Comprehensive characterization and resolution of discrepant spectrophotometric bilirubin results in patients on eltrombopag therapy.

Background Eltrombopag is a thrombopoietin receptor agonist used for the treatment of thrombocytopenic conditions. It can cause pH-dependent discoloration of plasma/serum. Eltrombopag is potentially hepatotoxic. It can affect the assessment of hyperbilirubinemia because of its (i) absorbance at ~450 nm (bilirubin), (ii) absorbance at ~550 nm (diazo-bilirubin) and (iii) it can cause yellowish discoloration of the eyes at normal circulating bilirubin levels. Methods We collected 66 samples from patients on a range of eltrombopag dosages up to 150 mg daily. Bilirubin was measured using multiple routine spectrophotometric analyzers, the Doumas reference method and high-performance liquid chromatography (HPLC). Plasma/serum eltrombopag concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spike-in and admixture experiments delineated the effects of eltrombopag and its metabolites. Results Forty-nine of 52 samples from patients on ≥50 mg daily eltrombopag therapy showed significantly discrepant inter-analyzer total bilirubin results, a difference up to 64 µmol/L (3.7 mg/dL). In one sample, total bilirubin varied from 8 to 65 µmol/L (0.4-3.8 mg/dL) by different routine analyzers, with direct bilirubin ≤4 µmol/L (0.2 mg/dL). There was a positive correlation between total bilirubin difference and plasma eltrombopag concentration (r = 0.679), and spike-in experiments demonstrated that Beckman AU and Doumas reference methods were susceptible to positive interference. HPLC can quantify bilirubin after separating eltrombopag, and results suggest different analyzers are affected to varying degrees by eltrombopag and its metabolites. Conclusions Eltrombopag and its metabolites can cause positive interference to the spectrophotometric measurements of total bilirubin. Accurate measurements of total bilirubin may improve our understanding of the prevalence of hyperbilirubinemia in patients on eltrombopag therapy.

Early detection of nasopharyngeal carcinoma by plasma Epstein-Barr virus DNA analysis in a surveillance program.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is prevalent in Southeast Asia. Over the last decade, plasma Epstein-Barr virus (EBV) DNA has been developed as a tumor marker for NPC. In this study, the authors investigated whether plasma EBV DNA analysis is useful for NPC surveillance. METHODS: In total, 1318 volunteers ages 40 to 60 years were prospectively recruited. Plasma EBV DNA and serology for viral capsid antigen immunoglobulin A (IgA) were measured. Participants who had detectable plasma EBV DNA or positive IgA serology underwent nasal endoscopic examination and a follow-up plasma EBV DNA analysis in approximately 2 weeks. All participants were followed for 2 years to record the development of NPC. RESULTS: Three individuals with NPC were identified at enrolment. All of them were positive for EBV DNA and remained positive in follow-up analysis. Only 1 of those patients was positive for EBV serology. In 1 patient who had NPC with a small tumor confined to the mucosa, the tumor was not detectable on endoscopic examination. Because of a 2-fold increase in plasma EBV DNA on the follow-up analysis, that patient underwent magnetic resonance imaging, which revealed the tumor. Among the participants who did not have NPC but had initially positive plasma EBV DNA results, approximately 66% had negative EBV DNA results after a median of 2 weeks. CONCLUSIONS: Plasma EBV DNA analysis proved useful for detecting early NPC in individuals without a clinical suspicion of NPC. Repeating the test in those who had initially positive results differentiated those with NPC from those who had false-positive results. Cancer 2013. © 2013 American Cancer Society.

Continuous Glucose Monitoring Metrics in the Assessment of Glycemia in Moderate-to-Advanced CKD in Diabetes.

Introduction: Glycated hemoglobin A1c (HbA1c) has reduced reliability in advanced chronic kidney disease (CKD) owing to factors influencing red cell turnover. Recent guidelines support the use of continuous glucose monitoring (CGM) in glycemic assessment in these patients. We evaluated relationships between HbA1c and CGM metrics of average glycemia and glucose variability (GV) in moderate-to-advanced CKD. Methods: There were a total of 90 patients with diabetes in CKD stages G3b (n = 33), G4 (n = 43), and G5 (nondialysis) (n = 14) (age [mean ± SD] 65.4 ± 9.0 years, estimated glomerular filtration rate [eGFR] 26.1 ± 9.6 ml/min per 1.73 m2, and HbA1c 7.4 ± 0.8%). CGM metrics were estimated from blinded CGM (Medtronic Ipro2 with Enlite sensor) and compared with HbA1c in the same week. Results: Correlations between glucose management indicator (GMI) and HbA1c attenuated with advancing CKD (G3b [r = 0.68, P < 0.0001], G4 [r = 0.52, P < 0.001], G5 [r = 0.22, P = 0.44], P = 0.01 for CKD stage). In G3b and G4, HbA1c correlated significantly with time-in-range (TIR) (3.9-10.0 mmol/l) (r = -0.55 and r = -0.54, respectively) and % time > 13.9 mmol/l (r = 0.53 and r = 0.44, respectively), but not in G5. HbA1c showed no correlation with % time <3.0 mmol/l (r = -0.045, P = 0.67) or % coefficient of variation (CV) (r = -0.05, P = 0.64) in any CKD stage. Only eGFR was a significant determinant of bias for the difference between GMI and HbA1c (difference -0.28%, 95% CI [-0.52 to -0.03] per 15 ml/min per 1.73 m2 decrement, P = 0.03). Conclusion: CGM-derived indices might serve as an adjunct to HbA1c monitoring to guide glycemic management, especially in those with eGFR <30 ml/min per 1.73 m2. Time in hypoglycemia and glycemic variability are relevant glycemic targets for optimization not reflected by HbA1c.

Hyperandrogenism, Elevated 17-Hydroxyprogesterone and Its Urinary Metabolites in a Young Woman with Ovarian Steroid Cell Tumor, Not Otherwise Specified: Case Report and Review of the Literature.

We describe a case of a 24-year-old overweight woman who presented with hirsutism, secondary amenorrhea, clitoromegaly, and symptoms of diabetes mellitus (DM). While a diagnosis of polycystic ovary syndrome (PCOS) with its associated metabolic disturbances was initially considered, serum total testosterone, androstenedione, and 17-hydroxyprogesterone (17-OHP) measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) were significantly increased. As 17-OHP did not increase upon ACTH (Synacthen) stimulation and the urinary steroid profile (USP) was compatible with an ovarian source of 17-OHP excess rather than adrenal, non classical congenital adrenal hyperplasia (NCCAH) was unlikely and an androgen-secreting tumor was suspected. Transabdominal ultrasound revealed the presence of an enlarged right ovary with a polycystic ovary morphology and no discrete mass. Transvaginal ultrasound and [18F]- fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) enabled the localization of a right ovarian tumor. Laparoscopic right salpingo-oophorectomy was performed and a histological diagnosis of steroid cell tumor, not otherwise specified (SCT-NOS) was made. Hyperandrogenism and menstrual disturbances resolved postoperatively. A literature review revealed that 17-OHP-secreting SCT-NOS may uncommonly show positive responses to ACTH stimulation similar to 21-hydroxylase deficiency. Alternatively, USP might be useful in localizing the source of 17-OHP to the ovaries. Its diagnostic performance should be evaluated in further studies.

Recurrent heat-related illnesses during antipsychotic treatment.

OBJECTIVE: To report a case of recurrent heat-related illnesses associated with the use of benzhexol, chlorpromazine, and zuclopenthixol decanoate. CASE SUMMARY: During the summer of 2004, a 48-year-old man with a history of diabetes mellitus and schizophrenia was twice admitted to the hospital because of heat-related illnesses. On both occasions, he had been working under the sun in an open car park. His medications included benzhexol 2 mg twice daily, chlorpromazine 650 mg at bedtime, and zuclopenthixol decanoate intramuscular injection 600 mg every 4 weeks. In the first admission, the clinical diagnosis was heat stroke. He was discharged home on day 14, with precautionary advice against heat stroke. In the second admission, the clinical diagnosis was heat exhaustion. He was discharged home on day 4 and reminded of the precautions against heat stroke. An objective causality assessment revealed that the adverse event was possibly drug related in the first admission and probably drug related in the second admission. DISCUSSION: Several drugs can impair thermoregulation during exercise or under conditions of environmental heat stress. Anticholinergic drugs or drugs with anticholinergic effects can inhibit sweating and reduce heat elimination. Neuroleptics (antipsychotics), such as phenothiazines, have combined anticholinergic and central thermoregulatory effects. The set point of the temperature regulation center can be elevated by the antidopaminergic effect of antipsychotics, such as phenothiazines and thioxanthenes. CONCLUSIONS: Certain drugs may induce or worsen heat-related illnesses. During a heat wave, special attention should be given to those most at risk, and the importance of preventive measures should be emphasized.