The beneficial effect of high-dose mizoribine combined with cyclosporine, basiliximab, and corticosteroids on CMV infection in renal transplant recipients

Inhibitors of Nucleotide Biosynthesis as Candidates for a Wide Spectrum of Antiviral Chemotherapy

Emerging and re-emerging viruses have been a challenge in public health in recent decades. Host-targeted antivirals (HTA) directed at cellular molecules or pathways involved in virus multiplication represent an interesting strategy to combat viruses presently lacking effective chemotherapy. HTA could provide a wide range of agents with inhibitory activity against current and future viruses that share similar host requirements and reduce the possible selection of antiviral-resistant variants. Nucleotide metabolism is one of the more exploited host metabolic pathways as a potential antiviral target for several human viruses. This review focuses on the antiviral properties of the inhibitors of pyrimidine and purine nucleotide biosynthesis, with an emphasis on the rate-limiting enzymes dihydroorotate dehydrogenase (DHODH) and inosine monophosphate dehydrogenase (IMPDH) for which there are old and new drugs active against a broad spectrum of pathogenic viruses.

The Efficacy and Safety of Mizoribine versus Mycophenolate Mofetil for the Treatment of Renal Transplantation: A Systematic Review and Meta-Analysis

Background

Mizoribine (MZR) is widely used in Asia due to its high safety and low cost, and comparative studies of its safety and efficacy with the first-line drug mycophenolate mofetil (MMF) have been carried out. This paper aimed to compare the efficacy and safety of MZR and MMF in immunosuppressive therapy of renal transplantation by meta-analysis.

Methods

We searched randomized controlled trials (RCTs) comparing MZR versus MMF for renal transplantation in PubMed, Excerpta Medica Database (EMBASE), Cochrane Library, Web of Science, WanFang Database, China National Knowledge Infrastructure (CNKI), and Chinese Biomedical Database (CBM). Articles were assessed for their risk of bias using the Cochrane Collaboration. Forest plots and funnel plots were also performed on the included articles.

Results

A total of twelve studies with 1103 patients were selected in the analysis. No significant difference were observed between the MZR group and the MMF group for the rate of acute rejection (RR = 1.50, 95% CI 1.11 to 2.01, P = 0.008), patient survival (RR = 1.01, 95% CI 0.99 to 1.03, P = 0.56), graft survival (RR = 1.02, 95% CI 1.00 to 1.04, P = 0.12), leucopenia (RR = 0.69, 95% CI 0.44 to 1.10, P = 0.12), and liver damage (RR = 0.72, 95% CI 0.46 to 1.13, P = 0.15). The MZR group was associated with a lower risk of gastrointestinal disorder (RR = 0.28, 95% CI 0.13 to 0.62, P = 0.002) and cytomegalovirus infection (RR = 0.59, 95% CI 0.42 to 0.84, P = 0.003) but had a higher risk of hyperuricemia (RR 1.79, 95% CI 1.17 to 2.75, P = 0.007). No significant publication bias was observed among included studies. Discussion. MZR is similar to MMF in efficacy, and in terms of safety, MZR has a lower risk of gastrointestinal disorder and cytomegalovirus infection but a higher risk of hyperuricemia.

Comparative efficacy and safety of mizoribine and mycophenolate mofetil for treating systemic lupus erythematosus: a retrospective cohort study

Background

Mizoribine (MZR) is an immunosuppressive agent that selectively inhibits inosine monophosphate dehydrogenase; its actions are considerably similar to those of mycophenolate mofetil (MMF). This study aimed to clarify whether MZR can be a good treatment option for systemic lupus erythematosus (SLE) and to compare the efficacy and safety of MZR and MMF in patients with active SLE.

Methods

We retrospectively compared the efficacy, continuation rate, and safety of MZR (52 patients) and MMF (31 patients) after adjusting for stabilized inverse probability of treatment weighting based on propensity scores. The efficacy endpoints were as follows: cumulative incidence of lupus low disease activity state (LLDAS) or remission attainment and flares and change in prednisolone dose over 2 years. Drug continuation rates were defined as the time from drug initiation to discontinuation for any cause, owing to the lack of efficacy, or owing to adverse events. The safety endpoint was the frequency of adverse events.

Results

Overall, 25 (48.1%) and 13 (25.0%) patients in the MZR group and 18 (58.1%) and 15 (48.3%) in the MMF group achieved LLDAS and remission during the follow-up period, respectively; thus, the cumulative incidence of LLDAS and remission attainment of the two groups was similar after adjustment. Prednisolone dose was steadily reduced in both the groups, and the change in prednisolone dose was nearly identical between the two groups. Drug discontinuation rate due to adverse events and the frequency of all adverse events and infections were higher in the MMF group than in the MZR group, albeit without significance after adjustment.

Conclusion

MZR is as effective as MMF in controlling SLE activity. The adverse events of MZR, whose profile differs from MMF, are comparable to or less than those of MMF. MZR may be a valuable option as an immunosuppressive agent for SLE, as well as MMF.

Total nephroureterocystectomy and urethrectomy due to urothelial carcinoma associated with the BK polyomavirus infection after kidney transplantation: a case report with literature review

Background

BK polyomavirus (BKPyV) infection after kidney transplantation is an important cause of graft failure among kidney transplant recipient and may cause malignant tumor, although the association between BKPyV infection and malignant tumor has been controversial yet.

Case presentation

We report a case of a 39-year-old-male kidney transplantation (KTx) recipient with urine BKPyV replication who developed a graft pelvic tumor with the positive Simian virus 40 large T antigen (SV40 TAg). The patients received a living-related KTx from his 65-year-old mother. A protocol biopsy at 14 months after KTx showed BKPyV-associated nephropathy. Therefore, the dose of immunosuppressants was reduced, resulting in improved BKPyV viremia, but viruria persisted. About 117 months after KTx, urine cytology showed atypical cells suspicious for malignancy. Cystoscopy revealed a tumor on the neck of the bladder. Transurethral resection of the bladder tumor (TUR-BT) was performed; however, the diagnosis of malignancy was not confirmed at that time. Six months after the TUR-BT, urine cytology showed atypical cells definite for malignancy. Computed tomography and retrograde pyelography showed no evidence of urinary tract tumor and metastasis. Subsequently, total nephroureterocystectomy and urethrectomy were performed. Histological examination of the graft ureter revealed a high-grade urothelial carcinoma, with glandular differentiation, pT1. Immunohistochemically, the tumor showed positivities for SV40 TAg and p53, along with increased Ki67 labeling cells were increased. By contrast, nonneoplastic cells were negative for SV40 TAg. At the time of writing the present manuscript, the patient is free from recurrence or residual tumor and being closely monitored without additional therapy, 32 months after the surgery.

Conclusion

The relationship between BKPyV infection after KTx and bladder carcinogenesis remains to be elucidated. However, when the KTx recipients who continue to have BKPyV infection for a long time are treated, the possibility of risk factors for renourinary carcinoma should always be carefully considered.

Efficacy and Safety of a Quadruple Regimen Compared with Triple Regimens in Patients with Mycophenolic Acid-Related Gastrointestinal Complications After Renal Transplantation: A Short-Term Single-Center Study

Background

At present, there is no ideal conventional triple regimen that can effectively treat gastrointestinal (GI) complications in patients after kidney transplantation. We aimed to investigate the efficacy and safety of a quadruple regimen including standard-dose tacrolimus, low-dose enteric-coated mycophenolate sodium (EC-MPS), low-dose mizoribine (MZR), and corticosteroids, compared with regimens containing standard-dose tacrolimus, corticosteroids, plus either low-dose EC-MPS or standard-dose MZR in patients with mycophenolic acid (MPA)-related GI complications after renal transplantation.

Material/Methods

Between August 2016 and October 2018 in Qilu Hospital of Shandong University, 115 living donor kidney transplant recipients with MPA-related GI complications were enlisted in a single-center, prospective, randomized, control study. Thirty-six recipients were assigned to the low-dose EC-MPS plus low-dose MZR group, 37 recipients were assigned to the low-dose EC-MPS group, and 39 recipients were assigned to the standard-dose MZR group. We analyzed the Gastrointestinal Symptom Rating Scale (GSRS), estimated glomerular filtration rate (eGFR), graft rejection, serum creatinine, human leukocyte antigen (HLA) antibody, and the occurrence of adverse events among the 3 groups.

Results

Compared with baseline, gastrointestinal symptoms improved significantly in all 3 groups. The reduction in mean subscale scores from baseline to month 3 was more significant in the standard-dose MZR group compared with the other 2 groups. The low-dose EC-MPS plus low-dose MZR group had better renal function. The incidence of graft rejection and cytomegalovirus (CMV) and polyomavirus BK (BKV) infection, as well as the incidence of hyperuricemia, in the low-dose EC-MPS plus low-dose MZR group were all significantly reduced.

Conclusions

This quadruple regimen may be equivalent to regimens containing standard-dose tacrolimus, corticosteroids plus either low-dose EC-MPS or standard-dose MZR in improving GI symptoms after kidney transplant, and is also advantageous for kidney function, graft rejection, and the rates of adverse events.

Efficacy and Safety of Mizoribine Combined With Tacrolimus in Living Donor Kidney Transplant Recipients: 3-Year Results by a Chinese Single Center Study

BACKGROUND

Mizoribine (MZR) was effective and safe for living Chinese donor kidney transplantation (LDKT) on tacrolimus-based treatment 1 year after transplantation. We investigated whether MZR was effective and safe for LDKT on tacrolimus-based treatment with long follow-up periods.

METHODS

We compared 22 LDKT recipients who were administered MZR, tacrolimus, and corticosteroids with a control group (n = 20) treated with mycophenolate mofetil (MMF), tacrolimus, and corticosteroids. Primary efficacy endpoints were 3-year patient survival, 3-year graft survival, and acute rejection (AR) rate within 3 years after transplantation.

RESULTS

The 3-year patient and graft survival rates for the MZR and MMF groups were 100%. The AR rate after transplantation was 18.2% for the MZR group and 10.0% for the MMF group; the difference was not significant (P = .665). There was no significant difference in serum creatinine levels, glomerular filtration rates (eGFR), serum urate levels, blood urea nitrogen, and cystatin C levels 12, 24, and 36 months after transplantation. No significant differences in the CD3, CD4, CD8, CD4/CD8, and CD45 were observed between the 2 groups 12, 24, and 36 months after transplantation. There were no significant differences in adverse events among the MZR or the MMF group, whereas the prevalence of gastrointestinal symptoms were significantly lower in the MZR treatment group (P = .003), especially acid reflux (P = .007). Compared with the MMF group, the MZR group should lighten the burden on patients.

CONCLUSION

MZR with tacrolimus and corticosteroids provides satisfactory immunosuppression and higher safety for Chinese LDKT over a 3-year follow-up.

Hyperuricemia in Living Donor Kidney Transplantation Patients During Mizoribine Administration Caused Mainly by Changes in Kidney Function

BACKGROUND

Although mizoribine (MZR) is used as an immunosuppressant after renal transplantation, the occurrence of hyperuricemia has been reported. The onset of hyperuricemia is often observed within the first several months after surgery. Since MZR is a renal excretion-type drug excreted as an unchanged drug from the kidneys, MZR blood concentrations may rise due to the influence of renal function. We investigated whether the onset of hyperuricemia after MZR administration was associated with the direct effect of a change in renal function.

METHODS

Serum uric acid (serum UA), serum creatinine (sCr), serum β2-microglobulin (serum β2-MG), and serum cystatin C (serum Cys-C) were measured for about 3 months in 22 subjects. Correlation coefficients were calculated using the change rates of serum UA and sCr (Δ serum UA, Δ sCr), serum UA and serum β2-MG (Δ serum UA, Δ serum β2-MG), and serum UA and serum Cys-C (Δ serum UA, Δ serum Cys-C) at the onset of hyperuricemia.

RESULTS

The correlation coefficients between Δ serum UA and Δ sCr, Δ serum UA and Δ serum β2-MG, and Δ serum UA and Δ serum Cys-C were 0.723 (P < .001), 0.863 (P < .001) and 0.548 (P < .001), respectively. Further, serum UA and sCr level reached their highest peak on the same day after MZR administration, and the behavior was mostly consistent.

CONCLUSION

It was suggested that hyperuricemia occurred about 3 months after MZR administration due mainly to temporary changes in kidney function.

Conversion From Mycophenolates to Mizoribine Is Associated With Lower BK Virus Load in Kidney Transplant Recipients: A Prospective Study

BACKGROUND

BK virus allograft nephropathy (BKVAN) is a graft-threatening complication after kidney transplantation. Current consensus regarding the prevention of BKVAN is to screen for BK viremia and to treat sustained BK viremia through reducing immunosuppression. This study assessed the effect of conversion from mycophenolates to mizoribine (MZR) on the prevention of BK viremia in kidney transplant recipients.

METHODS

De novo kidney transplant recipients were screened for BK viruria. Sustained high levels of BK viruria (>10⁷ copies/mL) were treated by switching from mycophenolates to MZR. The reduction and clearance of BK viruria and viremia were evaluated.

RESULTS

Fifty kidney transplant recipients with high levels BK viruria were enrolled, including 11 recipients with BK viremia. After 6 months of MZR therapy, only 3 recipients still had high levels of BK viruria. The clearance rate of BK viremia was 100%. One episode of acute rejection occurred (2.0%) and was reversed by steroid administration. The serum uric acid level of the recipients was similar before and after switching to MZR, but the proportion of recipients receiving uric acid-reducing drugs increased significantly after 3 months of MZR therapy (19/50 vs 31/50; P = .02). No new cases of BK viremia were observed after conversion to MZR.

CONCLUSION

Conversion from mycophenolates to MZR in kidney transplant recipients with sustained high levels of BK viruria was associated with reduction of BK viruria and clearance of BK viremia. This may be an effective approach to prevent BK viremia and BKVAN.

Everolimus delayed and suppressed cytomegalovirus DNA synthesis, spread of the infection, and alleviated cytomegalovirus infection

Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) and reduces the risk of cytomegalovirus (CMV) infection in transplant recipients. Everolimus inhibits mTOR complex 1, which regulates factors involved in several crucial cellular functions and is required for CMV replication. However, it is not clear how everolimus regulates CMV replication and prevents and alleviates CMV infection. Effects of everolimus on CMV infection, spread, and DNA synthesis and release from infected cells were assessed by plaque formation, infectious centre assay, real-time PCR of infected cells, and culture supernatant in CMV-infected cultures with and without everolimus. Everolimus enhanced plaque formation by 3.6 times, but the size of the plaques was reduced to 36.4% of untreated cultures in the absence of a pretreatment period. Everolimus reduced viral adsorption but enhanced the replication efficiency of inoculated virus, resulting in an increase in plaque number in the early phase of infection. Preinfection treatment of cells with everolimus efficiently exhibited its antiviral efficacy, and everolimus delayed and suppressed viral DNA synthesis and release from infected cells. Everolimus had suppressed the spread of infection and reduced the number of total infected cells to 40% of untreated cells on day 9, indicating reduction of the size of CMV lesions to one-sixth in 2-3 replication cycles. Preinfection treatment of the cells with everolimus augmented its suppressive effect on CMV infection and replication. Everolimus reduced the total number of infected cells and limited the CMV lesions, and this reduction in the spread of CMV infection would alleviate CMV infection in transplant recipients.

The first year results of mizoribine/tacrolimus-based multitarget treatment for consecutive patients with lupus nephritis

BACKGROUND

Despite the high efficacy of mycophenolate mofetil (MMF)/tacrolimus-based multitarget treatment, risks of infections are a matter of concern. In the present study, we clarified the potential of multitarget therapy using mizoribine opposed to MMF.

METHODS

A total of 36 patients with biopsy-proven lupus nephritis were treated with mizoribine, tacrolimus, and glucocorticoids and then retrospectively evaluated. To determine the efficacy, proteinuria remission (≤ 0.2 g/day), complete remission (Liu et al. in Ann Intern Med 162:18-26, 2015) and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) remission rates, and the prednisolone dose at months 6 and 12 were evaluated. The associations between serum mizoribine/tacrolimus levels and clinical parameters were investigated. To assess safety, adverse events were inspected.

RESULTS

All patients could continue the original treatment regimen without withdrawal or exacerbations through month 12. At month 6, the proteinuria remission, complete remission, SLEDAI remission rates, and prednisolone dose were 69, 53, 36%, and 12.1 mg/day, respectively, whereas the values at 12 months were 92, 67, 50%, and 8.8 mg/day, respectively. The treatment was efficacious for every histologic type of nephritis and non-renal manifestations of SLE. Excluding one patient who was hospitalized due to upper respiratory tract infection, serious infections, including pneumonia and cytomegalovirus disease, were not observed. Higher trough tacrolimus levels were associated with normalization of complement, whereas higher peak mizoribine levels with prevention of cytomegalovirus viremia.

CONCLUSIONS

Our results suggest that multitarget therapy using mizoribine opposed to MMF is highly safe and effective through 12 months. The therapy may enable faster dose reduction of concomitant glucocorticoids.

Population Pharmacokinetic Analysis of Mizoribine in Chinese Renal Transplant Recipients

BACKGROUND

We calculated the population pharmacokinetics of mizoribine in adult Chinese patients and compared the parameters with those of Japanese patients to determine whether there are any ethnic differences in blood concentration transition between these 2 populations.

METHODS

The blood concentrations of mizoribine in 21 Chinese patients who were administered mizoribine after renal transplantation were measured at 304 time points. The absorption lag time, absorption rate constant, apparent distribution volume, and oral clearance were thereafter calculated and compared with the respective Japanese references.

RESULTS

The absorption lag time, absorption rate constant, and apparent distribution volume calculated in this study were, respectively, 0.353 hour, 0.856 hour^-1, and 0.776 L/kg. The oral clearance was calculated as 2.18 times the creatinine clearance using creatinine clearance as a function. The absorption rate constant, apparent distribution volume, and oral clearance are determinants of the maximum blood concentration, trough, and area under the blood concentration time curve. The relative absorption rate constant, apparent distribution volume, and oral clearance were 0.9-, 0.9-, and 1.2-fold, respectively, in Chinese patients compared with those in Japanese patients. These values are within the confidence limit, suggesting that there is no significant PK difference between the 2 ethnic groups.

CONCLUSIONS

Results of this study showed no ethnic difference in blood mizoribine concentration transition between Chinese and Japanese patients. In addition, the population pharmacokinetic parameters obtained in this study are useful in determining the initial dosage or in the Bayesian analysis of mizoribine concentrations using scarce time points.

Beneficial Effects of High-Dose Mizoribine on ABO-Incompatible Living-Related Kidney Transplantation: Two-Year Results by a Japanese Multicenter Study

BACKGROUND

Mizoribine (MZ) has been developed as an immunosuppressive agent in Japan, but it has a less-potent immunosuppressive effect up to 3 mg/kg/d. In the previous study, a Japanese multicenter study, we reported that high-dose MZ, at 6 mg/kg/d, with a calcineurin inhibitor was effective and safe in reducing the frequency of cytomegalovirus (CMV)-related events in ABO-incompatible (ABO-i) living-related kidney transplantation (LKT). In the present study, therefore, we investigated the effects of high-dose MZ with a CNI in ABO-i LKT recipients in a Japanese multicenter study.

METHODS

A total of 37 patients were treated with high-dose MZ (6 mg/kg), a CNI (cyclosporine [CsA] or tacrolimus [Tac]), basiliximab (Bas), rituximab (Rit), and corticosteroids. CsA was started at a dose of 7 mg/kg to maintain blood levels [200 ng/mL (C0), 6000 ng-h/mL (AUC 0-9)]. Tac was started at a dose of 0.2 mg/kg to maintain blood levels [8-10 ng/mL (C0), 100 ng-h/mL (AUC 0-9)]. Bas (20 mg/body) was administrated on day 0 and day 4 after transplantation. Rit (100-200 mg/body) was administrated on day -14 and day -7 before transplantation. MZ was adjusted to maintain target C0 levels of 1.5 to 2.0 μg/mL.

RESULTS

Patient and graft survival rates for 2 years were 100% in the CsA group (n = 22) and 93.3% in the Tac group (n = 15) (not significant, NS). Overall incidence of acute rejection for 2 years was 22.7% in the CsA group and 26.7% in the Tac group. Mean serum creatinine levels at 2 years were 1.29 ± 0.2 mg/dL in the CsA group and 1.21 ± 0.34 mg/dL in the Tac group (NS). The incidence of CMV disease was 0% in both groups, and positive rates of CMV antigenemia were 50.0% and 26.7% in the CsA and Tac groups, respectively (NS). Mean serum uric acid levels were 5.5 ± 1.3 mg/dL and 6.4 ± 1.2 mg/dL at 2 years (NS) in the CsA and Tac groups, respectively.

CONCLUSIONS

A high-dose MZ regimen including calcineurin inhibitor (CsA or Tac), Bas, Rit, and steroids was effective and safe in reducing the frequency of CMV-related events in ABO-i LKT.

High-dose mizoribine combined with calcineurin inhibitor (cyclosporine or tacrolimus), basiliximab and corticosteroids for renal transplantation: A Japanese multicenter study

OBJECTIVE

To evaluate the utility and safety of high-dose mizoribine combination therapy using cyclosporine and tacrolimus as calcineurin inhibitors in patients undergoing kidney transplant.

METHODS

The present study enrolled 156 patients who received kidney transplants in 18 institutions between 2009 and 2013. ABO-incompatible and/or pre-sensitized recipients were excluded. Immunosuppression used cyclosporine (88) or tacrolimus (68) as a calcineurin inhibitor, and the dosage was adjusted based on blood concentrations. Mizoribine was started at 6 mg/kg/day, and the target trough level was 1-2 ng/mL. Primary efficacy end-points of this study were 2-year patient survival, 2-year graft survival and the acute rejection rate within 2 years after transplantation.

RESULTS

The 2-year patient and graft survival rates in the cyclosporine group were 98.9% and 94.3%, respectively, whereas those in the tacrolimus group were 100% and 98.5%, respectively, with no significant difference between groups. Rates of onset of rejection during the observation period were also equivalent, at 22.7% in the cyclosporine group and 17.6% in the tacrolimus group. Furthermore, groups showed no significant differences in transplanted renal function. No notable differences in adverse events were observed between groups.

CONCLUSIONS

A regimen of high-dose mizoribine in combination with calcineurin inhibitors basiliximab, and corticosteroids can provide effective immunosuppression while lowering the rate of cytomegalovirus infection in kidney transplant patients.

Comparison of Mizoribine and Mycophenolate Mofetil With a Tacrolimus-Based Immunosuppressive Regimen in Living-Donor Kidney Transplantation Recipients: A Retrospective Study in China

BACKGROUND

A retrospective study was conducted to investigate the prevalence of gastrointestinal (GI) symptoms as well as the efficacy and safety of mizoribine (MZR) and mycophenolate mofetil (MMF) in Chinese living-donor kidney transplantation (LDKT).

METHODS

Forty-two recipients enrolled between January 2012 and March 2014 were treated with either MZR (n = 22) or MMF (n = 20). All patients were treated in combination with a tacrolimus-based immunosuppressive regimen, besides the study drugs.

RESULTS

GI symptoms were observed in 1 of 22 patients (4.5%) and 10 of 20 patients (50%) in MZR treatment group and MMF treatment group, respectively (P = .001), during the post-transplantation 1 year. No significant differences in the incidence of acid reflux, bloated stomach feeling, and constipation were observed between the two groups. No recipient developed diarrhea in the MZR treatment group, whereas 30% of the MMF treatment group developed diarrhea (P = .007). The averages of GI symptom severity total score and diarrhea score were significantly lower in the MZR treatment group compare with MMF treatment group. There were no inter-group differences in background characteristics. There were no significant differences in acute rejection rate and clinical findings between these two groups, whereas the prevalence of cytomegalovirus infection and leukopenia were significantly lower in the MZR treatment group. There was no significant difference on adverse events such as hyperuricemia or other adverse events.

CONCLUSIONS

This study demonstrated a significantly lower incidence of GI symptoms for treatment with MZR compared with MMF and good efficacy and safety in Chinese LDKT with MZR.

A Prospective Randomized, Comparative Trial of High-Dose Mizoribine Versus Mycophenolate Mofetil in Combination With Tacrolimus and Basiliximab for Living Donor Renal Transplant: A Multicenter Trial

OBJECTIVES

Our objectives were to compare the clinical outcomes of mizoribine (12 mg/kg/d) and mycophenolate mofetil (2000 mg/d) in combination with tacrolimus, basiliximab, and corticosteroids.

MATERIALS AND METHODS

We enrolled 83 recipients of living-donor renal transplant (performed between 2008 and 2013) in this study. This prospective multi-institutional randomized comparative study compared mizoribine (n = 41) and mycophenolate mofetil (n = 42) in combination with tacrolimus, basiliximab, and corticosteroids for living-donor renal transplant recipients. We compared the acute rejection and graft survival rates and adverse event rates within 1 year of renal transplant between the 2 groups using intention-to-treat analyses.

RESULTS

During the 1-year observation period, patient and graft survival rates were 100%. The acute rejection rate was 17.1% in the mizoribine group and 19% in the mycophenolate mofetil group. The incidence rate of cytomegalovirus infection seropositivity (recipient and donor with positive cytomegalovirus antibody status) was higher in the mycophenolate mofetil group than in the mizoribine group, although the difference in these rates was not statistically significant. The incidence of leukopenia was higher in the mizoribine group than in the mycophenolate mofetil group.

CONCLUSIONS

High-dose mizoribine at 12 mg/kg/day was a safe and efficacious immunosuppressive alternative to mycophenolate mofetil in living-donor renal transplant recipients. Leukopenia should be closely monitored in the initial period of insufficient kidney function after renal transplant.

A four-drug combination therapy consisting of low-dose tacrolimus, low-dose mycophenolate mofetil, corticosteroids, and mizoribine in living donor renal transplantation: A randomized study

OBJECTIVE

We compared a three-drug combination therapy (control group) consisting of tacrolimus, mycophenolate mofetil, and corticosteroids in living donor renal transplantation with a four-drug combination therapy (study group), in which the doses of tacrolimus and mycophenolate mofetil were halved and the immunosuppressive drug mizoribine was added, in order to determine whether the incidence rates of acute rejection after transplantation between the study group and the control group are similar, whether the study group regimen prevents the occurrence of calcineurin inhibitor-induced renal damage, and whether the study group regimen prevents adverse effects such as diarrhea caused by mycophenolate mofetil.

METHODS

We investigated the incidence of acute rejection, serum creatinine levels, and estimated glomerular filtration rate and the incidence of adverse effects such as diarrhea.

RESULTS

There was no significant difference between the two groups in the incidence of acute rejection. Renal function (estimated glomerular filtration rate and serum creatinine) was maintained in the control group whereas in the study group renal function gradually improved, with a statistical difference observed at 12 months. The incidence of gastrointestinal symptoms including diarrhea was significantly higher in the control group than in the study group. There was no significant difference in the incidence of cytomegalovirus infection and other adverse effects.

CONCLUSION

These results suggest the study group therapy is an effective regimen in preventing acute rejection and the deterioration of renal function. These results also show this therapy can reduce the incidence of adverse effects such as gastrointestinal symptoms.

Improvement in Severe Mycophenolic Acid-associated Gastrointestinal Symptoms after Changing Enteric-coated Mycophenolate Sodium to Mizoribine in Renal Transplant Recipients: Two Case Reports

Clinical results point to a better gastrointestinal tolerability with enteric-coated mycophenolate sodium as compared to mycophenolate mofetil. However, some transplant recipients who are treated with enteric-coated mycophenolate sodium still experience gastrointestinal symptoms. We herein present two cases of renal transplant recipients with severe gastrointestinal symptoms who were switched from enteric-coated mycophenolate sodium to mizoribine, and the symptom reversal effects were evaluated using the Gastrointestinal Symptom Rating Scale. The results of this study showed a significant improvement in severe gastrointestinal symptoms in renal transplant recipients after converting from enteric-coated mycophenolate sodium to mizoribine.

Comparative efficacy and safety of mizoribine with mycophenolate mofetil for Asian renal transplantation--a meta-analysis

OBJECTIVES

Mizoribine (MZR) with its high safety and low cost has been widely used in Asia. It has been questioned whether high or low dose of MZR could obtain the efficacy and safety similar to mycophenolate mofetil (MMF) following renal transplantation. This meta-analysis was done to compare the efficacy and safety of high- or low-dose MZR with MMF for immunosuppressive therapy in renal transplantation.

DESIGN AND METHODS

Available data comparing MZR with MMF in renal transplant recipients were searched. Subgroup analysis was conducted according to the administration dosage of MZR. Trials were pooled using Meta-analysis software and confidence intervals were set at 95%.

RESULTS

Altogether 1149 Asian patients from 7 RCTs and 9 cohort studies were included. The efficacy of different MZR doses put on par with MMF, but the safety was better than MMF. Specifically, recipients taking MZR favor significantly fewer episodes of leucocytopenia [RR 0.40 (0.26, 0.60)], gastrointestinal disorder [RR 0.54 (0.40, 0.73)], CMV infection [RR 0.47 (0.34, 0.64)] and more favorable outcome of hepatic dysfunction, although the difference failed to reach a statistical significance [RR 0.67 (0.44, 1.00)]. Unfortunately, hyperuricemia was significantly obvious in MZR group [RR 1.96 (1.47, 2.61)].

CONCLUSIONS

MZR is an effective and safe immunosuppressive agent and high-dose MZR can be recommended as an alternative to MMF following adult renal transplantation in Asia, but hyperuricemia and liver damage should be closely monitored during the medication period.