Joanna Gawinecka

Circulating FABP4 Is a Prognostic Biomarker in Patients With Acute Coronary Syndrome but Not in Asymptomatic Individuals

Objective—Blood-borne biomarkers reflecting atherosclerotic plaque burden have great potential to improve clinical management of atherosclerotic coronary artery disease and acute coronary syndrome (ACS). Approach and Results—Using data integration from gene expression profiling of coronary thrombi versus peripheral blood mononuclear cells and proteomic analysis of atherosclerotic plaque–derived secretomes versus healthy tissue secretomes, we identified fatty acid–binding protein 4 (FABP4) as a biomarker candidate for coronary artery disease. Its diagnostic and prognostic performance was validated in 3 different clinical settings: (1) in a cross-sectional cohort of patients with stable coronary artery disease, ACS, and healthy individuals (n=820), (2) in a nested case–control cohort of patients with ACS with 30-day follow-up (n=200), and (3) in a population-based nested case–control cohort of asymptomatic individuals with 5-year follow-up (n=414). Circulating FABP4 was marginally higher in patients with ST-segment–elevation myocardial infarction (24.9 ng/mL) compared with controls (23.4 ng/mL; P=0.01). However, elevated FABP4 was associated with adverse secondary cerebrovascular or cardiovascular events during 30-day follow-up after index ACS, independent of age, sex, renal function, and body mass index (odds ratio, 1.7; 95% confidence interval, 1.1–2.5; P=0.02). Circulating FABP4 predicted adverse events with similar prognostic performance as the GRACE in-hospital risk score or N-terminal pro–brain natriuretic peptide. Finally, no significant difference between baseline FABP4 was found in asymptomatic individuals with or without coronary events during 5-year follow-up. Conclusions—Circulating FABP4 may prove useful as a prognostic biomarker in risk stratification of patients with ACS.

Antibody Phage Display Assisted Identification of Junction Plakoglobin as a Potential Biomarker for Atherosclerosis

To date, no plaque-derived blood biomarker is available to allow diagnosis, prognosis or monitoring of atherosclerotic vascular diseases. In this study, specimens of thrombendarterectomy material from carotid and iliac arteries were incubated in protein-free medium to obtain plaque and control secretomes for subsequent subtractive phage display. The selection of nine plaque secretome-specific antibodies and the analysis of their immunopurified antigens by mass spectrometry led to the identification of 22 proteins. One of them, junction plakoglobin (JUP-81) and its smaller isoforms (referred to as JUP-63, JUP-55 and JUP-30 by molecular weight) were confirmed by immunohistochemistry and immunoblotting with independent antibodies to be present in atherosclerotic plaques and their secretomes, coronary thrombi of patients with acute coronary syndrome (ACS) and macrophages differentiated from peripheral blood monocytes as well as macrophage-like cells differentiated from THP1 cells. Plasma of patients with stable coronary artery disease (CAD) (n = 15) and ACS (n = 11) contained JUP-81 at more than 2- and 14-fold higher median concentrations, respectively, than plasma of CAD-free individuals (n = 13). In conclusion, this proof of principle study identified and verified JUP isoforms as potential plasma biomarkers for atherosclerosis. Clinical validation studies are needed to determine its diagnostic efficacy and clinical utility as a biomarker for diagnosis, prognosis or monitoring of atherosclerotic vascular diseases.

Genotype, phenotype and disease severity reflected by serum LysoGb3 levels in patients with Fabry disease

BACKGROUND Fabry disease (FD) is a rare X-linked lysosomal storage disease caused by mutations in the α-galactosidase A (GLA) gene causing deficiency of α-galactosidase A which results in progressive glycosphingolipid accumulation, especially globotriaosylceramide (Gb3), in body liquids and lysosomes. In a large cohort of FD patients, we aimed to establish genotype/phenotype relations as indicated by serum LysoGb3 (deacylated Gb3). METHODS In 69 consecutive adult FD patients (males: n=28 (41%)) with a GLA-mutation confirmed diagnosis, we conducted a multidisciplinary clinical characterization during their routine annual examinations, and measured serum LysoGb3 levels by high-sensitive electrospray ionization liquid chromatography tandem mass spectrometry. RESULTS Serum levels of LysoGb3 were significantly higher in Classic compared with Later-Onset phenotype and higher in the latter compared with controls, both in males (52 [40-83] vs 9.5 [4.5-20] vs 0.47 [0.41-0.61] ng/ml, P<0.001) and in females (9.9 [7.9-14] vs 4.9 [1.6-4.9] vs 0.41 [0.33-0.48] ng/ml, P<0.001), respectively. Multivariate linear regression analysis showed that LysoGb3 levels were independently associated with, serum creatinine (β=0.09, 95%CI 0.04-0.13, P<0.001) and the presence of cardiomyopathy (β=25, 95%CI 9.8-41, P=0.002). LysoGb3 levels were higher in males with frame-shift and nonsense mutations than in males with missense mutations (84 [72-109] vs 41 [37-52] ng/ml, P=0.002). CONCLUSION LysoGb3 relates to disease severity, enzyme replacement response, and to the genotype severity in males. LysoGb3 supports identifying patients at risk who require intensive monitoring and treatment. LysoGb3 appears to be one marker of metabolic phenotyping of FD.

Acute aortic dissection: pathogenesis, risk factors and diagnosis

Acute aortic dissection is a rare but life-threatening condition with a lethality rate of 1 to 2% per hour after onset of symptoms in untreated patients. Therefore, its prompt and proper diagnosis is vital to increase a patients chance of survival and to prevent grievous complications. Typical symptoms of acute aortic dissection include severe chest pain, hypotension or syncope and, hence, mimic acute myocardial infarction or pulmonary embolism. Advanced age, male gender, long-term history of arterial hypertension and the presence of aortic aneurysm confer the greatest population attributable risk. However, patients with genetic connective tissue disorders such as Marfan, Loeys Dietz or Ehlers Danlos syndrome, and patients with bicuspid aortic valves are at the increased risk of aortic dissection at a much younger age. Imaging provides a robust foundation for diagnosing acute aortic dissection, as well as for monitoring of patients at increased risk of aortic disease. As yet, easily accessible blood tests play only a small role but have the potential to make diagnosis and monitoring of patients simpler and more cost-effective.

Rule-out of non-ST elevation myocardial infarction by five point of care cardiac troponin assays according to the 0 h/3 h algorithm of the European Society of Cardiology

Abstract Background: Point of care (POC) assays for cardiac troponins I or T (cTnI or cTnT) may accelerate the diagnosis of patients with suspected acute coronary syndrome (ACS). However, their clinical utility according to the 0 h/3 h algorithm recommended by the European Society of Cardiology (ESC) for non-ST elevation myocardial infarction (NSTEMI) is unknown. Methods: Blood samples from 90 patients with suspected ACS were obtained at hospital admission and 3 h later. Concentrations of cTn were determined using five POC assays (AQT90 FLEX cTnI and cTnT; PATHFAST™ cTnI; Stratus CS 200 cTnI; and Triage MeterPro cTnI) and two guideline-acceptable high-sensitivity (hs) immunoassays. Results: For the diagnosis of NSTEMI (n=15), AUCs for Abbott hs-cTnI and Roche hs-cTnT were 0.86 [95% confidence interval (CI), 0.75–0.96] and 0.88 (95% CI, 0.80–0.95), respectively, at admission, and 0.96 and 0.94, respectively, 3 h later. With the 99th percentile cutoff, their sensitivities were 62% and 92%, respectively, at admission, and 77% and 100%, respectively, 3 h later. The PATHFAST™ cTnI assay showed AUCs of 0.90 (95% CI, 0.82–0.97) and 0.94 (95% CI, 0.89–1.00), respectively, and sensitivities of 67% and 75% at admission and 3 h later, respectively. The other cTn POC assays had AUCs of 0.71 (95% CI, 0.53–0.89) to 0.84 (95% CI, 0.71–0.96) and 0.86 (95% CI, 0.72–0.99) to 0.87 (95% CI, 0.75–0.99) and sensitivities of 39%–50% and 62%–77% at admission and 3 h later, respectively. Conclusions: PATHFAST™ cTnI assay proved itself as comparable to ESC-guideline acceptable hs-cTn assays. The lower sensitivity of the other POC assays limits their clinical utility and would require longer follow-up monitoring of patients for the safe NSTEMI rule-out.

Impact of a single oral dose of 100,000 IU vitamin D3 on profiles of serum 25(OH)D3 and its metabolites 24,25(OH)2D3, 3-epi-25(OH)D3, and 1,25(OH)2D3 in adults with vitamin D insufficiency

Abstract Background: We investigate the effect of a high dose of vitamin D3 on circulating concentrations of 25(OH)D3 and its metabolites 24,25(OH)2D3, 3-epi-25(OH)D3, and 1,25(OH)2D3 in healthy individuals with self-perceived fatigue and vitamin D insufficiency [25(OH)D3<50 nmol/L]. Methods: One hundred and seven study participants (age 20–50 years) were randomized to receive a single 100,000 IU dose of vitamin D3 (n=52) or placebo (n=55). Vitamin D metabolite concentrations in serum were measured before, and 4 weeks after, supplementation. Results: Overall, 52% of participants receiving vitamin D3 attained a serum 25(OH)D3 level >75 nmol/L. Among individuals who received vitamin D3, there were significant increases in serum concentrations of 25(OH)D3 and its metabolites 24,25(OH)2D3, 3-epi-25(OH)D3, and 1,25(OH)2D3 at 4 weeks; however, inter-individual variability in these changes was substantial. Positive correlations between serum 25(OH)D3 and 24,25(OH)2D3 and 3-epi-25(OH)D3, and a significant negative correlation between serum 1,25(OH)2D3 and 3-epi-25(OH)D3, were found 4 weeks after supplementation. The 24,25(OH)2D3/25(OH)D3 and 24,25(OH)2D3/1,25(OH)2D3 ratios were significantly increased, compared with baseline, in participants receiving vitamin D3. Baseline 25(OH)D3 concentration was the only factor predictive of the change in 25(OH)D3 after supplementation. Conclusions: Administration of a single high dose of vitamin D3 leads to a significant increase in concentrations of 25(OH)D3, 24,25(OH)2D3, 3-epi-25(OH)D3 and 1,25(OH)2D3; induction of the catabolic pathway predominates over the production of 1,25(OH)2D3. Due to the high inter-individual variation in the 25(OH)D3 response to supplementation, any given dose of vitamin D is unlikely to achieve optimal vitamin D status in all treated individuals

Reply to technical comment on: Gawinecka et al. Acute aortic dissection: pathogenesis, risk factors, diagnosis

1. As he explains, there are different classification systems for acute aortic dissection, and possibilities for interventional treatment are developing rapidly. Since our article was primarily devoted to the pathogenesis, possible risk factors, genetic factors and basic means of diagnosis, including biomarkers, we neither discussed nor compared possible classification systems nor looked at interventional treatment procedures. In the introduction we referred to the most common systems of classification, which are used by the current European guidelines [3]. 2. The entities of acute aortic syndrome represent a continuum. We mentioned acute aortic syndromes as the overarching term in the introduction only, but then focused on aortic dissection rather than discussed the macroscopic continuum. Depending on the situation in the individual patient, different microscopic and molecular causes, as well as pathophysiological mechanisms including shear forces, can manifest themselves in different acute aortic syndrome entities. As pointed out by Dr Qanadli, intramural haematomas are often responsible for delaying the start of treatment.