Changes in circulating ApoJ-Glyc levels in patients with suspected acute coronary syndrome: The EDICA trial.

BACKGROUND: Myocardial ischemia induces intracellular accumulation of non-glycosylated apolipoprotein J that results in a reduction of circulating glycosylated ApoJ (ApoJ-Glyc). The latter has been suggested to be a marker of transient myocardial ischemia. OBJECTIVE: This proof-of-concept clinical study aimed to assess whether changes in circulating ApoJ-Glyc could detect myocardial ischemia in patients attending the emergency department (ED) with chest pain suggestive of acute coronary syndrome (ACS). METHODS: In suspected ACS patients, EDICA (Early Detection of Myocardial Ischemia in Suspected Acute Coronary Syndromes by ApoJ-Glyc a Novel Pathologically based Ischemia Biomarker), a multicentre, international, cohort study assessed changes in 2 glycosylated variants of ApoJ-Glyc, (ApoJ-GlycA2 and ApoJ-GlycA6), in serum samples obtained at ED admission (0 h), and 1 h and 3 h thereafter, blinded to the clinical diagnosis (i.e. STEMI, NSTEMI, unstable angina, non-ischemic). RESULTS: 404 patients were recruited; 291 were given a clinical diagnosis of "non-ischemic" chest pain and 113 were considered to have had an ischemic event. ApoJ-GlycA6 was lower on admission in ischemic compared with "non-ischemic" patients (66 [46-90] vs. 73 [56-95] µg/ml; P = 0.04). 74% of unstable angina patients (all with undetectable hs-Tn), had ischemic changes in ApoJ-Glyc at 0 h and 89% at 1 h. Initially low ApoJ-Glyc levels in 62 patients requiring coronary revascularization increased significantly after successful percutaneous intervention. CONCLUSIONS: Circulating ApoJ-Glyc concentrations decrease early in ED patients with myocardial ischemia compared with "non-ischemic" patients, even in the absence of troponin elevations. ApoJ-Glyc may be a useful marker of myocardial ischemia in the ED setting.

A Novel ELISA for the Quantification of Serum Levels of 2 Glycosylated Variants of Apolipoprotein J: Biomarkers for Myocardial Ischemia.

BACKGROUND: Previous studies have pointed out a potential role of ApoJ-Glyc as a biomarker of cardiac ischemia. The aim of this study was to validate the analytical performance of 2 novel ELISAs against 2 different glycosylated ApoJ variants, ApoJ-GlycA2 and ApoJ-GlycA6. METHODS: The analytical measuring range, limit of blank (LoB), lower limit of quantification (LoQ), precision, accuracy, recovery, cross-reactivity, and stability were evaluated in serum samples. RESULTS: The analytical measuring range was 500-16 000 ng/mL for ApoJ-GlycA2 and 125-4000 ng/mL for ApoJ-GlycA6, with a LoB of 455 ng/mL and 121 ng/mL for ApoJ-GlycA2 and ApoJ-GlycA6, respectively. The LoQ was 500 ng/mL for ApoJ-GlycA2 and 125 ng/mL for ApoJ-GlycA6. The assay performance fulfills the acceptance criteria established in the European Medicines Agency Guideline on bioanalytical method validation. Specifically, the calibration range variability is <15% for ApoJ-GlycA2 and ApoJ-GlycA6; the accuracy is <15% for ApoJ-GlycA2 and ApoJ-GlycA6; the between- and within-run precision is <15% for ApoJ-GlycA6 and ≤20% for ApoJ-GlycA2; and the total allowable error is <30% for ApoJ-GlycA2 and ApoJ-GlycA6. Cross-reactivity studies revealed the absence of cross-reactivity with endogenous components of the matrix (using ApoJ-depleted serum), with nonglycosylated ApoJ and with transferrin (as a high abundant N-glycosylated serum protein). Both ApoJ-GlycA2 and ApoJ-GlycA6 measurements were stable after storage of serum samples at -80°C for 24 months. CONCLUSIONS: The newly developed ELISAs to quantify ApoJ-GlycA2 and ApoJ-GlycA6 serum levels showed an acceptable analytical performance according to European Medicines Agency guidelines on bioanalytical method validation in terms of precision, accuracy, recovery, cross-reactivity, and stability.

Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening.