Significant elevations of serum amylase caused by macroamylase: Case reports and detection possibilities.

BACKGROUND: The presence of isolated elevated serum amylase levels can be caused by high molecular mass complexes. We describe 13 cases of hyperamylasemia detected in adult patients without clinical symptoms of a pancreatic disorder. Five of them were thoroughly examined using different tools for the detection of macrocomplexes. METHODS: We performed both screening and more advanced methods of macroamylase detection, including polyethylene glycol precipitation, sample storage at 4°C and separation by gel filtration. RESULTS: The presence of macroamylase in the suspected samples was confirmed by the methods described, except for the sample storage at 4°C. In this method, the enzyme activity did not decrease. The polyethylene glycol precipitation activity (% PPA) averaged 89.1% for amylase, whereas the control samples averaged 30.7%. Gel filtration chromatography confirmed an IgA macroamylase peak in three samples and an IgG macroamylase peak in two samples. CONCLUSION: The presence of macroamylase should be suspected whenever the clinical history and condition of the patient do not match the measured enzyme value to avoid diagnostic errors and unnecessary invasive examinations. The presence of macrocomplexes is considered a benign process that may occur in apparently healthy individuals. Cooperation between clinicians and laboratory staff is necessary.

Galectin-3 as an independent prognostic factor after heart transplantation.

BACKGROUND: Galectin-3 (GAL3) is linked to the prognosis of patients with heart failure and after heart transplantation (HTx). We assessed the prognostic role of GAL3 in a long-term follow-up after HTx. METHODS: HTx patients (N = 121) were evaluated in a single-center, noninterventional, prospective, observational study. The median follow-up was 96 months (2942 days, interquartile range (IQR) 2408-3264 days), and 40 patients died. GAL3 was measured before HTx, +10 days after HTx, and during the first posttransplant year. Survival analysis (all-cause mortality) was performed with adjustments for clinical and laboratory variables. RESULTS: The median pretransplant GAL3 level was 18.0 µg/L (IQR 14.0-25.9), and higher values were associated with older age, worse kidney function, left ventricular assist device use before HTx, a higher IMPACT score, and mortality. Increased pretransplant GAL3 predicted shorter survival time (HR 2.05, 95% CI 1.09-3.85, p < .05). Similar prognostic power had GAL3 on the 10th posttransplant day (HR 2.03, 95% CI 1.08-3.82, p < .05). GAL3 was an independent predictor of death after adjustment for clinical variables (age, infection, diabetes, smoking, IMPACT score, and troponin). CONCLUSIONS: GAL3 was significantly associated with all-cause mortality after adjusting for clinical and laboratory variables and may serve as an additional prognostic biomarker.

Impact of access route to the left ventricle on asymptomatic periprocedural brain injury: the results of a randomized trial in patients undergoing catheter ablation of ventricular tachycardia.

AIMS: Catheter ablation of ventricular tachycardia (VT) is an effective treatment in patients with structural heart disease (SHD) and recurrent arrhythmias. However, the procedure is associated with the risk of complications, including both manifest and asymptomatic cerebral thromboembolic events. We hypothesized that periprocedural asymptomatic brain injury (ABI) can be reduced by using transseptal instead of the retrograde access route to the left ventricle (LV). METHODS AND RESULTS: Consecutive patients undergoing VT ablation for SHD were randomized 1:1 to either retrograde or transseptal LV access. All patients underwent radiofrequency ablation in conscious sedation with the use of an irrigated tip catheter. The degree of brain damage was evaluated by serum level of biomarker S100B. Significant ABI was defined as a post-ablation relative increase of S100B level >30%. A total of 144 patients (66 ± 9 years; 14 females; 90% coronary artery disease; LV ejection fraction: 30 ± 8%) were enrolled and 72 were allocated to each study groups. Symptomatic neurological complication of the procedure was not observed in any subject. A significant ABI was detected in 19.4% of patients. It was more commonly observed in subjects randomized to retrograde vs. transseptal LV access (26.4% vs. 12.5%, P = 0.04). In a multivariate analysis, only retrograde LV access and advanced age were independent determinants of significant ABI. CONCLUSION: Significant ABI after ablation of VT in patients with SHD can be detected in one-fifth of subjects. Retrograde access to LV is associated with a two-fold higher probability of significant ABI.

Changes in Sepsis Biomarkers after Immunosuppressant Administration in Transplant Patients.

Sepsis biomarkers change continuously during the postoperative period. We aimed to demonstrate the influence of immunosuppressants after transplantation (Tx) on presepsin, procalcitonin, CRP, white blood cells, and IL-6. A group of 140 patients after major surgery (86 non-Tx, 54 Tx) without any signs of sepsis or infectious complications was followed for 7 days. The changes in biomarkers were analyzed with respect to the type of surgery, organ, and induction immunosuppressant used (antithymocyte globulin, corticosteroids, or basiliximab/rituximab). Concentrations (95th percentiles) of presepsin and procalcitonin were higher in the Tx group (presepsin: Tx < 2380 vs. non-Tx < 1368 ng/L, p < 0.05; procalcitonin: <28.0 vs. 3.49 µg/L, p < 0.05). In contrast, CRP and IL-6 were lower in the Tx group (CRP: Tx < 84.2 vs. non-Tx < 229 mg/L, p < 0.05; IL-6: <71.2 vs. 317 ng/L, p < 0.05). Decreases in CRP and IL-6 were found for all immunosuppressants, and procalcitonin was increased after antithymocyte globulin and corticosteroids. Negligible changes were found for white blood cells. Different responses of presepsin, procalcitonin, CRP, and IL-6 were therefore found in patients without any infectious complications after major surgery or transplantation. Immunosuppression decreased significantly IL-6 and CRP in comparison to non-Tx patients, while procalcitonin was increased after corticosteroids and antithymocyte globulin only. Cautious interpretation of sepsis biomarkers is needed in the early posttransplant period. This work was conducted as a noninterventional (nonregistered) study.

Peritoneal dialysis induces alterations in the transcriptome of peritoneal cells before detectible peritoneal functional changes.

Long-term peritoneal dialysis (PD) is associated with functional and structural alterations of the peritoneal membrane. Inflammation may be the key moment, and, consequently, fibrosis may be the end result of chronic inflammatory reaction. The objective of the present study was to identify genes involved in peritoneal alterations during PD by comparing the transcriptome of peritoneal cells in patients with short- and long-term PD. Peritoneal effluent of the long dwell of patients with stable PD was centrifuged to obtain peritoneal cells. The gene expression profiles of peritoneal cells using microarray between patients with short- and long-term PD were compared. Based on microarray analysis, 31 genes for quantitative RT-PCR validation were chosen. A 4-h peritoneal equilibration test was performed on the day after the long dwell. Transport parameters and protein appearance rates were assessed. Genes involved in the immune system process, immune response, cell activation, and leukocyte and lymphocyte activation were found to be substantially upregulated in the long-term group. Quantitative RT-PCR validation showed higher expression of CD24, lymphocyte antigen 9 (LY9), TNF factor receptor superfamily member 4 (TNFRSF4), Ig associated-α (CD79A), chemokine (C-C motif) receptor 7 (CCR7), carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), and IL-2 receptor-α (IL2RA) in patients with long-term PD, with CD24 having the best discrimination ability between short- and long-term treatment. A relationship between CD24 expression and genes for collagen and matrix formation was shown. Activation of CD24 provoked by pseudohypoxia due to extremely high glucose concentrations in dialysis solutions might play the key role in the development of peritoneal membrane alterations.

Clinical and Humoral Determinants of Congestion in Heart Failure: Potential Role of Adiponectin.

BACKGROUND: Some patients with heart failure (HF) are more prone to systemic congestion than others. The goal of this study was to identify clinical and humoral factors linked to congestion and its prognostic impact in HF patients. METHODS: A total of 371 advanced HF patients underwent physical examination, echocardiography, right heart catheterization, blood samplings, and Minnesota Living with HF Questionnaire. Subjects were followed-up for adverse events (death, urgent transplantation, or assist device implantation without heart transplantation). RESULTS: Thirty-one percent of patients were classified as prone to congestion. During a median follow-up of 1,093 days, 159 (43%) patients had an adverse event. In the Cox analysis, the congestion-prone (CP) status was associated with a 43% higher event risk. The CP status was strongly (p ˂ 0.001) associated with body weight loss, right ventricular dysfunction (RVD), dilated inferior vena cava (IVC), diuretics, and beta-blockers prescription and the majority of tested hormones in the univariate analysis. In the multivariate analysis, the only independent variables associated with the CP status were adiponectin, albumin, IVC diameter, and RVD. Adiponectin by itself was predictive of adverse events. In a multivariate model, CP status was no longer predictive of adverse events, in contrast to adiponectin. CONCLUSIONS: CP patients experienced more severe symptoms and had shorter survival. Potential role of adiponectin, a new independent predictor of CP status, should be further examined.

Presepsin: what is important for correct interpretation.

INTRODUCTION: Presepsin (soluble CD14 subtype) is a new biomarker of infection and sepsis. Correct interpretation is based on the knowledge of analytical reliability, biological variation, decision limits, and diagnostic effectivity. AIM: The aim of the study was to verify analytical precision of presepsin measurements, to assess biological variation in healthy subjects, to verify reference and decision limits, to assess diagnostic effectivity, and to compare data with commonly used septic biomarkers - procalcitonin (PCT), CRP and interleukin 6 (IL6). MATERIAL AND METHODS: Analyti-cal precision (repeatability and intermediate precision) was estimated by repeated measurements of commercial control materials. Biological variation was evaluated in a group of 20 healthy volunteers in a 7-week experi-ment. Reference ranges were extracted from the literature and compared with data from healthy subjects. RESULTS: Precisions of presepsin measurements were 2.0-4.0 % (“within-run”) and 6.1-9.5 % (“between-run”). Intraindividual biological variation of presepsin was 22.3 %, interindividual variation 20.8 %. Index of individuality was 1.07, reference change value (RCV - critical difference) was 72 %. Upper reference limit was around 180 ng/l. CONCLUSION: Ana-lytical quality of presepsin measurement is suitable for clinical use. Biological variation parameters enable the use of reference limits, upper reference limit of presepsin is around 180 ng/l. None of the tested biomarkers has universal cut-off value, multiple biomarkers are needed and repeated measurements are advisable.

Kidney Response to Heart Failure: Proteomic Analysis of Cardiorenal Syndrome.

BACKGROUND/AIMS: Chronic heart failure (HF) disrupts normal kidney function and leads to cardiorenal syndrome that further promotes HF progression. To identify potential participants in HF-related injury, we analyzed kidney proteome in an established HF model. METHODS: HF was induced by chronic volume overload in male HanSD rats using aorto-caval fistula. After 21 weeks, cardiac and renal functions (in-situ kidney study) and renal proteomics were studied in sham-operated (controls) and HF rats, using iTRAQ labeling and LC-MS with Orbitrap Fusion, leading to identification and quantification of almost 4000 proteins. RESULTS: Compared to controls, HF rats had cardiac hypertrophy, systemic and pulmonary congestion. Kidneys of HF rats had reduced renal blood flow, sodium excretion and urine production. While glomerular filtration rate, serum cystatin C and creatinine were still normal compared to controls, HF kidneys showed albuminuria and markedly increased tissue angiotensin-II levels (5-fold). HF kidneys (versus controls) displayed differential expression (˃1.5-fold) of 67 proteins. The most upregulated were angiotensin-converting enzyme (ACE, ˃20-fold), advanced glycosylation product-specific receptor (RAGE, 14-fold), periostin (6.8-fold), caveolin-1 (4.5-fold) and other proteins implicated in endothelial function (vWF, cavins 1-3, T-kininogen 2), proinflammatory ECM activation (MFAP4, collagen-VI, galectin-3, FHL-1, calponin) and proteins involved in glomerular filtration membrane integrity (CLIC5, ZO-1). Carboxylesterase-1D (CES1D), an enzyme that converts ACE inhibitors or sacubitril into active drugs, was also upregulated in HF kidneys. CONCLUSION: Chronic HF leads to latent kidney injury, associated with deep changes in kidney protein composition. These alterations may act in concert with intrarenal renin-angiotensin system activation and may serve as markers and/or targets to tackle cardiorenal syndrome.

Falsely elevated human epididymis protein 4 results and Risk of Ovarian Malignancy Algorithm in polymorbid women after solid organ transplantation: A pilot and case-control study.

BACKGROUND: Cancer prevention is essential after transplantation (Tx). The use of HE4 and Risk of Ovarian Malignancy Algorithm (ROMA) is recommended as a tool for selective ovarian cancer screening; however, creatinine is a known confounder. This study assessed the reliability of HE4, CA125, and ROMA after Tx. METHODS: We matched a total of 202 women without gynecological malignancies and 236 men by age and serum creatinine. Each pair consisted of a patient after Tx (kidney, liver, heart, and pancreas) and a diseased but non-Tx consecutive patient. Serum HE4, CA125 (Roche Cobas 6000), and creatinine (enzymatic, Abbott Architect) were measured in all patients. RESULTS: Creatinine correlated with HE4 (women: r = .864, P < .0001; men: r = .848, P < .0001). Age correlated slightly with HE4 in women (r = .250, P < .005) and men (r = .240, P < .0005). HE4 in women after Tx (median of 84.8 pmol/L) was significantly higher than non-Tx women (53.7 pmol/L, P < .0001) in the reference range of serum creatinine. Neither HE4 nor CA125 correlated with tacrolimus concentration, but anemia, hyperparathyroidism, kidney, liver, and lung diseases were possible confounders for HE4 after transplantation (P < .05). CONCLUSION: Human epididymis protein 4 (HE4) was significantly increased in women after solid organ transplantation compared to levels without transplants matched by age and serum creatinine. HE4 results may be misleading in these patients.

[Remarks on biomarkers of cardiovascular risk]. / Poznámky k analytice biomarkeru kardiovaskulárního rizika.

Authors describe state-of-the-art in the routine laboratory diagnostics of cardiovascular risk with special emphasis on metrology, traceability, external quality assessment, biological variation, and reference change value. While analytical quality of total cholesterol, triglycerides, glucose, and HbA1c is satisfactory, improvements are needed for HDL-cholesterol, LDL-cholesterol, apolipoprotein A1, apolipoprotein B, Lp(a), and LpPLA2 measurements. Biological variation is a strong player in the lipid diagnostics, because reference change value is above 20 % for majority of biomarkers. Current methodology for the measurement of remnant cholesterol is far from optimum and standardization is therefore needed.Key words: biological variation - clinical chemistry - interpretation - lipid profile - metrology - remnant cholesterol.

Serial measurement of presepsin, procalcitonin, and C-reactive protein in the early postoperative period and the response to antithymocyte globulin administration after heart transplantation.

Differentiation between systemic inflammatory response syndrome and sepsis in surgical patients is of crucial significance. Procalcitonin (PCT) and C-reactive protein (CRP) are widely used biomarkers, but PCT becomes compromised after antithymocyte globulin (ATG) administration, and CRP exhibits limited specificity. Presepsin has been suggested as an alternative biomarker of sepsis. This study aimed to demonstrate the role of presepsin in patients after heart transplantation (HTx). Plasma presepsin, PCT, and CRP were measured in 107 patients serially for up to 10 days following HTx. Time responses of biomarkers were evaluated for both noninfected (n=91) and infected (n=16) patients. Areas under the concentration curve differed in the two groups of patients for presepsin (P<.001), PCT (P<.005), and CRP (P<.001). The effect of time and infection was significant for all three biomarkers (P<.05 all). In contrast to PCT, presepsin was not influenced by ATG administration. More than 25% of noninfected patients had PCT above 42 µg/L on the first day, and the peak concentration of CRP in infected patients was reached on the third post-transplant day (median 135 mg/L). Presepsin seems to be as valuable a biomarker as PCT or CRP in the evaluation of infectious complications in patients after HTx.

Procalcitonin Dynamics After Long-Term Ventricular Assist Device Implantation.

BACKGROUND: Infectious complications (IC) are one of the main causes of worsening prognosis after long-term ventricular assist device (LVAD) implantation. Procalcitonin (PCT) is widely used for diagnosis of a bacterial infection. The objective of this study was to assess PCT dynamics after LVAD surgery and their relationship to the infectious complications. METHODS: A total of 25 consecutive patients indicated for LVAD implantation as a bridge to heart transplant were included. Procalcitonin levels were prospectively assessed before surgery and during the postoperative period (day 1, 2, 14 and 30). Values were compared according to the presence of IC. RESULTS: Procalcitonin levels were low before surgery, raised significantly within 1st and 2nd day after operation and decreased in the 14th and 30th days back to the baseline. There was no significant difference in PCT values between patients with or without IC as well as with or without right ventricle assist device (RVAD). Acute renal failure (ARF) increased PCT significantly only 14 days after LVAD implantation. In patients with ARF and/or RVAD we observed significantly higher PCT values in the 2nd, 14th and 30th day after operation. In subjects with IC and/or ARF and/or RVAD we also observed significantly elevated PCT concentrations 2 and 14 days after surgery. CONCLUSIONS: Our data show that the ability of PCT to detect IC in patients after LVAD implantation is limited and its concentrations more likely correlate with postoperative complications in general.

Multiple qualitative and quantitative methods for free light chain analysis are necessary as first line tests for AL amyloidosis.

The objective of this study was to demonstrate the necessity of using different methods for amyloidogenic light chain detection. Serum and urine agarose gel electrophoresis and immunofixation, as well as serum free light chain (FLC) immunoassay measurements, were evaluated in a patient with verified multiple myeloma and consequent AL amyloidosis confirmed by Congo red staining and immunofluorescence techniques. Conventional chemistry tests [serum and urine electrophoresis (SPE and UPE); serum and urine immunofixation (SIFE and UIFE)] were inconclusive. Only quantitative FLC immunoassay (serum free light chain immunoanalysis, SFLC) provided correct diagnostic information. A combination of gel-based SIFE and UIFE with more novel quantitative FLC immunoassays appears necessary when searching for monoclonal immunoglobulin light chain-related diseases.

The role of timely measurement of galectin-3, NT-proBNP, cystatin C and hsTnT in predicting prognosis and heart function after heart transplantation.

BACKGROUND: Changes of biomarkers measured soon after heart transplantation (HTx) can reflect different processes: cardiomyocyte necrosis (troponins, high-sensitivity cardiac TnT and TnI), heart function (natriuretic peptides, BNP and NT-proBNP), fibrosis (galectin-3 and ST2), and global cardiorenal risk (cystatin C). We assessed the prognostic role of hsTnT, NT-proBNP, galectin-3 and cystatin C during the early post-transplant period. METHODS: A total of 121 consecutive post-HTx patients were assessed. The main outcomes were survival, left ventricular ejection fraction (LVEF) and rejection periods. Survival was assessed after intermediate (12 months) and long periods (total follow-up during study, median of survival 763 days, IR 527-1038 days). LVEF was assessed 12 months after HTx. Rejection was evaluated during follow-up. We report biomarker concentrations measured 10 days and 12 months after HTx. RESULTS: Ten days after HTx, cystatin C and hsTnT predicted death both under univariable and multivariable analysis. These two biomarkers along with galectin-3 were increased in patients with decreased LVEF measured 1 year after HTx. NT-proBNP did not show early prognostic power. None of the measured biomarkers predicted rejection, but hsTnT and NT-proBNP were increased significantly 12 months after HTx in patients with at least one rejection. CONCLUSIONS: Cystatin C and hsTnT measured 10 days after HTx can provide prognostic information on survival and galectin-3 measured at the same time may display a relationship to heart function assessed 1 year after HTx. Further study should be carried out in a large cohort of patients.

Analysis of Four Automated Urinalysis Systems Compared to Reference Methods.

BACKGROUND: The aim of this study was to compare four automated urinalysis systems: the Iris iQ200 Sprint (Iris Diagnostics, U.S.A.) combined with the Arkray AUTION MAX AX 4030, Iris + AUTION, Arkray AU 4050 (Arkray Global Business, Inc., Japan), Dirui FUS 2000 (Dirui Industrial Co., P.R.C.), and Menarini sediMAX (Menarini, Italy). METHODS: Urine concentrations of protein and glucose (Iris, Dirui) were compared using reference quantitative analysis on an Abbott Architect c16000. Leukocytes, erythrocytes, epithelia, and casts (Iris, Arkray, Diuri, Menarini) were compared to urine sediment under reference light microscopy, Leica DM2000 (Leica Microsystems GmbH, Germany) with calibrated FastRead plates (Biosigma S.r.l., Italy), using both native and stained preparations. RESULTS: Total protein and glucose levels were measured using the Iris + AUTION system with borderline trueness, while the Dirui analysis revealed worse performances for the protein and glucose measurements. True classifications of leukocytes and erythrocytes were above 85% and 72%, respectively. Kappa statistics revealed a nearly perfect evaluation of leukocytes for all tested systems; the erythrocyte evaluation was nearly perfect for the Iris, Dirui and Arkray analyzers and substantial for the Menarini analyzer. The epithelia identification was connected to high false negativity (above 15%) in the Iris, Arkray, and Menarini analyses. False-negative casts were above 70% for all tested systems. CONCLUSIONS: The use of automated urinalysis demonstrated some weaknesses and should be checked by experienced laboratory staff using light microscopy.

B-type natriuretic peptide: powerful predictor of end-stage chronic heart failure in individuals with systolic dysfunction of the systemic right ventricle.

AIM: To assess whether B-type natriuretic peptide (BNP) can serve as a predictor of end-stage chronic heart failure (CHF) in patients with severe systolic dysfunction of the systemic right ventricle (SRV). METHODS: We performed a retrospective analysis in 28 patients with severe systolic dysfunction of the SRV (ejection fraction 23 ± 6%) who were evaluated as heart transplant (HTx) candidates between May 2007 and October 2014. The primary endpoints of the study (end-stage CHF) were progressive CHF, urgent HTx, and ventricular assist device (VAD) implantation. Plasma BNP levels were measured using a chemiluminescent immunoassay. RESULTS: During median follow-up of 29 months (interquartile range, 9-50), 3 patients died of progressive CHF, 5 patients required an urgent HTx, and 6 patients underwent VAD implantation. BNP was a strong predictor of end-stage CHF (hazard ratio per 100 ng/L: 1.079, 95% confidence interval, 1.042-1.117, P<0.001). The following variables with corresponding areas under the curve (AUC) were identified as the most significant predictors of end-stage CHF: BNP (AUC 1.00), New York Heart Association functional class class III or IV (AUC 0.98), decompensated CHF in the last year (AUC 0.96), and systolic dysfunction of the subpulmonal ventricle (AUC 0.96). CONCLUSION: BNP is a powerful predictor of end-stage CHF in individuals with systolic dysfunction of the SRV.

[The common position of the Czech professional associations on the consensus of the European Atherosclerosis Society and the European Federation of Clinical Chemistry and Laboratory Medicine regarding investigation on blood lipids and interpretation of their levels]. / Spolecné stanovisko ceských odborných spolecností ke konsenzu European Atherosclerosis Society a European Federation of Clinical Chemistry and Laboratory Medicine k vysetrování krevních lipidu a k interpretaci jejich hodnot.

The aim of this opinion is to summarize and to comment the consensus of the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine, which covers two main areas: 1) whether it is necessary / required to be fasting or non-fasting before blood sampling for lipids measurement, and what are the changes in the concentration of blood lipids during the day; 2) What decision limits (cut off value) of lipids and lipoproteins should be reported from laboratories and what is the recommended procedure for people with extreme / critical blood lipid values. Following parameters are discused: total cholesterol, LDL cholesterol, HDL cholesterol, non-HDL cholesterol, triglycerides, apolipoprotein A1, apolipoprotein B, lipoprotein(a). This opinion should be the object of interest both for professionals in clinical laboratories and for physicians in hospitals and out-patients departments.Key words: apolipoproteins - blood collection - cholesterol - laboratory testing - lipoprotein(a) - cut off limits - triglycerides.

Long-term biological variability of galectin-3 after heart transplantation.

BACKGROUND: Galectin-3 is an emerging biomarker of heart failure and of myocardial fibrosis risk. Monitoring of galectin-3 is essential during treatment with galectin-3 inhibitors. The aim of our study was to assess long-term biological variability in a specific group of unhealthy subjects. METHODS: The biological variability of galectin-3 was measured in a group of 44 patients after heart transplantation (HTx). Six samples were taken from each patient during a 12-month period. Galectin-3 was measured with an Abbott Architect automated immunoassay. RESULTS: Intraindividual (CVi) and interindividual (CVg) variabilities were calculated together with the reference change value (RCV), the log-normal RCV for increase (RCV+), and the log-normal RCV for decrease (RCV-). The CVi, CVg, RCV, RCV+, and RCV- were 28.2%, 35.6%, 78.6%, 116%, and -53.7%, respectively. The index of individuality was 0.79. CONCLUSIONS: The concentrations of galectin-3 in patients followed 12 months after HTx fluctuated around the homeostatic point, with CVi of approximately 28%. RCVs of +116% (log-normal increase) and -54% (log-normal decrease) mean that the concentration of galectin-3 would need to approximately double or decrease by half to indicate a new process.

A novel biomarker-based approach for the detection of asymptomatic brain injury during catheter ablation of atrial fibrillation.

BACKGROUND: Diffusion-weighted magnetic resonance imaging (DW-MRI) is a widely used method for studying of asymptomatic brain injury during catheter ablation of atrial fibrillation (AF). However, this technique lacks sensitivity for subtle or diffuse brain lesions. We investigated whether detection of the ablation-related brain injury can improve by assessment of a biomarker of brain damage-protein S100B. METHODS AND RESULTS: DW-MRI and assessment of S100B were performed in 58 patients undergoing radiofrequency catheter ablation of paroxysmal or persistent AF 1 day before and after the procedure. We observed no symptomatic neurological complications. S100B levels increased after ablation above the upper reference limit of 105 ng/L in 3 patients. One of them developed a new ischemic lesion on the DW-MRI. No acute lesions emerged on DW-MRI in the patients with normal postablation S100B levels. CONCLUSION: Serial assessment of serum protein S100B may improve detection of asymptomatic acute brain injury in patients undergoing radiofrequency catheter ablation of AF. In our study, the incidence of these events was 1.7% when evaluated only by DW-MRI, but the incidence increased to 5% after employing the more sensitive biomarker-based approach.

Analytical evaluation of the automated galectin-3 assay on the Abbott ARCHITECT immunoassay instruments.

BACKGROUND: Galectin-3 is secreted from macrophages and binds and activates fibroblasts forming collagen. Tissue fibrosis is central to the progression of chronic heart failure (CHF). We performed a European multicentered evaluation of the analytical performance of the two-step routine and Short Turn-Around-Time (STAT) galectin-3 immunoassay on the ARCHITECT i1000SR, i2000SR, and i4000SR (Abbott Laboratories). METHODS: We evaluated the assay precision and dilution linearity for both routine and STAT assays and compared serum and plasma, and fresh vs. frozen samples. The reference interval and biological variability were also assessed. Measurable samples were compared between ARCHITECT instruments and between the routine and STAT assays and also to a galectin-3 ELISA (BG Medicine). RESULTS: The total assay coefficient of variation (CV%) was 2.3%-6.2% and 1.7%-7.4% for the routine and STAT assays, respectively. Both assays demonstrated linearity up to 120 ng/mL. Galectin-3 concentrations were higher in plasma samples than in serum samples and correlated well between fresh and frozen samples (R=0.997), between the routine and STAT assays, between the ARCHITECT i1000 and i2000 instruments and with the galectin-3 ELISA. The reference interval on 627 apparently healthy individuals (53% male) yielded upper 95th and 97.5th percentiles of 25.2 and 28.4 ng/mL, respectively. Values were significantly lower in subjects younger than 50 years. CONCLUSIONS: The galectin-3 routine and STAT assays on the Abbott ARCHITECT instruments demonstrated good analytical performance. Further clinical studies are required to demonstrate the diagnostic and prognostic potential of this novel marker in patients with CHF.