Dieplinger B.,Konventhospital Barmherzige Brueder Linz |
Egger M.,Konventhospital Barmherzige Brueder Linz |
Gabriel C.,Red Cross |
Poelz W.,Johannes Kepler University |
And 7 more authors.
Clinica Chimica Acta | Year: 2013
Background: Comparative proteomics has recently identified afamin, the newest member of the albumin gene family, as a potential biomarker for ovarian cancer. The aim of this study was the analytical and clinical evaluation of a sandwich enzyme-linked immunosorbent assay for the determination of afamin in human plasma. Methods: We evaluated precision, linearity, and detection limit of the assay, analyte stability and biological variability, determined reference values and quantified afamin concentrations in various diseases. Results: Within-run and total coefficients of variation were <. 10%. The method was linear across the tested measurement range. Detection limit was 7. mg/L for the assay. The analyte was stable for 24. h at room temperature, for 48. h at 4. °C, and for at least one year at - 20. °C and - 80. °C. The reference change value for healthy individuals was 24%. Age- and sex-independent reference values in healthy blood donors were 45-99. mg/L (median 68. mg/L). In the clinical assay evaluation afamin plasma concentrations were modestly decreased in patients with heart failure. Patients with pneumonia or sepsis exhibited markedly decreased afamin plasma concentrations. However, patients with chronic renal disease or chronic obstructive pulmonary disease showed no difference in afamin plasma concentrations as compared to healthy individuals. Correlation analyses revealed an inverse association between afamin and inflammatory biomarkers. Conclusions: The afamin assay meets quality specifications for laboratory medicine. The results of the clinical assay evaluation revealed novel insights with respect to afamin as a potential negative acute phase protein and should encourage further studies. © 2013.
Kronenberg F.,Innsbruck Medical University |
Kollerits B.,Innsbruck Medical University |
Kiechl S.,Innsbruck Medical University |
Lamina C.,Innsbruck Medical University |
And 21 more authors.
Circulation: Cardiovascular Genetics | Year: 2014
Background-Afamin is a human plasma vitamin E-binding glycoprotein primarily expressed in the liver and secreted into the bloodstream. Because little is known about (patho)-physiological functions of afamin, we decided to identify phenotypes associated with afamin by investigating transgenic mice overexpressing the human afamin gene and performing large-scale human epidemiological studies. Methods and Results-Transgenic mice overexpressing afamin revealed increased body weight and serum concentrations of lipids and glucose. We applied a random-effects meta-analysis using age- and sex-adjusted baseline and follow-up investigations in the population-based Bruneck (n=826), Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR; n=1499), and KOoperative Gesundheitsforschung in der Region Augsburg (KORA) F4 studies (n=3060). Mean afamin concentrations were 62.5±15.3, 66.2±14.3, and 70.6±17.2 mg/L in Bruneck, SAPHIR, and KORA F4, respectively. Per 10 mg/L increment in afamin measured at baseline, the number of metabolic syndrome components increased by 19% (incidence rate ratio=1.19; 95% confidence interval [CI], 1.16-1.21; P=5.62×10-64). With the same afamin increment used at baseline, we observed an 8% gain in metabolic syndrome components between baseline and follow-up (incidence rate ratio=1.08; 95% CI, 1.06-1.10; P=8.87×10-16). Afamin concentrations at baseline were highly significantly related to all individual metabolic syndrome components at baseline and at follow-up. This observation was most pronounced for elevated waist circumference (odds ratio, 1.79; 95% CI, 1.54-2.09; P=4.15×10-14 at baseline and odds ratio, 1.46; 95% CI, 1.31-1.63; P=2.84×10-11 for change during follow-up) and for elevated fasting glucose concentrations (odds ratio, 1.46; 95% CI, 1.40-1.52; P=1.87×10-69 and odds ratio, 1.46; 95% CI, 1.24-1.71; P=5.13×10-6, respectively). Conclusions-This study in transgenic mice and >5000 participants in epidemiological studies shows that afamin is strongly associated with the prevalence and development of metabolic syndrome and all its components. © 2014 American Heart Association, Inc.
Plasma concentrations of the vitamin E-binding protein afamin are associated with overall and progression-free survival and platinum sensitivity in serous ovarian cancer - A study by the OVCAD consortium
Melmer A.,Innsbruck Medical University |
Fineder L.,Innsbruck Medical University |
Lamina C.,Innsbruck Medical University |
Kollerits B.,Innsbruck Medical University |
And 12 more authors.
Gynecologic Oncology | Year: 2013
Objective: Comparative proteomics identified the plasma protein afamin as potential biomarker for ovarian cancer (OC). Significantly decreased afamin plasma concentrations in pre-therapeutic OC patients reconstituted to control values after successful tumor surgery. This study evaluates the association of afamin with survival and response to therapy in serous OC patients within the OVCAD consortium project. Methods: We measured afamin in 215 pre-therapeutic plasma samples, 246 tumor lysates and 109 plasma samples taken 6 months after finishing platinum-based chemotherapy. Differences in afamin plasma concentrations among FIGO stages were tested by Kruskal-Wallis test; association of afamin concentrations with overall and progression-free survival was evaluated using Kaplan-Meier survival plots and multivariate adjusted COX regression analysis. Results: Pre-therapeutic afamin correlated significantly with FIGO stages (p = 0.012) and was lower in the presence of metastases (p = 0.013) and poorly differentiated OC in patients responding to therapy (p = 0.016). Afamin ≥ 48.0 mg/L was also associated with a lower hazard ratio for recurrent disease as compared to afamin < 48.0 mg/L (p = 0.007). Post-therapeutic afamin ≥ 48 mg/L was positively correlated with overall (p < 0.001) and progression-free (p = 0.012) survival and was lower in non-responders than in responders (p = 0.048). Thus, afamin returned post-therapeutically to values of healthy controls in responders (p < 0.001) but not in non-responders (p = 0.114). Afamin in tumor lysates was lower in poorly differentiated OC than in G 1 + 2 tumors (p = 0.041). Higher afamin concentrations in tumor lysates were associated with increased overall survival (p = 0.003). Conclusion: These data indicate that afamin is associated with therapy response and survival rate in advanced OC patients. © 2012 Elsevier Inc.
Dieplinger H.,Innsbruck Medical University |
Dieplinger H.,Vitateq Biotechnology GmbH |
Dieplinger B.,Konventhospital Barmherzige Brueder
Clinica Chimica Acta | Year: 2015
The human glycoprotein afamin was discovered as the fourth member of the albumin gene family. Despite intense research over the last 20. years, our knowledge of afamin's physiological or pathophysiological functions is still very limited. Circulating afamin is primarily of hepatic origin and abundant concentrations are found in plasma, cerebrospinal, ovarian follicular and seminal fluids. In vitro binding studies revealed specific binding properties for vitamin E. A previously performed analytical characterization and clinical evaluation study of an enzyme-linked immunosorbent assay for quantitative measurement of afamin in human plasma demonstrated that the afamin assay meets the quality specifications for laboratory medicine. Comparative proteomics has identified afamin as a potential biomarker for ovarian cancer and these findings were confirmed by quantitative immunoassay of afamin and validated in independent cohorts of patients with ovarian cancer. Afamin has also been investigated in other types of carcinoma. Most of these studies await further evaluation with validated quantitative afamin assays and require validation in larger patient cohorts. Transgenic mice overexpressing the human afamin gene revealed increased body weight and increased blood concentrations of lipids and glucose. These transgenic mouse data were in line with three large human population-based studies showing that afamin is strongly associated with the prevalence and development of the metabolic syndrome. This review summarizes and discusses the molecular, biochemical and analytical characterization of afamin as well as possible clinical applications of afamin measurement. © 2015.
Seeber B.,Innsbruck Medical University |
Morandell E.,Innsbruck Medical University |
Lunger F.,Innsbruck Medical University |
Wildt L.,Innsbruck Medical University |
And 2 more authors.
Reproductive Biology and Endocrinology | Year: 2014
Background: High plasma concentrations of the vitamin E-binding protein afamin have been previously shown to be associated with insulin resistance and metabolic syndrome. We set out to determine whether the concentration of afamin in the serum of women with polycystic ovarian syndrome (PCOS) is elevated in relation to the presence and severity of insulin resistance (IR).Methods: This cross-sectional study looked at 53 patients with PCOS and 49 non-PCOS patients. IR was diagnosed as a HOMA Index >2.4 and confirmed with a three-hour glucose tolerance test. Serum concentrations of afamin were determined using enzyme-linked immunosorbent assay (ELISA). Clinical characteristics, hormone and metabolic parameters were correlated to afamin concentrations.Results: Serum concentrations of afamin did not differ between women with PCOS and controls. When separated according to the presence of IR a significant difference in median afamin levels was seen between PCOS with IR and PCOS without IR (73.06+/-27.36 mg/L and 64.25+/-17.41 mg/L, p = 0.033). No difference in afamin levels was detected when comparing the few controls with IR and the controls without IR (76.20+/-27.96 mg/L and 60.44+/-21.03 mg/L, p = 0.235). On univariate analyses, afamin serum concentrations significantly correlated with BMI, triglycerides, HOMA Index, and AUC-Insulin. On multivariate linear regression analysis, only triglyceride concentration was seen to be an independent predictor of afamin. Subjects with metabolic syndrome had higher median afamin concentrations than did those without metabolic syndrome (77.43+/-28.60 mg/L and 65.08+/-18.03 mg/L, p = 0.010).Conclusions: Elevated afamin concentrations are associated with the presence of metabolic syndrome in young women and may potentially serve as an independent predictor for the development of metabolic syndrome in at-risk women, especially those with IR. © 2014 Seeber et al.; licensee BioMed Central Ltd.
Hubalek M.,Innsbruck Medical University |
Buchner H.,Ludwig Maximilians University of Munich |
Mortl M.G.,Medical University of Graz |
Schlembach D.,Medical University of Graz |
And 9 more authors.
Clinica Chimica Acta | Year: 2014
Background: Afamin is a liver-derived plasma glycoprotein with vitamin E-binding properties and a putative function in fertility. This study evaluated serum afamin concentrations during and postpartum to uncomplicated pregnancies and investigated a potential association between afamin concentrations and pregnancy outcome. Methods: Afamin serum concentrations were measured in women with uncomplicated pregnancies in a retrospective cohort (n=466) at different gestational ages and a prospective observational study (n=76) in the first, second and third trimester. Furthermore, afamin was determined in the first trimester in a cross-sectional pilot study including women with preeclampsia (PE), pregnancy-induced hypertension (PIH) and women without pregnancy complications (n=13 each). Finally, expression of afamin was investigated in human placental tissue by RT-PCR and immunohistochemistry. Results: Afamin concentrations increased linearly almost two-fold during pregnancy in both retrospective and prospective studies in women without pregnancy complications with median afamin serum concentrations of 61.9. mg/l, 79.6. mg/l, and 98.6. mg/l in the first, second, and third trimester, respectively. After delivery, median afamin concentrations decreased to baseline values of 54.6. mg/l. In the pilot study with pregnancy complications, women with PE displayed significantly higher median afamin concentrations than did women with uncomplicated pregnancy (70.0. mg/l vs. 55.4. mg/l, P=0.007). Expression analyses revealed no placental afamin expression at either mRNA or protein level in uncomplicated pregnancy. Conclusion: A linear increase in the maternally expressed glycoprotein afamin during pregnancy may serve as basic reference for subsequent investigations of afamin in pregnancy-related disorders. © 2014.
Vitateq Biotechnology GmbH | Date: 2016-06-29
The invention relates to a method for the detection and/or quantification of afamin in a sample comprising providing a carrier surface with an immobilized first antibody against afamin, contacting a sample which potentially comprises afamin with the first antibody, providing a second antibody against afamin detecting binding events of afamin, wherein the second antibody has the means to allow detection and/or quantification of binding events by visual inspection and/or spectrophotometry,characterised in that the first and the second antibody are monoclonal antibodies and bind to different epitopes of afamin.
Vitateq Biotechnology Gmbh | Date: 2012-06-28
Described is a method for in vitro diagnosing whether a pregnant woman has a risk for developing preeclampsia (PE) comprising the steps of determining the afamin content of the pregnant woman in a blood sample or a blood-derived sample, urine, amniotic and cerebrospinal fluid; or determining the content of afamin m-RNA in a liver tissue sample; and comparing the afamin content determined in the sample with a reference value.