Hyperuricemia and acute kidney injury secondary to spontaneous tumor lysis syndrome in low risk myelodysplastic syndrome

Drug screening in human physiologic medium identifies uric acid as an inhibitor of rigosertib efficacy

The nonphysiological nutrient levels found in traditional culture media have been shown to affect numerous aspects of cancer cell physiology, including how cells respond to certain therapeutic agents. Here, we comprehensively evaluated how physiological nutrient levels affect therapeutic response by performing drug screening in human plasma-like medium. We observed dramatic nutrient-dependent changes in sensitivity to a variety of FDA-approved and clinically trialed compounds, including rigosertib, an experimental cancer therapeutic that recently failed in phase III clinical trials. Mechanistically, we found that the ability of rigosertib to destabilize microtubules is strongly inhibited by the purine metabolism end product uric acid, which is uniquely abundant in humans relative to traditional in vitro and in vivo cancer models. These results demonstrate the broad and dramatic effects nutrient levels can have on drug response and how incorporation of human-specific physiological nutrient medium might help identify compounds whose efficacy could be influenced in humans.

Drug screening in human physiologic medium identifies uric acid as an inhibitor of rigosertib efficacy

The non-physiological nutrient levels found in traditional culture media have been shown to affect numerous aspects of cancer cell physiology, including how cells respond to certain therapeutic agents. Here, we comprehensively evaluated how physiological nutrient levels impact therapeutic response by performing drug screening in human plasma-like medium (HPLM). We observed dramatic nutrient-dependent changes in sensitivity to a variety of FDA-approved and clinically trialed compounds, including rigosertib, an experimental cancer therapeutic that has recently failed in phase 3 clinical trials. Mechanistically, we found that the ability of rigosertib to destabilize microtubules is strongly inhibited by the purine metabolism waste product uric acid, which is uniquely abundant in humans relative to traditional in vitro and in vivo cancer models. Structural modelling studies suggest that uric acid interacts with the tubulin-rigosertib complex and may act as an uncompetitive inhibitor of rigosertib. These results offer a possible explanation for the failure of rigosertib in clinical trials and demonstrate the utility of physiological media to achieve in vitro results that better represent human therapeutic responses.

Acute kidney injury with extreme hyperuricemia after antithymocyte globulin treatment in a kidney transplant recipient with underlying aplastic anemia: a case report

BACKGROUND

The occurrences of hyperuricemia and acute kidney injury after antithymocyte globulin treatment are unusual in kidney transplant recipients. Here, we report a unique case of acute kidney injury with extreme hyperuricemia after antithymocyte globulin treatment in a kidney transplant recipient with underlying aplastic anemia.

CASE PRESENTATION

A 40-year-old woman with aplastic anemia who received a kidney transplant 5 years 6 months before presented to our emergency department with complaints of oliguria, generalized edema, and general weakness 6 days after receiving antithymocyte globulin treatment for acute T-cell-mediated rejection. Urinalysis revealed 100 uric acid crystal particles. The blood chemistry test results showed rapid increases in serum creatinine (from 2.86 mg/dL to 5.58 mg/dL) and uric acid levels (from 10.2 mg/dL to 32.7 mg/dL), which suggested acute uric acid nephropathy. Tumor lysis syndrome was suspected to be the cause of the acute uric acid nephropathy; hence, the patient was reevaluated for aplastic anemia. Human leukocyte antigen-DR15 was positive, and flow cytometry revealed a low percentage of glycophosphatidyl inositol-deficient granulocytes (2.9%), which suggested paroxysmal nocturnal hemoglobinuria clones. These findings indicate that the previously diagnosed aplastic anemia had either originally been hypocellular myelodysplastic syndrome (MDS) or later transformed into hypocellular MDS, which is a type of bone marrow failure syndrome.

CONCLUSIONS

Clinicians should consider unexpected tumor lysis syndrome to be the cause of complications after antithymocyte globulin treatment in kidney transplant recipients with underlying bone marrow failure syndrome.

A Retrospective, Cross-Sectional Study on the Prevalence of Hyperuricemia Using a Japanese Healthcare Database

Objectives

This study aims to evaluate the prevalence of hyperuricemia (HU) considering both serum uric acid (SUA) levels and medication status of urate-lowering drugs (ULDs), and the association between HU and its comorbidities using a Japanese healthcare database.

Materials and methods

The study population consisted of 60,828 subjects who had at least one serum uric acid measurement between the fiscal years (FYs) 2010 and 2014 in a Japanese employment-based health insurance database (MinaCare Co., Ltd., Tokyo, Japan), which includes mutually linked medical/pharmaceutical claims data and health check-up data. Hyperuricemia was defined as a SUA level >7.0 mg/dL of the health check-up data and/or a prescription for a ULD. The association between HU and comorbidities were analyzed by comparing the prevalence of HU of each subgroup defined by presence or absence of comorbidity.

Results

The prevalence of HU in FY 2014 was 26.8% [95% confidence interval (CI): 26.2 to 27.3%] in male subjects and 0.9% (95% CI: 0.7 to 1.0%) in female subjects. According to the analyses by sex and age, a trend of increasing prevalence with age was observed in both males and females. The prevalence of HU remained stable both in males and females from FYs 2010 to 2014. The positive association between HU and well-known comorbidities were confirmed with the exception of diabetes mellitus and smoking status in male subjects.

Conclusion

Our results provided a more accurate prevalence of HU in Japanese population. It is important to increase the awareness on HU in the society to reduce the burden of HU-related diseases.

Rapidly Progressing Myelodysplastic Syndrome Initially Presenting as Acute Leukemia

Myelodysplastic syndrome (MDS) refers to a group of various stem cell disorders, characterized by dysplastic and ineffective production in one or more cell lines. In general, MDS tends to present slowly over months to years and is commonly detected with routine bloodwork by primary care physicians. Patients may be asymptomatic and depending on age, comorbidities and risk classification of MDS may not require aggressive therapy. However, MDS carries the risk of progressing to acute leukemia over time. We present a case of rapidly progressive MDS in a previously healthy middle-aged female, originally presenting and treated as acute leukemia.

Tumor Lysis-like Syndrome in Eosinophilic Disease of the Lung: A Case Report and Review of the Literature

Tumor lysis syndrome (TLS) is a metabolic disorder that is generally associated with a malignancy leading to hyperuricemia, hyperphosphatemia, and acute kidney injury. On the other hand, we sometimes encounter these phenomena in nonmalignant disease, which has been referred to as tumor lysis-like syndrome in some studies. We herein experienced a case in which tumor lysis-like syndrome occurred in the course of therapy for eosinophilic disease of the lung, a nonmalignant disease. Even in nonmalignant disease, massive cell lysis induced by therapy can cause phenomena such as TLS or tumor lysis-like syndrome.