The Effect of Chronic Immunosuppressive Regimen Treatment on Apoptosis in the Heart of Rats

Chronic immunosuppressive therapy is currently the only effective method to prevent acute rejection of a transplanted organ. Unfortunately, the expected effect of treatment brings a number of grave side effects, one of the most serious being cardiovascular complications. In our study, we wanted to investigate how treatment with commonly used immunosuppressive drugs affects the occurrence of programmed cardiac cell death. For this purpose, five groups of rats were treated with different triple immunosuppressive regimens. Cardiac tissue fragments were subjected to the TUNEL assay to visualize apoptotic cells. The expression of Bcl-2 protein, Bax protein, caspase 3 and caspase 9 was also assessed. This study indicates that all immunosuppressive protocols used chronically at therapeutic doses result in an increased percentage of cells undergoing apoptosis in rat heart tissue. The greatest changes were recorded in the TMG (rats treated with tacrolimus, mycophenolate mofetil and glucocorticosteroids) and CMG (rats treated with cyclosporin A, mycophenolate mofetil and glucocorticosteroids) groups. The TRG (rats treated with rapamycin, tacrolimus and glucocorticosteroids) group showed the lowest percentage of apoptotic cells. The internal apoptosis pathway was confirmed only in the TMG group; in the remaining groups, the results indicate programmed cell death via the receptor pathway.

The pharmacogenetics of tacrolimus in renal transplant patients: association with tremors, new-onset diabetes and other clinical events

Our study is the first study to investigate the effect of SNPs in CYP3A5, CYP3A4, ABCB1 and POR genes on the incidence of tremors, nephrotoxicity, and diabetes mellitus. A total of 223 renal transplant patients receiving tacrolimus and mycophenolate mofetil (MMF) were recruited. Both adults and children patients participated in the study. Genotyping was performed using PROFLEX-PCR followed by RFLP. MPA and tacrolimus plasma concentrations were measured by immunoassay. The AUC0-12h of MMF was estimated by a Bayesian method. We found a statistically significant association between the CYP3A5*3 and CYP3A4*1B genotypes and the tacrolimus exposure. We found a lower occurrence of nephrotoxicity (p = 0.03), tremor (p = 0.01), and new-onset diabetes (p = 0.002) associated with CYP3A5*1 allele. The CYP3A4*1B allele was significantly associated with a lower occurrence of new-onset diabetes (p = 0.026). The CYP3A5*1 allele was significantly associated with an increased risk of acute and chronic rejection (p = 0.03 and p < 0.001, respectively). Our results support the usefulness of tacrolimus pharmacokinetics in pre-kidney transplant assessments.

Posttransplantation tuberculosis management in terms of immunosuppressant cost: a case report in Myanmar

Drug interactions between anti-tuberculosis and immunosuppressive medications after renal transplantation are a common problem in Myanmar. The efficacy of both types of drugs can be reduced during the treatment period, which can lead to graft failure and flare-ups of infection. Drug adjustments, with frequent monitoring and close follow-up, are crucial in this period. Ketoconazole decreases tacrolimus metabolism by inhibiting cytochrome P450-3A5 enzymes and P-glycoprotein. It is cost effective and has been frequently used to reduce the dose and cost of tacrolimus. Here, we report the case of a 56-year-old male renal transplant recipient with anti-tuberculosis medications.

Exploring the safety and efficacy of adding ketoconazole to tacrolimus in pediatric renal transplant immunosuppression

BACKGROUND

Guatemala is a developing country in Central America with limited health resources. In order to expand successful renal transplant care to children and adolescents at the lowest possible cost, our pediatric renal transplant clinic uses a post-transplant tacrolimus-sparing strategy via inhibition of CYP3A4.

AIM

To study the safety, efficacy and the associated cost reduction of ketoconazole in combination with tacrolimus in this pediatric population.

METHODS

A retrospective chart review was carried out among the cohort of pediatric renal transplant recipients treated at the Foundation for pediatric renal patients (Fundación para el Niño Enfermo Renal - FUNDANIER), a pediatric tertiary care renal transplant center in Guatemala City, Guatemala. Patient charts were reviewed to ascertain the number of transplant recipients who were transitioned from tacrolimus based immunosuppression to combination therapy with ketoconazole and tacrolimus. Twenty-five post-transplant patients that used ketoconazole combined with tacrolimus were identified. Anthropometric, clinical and laboratory data was collected from patient charts before and after the transition.

RESULTS

Of the 25 patient charts reviewed 12 (48%) patients were male and the average patient age was 13 years. Twenty-four (96%) transplants were from living donors. There was a non-significant difference between the mean tacrolimus doses six months and two months prior to ketoconazole: -0.10 ± 0.04 (95%CI: 0.007, -0.029), P = 0.23. However, the difference between the mean tacrolimus doses six months prior to ketoconazole initiation and six months after ketoconazole addition was significant: 0.06 ± 0.05 (95%CI: -0.034, -0.086) P < 0.001. All tacrolimus doses were reduced by 45% after the addition of ketoconazole. Therapeutic levels of tacrolimus ranged between 6.8-8.8 ng/mL during the study period and patients demonstrated an increase in estimated glomerular filtration rate. The combination of tacrolimus and ketoconazole resulted in a 21% reduction in cost.

CONCLUSION

Patients experienced an effective dose-reduction of tacrolimus with the administration of ketoconazole. There was no relevant variations in tacrolimus serum levels, number of rejections, or significant liver toxicity. The strategy allowed a cost reduction in pediatric immunosuppressive therapy.

Induction therapy with thymoglobulin or interleukin-2 receptor antagonist for Chinese recipients of living donor renal transplantation: a retrospective study

Background

Recipients of living donor renal transplantation are typically considered to have a relatively lower immunological risk. This retrospective study aimed to compare the therapeutic efficacy and safety between rabbit antithymocyte globulin (rATG) or interleukin-2 receptor antagonist (IL2-RA) induction therapies in Chinese population.

Methods

A total of 188 patients receiving living donor renal transplantation between February 2004 and December 2013 were included and divided into the rATG group and based on their induction therapy. The primary outcome was clinically-suspected rejection. The incidences of de novo donor-specific antigen (dn-DSA), graft survival, and infection were also compared between groups. A multivariate Cox regression analysis was performed to investigate the influential factors associated with clinically-suspected acute rejection and graft survival.

Results

The rATG group had a higher panel reactive antibody (PRA) score and more complete HLA mismatches than the IL2-RA group (both P < 0.001). The incidences of clinically-suspected acute rejection (9.8% vs. 8.8%; P = 0.832) and dn-DSA formation (4.9% vs. 5.4%, P = 0.44) were not significantly different between groups. Kaplan-Meier curve analysis demonstrated that the graft survivals of two groups were comparable (P = 0.857). After adjusting for patients’ age, sex, PRA, HLA mismatch confounders, and the use of corticoids, the multivariate Cox regression analysis showed that methods of induction therapy were not associated with clinically-suspected acute rejection and graft survival (both P > 0.05). The incidences of complications (infections, pneumonia, liver injury and myelosuppression) were all comparable between groups (all P > 0.05).

Conclusions

These results suggested that rATG could be a safe and efficient immunosuppressant when used in a Chinese recipient population with a higher immunological risk in living donor renal transplantation.

Long-term outcome of ketoconazole and tacrolimus co-administration in kidney transplant patients

AIM: To study the long-term outcome of ketoconazole and tacrolimus combination in kidney transplant recipients.

METHODS: From 2006 to 2010, ketoconazole was given in 199 patients and was continued for at least 1 year or until graft failure (Group 1), while 149 patients did not receive any ketoconazole (Group 2). A combination of tacrolimus, mycophenolate and steroid was used as maintenance therapy. High risk patients received basiliximab induction.

RESULTS: Basic demographic data was similar between the 2 groups. The 5-year cumulative incidence of biopsy-confirmed and clinically-treated acute rejection was significantly higher in Group 1 than in Group 2 (34% vs 18%, P = 0.01). The 5-year Kaplan-Meier estimated graft survival (74.3% vs 76.4%, P = 0.58) and patient survival (87.8% vs 87.5%, P = 0.93) were not different between the 2 groups. Multivariable analyses identified ketoconazole usage as an independent risk of acute rejection (HR = 2.33, 95%CI: 1.33-4.07; P = 0.003) while tacrolimus dose in the 2^nd month was protective (HR = 0.89, 95%CI: 0.75-0.96; P = 0.041).

CONCLUSION: Co-administration of ketoconazole and tacrolimus is associated with significantly higher incidence of acute rejection in kidney transplant recipients.