Galectin-3 as a Prognostic Biomarker in Subclinical Atherosclerosis Patients with Lymphoproliferative Diseases

Aim: evaluate the prognostic value of galectin-3 (Gal-3) for cumulative survival in subclinical atherosclerosis patients with controlled lymphoproliferative diseases. Methods: One hundred eighty two out subjects with full or partial remission of lymphoproliferative diseases (43 patients with multiple myeloma, 101 subjects with chronic lymphoid leukemia, and 10 patients with Hodgkin's and non-Hodgkin's lymphoma. Observation period was up to 3 years. Blood samples for biomarkers measurements were collected. ELISA method for measurements of circulating level of Gal-3 was used. Concentrations of Gal-3 and NT-pro-brain natriuretic peptide (BNP) for cumulative survival cases due to advanced CHF were tested. Results: One hundred ninety six cumulative clinical events occurred in 42 patients (23.1%) within the follow-up, with their distribution being as follows: 29 deaths, 65 cardiac arrhythmias, 17 cardiac ischemic events, 9 strokes, 37 chronic heart failures and 39 hospital admissions for cardiovascular reasons. Medians of circulat-70 Borys B. Samura ing levels of Gal-3 in subjects without and with cardiovascular events were 5.10 ng/ml (95% confidence interval [CI] = 4.70-5.50 ng/ml) and 16.5 ng/ml (95% CI = 14.80-18.10 ng/ml) (P<0.001) respectively. The results of regression analysis showed directly related circulating Gal-3 with Е/Аm (r = 0. lesion of coronary artery were selected as predictors in the univariate logistic regression analysis. Multivariate logistic regression revealed independent predictive value of circulating Gal-3 for three-year cumulative cardiovascular events NT-pro-BNP, GFR, and LVEF remained statistically significant predictors for cumulative cardiovascular events, whereas T2DM, hypertension, obesity, and multi-vessel lesion did not. Conclusion: Increased circulating Gal-3 associates with increased 3-year cumulative cardiovascular events among patients with documented lymphoproliferative diseases and known asymptomatic atherosclerosis.


Introduction
Nature development of lymphoma and multiple myeloma associates with increased risk of cardiovascular diseases and atherotrombotic events [8].Activation of inflammatory cells, such as macrophages, due to lymphoproliferative diseases progression contributes plaque instability, vascular microcalcification, endothelial dysfunction, that are considered the pivotal mechanism of worsening vascular disease [10].In fact, that some drugs (bendamustin, kladribin) that used for treatment in lymphoma and multiple myeloma patients may induced endothelial dysfunction and discorded vascular repair mechanisms [6].As cell-to-cell interactions are critical in the processes of lymphoproliferative diseases, galectin-3 (Gal-3) have become of interest as novel regulators of inflammation.Gal-3 is a member of a family of β-galactosidebinding lectins that recognize specific oligosaccharide, ligand glycoproteins or glycolipids on the membranes of neighboring cells or in the extracellular matrix [5].Gal-3 is produced by activated macrophages and it is predominantly expressed in subclinical atherosclerosis, unstable and stable coronary artery disease, heart failure [2,7,9].Therefore, Gal-3 is not only key player in inflammation and as well as in tumor progression by displaying intracellular and extracellular activities [4].However, the predictive role of Gal-3 in stable patients with lymphoproliferative diseases is not understood.The aim of the study to evaluate the prognostic value of galectin-3 for cumulative survival in subclinical atherosclerosis patients with controlled lymphoproliferative diseases.

Design and Methods
One hundred eighty two out subjects with full or partial remission of lymphoproliferative diseases (43 patients with multiple myeloma, 101 subjects with chronic lymphoid leukemia, and 10 patients with Hodgkin's and non-Hodgkin's lymphoma) who underwent cardiac computer tomography (CT) angiography and documented asymptomatic coronary artery disease (CAD) were enrolled in the study.All subjects gave their written informed consent to participation in the study.Diagnosis and staging of lymphoproliferative diseases were defined by current clinical practice guidelines [12,13].To be achieving remission chemotherapy with FC, R-FC, R-CHOP, CHOP, mini-CHOP, COP, ABVD, VTD, CTD, TD, bendamustine, kladribine was used accordingly contemporary clinical guidelines.All subjects were at full or partial remission stage at baseline.
Echocardiography in B-mode was performed accordingly to Recommendation of American Society of Echocardiography on the scanner "MyLab 50" (Italy) using a transducer with a frequency of 2.5-3.5 MHz.Enddiastolic and end-systolic LV volumes were obtained using a two-dimensional reference sector according to Simpson's method, and LV ejection fraction (LVEF) was calculated by accordingly conventional methods [3].
Coronary vessel-wall, and plaque geometrical, and compositional parameters were measured on contrast-enhanced spiral computer tomography (CT) angiography [1].Contrast-enhanced spiral CT was performed on the "OPTIMA CT 660" scanner (GE Medical Systems, and Milwaukee, USA) with 2 rows of detectors (32 × 2 CT system) during the end-expiratory breath-hold.After noncontrast localization image acquisition, injection of nonionic contrast "Omnipak" (Amersham Health, Ireland) was used to determine the optimal coronary arterial image.Standardized calcium scores were obtained with beam energy of 120 kV, full rotation time of 350 milliseconds, and tube current of 300 mA.The images were reconstructed in 0.6-mm axial slices.Scans were electrocardiogram-gated and were triggered at either 40% or 75% phase contingent on heart rate.
All blood samples were collected after fasting in cooling vacutaner and after that it was immediately centrifugated (4°C for 6.000 × 15 min).After centrifugation serum was blind coded and stored at -70° until used.Human Gal-3 and NT-pro-brain natriuretic peptide (BNP) were measured by ELISA technique (ELISA kits manufactured by R&G, United Kingdom) used for examination.All determinations were done by duplicating.Fasting plasma glucose (FPG) was quantified by the glucose oxidase procedure; HbA1c was measured by ion-exchange high-performance liquid chromatography (HPLC; Bio-Rad, Hercules, CA, USA).
Concentrations of total cholesterol (TC) and high density lipoprotein (HDL) cholesterol were determined by a Dimension Clinical Chemistry System (Dade Behring Inc, Newark, NJ).Low density lipoprotein (LDL) cholesterol was calculated by using the formula of Friedewald W.T., Levy R.I., Fredrickson D.S. (1972).All measurements and blood sample for were collected at the same visit.

Clinical Events: Screening and Diagnostics
Clinical interviews were carried out every month for three years after baseline.The following are the clinical events verified: newly diagnosed strokes or TIAs; death for any reasons and sudden cardiac death; coronary ischemic events (myocardial infarction, unstable angina) that needed hospital admission for cardiovascular reasons, new-onset chronic heart failure.Newly diagnosed strokes were confirmed with CT.All clinical events were presented as cumulative.

Statistical Analysis
All statistical analyses were performed in SPSS for Windows v. 17.0 (SPSS Inc., Chicago, IL, USA).All values were given as mean and 95% CI or median and percentiles.An independent group t-test was used for comparisons for all interval parameters meeting the criteria of normality and homogeneity of variance.For interval parameters not meeting these criteria, the non-paramentric Mann-Whitney test was used to make comparisons between the groups.Comparisons of categorical variables between the groups were performed using the Chi2 test, and the Fisher exact test.The potential factors that may be associated with cardiovascular events was identified first by the univariate analysis, then multivariate logistic regression analyses were used to identify the predict factors.A calculated difference of P<0.05 was considered significant.

Results
One hundred ninety six cumulative clinical events occurred in 42 patients (23.1%) within the follow-up, with their distribution being as follows: 29 deaths, 65 cardiac arrhythmias, 17 cardiac ischemic events, 9 strokes (5 lacunar infarctions and 2 cardioembolic strokes), 37 CHF and 39 hospital admissions for cardiovascular reasons.
General characteristics of study patients are presented in table 1.The patients of both cohorts were age-, sex-, conventional risk factor-, hemodynamic parameters matched.There was significant difference between both cohorts in incidences of heart failure (P<0.001).Therefore, circulating level of NT-pro-BNP was higher in free-events subject cohort when compared with subjects cohort with cardiovascular events occurred.
All hypertensive patients were treated according to current clinical guidelines with diet, lifestyle modification and drug therapy that included ACE Galectin-3 as a prognostic biomarker 73 inhibitors / ARBs, aspirin or other antiagregants, statins.Metformin was prescribed in 3 (2.1%) and 5 (11.9)T2DM patients in both cohorts, in other cases diet and life-style modification were recommended only.Because incidences of CHF was seen significantly often in subjects cohort with cardiovascular events in comparison with free-events subject cohort, however, ACEI / ARAs, mineralcorticoid receptor antagonists, and diuretics have been used frequent.

Discussion
Gal-3 is a unique chimera-type member of the β-galactoside-binding soluble lectin family involved in several biological functions such as intracellular signaling, cell to cell interaction and exchanges between cells and the extracellular matrix.It is well known that Gal-3 is therefore participating to the control of gene expression, the regulation of immune response and the control of cell growth and viability [5].Recent researches suggest that Gal-3 plays various roles in pathogenesis of cardiovascular diseases and malignancy [2,9,11].Gal-3 is also involved in immune-mediated cell damage through inducting cell apoptosis, increasing both IL-17 and IFN-gamma synthesis, but decreasing IL-10 production [11].All this mechanisms are not unique and are involved in plaque instability.Results of the study showed that exaggerated circulating level of Gal-3 in stable patients with lymphoproliferative diseases may consider biomarker with power predictive value for cardiovascular events whether for tumor progression did not.Probably it may be related with small size of the study or short-term period of the observation.However, association of Gal-3 with tumor progression was not found.Author think that it is needed more studies with higher statistical power to be recognized prognostic potential of Gal-3 in two directions: cardiovascular outcomes and tumor progression.Taken together, it could be discussed around cut-off of Gal-3 plasma level that is suitable for stable and unstable patients with lymphoproliferative diseases associated with different rick of tumor progression.
In conclusion, it is found that increased circulating Gal-3 associates with increased 3-year cumulative cardiovascular events among patients with documented lymphoproliferative diseases and known asymptomatic coronary atherosclerosis.

Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Limitations of the study.This study has some limitations.We believed that a greater cohort would be desirable to improve the power of the study.We also relied on clinical data to rule out infection and other inflammatory diseases before sampling, but we couldn't exclude that some patients had unrecognized the conditions responsible for the elevated Gal-3 levels.

Figure 1 :
Figure 1: Boxplot shows a significant difference between medians of circulating Gal-3 in died and survived patients

Table 1
General characteristic of patients participating in the study

Table 2 :
Univariate and multivariate predictors of three-year cumulative cardiovascular events