ObjectivesThe aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population.Design and methodsRetrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR).ResultsRetrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6%) exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5%) exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1%) of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods.ConclusionsVanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations.

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Retroperitoneal fibrosis (RPF) is a very rare disease that is even more rare in the pediatric population. Even less common are idiopathic pediatric cases of retroperitoneal fibrosis, with a majority of reported pediatric retroperitoneal fibrosis cases being associated with secondary etiologies. We present an 11-year-old Caucasian female that was diagnosed with idiopathic retroperitoneal fibrosis using magnetic resonance imaging (MRI) to work-up severe bilateral hydronephrosis that was identified with retroperitoneal ultrasound. Given the uncommon nature of this serious condition, we present this case to illustrate the importance for physicians to include retroperitoneal fibrosis in the differential diagnosis of a pediatric patient presenting with obstructive urinary findings and understand the utility of using MRI to diagnosis and monitor this disease.

While urothelial carcinoma is the most common histologic type of bladder cancer in the United States, leiomyosarcoma is a rare and aggressive variant. The rarity of bladder leiomyosarcoma results in uncertainty regarding the optimal treatment pathway. We report on a patient with a giant non-metastatic bladder leiomyosarcoma effectively managed with primary surgical intervention without chemoradiation.

2552 Background: Identification of tumor characteristics that may be associated with survival in patients with glioblastoma (GBM) has been largely characterized by IDH mutations and MGMT promoter methylation status. However, these genetic changes and other currently available data are not sufficient to explain the longevity experienced by a subset of long-term survivors (LTS) - patients surviving longer than 3 years past diagnosis. Methods: The study identified GBM patients established and treated at University of Iowa Holden Comprehensive Cancer Center from 2007-2017 whose disease recurred after initial resection. Patients were categorized LTS if they survived > = 3 years beyond initial definitive resection; short-term survivors (STS) if less than 3 years. Pathologic specimens at initial and repeat resection underwent genome wide methylation analysis using the Infinium EPIC microarray system. Data were analyzed to identify genes that exhibited differentially methylated CpG regions. Results: Resection specimens from GBM survivors were compared to those of STS. A total of 29 samples were analyzed and compared (15 LTS and 14 STS samples). Multidimensional scaling plots identified significant differences in genomic constitution between LTS and STS specimens. Granular analysis yielded 89 differentially methylated regions significantly associated with long-term survival (adjusted p < 0.05). PTPRN2 (p = 0.000376), PTPN11 (p = 1.38E-05), and PAX6 (p = 0.000671) were found to exhibit numerous differentially methylated CpG sites between MGMT-methylated vs. unmethylated specimens. Further notable, higher levels of differentially methylated CpG shores and open-seas regions on chromosome 12 were associated with long-term survival (p = 1.89E-08). Conclusions: Our study identified multiple significant epigenetic differences that, functionally or consequentially, may be associated with extended survival in GBM patients. The implication that CpG shores, rather than islands, are associated with long-term survival raises further intriguing questions regarding the depth of epigenetic complexity in this disease. More immediately, the surprising association of multiple protein phosphatases with LTS in our study may hint at the class’ previously unspecified, yet integral, role in delaying disease progression and identify new, novel avenues for therapy.