Hyperuricemia and Acute Renal Failure in Renal Transplant Recipients Treated With High-Dose 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.

Integrating network pharmacology and experimental validation to clarify the anti-hyperuricemia mechanism of cortex phellodendri in mice

Hyperuricemia (HUA), a common metabolic disease, is treated as the second-largest metabolic disease after diabetes in China. Cortex Phellodendri (CP) is one of the most frequently used herbal medicines for treating gout or HUA. However, the mechanism underlying the anti-HUA effect of CP is still unrevealed. Hence, this study aimed to explore the pharmacological mechanism of CP against HUA using network pharmacology coupled with in vivo experimental validation. Active compounds and potential targets of CP, as well as the potential targets related to HUA, were retrieved from multiple open-source databases. The drug-disease overlapping targets were obtained by Venn diagram analysis and used to construct the herb-component-target (HCT), protein-protein-interaction (PPI), and component-target-pathway (CTP) networks. The functional enrichment analysis was also performed for further study. Furthermore, a HUA mouse model was induced by a combination of intraperitoneal injection of potassium oxonate (PO, 300 mg/kg) and intragastric administration of hypoxanthine (HX, 300 mg/kg) daily for 10 days. Different dosages of CP (200, 400, and 800 mg/kg) were orally given to mice 1 h after modeling. The results showed that 12 bioactive compounds and 122 drug-disease overlapping targets were obtained by matching 415 CP-related targets and 679 HUA-related targets, and berberine was one of the most important compounds with the highest degree value. The core targets of CP for treating HUA were TP53, MAPK8, MAPK3, IL-6, c-Jun, AKT1, xanthine oxidase (XOD), and ATP-binding cassette subfamily G member 2 (ABCG2). The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results showed that the anti-HUA effect of CP mainly involved the pathways of inflammation and apoptosis, such as PI3K/Akt, TNF, MAPK, TLR, AMPK, NF-κB, and NLRP3 signaling pathways. In vivo animal experiment further confirmed the hypouricemic effect of CP in a HUA mouse model, as evidenced by significantly restored kidney histological deteriorations, and considerably decreased levels of serum uric acid (sUA), creatinine (Cre), blood urea nitrogen (BUN), and hepatic UA. Furthermore, the hypouricemic action of CP in vivo might be attributed to its suppression of XOD activity in the liver, rather than ABCG2 in the kidney. Real-time qPCR (RT-qPCR) and Western blot analysis also confirmed the key roles of the hub genes in CP against HUA. In conclusion, CP exhibited therapeutic effect against HUA via multi-compounds, multi-targets, and multi-pathways. It possessed anti-HUA and nephroprotective effects via suppressing XOD activity, and reversed the progression of renal injury by exerting anti-inflammatory and anti-apoptotic effects.

Sonneratia apetala seed oil attenuates potassium oxonate/hypoxanthine-induced hyperuricemia and renal injury in mice

Sonneratia apetala seeds are considered as prospective nutraceuticals with a high content of unsaturated fatty acids (UFAs) which are mainly distributed in the oil. It is well-known that UFAs could exhibit urate-lowering potency and protect against renal injury, indicating that S. apetala seed oil (SSO) may possess hypouricemic and nephroprotective effects. Consequently, the present work attempted to probe into the effects and mechanisms of SSO on potassium oxonate/hypoxanthine-induced hyperuricemia and associated renal injury. The results indicated that SSO treatment prominently inhibited the increase of serum uric acid (UA), creatinine (CRE), and urea nitrogen (BUN) levels and hepatic xanthine oxidase (XOD) activity in hyperuricemia mice. Kidney indexes and histopathological lesions were also remarkably ameliorated. Additionally, SSO treatment improved the renal anti-oxidant status in hyperuricemia mice by significantly reversing the increase in ROS and MDA levels as well as the decline in SOD, CAT and GSH-Px activities. SSO dramatically downregulated the expression and secretion of pro-inflammatory factors involving MCP-1, IL-1β, IL-6, IL-18 and TNF-α elicited by hyperuricemia. Furthermore, after SSO treatment, increased protein expressions of GLUT9, URAT1 and OAT1 in the hyperuricemia mice were obviously reversed. SSO treatment enormously restored Nrf2 activation and subsequent translation of related anti-oxidative enzymes in the kidneys. TXNIP/NLRP3 inflammasome activation was also obviously suppressed by SSO. In conclusion, SSO exerted favorable hypouricemic effects owing to its dual functions of downregulating the XOD activity and modulating the expressions of renal urate transport-associated proteins, and it also could alleviate hyperuricemia-induced renal injury by restoring the Keap1-Nrf2 pathway and blocking the TXNIP/NLRP3 inflammasome activation.

Acute and severe ribavirin-associated hyperuricemia and acute kidney injury: An underrecognized adverse effect

Disclaimer

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Purpose

To report a case of ribavirin-associated severe hyperuricemia in an immunocompromised patient treated for respiratory syncytial virus (RSV) infection.

Summary

A 21-year-old male with a past medical history of B-cell acute lymphoblastic leukemia was in full remission after allogenic bone marrow transplantation complicated with chronic graft-versus-host disease. He was hospitalized due to fever, malaise, and respiratory syndromes. A diagnosis of RSV upper respiratory tract infection complicated by secondary pneumonia was made, and oral ribavirin (600 mg in 3 divided doses daily) and intravenous levofloxacin (750 mg once daily) were initiated. On day 2 of the hospital admission, the patient’s uric acid levels had increased from a baseline of 4 to 6 mg/dL to values of 19.3 and 22.2 mg/dL after the fourth and fifth doses of ribavirin, respectively, and his serum creatinine steadily had increased from a baseline of 0.7 to 0.8 mg/dL to a value of 1.6 mg/dL. Ribavirin was discontinued after the sixth dose, and a single dose of intravenous rasburicase (7.5 mg) was administered. On day 3, the patient’s serum uric and creatinine concentrations had decreased to 4.7 mg/dL and 1.1 mg/dL, respectively. He continued to recover on antibiotics and was discharged with normal uric acid and serum creatinine levels.

Conclusion

We report a case of severe hyperuricemia and acute kidney injury that developed early after initiation of ribavirin for RSV infection and suspected bacterial pneumonia in an immunocompromised patient without hepatitis C, requiring ribavirin discontinuation and rasburicase administration. To our knowledge, this is the first reported case of severe hyperuricemia in a patient treated with ribavirin for RSV infection rather than chronic hepatitis C. Clinicians should be aware of the possibility of acute and severe hyperuricemia following ribavirin administration.

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.

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.

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.