Search Results

You are looking at 1 - 6 of 6 items for

  • Author: Andrzej Januszewicz x
Clear All Modify Search
Free access

Dirk Weismann, Mirko Peitzsch, Anna Raida, Aleksander Prejbisz, Maria Gosk, Anna Riester, Holger S Willenberg, Reiner Klemm, Georg Manz, Timo Deutschbein, Matthias Kroiss, Roland Därr, Martin Bidlingmaier, Andrzej Januszewicz, Graeme Eisenhofer and Martin Fassnacht

Background

Reports conflict concerning measurements of plasma metanephrines (MNs) for diagnosis of pheochromocytomas/paragangliomas (PPGLs) by immunoassays compared with other methods. We aimed to compare the performance of a commercially available enzyme-linked immunoassay (EIA) kit with liquid chromatography–tandem mass spectrometric (LC–MS/MS) measurements of MNs to diagnose PPGLs.

Methods

In a substudy of a prospective, multicenter trial to study the biochemical profiles of monoamine-producing tumors, we included 341 patients (174 males and 167 females) with suspected PPGLs (median age 54 years), of whom 54 had confirmed PPGLs. Plasma MNs were measured by EIA and LC–MS/MS, each in a specialized laboratory.

Results

Plasma normetanephrine (NMN) and MN were measured 60 and 39% lower by EIA than by LC–MS/MS. Using upper cut-offs stipulated for the EIA, diagnostic sensitivity was only 74.1% at a specificity of 99.3%. In contrast, use of similar cut-offs for MN and overall lower age-adjusted cut-offs for NMN measured by LC–MS/MS returned a diagnostic sensitivity and specificity of 98.1 and 99.7%. Areas under receiver-operating characteristic curves, nevertheless, indicated comparable diagnostic performance of the EIA (0.993) and LC–MS/MS (0.985). Diagnostic sensitivity for the EIA increased to 96.2% with a minimal loss in specificity (95.1%) following use of cut-offs for the EIA adapted to correct for the negative bias.

Conclusions

The EIA underestimates plasma MNs and diagnostic sensitivity is poor using commonly stipulated cut-offs, resulting in a high risk for missing patients with PPGLs. Correction of this shortcoming can be achieved by appropriately determined cut-offs resulting in comparable diagnostic performance of EIA and LC–MS/MS assays.

Free access

Laura Gieldon, Jimmy Rusdian Masjkur, Susan Richter, Roland Därr, Marcos Lahera, Daniela Aust, Silke Zeugner, Andreas Rump, Karl Hackmann, Andreas Tzschach, Andrzej Januszewicz, Aleksander Prejbisz, Graeme Eisenhofer, Evelin Schrock, Mercedes Robledo and Barbara Klink

Objective

Our objective was to improve molecular diagnostics in patients with hereditary pheochromocytoma and paraganglioma (PPGL) by using next-generation sequencing (NGS) multi-gene panel analysis. Derived from this study, we here present three cases that were diagnosed with NF1 germline mutations but did not have a prior clinical diagnosis of neurofibromatosis type 1 (NF1).

Design

We performed genetic analysis of known tumor predisposition genes, including NF1, using a multi-gene NGS enrichment-based panel applied to a total of 1029 PPGL patients. We did not exclude genes known to cause clinically defined syndromes such as NF1 based on missing phenotypic expression as is commonly practiced.

Methods

Genetic analysis was performed using NGS (TruSight Cancer Panel/customized panel by Illumina) for analyzing patients’ blood and tumor samples. Validation was carried out by Sanger sequencing.

Results

Within our cohort, three patients, who were identified to carry pathogenic NF1 germline mutations, attracted attention, since none of the patients had a clinical suspicion of NF1 and one of them was initially suspected to have MEN2A syndrome due to co-occurrence of a medullary thyroid carcinoma. In these cases, one splice site, one stop and one frameshift mutation in NF1 were identified.

Conclusions

Since phenotypical presentation of NF1 is highly variable, we suggest analysis of the NF1 gene also in PPGL patients who do not meet diagnostic NF1 criteria. Co-occurrence of medullary thyroid carcinoma and PPGL was found to be a clinical decoy in NF1 diagnostics. These observations underline the value of multi-gene panel NGS for PPGL patients.

Free access

Daniel A Heinrich, Christian Adolf, Lars C Rump, Ivo Quack, Marcus Quinkler, Stefanie Hahner, Andrzej Januszewicz, Jochen Seufert, Holger S Willenberg, Nina Nirschl, Lisa Sturm, Felix Beuschlein and Martin Reincke

Objective

Primary aldosteronism (PA) is the most common endocrine form of arterial hypertension. The German Conn’s Registry’s purpose is to improve treatment outcomes of PA. We assessed whether key clinical, biochemical and epidemiological characteristics of newly diagnosed PA cases have changed over time, potentially indicating a different screening and referral practice in Germany evolving from 2008 to 2016.

Design

The German Conn’s Registry is a multicenter database prospectively analyzing morbidity and long-term outcome of patients with PA.

Methods

Phenotypic changes between three year periods were calculated using Mann–Whitney U tests and Kruskal–Wallis tests for independent variables.

Results

Over three time periods from 2008 to 2016, we noted a relative decrease of unilateral PA cases (67 vs 43%). Significantly more females were diagnosed with PA (33 vs 43%). Median daily defined drug doses decreased (3.1 vs 2.0) in the presence of unchanged SBP (150 vs 150 mmHg), plasma aldosterone (199 vs 173 ng/L) and PRC (3.2 vs 3.2 U/L). Median ARR values decreased (70 vs 47 ng/U) and median potassium levels at diagnosis (3.5 vs 3.7 mmol/L) increased as the percentage of normokalemic patients (25 vs 41%), indicating milder forms of PA.

Conclusions

Our results are in accordance with an increased screening intensity for PA. We identified a trend toward diagnosing milder forms, increasingly more females and less unilateral cases of PA.

Open access

Dipti Rao, Mirko Peitzsch, Aleksander Prejbisz, Katarzyna Hanus, Martin Fassnacht, Felix Beuschlein, Christina Brugger, Stephanie Fliedner, Katharina Langton, Christina Pamporaki, Volker Gudziol, Anthony Stell, Andrzej Januszewicz, Henri J L M Timmers, Jacques W M Lenders and Graeme Eisenhofer

Context

Measurements of plasma methoxytyramine, the O-methylated dopamine metabolite, are useful for detecting rare dopamine-producing pheochromocytomas and paragangliomas (PPGLs) and head and neck paragangliomas (HNPGLs), but utility for screening beyond that achieved using standard measurements of normetanephrine and metanephrine is unclear.

Objective

Evaluation of the additional utility of methoxytyramine compared to plasma normetanephrine and metanephrine for diagnosis of PPGLs and HNPGLs.

Design

Comparative prospective study.

Methods

Comparison of mass spectrometric-based measurements of plasma methoxytyramine, normetanephrine and metanephrine in 1963 patients tested for PPGLs at six tertiary medical centers according to reference intervals verified in 423 normotensive and hypertensive volunteers.

Results

Of the screened patients, 213 had PPGLs and 38 HNPGLs. Using an upper cut-off of 0.10 nmol/L for methoxytyramine, 0.45 nmol/L for metanephrine and age-specific upper cut-offs for normetanephrine, diagnostic sensitivity with the addition of methoxytyramine increased from 97.2% to 98.6% for patients with PPGLs and from 22.1% to 50.0% for patients with HNPGLs, with a small decrease in specificity from 95.9% to 95.1%. Addition of methoxytyramine did not significantly alter areas under receiver operating characteristic curves for patients with PPGLs (0.984 vs 0.991), but did increase (P < 0.05) areas for patients with HNPGLs (0.627 vs 0.801). Addition of methoxytyramine also increased the proportion of patients with PPGLs who showed highly positive predictive elevations of multiple metabolites (70.9% vs 49.3%).

Conclusions

While the benefit of additional measurements of plasma methoxytyramine for the detection of PPGLs is modest, the measurements do assist with positive confirmation of disease and are useful for the detection of HNPGLs.

Restricted access

Aikaterini Geroula, Timo Deutschbein, Katharina Langton, Jimmy Masjkur, Christina Pamporaki, Mirko Peitzsch, Stephanie Fliedner, Henri J L M Timmers, Stefan R Bornstein, Felix Beuschlein, Anthony Stell, Andrzej Januszewicz, Aleksander Prejbisz, Martin Fassnacht, Jacques W M Lenders and Graeme Eisenhofer

Objective

Hypertension and symptoms of catecholamine excess are features of pheochromocytomas and paragangliomas (PPGLs). This prospective observational cohort study assessed whether differences in presenting features in patients tested for PPGLs might assist establishing likelihood of disease.

Design and methods

Patients were tested for PPGLs because of signs and symptoms, an incidental mass on imaging or routine surveillance due to previous history or hereditary risk. Patients with (n = 245) compared to without (n = 1820) PPGLs were identified on follow-up. Differences in presenting features were then examined to assess the probability of disease and relationships to catecholamine excess.

Results

Hyperhidrosis, palpitations, pallor, tremor and nausea were 30–90% more prevalent (P < 0.001) among patients with than without PPGLs, whereas headache, flushing and other symptoms showed little or no differences. Although heart rates were higher (P < 0.0001) in patients with than without PPGLs, blood pressures were not higher and were positively correlated to BMI, which was lower (P < 0.0001) in patients with than without PPGLs. From these differences in clinical features, a score system was established that indicated a 5.8-fold higher probability of PPGLs in patients with high than low scores. Higher scores among patients with PPGLs were associated, independently of tumor size, with higher biochemical indices of catecholamine excess.

Conclusions

This study identifies a complex of five signs and symptoms combined with lower BMI and elevated heart rate as key features in patients with PPGLs. Prevalences of these features, which reflect variable tumoral catecholamine production, may be used to triage patients according to likelihood of disease.

Restricted access

Zoran Erlic, Max Kurlbaum, Timo Deutschbein, Svenja Nölting, Aleksander Prejbisz, Henri Timmers, Susan Richter, Cornelia Prehn, Dirk Weismann, Jerzy Adamski, Andrzej Januszewicz, Martin Reincke, Martin Fassnacht, Mercedes Robledo, Graeme Eisenhofer, Felix Beuschlein and Matthias Kroiss

Objective

Excess catecholamine release by pheochromocytomas and paragangliomas (PPGL) leads to characteristic clinical features and increased morbidity and mortality. The influence of PPGLs on metabolism is ill described but may impact diagnosis and management. The objective of this study was to systematically and quantitatively study PPGL-induced metabolic changes at a systems level.

Design

Targeted metabolomics by liquid chromatography-tandem mass spectrometry of plasma specimens in a clinically well-characterized prospective cohort study.

Methods

Analyses of metabolic profiles of plasma specimens from 56 prospectively enrolled and clinically well-characterized patients (23 males, 33 females) with catecholamine-producing PPGL before and after surgery, as well as measurement of 24-h urinary catecholamine using LC-MS/MS.

Results

From 127 analyzed metabolites, 15 were identified with significant changes before and after surgery: five amino acids/biogenic amines (creatinine, histidine, ornithine, sarcosine, tyrosine) and one glycerophospholipid (PCaeC34:2) with increased concentrations and six glycerophospholipids (PCaaC38:1, PCaaC42:0, PCaeC40:2, PCaeC42:5, PCaeC44:5, PCaeC44:6), two sphingomyelins (SMC24:1, SMC26:1) and hexose with decreased levels after surgery. Patients with a noradrenergic tumor phenotype had more pronounced alterations compared to those with an adrenergic tumor phenotype. Weak, but significant correlations for 8 of these 15 metabolites with total urine catecholamine levels were identified.

Conclusions

This first large prospective metabolomics analysis of PPGL patients demonstrates broad metabolic consequences of catecholamine excess. Robust impact on lipid and amino acid metabolism may contribute to increased morbidity of PPGL patients.