A case of membranous nephropathy complicated by Cronkhite-Canada syndrome successfully treated with mizoribine.

Cronkhite-Canada syndrome (CCS) is a non-hereditary disorder characterized by non-neoplastic hamartomatous gastrointestinal polyposis, hair loss, nail atrophy, hyperpigmentation, and diarrhea. While the relationship between CCS and nephritis remains unclear, seven cases of nephritis complicated by CCS have been reported to date, all of which were membranous nephropathy (MN). A 57-year-old man presented with taste disturbance, hair loss, nail plate atrophy, skin pigmentation, and frequent diarrhea. Endoscopic findings showed multiple polyposis of the stomach and large intestine. Given the above, he was diagnosed with CCS. The symptoms gradually improved with prednisolone treatment, although urinary protein and hypoproteinemia appeared during the tapering of prednisolone. He was diagnosed with MN using a renal biopsy, and immunofluorescence microscopy with IgG subclass staining showed predominantly diffuse granular capillary wall staining of IgG4. The cause of secondary MN was not found, including malignant tumors. Nephrotic-range proteinuria persisted despite treatment with prednisolone and cyclosporine. Additional treatment with mizoribine resulted in incomplete remission type 1 of nephrotic syndrome, suggesting that mizoribine may be a treatment option for patients with CCS with steroid-resistant MN. Considering a high prevalence of hypoproteinemia due to chronic diarrhea and protein-losing enteropathy in patients with CCS, proteinuria might be overlooked; thus, follow-up urinalysis would be recommended in patients with CCS.

Mizoribine Promotes Molecular Chaperone HSP60/HSP10 Complex Formation.

It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid arthritis. The molecular chaperone HSP60 alone induces inflammatory cytokine IL-6 and the co-chaperone HSP10 alone inhibits IL-6 induction. HSP60 and HSP10 form a complex in the presence of ATP. We analyzed the effects of Mizoribine, which is structurally similar to ATP, on the structure and physiological functions of HSP60-HSP10 using Native/PAGE and transmission electron microscopy. At low concentrations of Mizoribine, no complex formation of HSP60-HSP10 was observed, nor was the expression of IL-6 affected. On the other hand, high concentrations of Mizoribine promoted HSP60-HSP10 complex formation and consequently suppressed IL-6 expression. Here, we propose a novel mechanism of immunosuppressive action of Mizoribine.

Acute renal failure after kidney transplantation due to mizoribine-induced ureteral stones.

INTRODUCTION: Mizoribine (MZR) is used to prevent rejection reactions after kidney transplantation and increase the risk of hyperuricemia. There is a lack of reports of MZR-induced ureteral stones after kidney transplantation. The surgery treatment of ureteral stones in transplanted kidney is a challenging clinical issue that should only be performed by experienced urologists at professional centers. It is very important to have a thorough understanding of the patient's medical history, analyze the causes of stone formation, and choose a reasonable treatment plan based on the characteristics of the stones. The case report is aim to emphasize the recognition of the possibility of mizoribine-induced ureteral uric acid stones in transplanted kidney and to avoid unnecessary surgery. CASE PRESENTATION: A patient after kidney transplantation was diagnosed with acute renal failure caused by ureteral stones. The medical history, CT images of the renal graft, the results of laboratory test and stone composition analysis were provided. Based on medical history and laboratory test results, it was determined that the ureteral stones of renal graft was induced by MZR. To our best knowledge, this is the first report of MZR-induced stones in transplanted kidney and ureters. It was completely cured by urinary alkalinization, avoiding surgery treatment. We summarize the characteristics, treatment and methods for preventing the formation of uric acid stones of patients with MZR. CONCLUSION: By analyze our case report, it shows that acute renal failure with ureteral stones after kidney transplantation can caused by MZR. Urinary alkalinization for MZR induced uric acid stones is simple and effective.

Synthesis of mizoribine prodrugs and their in vivo evaluation as immunosuppressive agents.

Mizoribine is a well-known immunosuppressive drug, based on a nucleoside scaffold, that targets inosine-monophosphate dehydrogenase (IMPDH). In an effort to increase its in vivo efficacy, three different types of prodrugs (a phosphoramidate prodrug, a lipophilic ester derivative and an amino acid conjugate) were prepared. Screening of these prodrugs in a rapid whole blood assay revealed that the two ester-based mizoribine prodrugs potently inhibited interleukin 2 secretion. Moreover, these prodrugs were able to prolong graft survival, when evaluated in a mouse model of cardiac allograft transplantation. Strikingly, a combination therapy of these mizoribine prodrugs with tacrolimus had a synergistic in vivo effect.

Differences in response to treatment in children with severe IgA nephropathy according to patient age.

AIM: To clarify whether the response to treatment of IgA nephropathy (IgAN) differs depending on patient age, we examined the response to treatment according to age of onset in children with IgAN. METHODS: We collected data for 44 children with severe IgAN. The children were retrospectively divided into three groups based on their age at disease onset. Group 1 consisted of 24 children under 11 years old, group 2 consisted of 9 children aged 12 to 13 years, and group 3 consisted of 11 children aged over 14 years old. The clinical features and prognosis were analyzed for each group. RESULTS: The urinary protein excretion and serum IgA values in group 3 were higher than those in groups 1 and 2 at the most recent follow up, and histological findings showed that the MESTCG scores in group 3 were higher than those in group 1. Furthermore, the incidence of patients with persistent nephropathy or renal insufficiency in group 3 was higher than those in groups 1 and 2. CONCLUSIONS: Patients aged 14 years and older with IgAN may respond poorly to treatment compared with those younger than 14 years old. Therefore, care must be taken regarding response to treatment and relapse when treating older children.

Efficacy and Safety of Mizoribine for the Treatment of Refractory Nephrotic Syndrome: Protocol for a Multicenter, Controlled, Open-label, Randomized Controlled Trial.

BACKGROUND: Nephrotic syndrome that is resistant to steroid therapy is termed refractory nephrotic syndrome (RNS), a condition that is associated with an increased risk of end-stage renal disease. Immunosuppressants are used to treat RNS; however, prolonged use may lead to significant adverse effects. Mizoribine (MZR) is a novel agent used in long-term immunosuppressive therapy, which has few adverse effects, but data on its long-term use in patients with RNS are unavailable. OBJECTIVE: We propose a trial to examine the efficacy and safety of MZR compared with cyclophosphamide (CYC) in Chinese adult patients with RNS. METHODS: This is a multicenter, randomized, controlled interventional study with a screening phase (1 week) and a treatment phase (52 weeks). This study has been reviewed and approved by the Medical Ethics Committees of all 34 medical centers that are participating. Patients with RNS consent to participation, and are enrolled and randomized to an MZR group or a CYC group (1:1 ratio), with each group receiving tapering doses of oral corticosteroids. Participants are assessed for adverse effects, and laboratory results are collected at 8 visits during the treatment phase (weeks 4, 8, 12, 16, 20, 32, 44, and 52 [exit visit]). Participants are able to withdraw voluntarily, and investigators are required to remove patients when there are safety concerns or deviations from the protocol. RESULTS: The study started in November 2014 and was completed in March 2019. A total of 239 participants from 34 hospitals in China have been enrolled. Data analysis has been completed. The results are being finalized by the Center for Drug Evaluation. CONCLUSIONS: This study examines the safety and efficacy of MZR as a long-term treatment approach for Chinese adults with RNS. It is the longest lasting and largest randomized controlled trial to examine MZR in Chinese patients. The results can help determine whether RNS should be considered as an additional indication for MZR treatment in China. TRIAL REGISTRATION: ClinicalTrials.gov NCT02257697; https://clinicaltrials.gov/ct2/show/NCT02257697. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/46101.

Fanconi syndrome in an elderly patient with membranous nephropathy during treatment with the immunosuppressant mizoribine.

We report on an 80-year-old man diagnosed with Fanconi syndrome induced by mizoribine after 4 weeks of administration to treat membranous nephropathy. Mizoribine is an oral immunosuppressant that inhibits inosine monophosphate dehydrogenase and is widely used in Japan for the treatment of autoimmune diseases and nephrotic syndrome, as well as after renal transplantation. Acquired Fanconi syndrome is often caused by drugs (antibacterial, antiviral, anticancer, and anticonvulsant drugs) and is sometimes caused by autoimmune diseases, monoclonal light chain-associated diseases, or heavy metal poisoning. In our patient, hypokalemia, hypophosphatemia, glucosuria, hypouricemia, and severe proteinuria resolved gradually after discontinuation of mizoribine administration, despite oral administration of prednisolone followed by a single intravenous injection of rituximab. The patient was ultimately diagnosed with Fanconi syndrome induced by mizoribine based on his clinical course and his typical laboratory data with the absence of proximal tubular acidosis. To our knowledge, this is the first report of Fanconi syndrome possibly induced by mizoribine. Although the precise mechanism by which mizoribine induces proximal tubular dysfunction is unknown, we suggest that nephrologists should be aware of the onset of Fanconi syndrome, a rare complication during mizoribine treatment.

Mizoribine combined with steroids and dietary sodium restriction on the treatment of primary membranous nephropathy: a prospective study.

BACKGROUND: We aimed to initially explore the efficiency and safety of mizoribine (MZR) combined with steroids and dietary sodium restriction on the treatment of primary membranous nephropathy (MN) compared with cyclophosphamide (CPM)-based steroids. METHODS: Patients with primary MN were enrolled. According to the therapy, they were divided into the MZR combined with steroids and dietary sodium restriction group (N = 30) and CPM-based steroids group (N = 30). Both groups were followed up for 1 year to monitor safety and efficacy. RESULTS: Compared with the CPM-based steroids group, the MZR combined with steroids and dietary sodium restriction group had significantly lower daily sodium intake, serum sodium, blood pressure (BP), and 24 h urine protein (all P < 0.05). Conversely, plasma albumin and complete remission rate in the MZR group were higher at the 12th follow-up (40.39 ± 5.14 g/L vs. 37.63 ± 5.40 g/L; 86.67% vs. 66.67%; all P < 0.05). These two groups showed similar adverse events rates (20.00% vs. 26.67%, P = 0.54). CONCLUSION: This study demonstrates that MZR combined with steroids and dietary sodium restriction is superior to CPM-based steroids in terms of complete remission and 24 h urine protein in patients with primary MN.

Mizoribine halts kidney fibrosis in childhood IgA nephropathy: association with modulation of M2-type macrophages.

BACKGROUND: The immunosuppressant mizoribine (Miz) can reduce progression of childhood IgA nephropathy (IgAN). This study examined whether Miz affects CD163+ M2-type macrophages which are associated with kidney fibrosis in childhood IgAN. METHODS: A retrospective cohort of 90 children with IgAN were divided into groups treated with prednisolone (PSL) alone (P group; n = 42) or PSL plus Miz (PM group; n = 48) for a 2-year period. Normal human monocyte-derived macrophages were stimulated with dexamethasone (Dex), or Dex plus Miz, and analyzed by DNA microarray. RESULTS: Clinical and histological findings at first biopsy were equivalent between patients entering the P and PM groups. Both treatments improved proteinuria and haematuria, and maintained normal kidney function over the 2-year course. The P group exhibited increased mesangial matrix expansion, increased glomerular segmental or global sclerosis, and increased interstitial fibrosis at 2-year biopsy; however, the PM group showed no progression of kidney fibrosis. These protective effects were associated with reduced numbers of glomerular and interstitial CD163+ macrophages in the PM versus P group. In cultured human macrophages, Dex induced upregulation of cytokines and growth factors, which was prevented by Miz. Miz also inhibited Dex-induced expression of CD300E, an activating receptor which can prevent monocyte apoptosis. CD300e expression by CD163+ macrophages was evident in the P group, which was reduced by Miz treatment. CONCLUSION: Miz halted the progression of kidney fibrosis in PSL-treated pediatric IgAN. This was associated with reduced CD163+ and CD163+CD300e+ macrophage populations, plus in vitro findings that Miz can suppress steroid-induced macrophage expression of pro-fibrotic molecules. A higher resolution version of the Graphical abstract is available as Supplementary information.

Epidemiological characteristics of SARS-CoV-2 pneumonia in kidney transplant recipients : a single-center retrospective study / 器官移植

Objective To investigate the epidemiological characteristics of SARS-CoV-2 pneumonia in kidney transplant recipients and analyze the risk and protective factors of severe/critical infection with SARS-CoV-2. Methods Clinical data of 468 kidney transplant recipients infected with SARS-CoV-2 were retrospectively analyzed. According to the severity of infection, they were divided into mild SARS-CoV-2 infection recipients (n=439) and SARS-CoV-2 pneumonia group (n=29). Among the 439 mild SARS-CoV-2 infection recipients, 87 recipients who were randomly matched with their counterparts in the SARS-CoV-2 pneumonia group according to sex, age and transplantation time at a ratio of 3∶1 were allocated into the mild SARS-CoV-2 infection group. Twenty-nine recipients in the SARS-CoV-2 pneumonia group were divided into the moderate SARS-CoV-2 pneumonia group (n=21) and severe/critical SARS-CoV-2 pneumonia group (n=8). Baseline data of all recipients were collected. The risk and protective factors of SARS-CoV-2 infection in kidney transplant recipients were identified. Results The proportion of recipients complicated with 2-3 types of complications in the SARS-CoV-2 pneumonia group was higher than that in the mild SARS-CoV-2 infection group, and the proportion of recipients treated with tacrolimus(Tac)+mizoribine+glucocorticoid immunosuppression regimen in the SARS-CoV-2 pneumonia group was lower than that in the mild SARS-CoV-2 infection group, and significant differences were observed (both P<0.05). In 29 kidney transplant recipients with SARS-CoV-2 pneumonia in the SARS-CoV-2 pneumonia group, white blood cells, the absolute values of lymphocytes, eosinophils, total T cells, CD4+T cells and CD8+T cells, and serum uric acid levels were significantly lower, whereas ferritin levels were significantly higher than the values prior to SARS-CoV-2 pneumonia, and significant differences were observed (all P<0.05). Compared with the moderate SARS-CoV-2 pneumonia group, the proportion of recipients with hypoxemia was higher, the proportion of recipients treated with Tac/ciclosporin (CsA)+mycophenolate mofetil+glucocorticoid immunosuppression regimen was higher, and the proportion of recipients administered with 2-3 doses of SARS-CoV-2 vaccine was lower in the severe/critical SARS-CoV-2 pneumonia group, and significant differences were observed (all P<0.05). Conclusions More complications and immunosuppression regimen containing mycophenolate mofetil are the risk factor for SARS-CoV-2 infection in kidney transplant recipients. Vaccination with SARS-CoV-2 vaccine and immunosuppression regimen containing mizoribine are probably the protective factors for lowering the risk of SARS-CoV-2 infection. The levels of inflammatory cytokines are associated with the severity of SARS-CoV-2 pneumonia.

First-line Combination Strategy Provides Favorable 5-year Outcomes for Patients with Lupus Nephritis: A Single-center Observational Study.

This observational study aimed to clarify the long-term results of the combination of mizoribine (MZB), tacrolimus (TAC) and prednisolone as first-line therapy for lupus nephritis (LN). This was our institution's standard therapy between 2009 and 2015, when we saw 36 patients with LN. When a patient thus treated achieved SLEDAI remission (= 0) and/or the prednisolone dose could be tapered to 5 mg/day, either MZB or TAC was stopped, and the other was continued for maintenance therapy. If treatment failure or relapse occurred, second-line therapy was introduced. At years 1 and 5, overall complete renal response and SLEDAI remission were 94% and 88%, and 50% and 62%, respectively. Excluding 2 cases lost to follow-up, medications after 5 years were as follows: 20 (59%) were stable on 1 drug (MZB or TAC), 11 (32%) required continuation of both drugs (MZB + TAC), and 3 (9%) required second-line therapy. The 5-year retention rate was 91% (non-secondline), with 0% of relapse in this group. Our first-line combination strategy showed high remission rates in the induction phase, and subsequent maintenance therapy demonstrated good outcomes for up to 5 years. Research that fine-tunes the order of therapeutic agents and institutes appropriate treatment goals may further improve long-term outcomes for patients with LN.

The efficacy and safety of mizoribine for maintenance therapy in patients with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis: the usefulness of serum mizoribine monitoring.

BACKGROUND: The life prognosis of elderly patients with myeloperoxidase-anti-neutrophil cytoplasmic antibodies-associated vasculitis (MPO-AAV) has been improved by reducing the corticosteroid or cyclophosphamide dose to avoid opportunistic infection. However, many elderly MPO-AAV patients experience recurrence and renal death. An effective and safer maintenance treatment method is necessary to improve the renal prognosis of MPO-AAV. METHODS: Patients with MPO-AAV who reached complete or incomplete remission after induction therapy were prospectively and randomly divided into mizoribine (MZR; n = 25) and control (n = 28) groups. The primary endpoint was relapse of MPO-AAV. The patients' serum MZR concentration was measured before (C0) and 3 h after taking the MZR. The maximum drug concentration (Cmax) and the serum MZR concentration curves were determined using population pharmacokinetics parameters. We also assessed the relationship between the MZR concentrations and adverse events. The observation period was 12 months. RESULTS: Fifty-eight MPO-AAV patients from 16 hospitals in Japan were enrolled. Ten patients relapsed (MZR group, n = 6; control group, n = 4; a nonsignificant between-group difference). Changes in the serum MZR concentration could be estimated for 22 of the 25 MZR-treated patients: 2 of the 11 patients who reached a Cmax of 3 µg/mL relapsed, whereas 4 of the 11 patients who did not reach this Cmax relapsed. The treatment of one patient with C0 > 1 µg/mL was discontinued due to adverse events. No serious adverse events occurred. CONCLUSION: There was no significant difference in the recurrence rate of MPO-AAV between treatment with versus without MZR.

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.

Predictors of Treatment Response and Long-Term Outcomes in Young Children with Steroid-Dependent Nephrotic Syndrome Treated with High-Dose Mizoribine as First-Line Steroid-Sparing Agent.

Mizoribine may be a safe and effective treatment for children with steroid-dependent nephrotic syndrome (SDNS). However, predictors of treatment response and long-term outcomes after mizoribine discontinuation remain unknown. We retrospectively reviewed the clinical course of 22 children aged ≤ 10 years (median age, 5.3 years) with SDNS who received high-dose mizoribine as the initial steroid-sparing agent (SSA). Mizoribine was administered at a single daily dose of 10 mg/kg (maximum, 300 mg/day) after breakfast. The dose was adjusted to maintain 2-h post-dose mizoribine levels of > 3 µg/mL and was tapered off after 12 months of steroid-free remission. Patients who regressed to SDNS were switched from mizoribine to other SSAs. The primary endpoint was probability of survival without regression to SDNS after mizoribine initiation. Ten patients were able to discontinue SDNS (response group), whereas twelve were switched from mizoribine to other SSAs (non-response group) during a median observation period of 6.0 years after mizoribine. The steroid-dependent dose prior to mizoribine was significantly lower in the response group than in the non-response group (p < 0.05). The Kaplan-Meier analysis revealed that the probability of regression-free survival was significant higher in patients with steroid-dependent dose of < 0.25 mg/kg/day than in those with steroid-dependent dose of ≥ 0.25 mg/kg/day (p < 0.05). During a median follow-up of 5.5 years after mizoribine discontinuation, all but one patient did not develop SDNS. High-dose mizoribine may be an attractive treatment option as initial SSA in young children with low steroid-dependent dose for improved long-term outcomes.

Conversion from mycophenolate mofetil to mizoribine in the early stages of BK polyomavirus infection could improve kidney allograft prognosis: a single-center study from China.

BACKGROUND: Some studies have suggested mizoribine (MZR) could inhibit the replication of BK polyomavirus (BKPyV). The purpose of this study was to explore whether conversion from mycophenolate mofetil (MMF) to MZR in the early stages of BKPyV infection can improve kidney allograft prognosis. METHODS: Twenty-one kidney transplant recipients with BKPyV viruria/viremia and ten with BK polyomavirus-associated allograft nephropathy (BKPyVAN) received MZR conversion therapy were retrospectively identified. The clearance rate of urine and blood BKPyV DNA, change of serum creatinine (SCr), uric acid (UA), hemoglobin (HB), white blood cell (WBC), lymphocyte ratio, platelet (PLT), routine urinalysis, panel reactive antibody (PRA), and gastrointestinal disorders during follow-up of the 2 groups were evaluated and compared. RESULTS: After MZR conversion therapy, the clearance rate of urine and blood viral load in BKPyV viruria/viremia group were 85.7 and 100 %, while that in BKPyVAN were 40 and 87.5 %, respectively. Stable SCr were observed in all cases of BKPyV viruria/viremia group, while that of BKPyVAN was only 40 % (P < 0.001) and one even progressed to end-stage renal disease. The results of routine urinalysis in the two groups showed no significant changes before and after MZR conversion therapy. However, in BKPyV viruria/viremia group, four cases developed acute rejection and one had positive PRA-II but no donor specific antibody, requiring conversion back to MMF. Hyperuricemia was the common adverse effect of MZR. CONCLUSIONS: Conversion from MMF to MZR could help clear BKPyV infection. As compared to BKPyVAN, patients who underwent initiation of MZR conversion therapy in the early stages of BKPyV infection maintained stable allograft function. Prospective studies with larger sample size are needed to ascertain this preliminary finding.

Effectiveness and safety of mizoribine for the treatment of IgG4-related disease: a retrospective cohort study.

OBJECTIVE: Patients with IgG4-related disease (IgG4RD) usually require steroid-sparing agents due to relapse with tapering glucocorticoids (GC). We aimed to determine the efficacy and safety of mizoribine (MZR) among IgG4RD patients. METHODS: We retrospectively reviewed records of IgG4RD patients at Immuno-Rheumatology Center in St. Luke's International Hospital, Tokyo, Japan. Patients treated with MZR were classified into the MZR group, and those treated with GC alone or with other immunosuppressants were included in the control group. Disease exacerbation, GC dose, IgG-IgG4 titre and adverse events were evaluated using univariate analyses, including the Kaplan-Meier method. The Cox proportional hazard model was used to evaluate risk factors for disease exacerbation. RESULTS: A total of 14 and 29 cases were included in the MZR and control group. Multiple organ involvement (three or more organs) was significantly more frequent in the MZR group [10 (71.4%) vs 9 (31.0%), P= 0.021]. Kaplan-Meier analysis revealed a significant reduction inexacerbation in patients with multiple organ involvement (P< 0.001) but not in total (P= 0.42). The adjusted hazard ratios of MZR use and multiple organ involvement for exacerbation were 0.34 (95%CI 0.12-1.01; P = 0.052) and 3.51 (95%CI 1.29-9.51; P= 0.014). The cumulative GC dose (mg per year, interquartile range) tended to be lower in the MZR group [1448 (1003-1642) vs 2179 (1264-3425); P= 0.09]. CONCLUSION: MZR decreased disease exacerbation among IgG4RD patients with multi-organ involvement and showed a steroid-sparing effect. MZR could be a treatment option for IgG4RD.

Effect of mizoribine pulse therapy in adult membranous nephropathy.

Membraneous nephropathy (MN) is one of the complicated kidney diseases associated with proteinuria. Mizoribine (MZR) is an emerging treatment option for nephrotic syndrome; however, its dosage and administration are yet lack of consensus. This study aims to evaluate the efficacy and safety of high-dose MZR pulse therapy for adult membraneous nephropathy. Sixty patients with membraneous nephropathy were recruited, and assigned to two treatment groups. One group received conventional treatment of steroid combining with cyclophosphamide (CPM), the other group received steroid combining with high-dose MZR pulse administration. Both groups were followed up for 1 year. Treatment efficacy and side effects were measured regularly. Fifty-nine patients completed the treatment courses. There was no significant difference in demographic and disease conditions prior to treatment between two treatment groups. Both groups showed significant decrease of urine proteins and increase of serum albumin levels after treatments with no severe side effects. After 6 months of treatment, MZR group has 71% reduction (compared to 74.4% reduction in CPM group) in urine protein compared to baseline after adjusting for age and gender. 89.7% of patients in CPM and 93.3% in MZR groups had partial/ complete remission after 12 months. This study demonstrated satisfactory safety and efficacy of high-dose mizoribine pulse administration combining with steroid treatment for adult patients with membranous nephropathy.

Genetic and clinical determinants of mizoribine pharmacokinetics in renal transplant recipients.

AIM: Mizoribine (MZR) is an immunosuppressant for the prevention of allograft rejection in Asian countries, but the great variability in pharmacokinetics (PK) limits its clinical use. This study was to explore genetic and clinical factors that affect the MZR PK process. METHODS: Blood samples and clinical data were collected from 60 Chinese renal transplant recipients. MZR plasma concentration was measured at pre-dose (0 h) and 0.5, 1, 2, 3, 4, 5, 6, 8, and 12 h post-dose by high performance liquid chromatography with an ultraviolet detector. PK parameters were calculated by non-compartmental analysis. High-throughput sequenced single nucleotide polymorphism was applied screening possible genetic factors. RESULTS: Extensive inter-individual MZR PK differences were reflected in the process of elimination (ke, CL/F, MRT and t1/2) and intestinal absorption (Cmax and Tmax), as well as in the dose-normalized exposure (AUC0-12h/D). From 146 SNPs within 39 genes screened, AUC0-12h/D was found higher in recipients with CREB1 rs11904814 TT than with G allele carriers (3.135 ± 0.928 versus 2.084 ± 0.379 µg h ml-1 mg-1, p = 0.007). Recipients with SLC28A3 rs10868138 TT had lower t1/2 as compared to C allele carriers (0.728 ± 0.189 versus 0.951 ± 0.196 h, p = 0.001). Serum creatinine (SCr) explained 35.5% of C0/D variability (p < 0.001). Pure effects of genotypes CREB1 and SLC28A3 were 13.7% (p = 0.004) and 17.5% (p = 0.001) for AUC0-12h/D and t1/2, respectively. When additionally taking SCr into models, CREB1 and SLC28A3 genotypes explained 20.0% (p = 0.038) and 46.5% (p < 0.001) of AUC0-12h/D and t1/2 variability, respectively. CONCLUSION: CREB1 and SLC28A3 genotypes, as well as SCr, are identified as determinants in predicting inter-individual MZR PK differences in renal transplant recipients.

Low-dose corticosteroid with mizoribine might be an effective therapy for elderly-onset ISKDC grade VI IgA vasculitis.

Both the diagnosis of elderly-onset IgA vasculitis (IgAV) and its prognosis can be difficult because of its rarity and the likely presence of comorbidities. Furthermore, the treatment of elderly-onset IgAV remains controversial: the ideal dosages of corticosteroid and/or immunosuppressants have not been determined. In the elderly, corticosteroid adverse effects can lead to severe outcomes, and a consensus regarding its benefit and risk balance has not been reached. We report a case of IgAV in an 89-year-old patient who was admitted to our hospital to investigate a 30-day history of palpable purpura and pitting edema on her leg. A renal biopsy showed membranoproliferative glomerulonephritis with IgA deposits (The International Study of Kidney Disease in Children (ISKDC) grade VI), which is a predictor of a poor prognosis; these findings led to early intervention with low-dose corticosteroid (15 mg/day) and mizoribine. As a result, a complete remission without obvious adverse effects was obtained. Early intervention with low-dose corticosteroid and mizoribine based on renal histopathology results might be an effective treatment for elderly-onset ISKDC grade VI IgAV.

Comparison of Treatment Effect and Tolerance of the Topical Application of Mizoribine and Cyclosporine A in a Mouse Dry Eye Model.

Purpose: To compare the treatment effects and tolerability of a topical application of mizoribine (MZR) and cyclosporine A (CsA) eye drops (Restasis; Allergan, Inc., Irvine, CA, USA) in a mouse dry eye model. Methods: C57BL/6 mice subjected to desiccating stress (DS) were treated with 0.05% MZR in phosphate-buffered saline (PBS) or Restasis eye drops four times a day for 5 days. Untreated mice served as control. Tear secretion, Oregon green dextran staining, and the conjunctival goblet cell quantity were evaluated. The apoptosis and matrix metalloproteinase 9 (MMP-9) in the ocular surface, conjunctival CD4, and T helper-related cytokines were verified. The ocular tolerance of these two drugs was evaluated by observing the mice's behavioral changes. Results: Topical administrations of MZR or Restasis both increased tear production, maintained goblet cell density, and improved corneal barrier function. Both MZR and Restasis suppressed the expression of MMP-9 and apoptosis in the ocular surface. Meanwhile, both MZR and Restasis decreased the infiltration of CD4+ T cells, reversed the production of interferon-γ, interleukin (IL)-17A, and IL-13 in conjunctiva under DS. The abovementioned efficacies between these two eye drops were not statistically significant. However, the number of scratching and wiping behaviors in the MZR-treated group was significantly less than in the Restasis-treated group. Conclusions: MZR (0.05% in PBS) could be a good competitive product for Restasis because of the comparable treatment effect in dry eye diseases and better ocular tolerability in ocular itch and pain. Translational Relevance: This study provided an immunosuppressive agent comparable to Restasis for the treatment of dry eye disease.