Serum and saliva levels of sialic acid are elevated in alcoholics

Salivary Carbohydrate-Deficient Transferrin in Alcohol- and Nicotine-Dependent Males

Serum carbohydrate-deficient transferrin (CDT), an 80 kDa glycoprotein, is one of the most commonly employed biomarkers to detect alcohol dependence. Some salivary glycoproteins such as α-amylase, clusterin, haptoglobin, light/heavy-chain immunoglobulin, and transferrin, which alter glycosylation in alcohol-dependent persons, have been suggested to be potential alcohol markers. However, their identification is based on indirect analysis of lectin glycosidic bonds and molecular weight. We investigated the CDT content in the saliva of alcohol- and nicotine-dependent men. The CDT concentration (ng/mL, ng/mg protein) was determined by an Enzyme-Linked Immunosorbent Assay (ELISA) commercial kit in 55 men: 20 healthy social drinkers (C), 10 chronic cigarette smokers (S), 10 alcohol-dependent non-smokers (A), and 15 alcohol-dependent smokers (AS). Surprisingly, there were no differences in the concentrations of CDT between the studied groups. Salivary pH was the lowest in the AS and the highest in the A group. Therefore, salivary CDT cannot be used as an alcohol dependence marker as measured by ELISA. We suggest that direct identification of glycoproteins is necessary to search for potential salivary alcohol biomarkers. Molecules smaller than 40 kDa, which easily translocate from blood to the saliva, might be preferred as salivary alcohol markers.

Long-term changes of salivary exoglycosidases and their applicability as chronic alcohol-drinking and dependence markers

OBJECTIVES

Investigation of long-term dynamic changes of salivary activity/output of exoglycosidases, deglycosylation processes and their applicability as alcohol markers.

METHODS

Exoglycosidase (α-fucosidase (FUC), β-galactosidase (GAL), β-glucuronidase (GLU), β-hexosaminidase (HEX, HEX A and HEX B isoenzymes) and α-mannosidase (MAN)) activities were measured in the saliva of healthy social drinking controls (C), alcohol-dependent non-smokers (ANS) and alcohol-dependent smokers (AS) at the 1st, 15th, 30th and 50th day of abstinence after chronic alcohol drinking.

RESULTS

The activity of exoglycosidases was 2-3-fold (MAN), 2-6 fold (FUC), 8-25-fold (HEX A) and 19-40-fold (GLU) higher in the ANS and AS groups than in controls, and had good/excellent sensitivity, specificity and accuracy. The higher outputs of exoglycosidases were in the AS and ANS groups than in controls at the 1st day (GLU, HEX A) and at the 50th day (GLU, FUC, MAN) of abstinence. We found numerous correlations between alcohol-drinking days with GLU and HEX A, alcohol amounts with HEX A and duration of alcohol dependence with FUC and MAN activity/output.

CONCLUSIONS

Salivary exoglycosidases/deglycosylation processes were still very high up to 50 days after the end of alcohol consumption. We found markers of chronic alcohol consumption (HEX A), alcohol dependence (FUC and MAN) and chronic alcohol consumption and dependence (GLU).

Total and free serum sialic acid concentration in liver diseases

Background. The objective of this study was to compare the levels of total (TSA) and free (FSA) sialic acid in acute and chronic liver diseases. Materials and Methods. The serum TSA and FSA levels were determined in 278 patients suffering from acute and chronic liver diseases of different etiologies. TSA was estimated by enzymatic method and FSA by the thiobarbituric method modified by Skoza and Mohos. Results. There were no significant differences in the serum TSA concentration between liver diseases of different etiologies, although in most of the liver diseases the mean TSA level was significantly lower than that in the control group. In contrast to TSA, the concentration of FSA appears to differ between liver diseases. In toxic hepatitis it was higher than that in nonalcoholic cirrhosis. However, neither of them differs between alcoholic and nonalcoholic cirrhosis or between liver tumors and tumors with cirrhosis. Conclusions. We conclude that the changes in concentrations of TSA and FSA during the same liver diseases indicate significant disturbances in sialylation of serum glycoproteins.

Effect of Alcohol Withdrawl on Glutathione S-transferase, Total Antioxidant Capacity and Amylase in Blood and Saliva of Alcohol-Dependent Males

INTRODUCTION

Alcohol biomarkers help in the early detection of alcoholism and its complications. There is a paucity of studies in India on the salivary markers of systemic diseases in general and on salivary alcohol biomarkers in particular.

OBJECTIVES

The present study was aimed at assessing the effect of alcohol withdrawal on the antioxidants and amylase in blood and saliva, and at finding the correlation between the blood and the salivary parameters in alcoholics.

METHODS

Sixty alcohol-dependent males who were in the age group of 30 - 70 years, who were admitted to the Deaddiction Centre for alcohol withdrawal treatment for one month, were the subjects of this study; age-matched healthy individuals were the controls. In the blood and saliva samples, the activities of Glutathione S-Transferase (GST) and amylase and the Total Antioxidant Capacity (TAC) were assayed.

RESULTS

The alcohol-dependent subjects showed significantly lower GST and amylase activities and the TAC in blood and saliva as compared to those in the controls (P<0.001). The alcohol withdrawal caused a significant increase in the GST and amylase activities and the TAC to near-control values. In the alcohol-dependent subjects, there was a significant correlation between the values in blood and saliva with respect to GST and TAC.

CONCLUSIONS

Alcoholism causes an impaired antioxidant capacity and a decreased secretion of amylase, which is ameliorated due to the alcohol withdrawal regimen . The strong correlation between blood and saliva with respect to the antioxidants suggests the potential future use of saliva as a laboratory tool in clinical medicine.

Salivary hexosaminidase in smoking alcoholics with bad periodontal and dental states

BACKGROUND

A sensitive alcohol marker, β-hexosaminidase (HEX), in the saliva of alcoholics, is investigated for the first time.

METHODS

The activity, specific-activity and output of total HEX and its isoenzymes HEX A and HEX B were measured in the saliva of healthy controls (C), alcohol-dependent non-smokers (ANS), and alcohol-dependent smokers (AS).

RESULTS

We observed a significantly increased activity/specific-activity and output of HEX A in the ANS and AS groups, due to the inflammatory state of the oral-cavity/salivary-glands. Significantly increased activity of HEX A contributed to an increase in the salivary activity of the total HEX in the ANS group. A significant decrease in the activity/specific-activity of HEX B in AS seemed to be due to HEX B inactivation by cigarette smoke. We noticed a tendency for deteriorated dental state (lower decayed-missing-filled-teeth index - DMFT), worse periodontal state (higher gingival index - GI and papilla-bleeding index - PBI) in AS, and worse periodontal state (higher GI) in ANS, as compared to the controls. We found no differences in the salivary protein concentrations between all groups and decreased salivary flow in both alcoholic groups as compared to the controls. In alcoholics, the area under the curve (AUC) for HEX A activity/specific-activity was significantly greater than for HEX and HEX B. The salivary HEX A activity/specific-activity had good/excellent sensitivity and specificity in smoking and non-smoking alcoholics, whereas salivary HEX and HEX B had poor/fair sensitivity and specificity.

CONCLUSIONS

Salivary HEX A may be helpful in the diagnosis of chronic alcohol intoxication, even in smokers.

Identification of N-acetyltaurine as a novel metabolite of ethanol through metabolomics-guided biochemical analysis

The influence of ethanol on the small molecule metabolome and the role of CYP2E1 in ethanol-induced hepatotoxicity were investigated using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics platform and Cyp2e1-null mouse model. Histological and biochemical examinations of ethanol-exposed mice indicated that the Cyp2e1-null mice were more resistant to ethanol-induced hepatic steatosis and transaminase leakage than the wild-type mice, suggesting CYP2E1 contributes to ethanol-induced toxicity. Metabolomic analysis of urinary metabolites revealed time- and dose-dependent changes in the chemical composition of urine. Along with ethyl glucuronide and ethyl sulfate, N-acetyltaurine (NAT) was identified as a urinary metabolite that is highly responsive to ethanol exposure and is correlated with the presence of CYP2E1. Subsequent stable isotope labeling analysis using deuterated ethanol determined that NAT is a novel metabolite of ethanol. Among three possible substrates of NAT biosynthesis (taurine, acetyl-CoA, and acetate), the level of taurine was significantly reduced, whereas the levels of acetyl-CoA and acetate were dramatically increased after ethanol exposure. In vitro incubation assays suggested that acetate is the main precursor of NAT, which was further confirmed by the stable isotope labeling analysis using deuterated acetate. The incubations of tissues and cellular fractions with taurine and acetate indicated that the kidney has the highest NAT synthase activity among the tested organs, whereas the cytosol is the main site of NAT biosynthesis inside the cell. Overall, the combination of biochemical and metabolomic analysis revealed NAT is a novel metabolite of ethanol and a potential biomarker of hyperacetatemia.

Salivary lipid peroxidation and total sialic acid levels during healthy gestation and postpartum: a longitudinal study

OBJECTIVES

This study investigated salivary lipid peroxidation (LPO) as an oxidative stress marker and salivary total sialic acid (TSA) as an inflammatory response during gestation and postpartum.

DESIGN AND METHODS

Salivary LPO and TSA levels, using the Ledwozyw and Warren methods respectively, were obtained in healthy pregnant women followed up during gestation and 6-8 weeks postpartum, and in healthy non-pregnant controls. All were with good oral health.

RESULTS

LPO was significantly higher than controls during all trimesters and postpartum and in the second trimester than in the third trimester and postpartum. TSA in the second trimester was significantly higher than in any other group. First trimester levels were significantly higher than postpartum . Oral health indices remained within normal levels for the duration.

CONCLUSION

The salivary LPO profile followed plasma gestation and postpartum profiles in the literature but the salivary TSA differed in that after the 2nd trimester, rather than persisting, it decreased.

Chronic alcohol consumption augments loss of sialic acid residues and alters erythrocyte membrane charge in type II diabetic patients

In this study, the effects of alcohol consumption on erythrocyte membrane properties in type 2 diabetic patients were investigated. Therefore, we measured total and lipid-bound sialic acid (LSA) levels, sialidase activities, and erythrocyte membrane negative charge. Three groups, including control group (n = 20), alcohol-consuming diabetic patients group (n = 14), and diabetic patients without alcohol consumption group (n = 42), were created. Plasma total sialic acid (TSA) levels of the alcohol-consuming diabetic group were elevated as compared to the healthy control and diabetic group (p < 0.001 and p < 0.01, respectively). TSA levels of the diabetic group were significantly elevated as compared to the healthy control group (p > 0.001). Plasma LSA levels of the alcohol-consuming diabetic group were higher than that in the healthy control and diabetic group (p < 0.05 and p < 0.05, respectively). LSA levels of the diabetic group were found to be high as compared to the healthy control group (p < 0.05). Plasma sialidase activities of the alcohol-consuming diabetic group and diabetic group were significantly elevated as compared to the healthy control group (p < 0.05 and p < 0.05, respectively). Sialidase activities of the alcohol-consuming diabetic group were elevated as compared to the diabetic group, but this was not statistically significant (p > 0.05). Erythrocyte membrane negativity levels of the alcohol-consuming diabetic group and diabetic group were significantly decreased (p < 0.001 and p < 0.001, respectively) as compared to the healthy control group. Erythrocyte membrane negativity levels of the alcohol-consuming diabetic group were decreased as compared to the diabetic group, but this was not statistically significant (p > 0.05). In conclusion, our results indicate that chronic alcohol consumption may augment membrane alterations in type 2 diabetic patients.

Relationship between serum sialic acid and sialylated glycoproteins in alcoholics

AIMS

Total sialic acid (TSA) has been suggested as a marker for chronic alcohol abuse. It seems that the elevation of TSA during excessive alcohol consumption reflects the changes in sialylated glycoproteins in the sera. On the other hand, chronic ethanol consumption increases the desialylation rate of many serum glycoproteins. The aim of this study was to evaluate the relationship between the total and free form of sialic acid levels (FSA), and the concentration of sialylated glycoproteins in alcoholics.

METHODS

We determined the serum concentration of many glycoproteins (alpha1-antitrypsin, alpha1-acid glycoprotein, haptoglobin, ceruloplasmin, transferrin, complement C3 protein, fibrinogen and immunoglobulin G) in a sample of 100 alcoholics and 30 healthy controls. Total sialic acid was determined by the enzymatic method and its free form by using a modification of the thiobarbituric acid method.

RESULTS

Among alcoholics, we found increased concentrations of alpha1-antitrypsin and alpha1-acid glycoprotein but decreased levels of transferrin. The concentrations of TSA and FSA were significantly higher in alcoholics than in healthy controls. The tested glycoproteins, except for transferrin and immunoglobulin G, positively correlated with TSA and FSA. The correlations with TSA were higher than that with FSA.

CONCLUSIONS

Chronic alcohol abuse alters the concentrations of some sialylated glycoproteins in the sera. The alpha1-antitrypsin, alpha1-acid glycoprotein, and transferrin are the only affected glycoproteins. The serum level of total and free form of sialic acid in the sera of alcoholics depends on the concentration of the most sialylated glycoproteins.

Serum free sialic acid as a marker of alcohol abuse

BACKGROUND

Previous studies have shown that serum total sialic acid (TSA) concentration significantly increases during alcohol abuse. Chronic ethanol consumption impairs glycosylation of many proteins. The increased desialylation rate of serum glycoproteins is one of the effects of alcohol abuse. The aim of this study was to investigate the diagnostic value of free sialic acid (FSA) as a marker of alcohol abuse.

METHODS

We determined serum FSA concentrations in the group of 156 alcoholic subjects and 35 healthy control subjects by means of a modification of the thiobarbituric acid method. The alcoholic group was divided into subgroups according to their history of abuse.

RESULTS

The FSA concentration was significantly higher in alcoholic subjects than in healthy controls. The subjects who consumed alcohol for longer than a week showed significantly higher FSA level than those who consumed alcohol for a shorter period. The serum FSA concentration was significantly higher in alcoholic subjects with elevated markers of liver dysfunction. The diagnostic accuracy of FSA was high, although it did not differ from TSA, and was limited by its low sensitivity.

CONCLUSIONS

This study shows that FSA concentration in the sera of alcoholic subjects is increased. The low diagnostic sensitivity is accompanied by high specificity, however the accuracy is high and similar to the accuracy of TSA. Free sialic acid does not seem to be a better marker of alcohol abuse than TSA and current markers.

Betaine prevents loss of sialic acid residues and peroxidative injury of erythrocyte membrane in ethanol-given rats

To evaluate chronic ethanol toxicity on erythrocyte membrane and preventive action of betaine as a methyl donor, 24 male Wistar albino rats were divided into three groups: control, ethanol and ethanol plus betaine group. Animals were fed 60 ml diet per day for two months. Rats in the ethanol group were fed ethanol 8 g/kg/day. The ethanol + betaine groups were fed ethanol plus betaine (0.5% w/v). After two months, all animals were killed. Malondialdehyde (MDA) and sialic acid (SA) levels were determined in plasma samples. Osmotic fragility tests were performed on whole blood samples and erythrocyte membrane thiol contents were determined using membrane suspensions. Plasma MDA levels in ethanol-given rats were increased significantly compared to the control group of rats (p < 0.05). MDA in the betaine group was significantly lower than that in the ethanol group (p < 0.05). Erythrocyte membrane thiol contents in ethanol group were decreased compared with those of the control group (p < 0.05). Thiol contents were increased slightly after betaine therapy, but this increase was not statistically significant (p > 0.05). Plasma sialic acid levels in the ethanol group were significantly higher than in the control group (p < 0.05). Sialic acid was decreased in the betaine group compared to the ethanol group (p < 0.05). In the osmotic fragility test, we observed that chronic ethanol consumption increased erythrocyte hemolysis. Betaine protected against ethanol-induced hemolysis. Our findings show that chronic ethanol administration affects erythrocyte membrane properties and this may be related to oxidative stress. Betaine protects erythrocyte membrane alterations against chronic ethanol toxicity. Therefore betaine as a nutritional agent, may protect ethanol induced clinical problems associated with membrane abnormalities.

[Biological markers of alcoholism]

Diagnosis of alcoholism is very important, given its high prevalence and possibility of influencing the disease course. For this reason, the so-called biological markers of alcoholism are useful. These are analytic parameters that alter in the presence of excessive alcohol consumption. The two most relevant markers are the gamma-glutamyltranspeptidase and carbohydrate deficient transferrin. With this clinical comment, we aim to contribute to the knowledge of these tests and promote its use in the clinical practice.

Method for localization of sialic acid on cell surface and cell interior in peripheral blood: A pilot study

This article presents a method for identification and localization of cell surface and intracellular sialoglycoconjugates of peripheral blood cells. To reveal cell surface conjugates, a sample of peripheral blood was incubated with lectin after centrifugation and rinsing. For intracellular localization in leukocytes, RBCs were lysed and the membranes were permeabilized prior to cytochemical reaction. Fluorescein isothiocyanate conjugated lectins were used for visualization in fluorescence microscope. All lectins bound specifically to the surface of erythrocytes. Confocal microscopy showed surface and intracellular labeling of permeabilized leukocytes. A part of the signal in eosinophils originated from binding of anionic fluorophore to cationic granular proteins.

Serum sialic acid and γ-glutamyltransferase levels in alcohol-dependent individuals

Alcohol abuse is a very common problem all over the world. Identification of alcoholism is crucial in preventing some adverse health effects, economical and social consequences of excessive alcohol consumption. The aim of this study was to determine sialic acid (SA) and gamma-glutamyltransferase (GGT) levels in serum samples of alcoholics and to compare the diagnostic accuracy of SA with the conventional marker, GGT. The results have shown that serum SA (p<0.01) and GGT levels (p<0.001) were significantly increased in alcohol-dependent individuals as compared with healthy controls. No significant relationship was observed between SA and GGT levels in alcohol-dependent subjects and control group. Interestingly, a positive correlation was found between amount of alcohol consumption and serum SA level (r = 0.381, p<0.05). In order to evaluate the ability of SA and GGT determinations to discriminate between alcohol-dependent subjects and healthy controls, an analysis of receiver operating characteristic (ROC) curve was performed. Data suggest that GGT and SA levels in serum may be used as valuable biological markers for detecting and monitoring alcohol abuse. In view of the findings, introducing serum SA determination can be recommended as a part of diagnostic tests for identifying alcohol abuse.

Current status of carbohydrate deficient transferrin, total serum sialic acid, sialic acid index of apolipoprotein J and serum beta-hexosaminidase as markers for alcohol consumption

AIMS

The purpose of this paper is to present a brief review of the literature and to summarize the current status of four biochemical markers for alcohol consumption, carbohydrate deficient transferrin (CDT), total serum sialic acid (TSA), sialic acid index of apolipoprotein J (SIJ) and serum beta-hexosaminidase (beta-HEX).

FINDINGS

Of these markers, CDT has been the most widely studied, is currently thought to be the most accurate predictor of alcohol consumption, is most readily available and is the only test approved by the FDA for the identification of heavy alcohol use. TSA and SIJ have the potential to be useful markers, but have only recently been discovered, are not readily available and have not yet been studied comprehensively. Finally, the relationship between serum beta-HEX and heavy alcohol consumption has been studied for about 20 years, but the test is not readily available and has not been widely accepted or used as a marker for heavy alcohol consumption.

CONCLUSIONS

These markers have the potential to be included in a combination of measurements to provide an accurate, more exact assessment of alcohol consumption in a variety of clinical and research settings.

Laboratory measures of alcohol (ethanol) consumption: strategies to assess drinking patterns with biochemical measures

Alcohol (ethanol) use is a global, health-related problem that spans a continuum ranging from low-risk, at-risk, and problem drinking to alcohol dependence and chronic abuse. Clinicians and researchers alike have the need to quantify drinking patterns to determine the risk for adverse, health-related events such as injury, liver damage, and cancer Biochemical measures of ethanol consumption are affected by temporal patterns of drinking as well as individual characteristics such as gender and age. The choice of a laboratory analysis to determine ethanol consumption is complex; no single laboratory test will predict drinking accurately across all drinking patterns, across the life span, and across gender. In conjunction with interviews and physical assessment, however, biochemical laboratory tests are sensitive tools used to measure both recent and long-term patterns of alcohol consumption.