecting the expression of DAAM1 in liver transplant patients.

Effect of CYP3A5 on the Once-Daily Tacrolimus Conversion in Stable Liver Transplant Patients

Cytochrome P450 (CYP) 3A5 polymorphism influences tacrolimus metabolism, but its effect on the drug pharmacokinetics in liver transplant recipients switched to once-daily extended-release formulation remains unknown. The aim of this study is to analyze the effect of CYP3A5 polymorphism on liver function after once-daily tacrolimus conversion in liver transplant patients. A prospective open-label study included 60 stable liver transplant recipients who underwent 1:1 conversion from twice-daily tacrolimus to once-daily tacrolimus. All participants were genotyped for CYP3A5 polymorphism. The study was registered at ClinicalTrials.gov (NCT 02882113). Twenty-eight patients were enrolled in the CYP3A5 expressor group and 32 in the non-expressor group. Although there was no statistical difference, incidence of liver dysfunction was higher in the expressor group than in the non-expressor group when converted to once-daily extended-release tacrolimus (p = 0.088). No biopsy-proven acute rejection, graft failure, and mortality were observed in either group. The decrease in dose-adjusted trough level (−42.9% vs. −26.1%) and dose/kg-adjusted trough level of tacrolimus (−40.0% vs. −23.7%) was significantly greater in the expressor group than in the non-expressors after the conversion. A pharmacokinetic analysis was performed in 10 patients and tacrolimus absorption in the non-expressor group was slower than in the expressor group. In line with this observation, the area under the curve for once-daily tacrolimus correlated with trough level (Cmin) in the non-expressors and peak concentration (Cmax) in the expressors. CYP3A5 genotyping in liver transplant recipients leads to prediction of pharmacokinetics after switching from a twice-daily regimen to a once-daily dosage form, which makes it possible to establish an appropriate dose of tacrolimus.