Rapid association of acetaldehyde with hemoglobin in human volunteers after low dose ethanol

Peripheral systems: neuropathy

Long-term, excessive consumption of alcoholic beverages produces a peripheral neuropathy with symptoms of decreased superficial sensation, hyperalgesia, and weakness. Alcoholic neuropathy is characterized by axonal degeneration with reduced density of both small and large fibers and axonal sprouting. Electrophysiologic studies reveal a marked reduction in the amplitude of sensory potentials and moderate slowing of nerve conduction, mainly in the lower extremities. Dietary deficiency of vitamins, which are often associated with chronic alcoholism, can contribute to the pathogenesis. Recent studies using animal models have identified several mechanisms by which ethanol impacts peripheral nerve function. Ethanol can exert direct neurotoxic effects on peripheral nerves via its metabolite acetaldehyde and by enhancing oxidative stress. Ethanol activation of protein kinase Cε signaling in primary afferent nociceptors plays an important role in lowering nociceptive threshold. Further, ethanol causes cytoskeletal dysfunction and inhibits both anterograde and retrograde axonal transport. Alcoholic neuropathy is potentially reversible and treatments include abstinence from alcoholic beverages and consumption of a nutritionally balanced diet supplemented with B vitamins. However, response to these treatment strategies can be variable, which underscores the need for novel therapeutic strategies. In this review, we provide an overview of the clinical findings and insights on molecular mechanisms from animal models.

Biomarkers in alcoholism

Alcoholism ranks as one of the main current threats to the health and safety of people in most Western countries. Therefore, a high priority should be given to aims at reducing its prevalence through more effective diagnosis and early intervention. The need for objective methods for revealing alcohol abuse in its early phase has also been widely acknowledged. It is postulated here that the diagnosis of alcohol use disorders could be markedly improved by a more systematic use of specific questionnaires and laboratory tests, including blood ethanol, serum gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mean corpuscular volume of erythrocytes (MCV). Recent research has provided new insights into the relationships between ethanol intake, biomarkers, and factors affecting their diagnostic validation, including gender, age, and the effects of moderate drinking and obesity. It appears that the concept of reference intervals for several ethanol-sensitive parameters in laboratory medicine needs to be revisited. CDT is currently the most specific marker of alcohol abuse, and when combined with GGT using a mathematically formulated equation a high sensitivity is reached without loss of assay specificity. Possible new biomarkers include minor ethanol metabolites (protein-acetaldehyde condensates and associated autoimmune responses, ethylglucuronide, and phosphatidylethanolamine), 5-hydroxytryptophol, and genetic markers although so far their routine applications have been limited.

Long-term ethanol consumption and macrocytosis: diagnostic and pathogenic implications

Although excessive alcohol consumption is known to elevate the mean cell volume (MCV) of erythrocytes, the relationships among the intensity of ethanol exposure, the generation of abnormal red blood cell indices, and the underlying pathogenic mechanisms have remained unclear. The authors examined 105 alcoholics with a wide range of ethanol consumption (40-500 g of ethanol/day), 62 moderate drinkers (mean consumption 1-40 g/day), and 24 abstainers, who underwent detailed interviews, measurements of blood cell counts, markers of liver status, and circulating antibodies against ethanol-derived protein modifications. Follow-up information was collected from healthy volunteers with detailed records on drinking habits. Data from the NORIP project for laboratory parameters in apparently healthy moderate drinkers or abstainers (n = 845) were used for reference interval comparisons. The highest MCV (P < 0.001) and mean cell hemoglobin (MCH) (P < 0.01) occurred in the alcoholics. However, the values in the moderate drinkers also responded to ethanol intake such that the upper normal limit for MCV based on the data from moderate drinkers was 98 fl, as compared with 96 fl from abstainers. Follow-up cases with carefully registered drinking habits showed parallel changes in MCV and ethanol intake. Anti-adduct IgA and IgM against acetaldehyde-induced protein modifications were elevated in 94% and 64% of patients with high MCV, respectively, the former being significantly less frequent in the alcoholics with normal MCV (63%) (P < 0.05). The data indicate dose-related responses in red blood indices upon chronic ethanol consumption, which may also be reflected in reference intervals for hematological parameters in health care. Generation of immune responses against acetaldehyde-modified erythrocyte proteins may be associated with the appearance of such abnormalities.

Excess Alcohol Consumption Is Common in Patients With Cytopenia: Studies in Blood and Bone Marrow Cells

BACKGROUND

Although alcohol abuse is known to create a variety of adverse effects on hematopoiesis, the associations between ethanol consumption and hematological abnormalities have not been fully established.

METHODS

We studied 144 consecutive adult patients who underwent clinical and bone marrow examinations due to abnormal findings in peripheral blood cell counts or red blood cell indices without previously established diagnoses of specific hematological diseases, malignancies, or infections. Assessment included the amount of alcohol consumption, complete blood cell counts, morphological review of peripheral blood and bone marrow, markers of liver status, and erythrocyte folate and serum vitamin B12 levels.

RESULTS

There were 57 (40%) patients who showed a history of hazardous drinking and 87 patients who were either nondrinkers or social drinkers. The incidence of anemia was 51% in the alcohol abusers, as compared with 69% of the nonalcoholics (p < 0.05). A diverse pattern of hematological effects was observed in the alcohol abusers. Abnormal platelet and leukocyte levels were common, especially in the anemic alcoholics. Both increased mean cell volume of erythrocytes (macrocytosis; 67 vs. 18%; p < 0.0001) and mean cell hemoglobin (63 vs. 22%; p < 0.0001) were more frequent in the alcoholics than in the nonalcoholics. Reticulocytosis (37%), thrombocytopenia (41%), and combined cytopenias (34-38%) were also common findings in the alcoholic patients. The blood smears from such patients typically showed round macrocytes, stomatocytes, and knizocytes. Bone marrow aspirates revealed vacuolization of pronormoblasts in 24% of the alcoholic patients. Interestingly, megakaryocytes in the cell periphery were also vacuolized in 20% of the alcohol abusers, especially in those with recent intoxication.

CONCLUSIONS

Our findings suggest that alcohol abuse results in diverse patterns of hematological effects and affects several cell lines. Therefore, in patients undergoing bone marrow examinations due to cytopenias, the probabilities for likely findings seem to be different between alcoholics and nonalcoholics. Information on ethanol consumption should be systematically included in the clinical assessment of such patients.

Alcoholic macrocytosis--is there a role for acetaldehyde and adducts?

Although alcohol abuse is known to cause a wide array of adverse effects on blood cell formation, the molecular mechanisms by which alcohol exerts its toxic actions have remained poorly defined. Elevated mean corpuscular volume (MCV), macrocytosis, is the most typical morphological abnormality induced by excessive ethanol consumption. This paper reviews recent data indicating that acetaldehyde, the first metabolite of ethanol, may play a role in the haematological derangements in peripheral blood cells and in bone marrow of alcoholic patients. Studies in experimental animals and in human alcoholics have shown that acetaldehyde can bind to proteins and cellular constituents forming stable adducts. Elevated adduct levels have been found from the erythrocytes of alcohol abusers, which may also be associated with ethanol-induced effects in haematopoiesis and adverse consequences in cellular functions.

Biochemical markers of alcohol use in pregnant women

OBJECTIVES

To describe the serious health consequences of alcohol (ethanol) use, especially as they relate to pregnancy and the development of fetal alcohol syndrome (FAS) and fetal alcohol effects (FAE). The classic markers of alcohol exposure, including blood/breath alcohol, gamma-glutamyl transferase (gammaGT), mean corpuscular volume (MCV), hemoglobin-associated acetaldehyde (HAA) and carbohydrate deficient transferrin (CDT), are valuable and their methods of analysis are reviewed.

CONCLUSIONS

Since both FAS and FAE represent two of the leading preventable causes of mental retardation and birth defects, identification of alcohol use early in pregnancy is important to avoid adverse fetal outcomes. Unfortunately, the diagnosis of FAS and FAE is usually made after birth, when alcohol damage has become irreversible and permanent. The clinical laboratory can help prevent this damage and make a valuable contribution in assessing prenatal alcohol use. The clinical utility of blood/breath alcohol, gammaGT, MCV, HAA and CDT in alcohol use identification, especially in pregnancy, is substantial. Although none of the markers singularly has adequate sensitivity and specificity for screening, their diagnostic utility increases when measured as a panel. This is especially true in detecting alcohol use in pregnancy where the presence of several positive markers was correlated with the presence of alcohol-related fetal effects.

Prevalence of ethanol consumption may be higher in women than men in a university health service population as determined by a biochemical marker: whole blood-associated acetaldehyde above the 99th percentile for teetotalers

To estimate ethanol consumption by university students attending a student health facility, a biochemical marker of alcohol intake [whole blood associated acetaldehyde (WBAA)] was quantified by fluorimetric HPLC. Over a two year period we studied blood samples, coded by date and sex, from 645 females and 332 males, and compared the results to previously established reference ranges for teetotalers by sex. Men had higher absolute values for WBAA than women (9.9 versus 9.5 microM in the present study). However, significantly greater numbers of women (74%) than men (44%) had WBAA levels above the 99th percentile for teetotalers. Variations occurred during the academic year, with significant elevations occurring in the late fall and winter months. Testing of WBAA levels in a student health service may be important especially for women to facilitate counseling on the dangers of alcohol abuse.

The prenatal detection of significant alcohol exposure with maternal blood markers

OBJECTIVE

To examine the efficacy of a combination of 4 blood markers of alcohol use in detecting alcohol-abusing pregnant women.

STUDY DESIGN

Two new markers of alcohol use, whole blood-associated acetaldehyde and carbohydrate-deficient transferrin, and 2 traditional markers of alcohol use, gamma-glutamyl transpeptidase and mean red blood cell volume, were measured in the blood of pregnant women. Each woman was interviewed about alcohol and drug use, medical and obstetric histories, and nutrition. Each infant was examined by a clinician who was blinded to exposure status.

RESULTS

All of the women who reported drinking an average of 1 or more ounces of absolute alcohol per day had at least 1 positive blood marker. The infants of mothers with 2 or more positive markers had significantly smaller birth weights, lengths, and head circumferences than the infants with negative maternal screens. The presence of 2 or more positive markers was more predictive of infant outcome than any self-reporting measure.

CONCLUSIONS

These markers, which detect more at-risk pregnant women than self-reporting methods, could lead to better efforts at detection and prevention of alcohol-induced fetal damage.

Structural analysis of peptide-acetaldehyde adducts by mass spectrometry and production of antibodies directed against nonreduced protein-acetaldehyde adducts

Acetaldehyde can form protein-acetaldehyde adducts (AAs) in vivo and may play a role in the genesis of alcoholic liver disease. The nature of the chemical modification of proteins by acetaldehyde in vivo has not been elucidated. In vitro, acetaldehyde can form reversible adducts including a Schiff's base with lysine (K) and imidazolidinone with terminal amino groups of proteins such as human hemoglobin (Hb). In this study, we used FAB/MS to analyze the products of peptide-AAs (pep-AAs) formed by incubating acetaldehyde with Hb peptides. We then used an octabranched multiple antigen peptide (MAP) system containing Hb peptide-AAs to raise antibodies. Three Hb peptides [i.e., 8-pep consisting of 8 residues (V1HLTPVEK8) at the N-terminus of beta-chain of human sickle-cell Hb, 11-pep-gly consisting of 11 residues (G56NPKVKAHGKK66) in a segment of beta-chain rich in lysine, and 11-pep-pro that consists of the same sequence as 11-pep-gly, except G56 was replaced by proline (P)] were incubated with 1 mM acetaldehyde at 4 degrees C for 7d without NaCNBH3 (nonreduced conditions). Analysis by FAB/MS showed that 8-pep formed an imidazolidinone at the N-terminal valine, 11-pep-gly formed a Schiff's base and imidazolidinone at the N-terminus, whereas 11-pep-pro that lacks a free alpha-amino group formed only a Schiff's base at K59. By contrast, incubation of these Hb peptides with 250 mM acetaldehyde and NaCNBH3 at 37 degrees C for 1 hr (reduced conditions) produced mono- and diethylated modifications of all available K residues, as well as the N-terminal amino group.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantifying ethanol by high performance liquid chromatography with precolumn enzymatic conversion and derivatization with fluorimetric detection

We quantified ethanol by measurement of the subsequent increase in acetaldehyde after reaction with alcohol dehydrogenase and nicotinamide adenine dinucleotide (ADH-NAD) with a fluorimetric HPLC method. Ethanol standards ranging from 0.3 to 200 mg/dl were investigated and the limit of quantitation of the fluorimetric HPLC method was found to be 6 mg/dl. The accuracy of the HPLC method was assessed by assaying blood samples containing 6-200 mg/dl of ethanol and comparing its results to those of the ADH-NAD enzymatic method (r2 = 0.993). The coefficients of variation for intraassay (assayed ten times) and interassay (assayed on 7 consecutive days) were 6.7% and 9.3% for blood samples containing 50 mg/dl of ethanol and 4.0% and 17.9% for blood samples containing 200 mg/dl of ethanol. The blood ethanol concentrations of a volunteer after a pulse of 0.3 g/kg of ethanol determined with the described HPLC method were correlated to the results from the ADH-NAD enzymatic method (r2 = 0.986). In conclusion, the fluorimetric HPLC method for measurement of ethanol here described is of potential clinical utility.

Studies of the oxidation of ethanol to acetaldehyde by oxyhemoglobin using fluorigenic high-performance liquid chromatography

We noted a rise in acetaldehyde levels in clinical samples of venous whole blood containing ethanol that did not occur in samples from teetotalers. Experiments were performed to define the mechanism involved in acetaldehyde production. The addition of 0.10% ethanol to whole blood produced an immediate increase in acetaldehyde due to acetaldehyde in the stock solution followed by a subsequent increase that became statistically significant by 48 hr. Separation of blood into components documented that the increase in acetaldehyde was associated with the red cell but not plasma fraction. Incubation of isolated hemoglobin with ethanol produced a rise in acetaldehyde levels. Incubation of oxygenated whole blood with ethanol produced a linear increase in acetaldehyde, whereas nitrogen-exposed blood produced no increase. The rise of acetaldehyde in the presence of ethanol was dependent on the concentration of oxygenated hemoglobin A0. Addition of inhibitors of catalase, alcohol dehydrogenase, and glycolytic enzymes (aminotriazole, azide, pyrazole, sodium fluoride, sodium citrate, and iodoacetate) did not inhibit the rise of acetaldehyde, but addition of the hemoglobin ligand cyanide abolished the rise in acetaldehyde. Kinetic analysis with oxygenated whole blood plus inhibitors revealed a Km of 2.5 mM and Vmax of 1.42 microM/min. We conclude that oxyhemoglobin contributes to the metabolism of ethanol to acetaldehyde. These findings may explain in part the high levels of acetaldehyde found in red cells compared with plasma. The results also have implications for the optimum storage of blood samples for acetaldehyde analysis.

Enzymes and circulating proteins as markers of alcohol abuse

The identification of alcohol abuse is an important social and clinical objective for which various biochemical procedures have been utilized, serum enzymes and circulating proteins being predominant. Tests are required to detect alcohol abuse as screening procedures in the general population as well as for the specific diagnosis of those presenting as hospital inpatients or outpatients, especially when liver disease is present or suspected. The amino-transferases are of limited value, although the mitochondrial isoenzyme of aspartate amino-transferase has been strongly advocated and is quite useful in detecting alcoholics among patients with liver disease. Gammaglutamyl transferase, by contrast, is raised in all forms of liver disease but can identify 30-50% of those consuming excessive amounts of alcohol before organic damage becomes manifest. Serum carbohydrate-deficient transferrin (CDT) is raised in many alcohol abusers without and most with liver damage, but is rarely elevated in other forms of liver disease. Haemoglobin-associated acetaldehyde, the newest biochemical index to be evaluated in alcoholics, is one of several adducts formed by the reaction of acetaldehyde with various proteins, and antibodies to these adducts may contribute, at least in part, to immunological tissue damage provoked by chronic excessive consumption of alcohol. Its assay is technically complex and it appears to be present in higher concentrations in heavy drinkers than in those who fulfill the criteria of addictive alcohol abuse. Many other markers have been introduced in the last decade but the search for a reliable index continues. CDT comes closest at the present time to matching the desired specificity, although it is of limited value in screening unselected non-hospitalized subjects.

Association of high density lipoprotein with whole blood-associated acetaldehyde levels

We hypothesized that while moderate drinking is associated with increasing levels of high density lipoprotein (HDL) levels, excessive drinking of ethanol might, in fact, be associated with lower HDL levels and by implication increased cardiovascular risk. We therefore performed analyses of whole blood-associated acetaldehyde (WBAA) as a measure of drinking behavior and HDL on blood samples from 2780 individuals applying for life insurance. Whole blood-associated acetaldehyde correlated positively with HDL in the entire sample set throughout the range of values (R = 0.101, p = 0.0001). The relationship held for females (N = 477, p = 0.036) but was stronger for males (N = 2277, p = 0.0001). We conclude that ethanol consumption correlates positively with HDL for both males and females and that the relationship persists through higher ranges of ethanol consumption.

Studies of whole blood-associated acetaldehyde levels in teetotalers

We measured whole blood-associated acetaldehyde (WBAA) levels in 225 teetotalers (123 females, 102 males) between the ages of 18 and 86 years. Values were normally distributed, but mean values for females were significantly lower than for males (7.6 +/- 0.6 vs. 7.9 +/- 0.7 microM, p < 0.0001). There was a significant positive correlation with age for the entire group (r2 = 0.149, p = 0.001) and for both sexes. The correlation with WBAA and age was stronger for females. Significant but lesser positive correlations were found between WBAA and other variables that increase with age, including glucose, fructosamine, cholesterol, alkaline phosphatase, serum glutamate pyruvate transaminase (SGPT), gamma glutamyl transpeptidase (GGT), and creatinine in the entire data set. Partial r analyses indicated that the correlations were mediated through the primary association of WBAA and age. We conclude that in individuals who do not consume ethanol there are significant sex differences in whole blood acetaldehyde and that the values increase throughout life.

Comparative evaluation of the clinical utility of three markers of ethanol intake: the effect of gender

We evaluated three markers of ethanol intake [whole blood associated acetaldehyde (WBAA), serum beta-hexosaminidase, and gamma-glutamyl transpeptidase (GGT)] in four groups of subjects: teetotalers (n = 104), random insurance applicants or "normals" (n = 1,010), subjects enrolling in an alcohol treatment program or "alcoholics" (n = 31), and subjects attending outpatient drug/alcohol treatment follow-up clinics (n = 128). Significant differences (p < 0.004 for each assay and each comparison) were found in the mean values between teetotalers and normals and normals and alcoholics. Male teetotalers and normals had significantly (p < 0.002) higher levels of WBAA than females of the same group. Male normals had significantly higher levels of GGT than females (p < 0.001). GGT increased with age in the normal population into the fifth decade and decreased thereafter. WBAA was the most sensitive assay with 97% of alcoholics having values above the 99th percentile for the teetotaler population (vs. 66% for serum beta-hexosaminidase and 70% for GGT). None of the alcoholic subjects had values for all three assays below the 99th percentile for teetotalers compared with 21% of those in follow-up and 72% of normals. We conclude that WBAA appears to be the best of the three markers studied and that measurement of multiple markers for ethanol use appears clinically useful and incremental.

The identification and partial characterization of acetaldehyde adducts of hemoglobin occurring in vivo: a possible marker of alcohol consumption

Chromatographic, peptide mapping and mass spectrometric analysis were used to examine hemoglobin (Hb) from heavy drinkers and abstainers for alcohol consumption-related modifications. Heavy drinker and abstainer hemoglobin samples contained similar amounts of glycosylated Hb and significantly different (p < 0.05) amounts of "fast" hemoglobin. The presence of higher amounts of "fast" Hb in heavy drinker relative to abstainer samples suggested the presence of alcohol-consumption related modifications. To further examine Hb for modifications, tryptic peptides of the "fast" hemoglobin HbA1c were isolated and analyzed by plasma desorption mass spectrometry (PDMS). [14C]acetaldehyde (AcH)-Hb was synthesized in vivo for use as a standard. Specific peptides were chosen based on co-migration with radiolabeled peptides from a tryptic digest of the [14C]acetaldehyde-Hb. The masses obtained by PDMS for two heavy drinker peptides were identical to two radiolabeled peptides; the two pairs of peptides co-migrated on HPLC. A comparison of the observed mass for the peptides with the theoretical masses for acetaldehyde-modified Hb peptides suggested that the peptides were AcH-modified alpha and beta chain N-termini of Hb. The modified peptides were found in five of six heavy drinker samples. This is the first description of site-specific AcH-Hb adducts occurring in vivo. The routine detection of such adducts has potential for characterizing usual alcohol intake.

Utility and evaluation of biochemical markers of alcohol consumption

Biochemical markers of alcohol consumption have a variety of clinical and research applications. Currently available markers such as the serum gamma-glutamyl transpeptidase (GGT), serum transaminases, and the mean corpuscular volume (MCV) lack sufficient sensitivity and specificity to be used for screening of alcoholism in ambulatory patients. However, these tests can be helpful in corroborating a clinical suspicion of alcoholism. A number of special laboratory markers of alcoholism recently have been developed which may have increased diagnostic accuracy. Promising potential markers include serum carbohydrate-deficient transferrin (CDT), red blood cell acetaldehyde, and acetaldehyde adducts. The application of reliable and practical markers of alcohol consumption could lead to significant improvements in the treatment of alcoholism and in the assessment of clinical trials.

Effect of acetaldehyde on hemoglobin: HbA1ach as a potential marker of heavy drinking

The appearance of a new acetaldehyde-induced hemoglobin fraction, HbA1ach, and the effect of alcohol consumption on it and on the ratio of HbA1ach and glycated hemoglobin, HbA1c, were studied in vivo by cation exchange liquid chromatography. The mean +/- SEM of blood HbA1ach level was 171 +/- 13.10(-3)% of total hemoglobin as measured in 34 male teetotallers. Blood HbA1ach levels of 127 social drinkers (182 +/- 6.10(-3)%) were compared with those of 72 heavy drinkers (213 +/- 8.10(-3)%, p less than 0.01), 79 alcoholics (209 +/- 6.10(-3)%, p less than 0.01) and 16 diabetics (419 +/- 28.10(-3)%, p less than 0.001). HbA1ach correlated positively with HbA1c (p less than 0.001) and negatively with HbAo (p less than 0.001). The ratio of HbA1ach/HbA1c was effective in detecting the alcohol-induced increase in the HbA1ach fraction because the ratio reduced the disturbing effect of glucose. The sensitivity of the HbA1ach/HbA1c ratio was 33% in the heavy drinker group as compared to 40% of gamma-glutamyltransferase and 24% of mean corpuscular volume. The HbA1ach fraction and the HbA1ach/HbA1c ratio seem to be valuable in detecting excessive alcohol consumption in its early phase.

Hemoglobin associated acetaldehyde correlates with the Self-Administered Alcoholism Screening Test but not glycated hemoglobin in type II diabetes mellitus

Twenty seven subjects with Type II diabetes mellitus underwent analysis of the Self-Administered Alcoholism Screening Test (SAAST) and hemoglobin associated acetaldehyde levels (HbAA). The SAAST scores and HbAA levels correlated with one another (r = .48, p = 0.009). No correlation between glycated hemoglobin levels (GHb) and HbAA levels or SAAST was found. Glucose incubation of whole blood led to an increase in GHb but no change in HbAA. We conclude that HbAA and SAAST correlate with each other when measured in patients with diabetes. Therefore each test appears clinically useful in quantifying alcohol consumption in individuals with Type II diabetes mellitus.

Hemoglobin-acetaldehyde adducts in human volunteers following acute ethanol ingestion

Rabbit antibodies against albumin-acetaldehyde adduct were used in an enzyme-linked immunosorbent assay to detect acetaldehyde-hemoglobin condensates from the blood of 12 volunteers following ingestion of 1.3 to 2.9 g of ethanol per kg body weight during 8 hr. Blood samples were drawn before drinking and between 2 to 46 hr after starting the drinking session. While there were no significant increases in blood acetaldehyde levels in these samples, acetaldehyde-hemoglobin adducts were significantly increased in the samples drawn after ethanol had been eliminated from the body. Administration of ethanol (0.1 g/kg) to an Oriental flusher resulted in an increase both in blood acetaldehyde and the hemoglobin-acetaldehyde adduct levels. These results suggest that acetaldehyde-hemoglobin condensates are formed in vivo following acute ethanol ingestion. Such condensates may be of value to mark alcohol consumption.

A comparative blinded study in miniature swine of whole blood-, hemoglobin-, platelet-, plasma-, and lymphocyte-associated acetaldehyde as markers for ethanol intake

Blood samples were obtained from miniature swine maintained on 0, 2, or 6 g/kg/24 hr ethanol for 8 months (N = 6 in each group). Samples from drinking pigs were taken after 8 hr of ethanol abstinence and all were coded and sent for "blinded" analysis. A fluorigenic high performance liquid chromatographic assay was used to quantify whole blood-associated acetaldehyde, hemoglobin-associated acetaldehyde, plasma-associated acetaldehyde, platelet-associated acetaldehyde, and lymphocyte-associated acetaldehyde. Detectable levels of acetaldehyde were found in each sample in both drinking and nondrinking pigs. Analysis of whole blood-associated acetaldehyde was most discriminatory in distinguishing nondrinking from drinking pigs (mean 21.4 +/- 1.0 microM for nondrinkers vs. 24.6 +/- 1.5 SD for the group consuming 2 g/kg ethanol, p = 0.001). Measurements of hemoglobin-associated acetaldehyde normalized to protein concentration (250 +/- 47 nmoles/g vs. 203 +/- 33 SD, p less than 0.05 drinking vs. nondrinking pigs) and platelet-associated acetaldehyde (0.46 0.34 vs. 0.15 +/- 0.16 nmoles/3 x 10(8) platelets, p = 0.05 drinking vs. nondrinking pigs) were also useful in discriminating drinking from nondrinking animals. Analysis of plasma-associated acetaldehyde and lymphocyte-associated acetaldehyde were not useful as markers of ethanol consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of self-administered alcoholism screening test with hemoglobin-associated acetaldehyde

Thirty subjects underwent analysis of the Self-Administered Alcoholism Screening Test (SAAST) and hemoglobin-associated acetaldehyde levels (HbAA). Eleven alcoholic individuals reporting for treatment, 10 self-defined "social drinkers" and 10 self-defined "teetotallers" who had consumed less than 6 drinks of ethanol per year ever in their lifetime and had not knowingly had ethanol for 6 months were included in the study. The SAAST scores and HbAA levels correlated with one another (r = .55, p = 0.002). For alcoholic individuals, the mean HbAA level was 180 +/- 64 nm/g Hb and the mean SAAST score was 17.3 +/- 6.3. Both analyses could distinguish the alcoholic from the teetotaller group (p = 0.03 for HbAA and p less than 0.001 for the SAAST) and from the group of social drinkers (p = 0.04 for HbAA and p less than 0.001 for the SAAST). The difference in HbAA levels between the social drinkers and teetotallers was not significant (132 +/- 25 vs. 129 +/- 15 nm/g Hb). After modification of the SAAST analysis for teetotallers, SAAST scores were significantly different between social drinkers and teetotallers (3.5 +/- 2.2 vs. 1.1 +/- 1.2, p = 0.009). We conclude that HbAA and SAAST correlate with each other may be clinically useful in distinguishing alcoholic from nonalcoholic individuals. While the SAAST appears to be the more sensitive test, it requires modification in the case of teetotallers.

The effect of cigarette smoking on breath and whole blood-associated acetaldehyde

Six pairs (1 habitual smoker and 1 nonsmoking control) of volunteers were studied to determine the effect of smoking tobacco on breath and whole blood acetaldehyde levels. On a given study day, samples of blood and breath were obtained from both participants at -0.25, 0, 0.25, 0.50, 0.75, 1.5, 2.5, and 3.5 hour time points. The smoking volunteer was told to smoke 1-3 cigarettes between the 0 and 0.25 hour time points. Acetaldehyde levels in breath and whole blood were quantified with a fluorigenic high performance liquid chromatographic assay. Acetaldehyde in breath rose six-fold in smokers at the 0.25 hour time point and returned to levels not significantly different from baseline values found in smokers or nonsmokers by 0.50 hr. Whole blood-associated acetaldehyde measurements remained unchanged in smokers throughout the experiment and were not different from nonsmokers. In conclusion, while smoking produces appreciable levels of acetaldehyde in expired air, the partitioning of acetaldehyde associated with smoking to blood or blood proteins appears to be below the level of detection of the assay employed (picomolar). Smoking of tobacco products may not interfere with assays designed to quantify ethanol intake by measuring acetaldehyde adducts with blood proteins.

Studies of whole blood associated acetaldehyde as a marker for alcohol intake in mice

Thirty C57BI mice were randomized into two groups. Group 1 served as controls while Group 2 was given 10% V/V ethanol with the drinking water. Whole blood- associated acetaldehyde (WBAA) was measured on capillary blood samples using a fluorigenic high performance chromatographic assay. WBAA peaked at Day 2. A stable mean plateau of 263 +/- 71 SD with a range of 160-400 nmoles/g hemoglobin WBAA was found in the group consuming ethanol compared with 122 +/- 17 SD and a range of 88-150 nmoles/g hemoglobin for controls (p less than 0.001). When ethanol was discontinued, levels of WBAA declined and became similar to those of controls by 9 days following cessation of ethanol. The quantitative difference between ethanol-consuming and control animals and also the rapid rise of whole blood-associated acetaldehyde and the relatively slow decline following cessation of ethanol intake indicate that such a test might be a useful monitor of drinking behavior.

Characterization of the increased binding of acetaldehyde to red blood cells in alcoholics

Using equilibrium dialysis, we found that acetaldehyde, at the levels commonly occurring after ethanol ingestion, did not bind detectably to plasma proteins, but there was significant binding to red blood cells, more in alcoholics than in nonalcoholics. The binding to red blood cells was inhibited by pyridoxal phosphate and N-ethylmaleimide, suggesting adduction to amino and thiol groups. Binding kinetics were consistent with at least two sites. The one with the highest affinity for acetaldehyde corresponded to hemoglobin. Its affinity and Bmax were not changed in alcoholics, but these binding sites accounted for only 44% of the sites available in the red blood cells of alcoholics and 80% of those in controls. Moreover, this binding was not inhibited by N-ethylmaleimide. There was no detectable binding to red cell ghosts. Nonprotein binding was then assessed by changes in NADH produced by the addition of protein-free fractions of the cells to an alcohol dehydrogenase system in equilibrium; this revealed a second binder of lower affinity, larger capacity and with sensitivity to both inhibitors. This binding (possibly due to thiazolidine formation with cysteine) was enhanced in alcoholics, whose red blood cell cysteine content was doubled. Levels of red blood cell cysteine and acetaldehyde remained high for 2 weeks after withdrawal. Because of the prolonged persistence after withdrawal, these changes may provide new markers of alcoholism.