Predicitve Value of FDG Uptake in the Remaining Adrenal Gland Following Adrenalectomy for Adrenocortical Cancer.

Following initial surgery, patients with adrenocortical carcinoma (ACC) are commonly treated with the adrenolytic substance mitotane in an adjuvant or therapeutic setting. Treatment responses, however, are variable. The objective of the study was to investigate a possible correlation between FDG-PET activity of the remaining adrenal gland and therapeutic response of mitotane treatment. This is a retrospective study enrolling patients from two German centers with operated ACC and minimal information on PET-CT scanning. Eighty-two ACC patients after adrenalectomy were included (66 treated with mitotane and 16 without medical therapy). FDG uptake of the contralateral adrenal gland, liver and mediastinum was analyzed from a total of 291 PET/CT scans (median 4 scans per patient) and correlated with clinical annotations including overall and recurrence free survival. The majority of patients (81%) displayed a temporary increase in adrenal FDG uptake within the first 18 months following surgery, which was not associated with a morphological correlate for potential malignancy. This increase was mainly present in patients treated with mitotane (51/61, 84%) but less frequent in the control group (4/7, 57%). No direct correlation with mitotane plasma levels were evident. Patients following R0 resection with high adrenal uptake showed a tendency towards better clinical outcome without reaching a significance value (HR 1.41; CI 0.42-4.75; p=0.059). FDG update of the contralateral adrenal gland may not be misinterpreted as sign of malignancy but might be rather associated with a trend towards better clinical outcome.

Adrenomedullary function, obesity and permissive influences of catecholamines on body mass in patients with chromaffin cell tumours.

BACKGROUND: Obesity-associated activation of sympathetic nervous outflow is well documented, whereas involvement of dysregulated adrenomedullary hormonal function in obesity is less clear. This study assessed relationships of sympathoadrenal function with indices of obesity and influences of circulating catecholamines on body mass. METHODS: Anthropometric and clinical data along with plasma and 24-h urine samples were collected from 590 volunteers and 1368 patients tested for phaeochromocytoma and paraganglioma (PPGL), among whom tumours were diagnosed in 210 individuals. RESULTS: Among patients tested for PPGL, those with tumours less often had a body mass index (BMI) above 30 kg/m2 (12 vs. 31%) and more often a BMI under 25 kg/m2 (56 vs. 32%) than those without tumours (P < 0.0001). Urinary outputs of catecholamines in patients with PPGL were negatively related to BMI (r = -0.175, P = 0.0133). Post-operative weight gain (P < 0.0001) after resection of PPGL was positively related to presurgical tumoural catecholamine output (r = 0.257, P = 0.0101). Higher BMI in men and women and percent body fat in women of the volunteer group were associated with lower plasma concentrations and urinary outputs of adrenaline and metanephrine, the former indicating obesity-related reduced adrenaline secretion and the latter obesity-related reduced adrenomedullary adrenaline stores. Daytime activity was associated with substantial increases in urinary adrenaline and noradrenaline excretion, with blunted responses in obese subjects. CONCLUSIONS: The findings in patients with PPGL support an influence of high circulating catecholamines on body weight. Additional associations of adrenomedullary dysfunction with obesity raise the possibility of a permissive influence of the adrenal medulla on the regulation of body weight.

Missed clinical clues in patients with pheochromocytoma/paraganglioma discovered by imaging.

CONTEXT: Pheochromocytomas and paragangliomas (PPGLs) are rare but potentially harmful tumors that can vary in their clinical presentation. Tumors may be found due to signs and symptoms, as part of a hereditary syndrome or following an imaging procedure. OBJECTIVE: To investigate potential differences in clinical presentation between PPGLs discovered by imaging (iPPGLs), symptomatic cases (sPPGLs) and those diagnosed during follow-up because of earlier disease/known hereditary mutations (fPPGL). DESIGN: Prospective study protocol, which has enrolled patients from 6 European centers with confirmed PPGLs. SETTING AND PATIENTS: Data were analyzed from 235 patients (37% iPPGLs, 36% sPPGLs, 27% fPPGLs) and compared for tumor volume, biochemical profile, mutation status, presence of metastases and self-reported symptoms. RESULTS: iPPGL patients were diagnosed at a significantly higher age than fPPGLs (p<0.001), found to have larger tumors (p=0.003) and higher metanephrine and normetanephrine levels at diagnosis (p=0.021). Significantly lower than in sPPGL, there was a relevant number of self-reported symptoms in iPPGL (2.9 vs. 4.3 symptoms, p<0.001). In 16.2% of iPPGL, mutations in susceptibility genes were detected, although this proportion was lower than in fPPGL (60.9%) and sPPGL (21.5%). CONCLUSIONS: Patients with PPGLs detected by imaging were older, have higher tumor volume and more excessive hormonal secretion in comparison to those found as part of a surveillance program. Presence of typical symptoms indicates that in a relevant proportion of those patients the PPGL diagnosis had been delayed. Précis: Pheochromocytoma/paraganglioma discovered by imaging are often symptomatic and carry a significant proportion of germline mutations in susceptibility genes.

Biochemical Diagnosis of Chromaffin Cell Tumors in Patients at High and Low Risk of Disease: Plasma versus Urinary Free or Deconjugated O-Methylated Catecholamine Metabolites.

BACKGROUND: Measurements of plasma or urinary metanephrines are recommended for diagnosis of pheochromocytoma and paraganglioma (PPGL). What test offers optimal diagnostic accuracy for patients at high and low risk of disease, whether urinary free metanephrines offer advantages over deconjugated metanephrines, and what advantages are offered by including methoxytyramine in panels all remain unclear. METHODS: A population of 2056 patients with suspected PPGLs underwent prospective screening for disease using mass spectrometric-based measurements of plasma free, urinary deconjugated, and urinary free metanephrines and methoxytyramine. PPGLs were confirmed in 236 patients and were excluded in others on follow-up evaluation. RESULTS: Measurements of plasma free metabolites offered higher (P < 0.01) diagnostic sensitivity (97.9%) than urinary free (93.4%) and deconjugated (92.9%) metabolites at identical specificities for plasma and urinary free metabolites (94.2%) but at a lower (P < 0.005) specificity for deconjugated metabolites (92.1%). The addition of methoxytyramine offered little value for urinary panels but provided higher (P < 0.005) diagnostic performance for plasma measurements than either urinary panel according to areas under ROC curves (0.991 vs 0.972 and 0.964). Diagnostic performance of urinary and plasma tests was similar for patients at low risk of disease, whereas plasma measurements were superior to both urinary panels for high-risk patients. CONCLUSIONS: Diagnosis of PPGLs using plasma or urinary free metabolites provides advantages of fewer false-positive results compared with commonly measured deconjugated metabolites. The plasma panel offers better diagnostic performance than either urinary panel for patients at high risk of disease and, with appropriate preanalytics, provides the test of choice. Measurements of methoxytyramine in urine show limited diagnostic utility compared with plasma.

Assessment of VAV2 Expression Refines Prognostic Prediction in Adrenocortical Carcinoma.

Context: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with overall poor prognosis. The Ki67 labeling index (LI) has a major prognostic role in localized ACC after complete resection, but its estimates may suffer from considerable intra- and interobserver variability. VAV2 overexpression induced by increased Steroidogenic Factor-1 dosage is an essential factor driving ACC tumor cell invasion. Objective: To assess the prognostic role of VAV2 expression in ACC by investigation of a large cohort of patients. Design, Setting, and Participants: A total of 171 ACC cases (157 primary tumors, six local recurrences, eight metastases) from seven European Network for the Study of Adrenal Tumors centers were studied. Outcome Measurements: H-scores were generated to quantify VAV2 expression. VAV2 expression was divided into two categories: low (H-score, <2) and high (H-score, ≥2). The Ki67 LI retrieved from patients' pathology records was also categorized into low (<20%) and high (≥20%). Clinical and immunohistochemical markers were correlated with progression-free survival (PFS) and overall survival (OS). Results: VAV2 expression and Ki67 LI were significantly correlated with each other and with PFS and OS. Heterogeneity of VAV2 expression inside the same tumor was very low. Combined assessment of VAV2 expression and Ki67 LI improved patient stratification to low-risk and high-risk groups. Conclusion: Combined assessment of Ki67 LI and VAV2 expression improves prognostic prediction in ACC.

PheoSeq: A Targeted Next-Generation Sequencing Assay for Pheochromocytoma and Paraganglioma Diagnostics.

Genetic diagnosis is recommended for all pheochromocytoma and paraganglioma (PPGL) cases, as driver mutations are identified in approximately 80% of the cases. As the list of related genes expands, genetic diagnosis becomes more time-consuming, and targeted next-generation sequencing (NGS) has emerged as a cost-effective tool. This study aimed to optimize targeted NGS in PPGL genetic diagnostics. A workflow based on two customized targeted NGS assays was validated to study the 18 main PPGL genes in germline and frozen tumor DNA, with one of them specifically directed toward formalin-fixed paraffin-embedded tissue. The series involved 453 unrelated PPGL patients, of whom 30 had known mutations and were used as controls. Partial screening using Sanger had been performed in 275 patients. NGS results were complemented with the study of gross deletions. NGS assay showed a sensitivity ≥99.4%, regardless of DNA source. We identified 45 variants of unknown significance and 89 pathogenic mutations, the latter being germline in 29 (7.2%) and somatic in 58 (31.7%) of the 183 tumors studied. In 37 patients previously studied by Sanger sequencing, the causal mutation could be identified. We demonstrated that both assays are an efficient and accurate alternative to conventional sequencing. Their application facilitates the study of minor PPGL genes, and enables genetic diagnoses in patients with incongruent or missing clinical data, who would otherwise be missed.

Towards absolute quantification of therapeutic monoclonal antibody in serum by LC-MS/MS using isotope-labeled antibody standard and protein cleavage isotope dilution mass spectrometry.

Although LC-MS methods are increasingly used for the absolute quantification of proteins, the lack of appropriate internal standard (IS) hinders the development of rapid and standardized analytical methods for both in vitro and in vivo studies. Here, we have developed a novel method for the absolute quantification of a therapeutic protein, which is monoclonal antibody (mAb). The method combines liquid chromatography tandem mass spectrometry (LC-MS/MS) and protein cleavage isotope dilution mass spectrometry with the isotope-labeled mAb as IS. The latter was identical to the analyzed mAb with the exception that each threonine contains four (13)C atoms and one (15)N atom. Serum samples were spiked with IS prior to the overnight trypsin digestion and subsequent sample cleanup. Sample extracts were analyzed on a C18 ACE column (150 mm x 4.6 mm) using an LC gradient time of 11 min. Endogenous mAb concentrations were determined by calculating the peak height ratio of its signature peptide to the corresponding isotope-labeled peptide. The linear dynamic range was established between 5.00 and 1000 microg/mL mAb with accuracy and precision within +/-15% at all concentrations and below +/-20% at the LLOQ (lower limit of quantification). The overall method recovery in terms of mAb was 14%. The losses due to sample preparation (digestion and purification) were 72% from which about 32% was due to the first step of the method, the sample digestion. This huge loss during sample preparation strongly emphasizes the necessity to employ an IS right from the beginning. Our method was successfully applied to the mAb quantification in marmoset serum study samples, and the precision obtained on duplicate samples was, in most cases, below 20%. The comparison with enzyme-linked immunosorbent assay (ELISA) showed higher exposure in terms of AUC and Cmax with the LC-MS/MS method. Possible reasons for this discrepancy are discussed in this study. The results of this study indicate that our LC-MS/MS method is a simple, rapid, and precise approach for the therapeutic mAb quantification to support preclinical and clinical studies.

Dysregulation of innate immune receptors on neutrophils in chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is the most common inherited disorder of neutrophil function, is caused by mutations in the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and results in recurrent bacterial infections. OBJECTIVE: We sought to investigate the expression and function of innate immune receptors on neutrophils in patients with CGD. METHODS: We quantified mRNA and protein expression of Toll-like receptors (TLRs), complement receptors, and chemokine receptors on neutrophils from 15 patients with CGD compared with that seen in healthy control subjects (n = 15) and control patients with bacterial pneumonia (n = 15). Phagocytosis, chemotaxis, and TLR function of isolated neutrophils were analyzed. The effect of NADPH oxidase inhibition on receptor expression and function was analyzed in control neutrophils. RESULTS: Neutrophils from patients with CGD had lower expression levels of TLR5, TLR9, CD11b, CD18, CD35, and CXCR1 compared with those from healthy control subjects, whereas similar or increased receptor expressions were found in patients without CGD but with bacterial pneumonia. Reduced TLR5 expression resulted in impaired neutrophil activation by bacterial flagella, reduced CD11b/CD18 expression was associated with impaired phagocytosis of Staphylococcus aureus, and reduced CXCR1 expression was associated with decreased chemotaxis. TLR5 and CD18 expression levels correlated with disease severity in patients with CGD. TLR5 and TLR9 expression were greater in patients with residual NADPH oxidase activity. Inhibition of the NADPH oxidase in control neutrophils in vitro decreased TLR5 and TLR9 expression and impaired TLR5 function. CONCLUSION: These results provide the first evidence that innate immune receptors are dysregulated in patients with CGD.

Experimental infection of Culex annulirostris, Culex gelidus, and Aedes vigilax with a yellow fever/Japanese encephalitis virus vaccine chimera (ChimeriVax-JE).

Australian mosquitoes from which Japanese encephalitis virus (JEV) has been recovered (Culex annulirostris, Culex gelidus, and Aedes vigilax) were assessed for their ability to be infected with the ChimeriVax-JE vaccine, with yellow fever vaccine virus 17D (YF 17D) from which the backbone of ChimeriVax-JE vaccine is derived and with JEV-Nakayama. None of the mosquitoes became infected after being fed orally with 6.1 log(10) plaque-forming units (PFU)/mL of ChimeriVax-JE vaccine, which is greater than the peak viremia in vaccinees (mean peak viremia = 4.8 PFU/mL, range = 0-30 PFU/mL of 0.9 days mean duration, range = 0-11 days). Some members of all three species of mosquito became infected when fed on JEV-Nakayama, but only Ae. vigilax was infected when fed on YF 17D. The results suggest that none of these three species of mosquito are likely to set up secondary cycles of transmission of ChimeriVax-JE in Australia after feeding on a viremic vaccinee.

SpeedScreen: The "missing link" between genomics and lead discovery.

SpeedScreen is a novel, label-free, in-solution, affinity-based selection methodology for high-throughput screening (HTS) developed at Novartis Pharma. The SpeedScreen protocol comprises in-solution affinity selection, followed by size exclusion chromatography in combination with microbore-liquid-chromatography/electrospray-ionization mass spectrometry (micro-LC/ESI-MS). The authors describe the basic concept behind assay development, HTS, and data analysis with the SpeedScreen technology. Advantages and limitations of SpeedScreen compared to alternative screening technologies are discussed, and an example is given from a SpeedScreen campaign applying this innovative affinity selection concept in HTS.