Macrocytosis, macrocytic anemia, and genetic polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 in Japanese alcoholic men

Prevalence and Associated Factors of Anemia Among Hospital Admitted Patients in Eastern Ethiopia

Background

Anemia is one of the most common comorbidities frequently seen in admitted patients. However, there is a scarcity of evidence regarding anemia among hospital admitted patients in Ethiopia, particularly in the Harari Region. Therefore, this study aimed to assess the prevalence and associated factors of anemia among hospital admitted patients in Eastern Ethiopia.

Methods

A hospital-based cross-sectional study was conducted from October 25 to December 30, 2022. Four milliliters of venous blood were collected and complete blood count was done using the DxH 800 (Beckman Coulter, Inc, Miami, FL) hematology analyzer. The data were entered in Epi-data version 4 and exported to SPSS version 26 for statistical analysis. Bivariable and multivariable logistic regression models were fitted. The level of significance was declared at a p-value of < 0.05.

Results

Of the 381 hospital admitted patients, 64.8% (95% CI = 60.01, 69.65) of the participants were anemic. Admitted patients who drank standard alcohol daily (AOR = 3.78, 95% CI = 1.71, 8.30), underweight (AOR = 9.39, 95% CI = 2.90, 30.46), and undernourished patients (AOR = 2.59, 95% CI = 1.15, 5.84), patients admitted with chronic kidney disease (AOR = 11.16, 95% CI = 4.06, 30.64), chronic liver disease (AOR = 3.20, 95% CI = 1.21, 8.47), deep vein thrombosis (AOR = 6.22, 95% CI = 1.98, 19.52), infectious disease (AOR = 9.71, 95% CI = 2.77, 34.02), and chronic non-communicable disease (AOR = 7.01, 95% CI = 1.90, 25.99) were all significantly associated with anemia.

Conclusion

Anemia was common among hospital admitted patients and should prompt the focus on admission diagnoses that are likely to play leading roles in etiology. This information indicates a need for routine screening of anemia for all admitted patients to improve their health.

Metachronous primary gastric cancer after endoscopic resection in patients with esophageal squamous cell carcinoma

BACKGROUND

This study aimed to evaluate the risk factors for developing metachronous primary Gastric Cancer (GC) after Endoscopic Resection (ER) for esophageal Squamous Cell Carcinoma (SCC).

METHODS

We studied 283 patients with esophageal SCC who underwent ER. The study outcomes were as follows: (1) incidence of metachronous primary GC after ER; and (2) predictors for the development of metachronous primary GC after ER by the Cox proportional hazards model.

RESULTS

The median follow-up was 43.1 months (1.81-79.1), and the 3-year cumulative incidence of metachronous primary GC was 6.5% (95%CI: 4.1-10.4). The incidence of metachronous primary GC during the follow-up period was 2.31 per 100 person-years. The frequencies of severe gastric atrophy and macrocytosis at the timing of ER were significantly higher in patients with than without metachronous primary GC (91.7% vs. 73.2%, p = 0.0422, 20.8% vs. 5.2%, p = 0.0046, respectively). Severe gastric atrophy was associated with the development of metachronous primary GC (sex-and-age adjusted hazard ratio (HR) [95%CI] = 4.12 [0.95-27.78], p = 0.0093). Macrocytosis was associated with the development of metachronous primary GC (sex-and-age adjusted HR = 4.76 [1.75-13.0], p = 0.0012) and found to be an independent predictor for metachronous primary GC by multivariate Cox proportional hazards analysis (HR [95%CI] = 4.35 [1.60-11.84], p = 0.004).

CONCLUSIONS

Severe gastric atrophy and macrocytosis should be noted in the development of metachronous primary GC after ER for esophageal SCC. In particular, macrocytosis at the timing of ER was considered an important predictor.

CLINICAL TRIALS REGISTRY NUMBER

UMIN000001676.

Physiologically decreased F-18 fluorodeoxyglucose uptake in the lower vertebrae associated with daily drinking habit in Japanese men with alcohol flushing reaction

Alcohol flushing reaction (AFR) is known as one of the risks for esophageal squamous cell cancer, and scientists have been elucidating this issue. However, little attention has been given to relevant imaging features. This study aims to investigate whether physiological ¹⁸F-fluorodeoxyglucose (FDG) uptake patterns in vertebrae are associated with drinking habits or AFR. Japanese male patients who underwent FDG positron emission computed tomography for evaluation of their known or suspected malignancies or inflammatory diseases were asked about their drinking habits and AFR. Altogether, 192 patients, 139 every-day drinkers and 53 non-drinkers were evaluated. Comparing the FDG uptake between that in the thoracic region and that in the lumbar region, vertebral uptake was visually classified into four patterns: Ld, dominant in lumbar region; TL, almost equal in both regions; BL, slightly higher in thoracic region (borderline pattern); Td, dominant in thoracic region. The uptake patterns were evaluated according to drinking habit (every-day drinker or non-drinker), AFR (flusher or non-flusher), and the combination of these two factors (habit/reaction: every-day drinker/flusher, every-day drinker/non-flusher, non-drinker/flusher, or non-drinker/non-flusher). There were 95 flushers (51 every-day drinkers and 44 non-drinkers) and 97 non-flushers (88 every-day drinkers and 9 non-drinkers). Ld, TL, BL, and Td patterns were observed in 0, 109 (56.8%), 31 (16.1%), and 52 (27.1%) patients, respectively. Td and BL patterns were more frequently observed in every-day drinkers compared with non-drinkers (p = 0.0467). Though the uptake patterns did not differ between flushers and non-flushers (p = 0.116), the Td pattern was more frequently observed in every-day drinkers/flushers (51%) compared with every-day drinkers/non-flushers (20.5%), non-drinkers/flushers (13.6%), and non-drinkers/non-flushers (22.2%) (p = 0.0014). The Td pattern was observed in patients with various diseases, with higher frequency in esophageal cancer, head and neck cancer, and lung cancer compared with other diseases. In conclusion, drinking habits and AFR were related to the vertebral uptake pattern with decreased uptake in the lumbar region in Japanese male patients.

Assessing the impact of alcohol consumption on the genetic contribution to mean corpuscular volume

The relationship between the genetic loci that influence mean corpuscular volume (MCV) and those associated with excess alcohol drinking are unknown. We used white British participants from the UK Biobank (n = 362 595) to assess the association between alcohol consumption and MCV, and whether this was modulated by genetic factors. Multivariable regression was applied to identify predictors of MCV. GWAS, with and without stratification for alcohol consumption, determined how genetic variants influence MCV. SNPs in ADH1B, ADH1C and ALDH1B were used to construct a genetic score to test the assumption that acetaldehyde formation is an important determinant of MCV. Additional investigations using mendelian randomisation and phenome-wide association analysis were conducted. Increasing alcohol consumption by 40 g/week resulted in a 0.30% (95% CI: 0.30 to 0.31%) increase in MCV (P < 1.0x10-320). Unstratified (irrespective of alcohol intake) GWAS identified 212 loci associated with MCV, of which 108 were novel. There was no heterogeneity of allelic effects by drinking status. No association was found between MCV and the genetic score generated from alcohol metabolising genes. Mendelian randomisation demonstrated a causal effect for alcohol on MCV. Seventy-one SNP-outcome pairs reached statistical significance in phenome-wide association analysis, with evidence of shared genetic architecture for MCV and thyroid dysfunction, and mineral metabolism disorders. MCV increases linearly with alcohol intake in a causal manner. Many genetic loci influence MCV, with new loci identified in this analysis that provide novel biological insights. However, there was no interaction between alcohol consumption and the allelic variants associated with MCV.

Prenatal alcohol-related alterations in maternal, placental, neonatal, and infant iron homeostasis

BACKGROUND

Prenatal alcohol exposure (PAE) is associated with postnatal iron deficiency (ID), which has been shown to exacerbate deficits in growth, cognition, and behavior seen in fetal alcohol spectrum disorders. However, the mechanisms underlying PAE-related ID remain unknown.

OBJECTIVES

We aimed to examine biochemical measures of iron homeostasis in the mother, placenta, neonate, and 6.5-month-old infant.

METHODS

In a prenatally recruited, prospective longitudinal birth cohort in South Africa, 206 gravidas (126 heavy drinkers and 80 controls) were interviewed regarding alcohol, cigarette, and drug use and diet at 3 prenatal visits. Hemoglobin, ferritin, and soluble transferrin receptor (sTfR) were assayed twice during pregnancy and urinary hepcidin:creatinine was assayed once. Infant ferritin and hemoglobin were measured at 2 weeks and 6.5 months and sTfR was measured at 6.5 months. Histopathological examinations were conducted on 125 placentas and iron transport assays (iron regulatory protein-2, transferrin receptor-1, divalent metal transporter-1, ferroportin-1, and iron concentrations) were conducted on 63.

RESULTS

In multivariable regression models, prenatal drinking frequency (days/week) was related to higher maternal hepcidin and to sequestration of iron into storage at the expense of erythropoiesis in mothers and neonates, as evidenced by a lower hemoglobin (g/dL)-to-log(ferritin) (ug/L) ratio [mothers: raw regression coefficient (β) = -0.21 (95% CI: -0.35 to -0.07); neonates: β = -0.15 (95% CI: -0.24 to -0.06)]. Drinking frequency was also related to decreased placental ferroportin-1:transferrin receptor-1 (β = -0.57 for logged values; 95% CI: -1.03 to -0.10), indicating iron-restricted placental iron transport. At 6.5 months, drinking frequency was associated with lower hemoglobin (β = -0.18; 95% CI: -0.33 to -0.02), and increased prevalences of ID (β = 0.09; 95% CI: 0.02-0.17) and ID anemia (IDA) (β = 0.13; 95% CI: 0.04-0.23). In causal inference analyses, the PAE-related increase in IDA was partially mediated by decreased neonatal hemoglobin:log(ferritin), and the decrease in neonatal hemoglobin:log(ferritin) was partially mediated by decreased maternal hemoglobin:log(ferritin).

CONCLUSIONS

In this study, greater PAE was associated with an unfavorable profile of maternal-fetal iron homeostasis, which may play mechanistic roles in PAE-related ID later in infancy.

Risk factors for esophageal iodine-unstained lesions and changing trends among Japanese alcohol-dependent men (2003-2018)

Globally, a decreasing incidence of male esophageal squamous cell carcinoma (ESCC) has been observed in recent decades. We evaluated the determinants of esophageal distinct iodine-unstained lesions (DIULs), high-cancer-risk lesions and ESCC, among 3858 Japanese alcohol-dependent men (40-79 years) who underwent chromoendoscopic screening between 2003 and 2018. The initial screening detected DIULs ≥ 5 mm in 541 patients (dysplasia in 319 and SCC in 129) and multiple DIULs in 640. The detection rates for DIULs and chronic atrophic gastritis (CAG), pack-years, and the mean corpuscular volume (MCV) decreased over the course of the study period, while the detection of hiatal hernia and/or columnar-lined esophagus (HH/CLE) and the carriers of inactive heterozygous aldehyde dehydrogenase-2 (ALDH2, rs671) increased. Multiple logistic regression analyses showed that an older age, larger number of pack-years, smaller body mass index, larger MCV, presence of a slow-metabolizing alcohol dehydrogenase-1B genotype (rs1229984), presence of an inactive heterozygous ALDH2 genotype, and more advanced degree of CAG increased the odds ratios (ORs) for DIULs, while the 2008-2013 and 2014-2018 screening periods had lower ORs for DIULs than the 2003-2007 screening period. The presence of HH/CLE decreased the OR for multiple DIULs and was associated with a more proximal location of ESCC. In conclusion, the detection of DIULs in an alcohol-dependent population decreased between 2003 and 2018. In addition to reported determinants of ESCC, CAG and HH/CLE were associated with the risk of DIULs. Enigmatically, however, the decline in the detection of DIULs was not adequately explained by these factors and warrants further research.

Daily Ethanol Drinking Followed by an Abstinence Period Impairs Bone Marrow Niche and Mitochondrial Function of Hematopoietic Stem/Progenitor Cells in Rhesus Macaques

BACKGROUND

Unhealthy consumption of alcohol is a major public health crisis with strong associations between immunological dysfunctions, high vulnerability to infectious disease, anemia, and an increase in the risk of hematological malignancies. However, there is a lack of studies addressing alcohol-induced changes in bone marrow (BM) and hematopoiesis as fundamental aspects of immune system function.

METHODS

To address the effect of chronic alcohol consumption on hematopoietic stem and progenitor cells (HSPCs) and the BM niche, we used an established rhesus macaque model of voluntary alcohol drinking. A cohort of young adult male rhesus macaques underwent a standard ethanol self-administration protocol that allowed a choice of drinking alcohol or water 22 hours/day with periods of forced abstinence that elevated subsequent intakes when alcohol availability resumed. Following the last month of forced abstinence, the monkeys were euthanized. HSPCs and bone samples were collected and analyzed in functional assays and by confocal microscopy.

RESULTS

HSPCs from alcohol animals exhibited reduced ability to form granulocyte-monocyte and erythroid colonies in vitro. HSPCs also displayed a decrease in mitochondrial oxygen consumption linked to ATP production and basal respiratory capacity. Chronic alcohol use led to vascular remodeling of the BM niche, a reduction in the number of primitive HSPCs, and a shift in localization of HSPCs from an adipose to a perivascular niche.

CONCLUSIONS

Our study demonstrates, for the first time, that chronic voluntary alcohol drinking in rhesus macaque monkeys leads to the long-term impairment of HSPC function, a reduction in mitochondrial respiratory activity, and alterations in the BM microenvironment. Further studies are needed to determine whether these changes in hematopoiesis are persistent or adaptive during the abstinent period and whether an initial imprinting to alcohol primes BM to become more vulnerable to future exposure to alcohol.

Association between macrocytosis and metachronous squamous cell carcinoma of the esophagus after endoscopic resection in men with early esophageal squamous cell carcinoma

BACKGROUND

Macrocytosis is associated with an increased risk of squamous cell carcinoma (SCC) arising in the esophagus in men. The aim of this study was to evaluate the association between macrocytosis and metachronous SCC of the esophagus after endoscopic resection (ER) of early esophageal SCC in men.

METHODS

The study group comprised 278 men with early esophageal SCC after ER. The main study variables were as follows: (1) cumulative incidence and total number of metachronous SCC of the esophagus according to the presence or absence of macrocytosis (mean corpuscular volume ≥ 106 fl) and (2) predictors of metachronous SCC of the esophagus as assessed with a multivariate Cox proportional-hazards model.

RESULTS

The median follow-up was 50.3 months. Macrocytosis was associated with a higher 2-year cumulative incidence of metachronous SCC of the esophagus (without macrocytosis vs. with macrocytosis: 11.4% vs. 38.1%, p = 0.002). Macrocytosis was also associated with a higher total number of metachronous SCC of the esophagus per 100 person-years (without macrocytosis vs. with macrocytosis: 7.7 vs. 31.5 per 100 person-years, p < 0.0001). In addition, macrocytosis was a significant predictor of metachronous SCC of the esophagus on multivariate Cox proportional-hazards analysis (relative risk 2.23).

CONCLUSION

Macrocytosis is a useful predictor of the risk of metachronous SCC of the esophagus after ER of early esophageal SCC in men.

Relationships of Habitual Alcohol Intake with Erythrocyte-Related Indices in Middle-Aged Japanese Men

BACKGROUND

Anemia is induced by chronic alcohol abuse. However, it remains to be clarified whether a habitual alcohol intake affects erythrocyte-related indices in a general population.

METHODS

The subjects were 16,014 Japanese male workers aged 30-65 years. The subjects were divided into non-, occasional, and regular drinkers based on the frequency of alcohol consumption. Regular drinkers were further quantitatively divided based on their daily alcohol consumption into light, moderate, and heavy drinkers. Relationships between alcohol drinking and erythrocyte-related indices were investigated.

RESULTS

Erythrocyte counts and hemoglobin levels tended to be lower and higher, respectively, with increases in the frequency and amount of drinking. In logistic regression analysis, the odds ratios (OR) for abnormally low erythrocyte counts of moderate and heavy drinkers vs. nondrinkers were significantly higher than the reference level of 1.00 and the values tended to be higher with an increase in the alcohol intake. The OR vs. nondrinkers for abnormally low levels of hemoglobin and hematocrit were significantly lower than the reference level in all of the drinker groups and they were lowest in light drinkers among the drinker groups.

CONCLUSION

A habitual alcohol intake has different associations with erythrocyte counts and hemoglobin and with low erythrocyte counts and low hemoglobin. Thus, alcohol is thought to have diverse effects on erythropoiesis.

Endoscopic screening using esophageal iodine staining and genotypes of ADH1B and ALDH2 in Japanese alcohol-dependent women

BACKGROUND

The presence of large or multiple esophageal distinct iodine-unstained lesions (DIULs) is a strong predictor of field cancerization in the upper aerodigestive tract. Several risk factors for DIULs, including genetic polymorphisms of alcohol and aldehyde dehydrogenases (ADH1B, rs1229984; ALDH2, rs671), have been demonstrated in Japanese alcohol-dependent men. However, few evaluations of alcohol-dependent women have been conducted in this field.

METHODS

Using multiple logistic regression models, we investigated the results of screening using esophageal iodine staining and the identification of determinants for esophageal DIULs in 472 Japanese alcohol-dependent women.

RESULTS

DIULs ≥5 mm, multiple DILUs, and both characteristics were observed in 35 (7.4%), 31 (6.6%), and 16 (3.4%) patients, respectively. DIULs ≥5 mm were histologically diagnosed as low-grade intraepithelial neoplasia in 26 patients and superficial squamous cell carcinoma in 9 patients. Although the inactive heterozygous ALDH2*1/*2 genotype was more common (33.3% vs. 11.4%, p = 0.002) in the group with DIULs ≥5 mm than in the group without DIULs ≥5 mm, no significant differences in the results of a questionnaire asking about current and past facial flushing after a glass of beer were seen between the groups with and without DIULs ≥5 mm. When individuals with current or former flushing were assumed to have inactive ALDH2, the sensitivity and specificity of current or former flushing to identify the presence of inactive ALDH2 were 50.0% and 93.5%, respectively; these values were previously reported to be 88% and 92%, respectively, in a Japanese general female population. The low sensitivity in the present study suggests that a lack of alcohol flushing may play a crucial role in the development of alcohol dependence in women with inactive ALDH2. No significant differences in age, usual alcohol consumption, or smoking habits were observed according to ADH1B and ALDH2 genotypes. Multiple logistic regression analyses showed that the slow-metabolizing ADH1B*1/*1 genotype (odds ratio [95% confidence interval], 12.5 [4.82-32.4] and 9.89 [3.50-27.9]), the inactive heterozygous ALDH2*1/*2 genotype (2.94 [1.18-7.38] and 3.79 [1.40-10.3]), a lower body mass index per -1 kg/m2 (1.17 [1.02-1.35] and 1.38 [1.14-1.67]), and a mean corpuscular volume ≥106 fl (3.70 [1.56-8.81] and 3.27 [1.24-8.64]) increased the risk of DIULs ≥5 mm and multiple DIULs, respectively. The combination of ADH1B*1/*1 and ALDH2*1/*2 markedly increased the risk of esophageal DIULs ≥5 mm (39.3 [10.6-146]).

CONCLUSIONS

Japanese alcohol-dependent women shared several common risk factors for esophageal squamous cell neoplasia with alcohol-dependent men, but with considerably different magnitudes.

The Bidirectional Effect of Defective ALDH2 Polymorphism and Disease Prevention

Despite the role of aldehyde dehydrogenase 2 (ALDH2) in the detoxification of endogenous aldehydes, the defective polymorphism (rs671), which is highly prevalent among East Asians, does not show a serious phenotype, such as congenital abnormality. However, unfavorable and favorable impacts of the variant allele, ALDH2*2, on various disease risks have been reported. The underlying mechanisms are often complicated due to the compensatory aldehyde detoxification systems. As the phenotypes emerge due to overlapping environmental factors (e.g., alcohol intake and tobacco smoke) or individual vulnerabilities (e.g., aging and apolipoprotein E ε4 allele), polymorphism is therefore considered to be important in the field of preventative medicine. For example, it is important to recognize that ALDH2*2 carriers are at a high risk of alcohol drinking-related cancers; however, their drinking habit has less adverse effects on physiological indices, such as blood pressure, body mass index, levels of lipids, and hepatic deviation enzymes in the blood, than in non-ALDH2*2 carriers. Therefore, opportunities to reconsider their excessive drinking habit before adverse events occur can be missed. To perform effective disease prevention, the effects of ALDH2*2 on various diseases and the biological mechanisms should be clarified.

Identification of three novel loci of ALDH2 Gene for Serum Folate levels in a Male Chinese Population by Genome-Wide Association Study

BACKGROUND

Serum folate is important in clinical researches and DNA synthesis and methylation. Some loci and genes that are associated with folate levels had been detected by genome-wide association studies (GWAS), such as rs1801133 in MTHFR and rs1979277 in SHMT1. Nevertheless, only a small part of variants has been clearly identified for serum folate. Hence, we conducted a GWAS to discover new inherited susceptibility and gene-environment interactions on serum folate concentration.

MATERIALS AND METHODS

In a healthy Chinese population of 1999 men, genotyping was performed using Illumina HumanOmni1-Quad BeadChip. Serum folate levels were measured by enzyme-linked immunosorbent assay (ELISA), pathway enrichment analysis and statistical analysis were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID) and Statistic Package for Social Science (SPSS).

RESULTS

We validated that rs1801133 in MTHFR was significantly involved in serum folate (P = 4.21 × 10^-19). Surprisingly, we discovered three novel loci rs3782886, rs671, and rs4646776 of ALDH2 gene were suggestively significantly associated with folate serum folate levels in the male population studied (P = 2.17 × 10^-7, P = 3.60 × 10^-7, P = 3.99 × 10^-7, respectively) after adjusting for population stratification, BMI and age. Men with the AA genotype had significantly higher serum folate levels compared with men with the GG/AG genotype. But we found ALDH2 gene mutation no relation to part of environmental factors on serum folate levels.

CONCLUSION

In a male Chinese population, genome-wide association study discovered that three novel SNPs rs3782886, rs671 and rs4646776 of ALDH2 gene were suggestively significantly associated with serum folate levels.

[Importance of an Aldehyde Dehydrogenase 2 Polymorphism in Preventive Medicine]

Unlike genetic alterations in other aldehyde dehydrogenase (ALDH) isozymes, a defective ALDH2 polymorphism (rs671), which is carried by almost half of East Asians, does not show a clear phenotype such as a shortened life span. However, impacts of a defective ALDH2 allele, ALDH2*2, on various disease risks have been reported. As ALDH2 is responsible for the detoxification of endogenous aldehydes, a negative effect of this polymorphism is predicted, but bidirectional effects have been actually observed and the mechanisms underlying such influences are often complex. One reason for this complexity may be the existence of compensatory aldehyde detoxification systems and the secondary effects of these systems. There are many issues to be addressed with regard to the ALDH2 polymorphism in the field of preventive medicine, including the following concerns. First, ALDH2 in the fetal stage plays a role in aldehyde detoxification; therefore, prenatal health effects of environmental aldehyde exposure are of concern for ALDH2*2-carrying fetuses. Second, ALDH2*2 carriers are at high risk of drinking-related cancers. However, their drinking habits result in less worsening of physiological findings, such as energy metabolism index and liver functions, compared with non-ALDH2*2 carriers, and therefore opportunities to detect excessive drinking can be lost. Third, personalized medicine such as personalized prescriptions for ALDH2*2 carriers will be required in the clinical setting, and accumulation of evidence is awaited. Lastly, since the ALDH2 polymorphism is not considered in workers' limits of exposure to aldehydes and their precursors, efforts to lower exposure levels beyond legal standards are required.

Recovery from anemia and leukocytopenia after abstinence in Japanese alcoholic men and their genetic polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2

BACKGROUND

The combination of the fast-metabolizing alcohol dehydrogenase-1B (ADH1B*2 allele) and inactive heterozygous aldehyde dehydrogenase-2 (ALDH2*1/*2) increases susceptibility to macrocytic anemia and leukocytopenia in alcoholics due to severe acetaldehydemia. More than half of Japanese drinkers with esophageal cancer have this genotype combination.

METHODS

To assess the recovery of hematologic abnormalities after drinking cessation, changes in blood erythrocyte indices and leukocyte count during 8-week hospital stay were evaluated in 925 Japanese alcoholic men. We used four categories in ascending order for high blood acetaldehyde exposure from drinking: A, ADH1B*1/*1 plus ALDH2*1/*1; B, ADH1B*2 plus ALDH2*1/*1; C, ADH1B*1/*1 plus ALDH2*1/*2; and D, ADH1B*2 plus ALDH2*1/*2.

RESULTS

Mean values of hemoglobin and hematocrit were the lowest, and those of mean corpuscular volume (MCV) were markedly the highest in the D group on admission, and returning toward normal after abstinence, but the inter-group differences remained significant throughout the 8 weeks. The mean leukocyte count was the lowest in the D group on admission, but increased during 4-week abstinence when the inter-group differences were no longer significant. Frequencies of MCV ≥110 fl (50.5%), hemoglobin levels <11.5 g/dL (32.7%), hemoglobin levels <10.0 g/dL (9.9%) and leukocytopenia <4000/μL (22.8%) were the highest in the D group on the admission day and decreased at the 4-week abstinence (28.7%, 18.8%, 4.0% and 7.9%, respectively). The inter-group differences in frequencies of the severe anemia and leukocytopenia disappeared after 4-week abstinence.

CONCLUSIONS

Drinking cessation before surgery and/or chemoradiation treatment for esophageal cancer may be effective for recovery from anemia and leukocytopenia in drinkers belonging to the D group.

Screening by Total Colonoscopy Following Fecal Immunochemical Tests and Determinants of Colorectal Neoplasia in Japanese Men With Alcohol Dependence

Aims

Alcohol consumption increases the risk of colorectal adenoma and cancer. The fecal immunochemical test (FIT) is a widely used screening method for detecting colorectal neoplasia. We evaluated the results of screening and risk factors for colorectal neoplasia in individuals with alcohol dependence.

Methods

Total colonoscopic screening was performed for 1006 Japanese men with alcohol dependence (462 FIT-positive and 544 FIT-negative). Advanced neoplasia was defined as neoplasia ≥10 mm, villous or tubulovillous adenoma, high-grade adenoma, or carcinoma.

Results

The detection rates for non-advanced adenoma, advanced neoplasia and intramucosal or invasive carcinoma were 38.7%, 39.4% and 9.7% for the FIT-positive group, and 33.3%, 10.8% and 2.2% for the FIT-negative group, respectively. Advanced neoplasia, especially carcinoma, was detected more frequently in the distal colon than in the proximal colon in the FIT-positive group. The respective multivariate odds ratios (ORs; 95% confidence interval) for non-advanced adenoma and advanced neoplasia were 2.83 (2.06–3.88) and 9.13 (6.19–13.5) for a positive FIT (vs. negative), 1.68 (1.39–2.02) and 1.83 (1.45–2.30) for age (per +10 years), 1.54 (1.06–2.23) and 1.88 (1.17–3.03) for current smoking (vs. non-smokers), and 1.35 (0.96–1.92) and 1.59 (1.02–2.48) for the presence of marked macrocytosis (mean corpuscular volume ≥106 fl vs. <106 fl). Genetic polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 did not affect the risk of colorectal neoplasia.

Conclusion

The detection rate for advanced colorectal neoplasia was extremely high in the FIT-positive group but remained high even in the FIT-negative group. An older age, smoking and macrocytosis were predictors of advanced colorectal neoplasia.

Short summary

Total colonoscopic screening was performed for 1006 Japanese alcoholic men (462 fecal immunochemical test [FIT]-positive and 544 FIT-negative). The detection rate for advanced colorectal neoplasia was extremely high in the FIT-positive group (39.4%) and high in the FIT-negative group (10.8%). Ageing, smoking and macrocytosis were predictors of advanced colorectal neoplasia.

Platelet Counts and Genetic Polymorphisms of Alcohol Dehydrogenase-1B and Aldehyde Dehydrogenase-2 in Japanese Alcoholic Men

BACKGROUND

Thrombocytopenia during intoxication, rebound thrombocytosis during 1 to 3 weeks of abstinence, and subsequent normalization of the platelet count are common in alcoholics.

METHODS

We evaluated 989 Japanese alcoholic men to identify the effects of genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B; rs1229984) and aldehyde dehydrogenase-2 (ALDH2; rs671) on platelet counts during an 8-week in-hospital abstinence period.

RESULTS

Thrombocytopenia (<15 × 10⁴ /μl) was observed in 25.9% of the subjects upon admission. The platelet counts increased from 21.4 ± 0.3 × 10⁴ /μl (mean ± SE) to 27.6 ± 0.3 × 10⁴ /μl, and a rebound platelet increase of  ≥10 × 10⁴ /μl was observed in 28.6% of the patients during the first 2 weeks after admission. By 4 weeks, the mean platelet counts had returned to intermediate levels and remained stable thereafter. The reversible suppression and rebound increase in the platelet counts were more prominent in the slow-metabolizing ADH1B*1/*1 group than in the fast-metabolizing ADH1B*2 group. Throughout the 8 weeks, the mean platelet counts of the active ALDH2*1/*1 group were consistently lower than those in the inactive ALDH2*1/*2 group. Cirrhosis was a strong determinant of a lower platelet count. After adjustments for nongenetic factors including cirrhosis, multiple linear regression analyses showed that the ADH1B*1/*1 genotype was associated with a lower platelet count (partial regression coefficient = -1.3 × 10⁴ /μl) on the admission day, but subsequently had a positive effect on the platelet count at 1 and 2 weeks after admission (+1.5 and +3.8 × 10⁴ /μl, respectively). The ALDH2*1/*1 genotype was associated with a lower platelet count (-2.1 to -3.9 × 10⁴ /μl) consistently throughout the 8 weeks. Multiple logistic regression analyses showed that the ADH1B*1/*1 genotype increased the risk of thrombocytopenia upon admission (odds ratio [95% confidence interval] = 1.61 [1.14 to 2.27]) and of a rebound platelet increase during the first 2 weeks (3.86 [2.79 to 5.34]). The ALDH2*1/*1 genotype increased the risk of thrombocytopenia upon admission (1.73 [1.06 to 2.82]).

CONCLUSIONS

In alcoholics, the ADH1B*1/*1 genotype increased the risk of thrombocytopenia upon admission and of a rebound platelet increase 2 weeks thereafter, while the ALDH2*1/*1 genotype was associated with lower platelet counts throughout the 8-week hospital stay.

Roles of defective ALDH2 polymorphism on liver protection and cancer development

Because serum transaminases elevate alcohol dose dependently as a consequence of liver injury, they serve as useful biological markers of excessive drinking. However, these markers are inadequate in individuals with a defective allele of the aldehyde dehydrogenase 2 gene, ALDH2*2, because they show a different correlation with the amount of ethanol. For example, the serum alanine aminotransferase (ALT) level could become even lower than the baseline after alcohol intake in ALDH2*2 carriers. In fact, multiple studies suggest that ALDH2*2 is a hepato-protective factor in healthy individuals. Importantly, excessive drinking is particularly dangerous in carriers of ALDH2*2 because the risk of alcohol-related cancer is much higher than that for ALDH2*1/*1 carriers. Without recognizing the genotype interaction on serum transaminase, the opportunity to warn people about potential cancer risks is missed owing to incorrect interpretation. This is particularly important in East Asian countries where approximately half of the population carries the ALDH2*2 allele. To date, the mechanism of liver protection from ethanol load in individuals with ALDH2*2 has not been fully elucidated. However, some reasonable mechanisms have been suggested by experimental studies, including remodelling of detoxifying systems. Further studies to uncover the whole mechanism are anticipated.

Blood Leukocyte Counts and Genetic Polymorphisms of Alcohol Dehydrogenase-1B and Aldehyde Dehydrogenase-2 in Japanese Alcoholic Men

BACKGROUND

Roughly 40% of East Asians have inactive aldehyde dehydrogenase-2 (ALDH2) encoded by the ALDH2*2 allele, and 90% have highly active alcohol dehydrogenase-1B (ADH1B) encoded by the ADH1B*2 allele. Macrocytosis and macrocytic anemia in alcoholics have been associated with ADH1B and ALDH2 gene variants which increase acetaldehyde (AcH) levels.

METHODS

We investigated the relationship between ADH1B*2, ALDH2*2, and leukocyte counts of Japanese alcoholic men (N = 1,661).

RESULTS

After adjusting for age, drinking habits, smoking habits, body mass index, presence of liver cirrhosis, and serum levels of C-reactive protein, we found that total and differential leukocyte counts were lower in the presence of the ALDH2*1/*2 genotype (vs. ALDH2*1/*1 genotype). ALDH2*2/*2 carriers were not found in our study population. Leukocyte, granulocyte, and monocyte counts were also lower in the presence of ADH1B*2 (vs. ADH1B*1/*1 genotype), but the lymphocyte count was higher. The ALDH2*1/*2 genotype was associated with leukocytopenia (<4,000/μl; adjusted odds ratio [95% confidence interval] = 1.89 [1.27 to 2.80]), granulocytopenia (<2,000/μl; 1.86 [1.22 to 2.82]), monocytopenia (<250/μl; 2.22 [1.49 to 3.29]), and lymphocytopenia (<1,000/μl; 1.93 [1.32 to 2.83]). In contrast, the ADH1B*2 had the opposite effect on lymphocytopenia (0.65 [0.46 to 0.93]). Considering genotype effects under conditions of immune stimulation, we observed suppressive effects of ADH1B*2 allele on leukocytosis (≥9,000/μl; 0.69 [0.50 to 0.97]), granulocytosis (≥6,500/μl; 0.66 [0.47 to 0.93]), and monocytosis (≥750/μl; 0.56 [0.39 to 0.79]). The ADH1B*2 plus ALDH2*1/*2 combination had the greatest suppressive effects on the leukocyte, granulocyte, and monocyte counts.

CONCLUSIONS

The total and differential blood leukocyte counts of Japanese alcoholics were strongly affected by their ADH1B and ALDH2 gene variants. High AcH exposure levels probably play a critical role in the suppression of blood leukocyte counts in alcoholics.

[Fundamental Properties of Aldehyde Dehydrogenase 2 (ALDH2) and the Importance of the ALDH2 Polymorphism]

Human aldehyde dehydrogenase 2 (ALDH2) is a 56 kDa mitochondrial protein that forms homodimers through hydrogen bonding interactions between the Glu487 and Arg475 residues of two ALDH2 proteins. Two ALDH2 homodimers can interact to form an ALDH2 tetramer. ALDH2 is widely distributed throughout the organs of the body. In addition to its dehydrogenase activity, ALDH2 also exhibits esterase and reductase activities, with the main substrates for these three activities being aldehydes, 4-nitrophenyl acetate and nitroglycerin, respectively. ALDH2 can be readily inhibited by a wide variety of endogenous and exogenous chemicals, but the induction or activation of this enzyme remains unlikely. The polymorphism of ALDH2 to the corresponding ALDH2*2 variant results in a severe deficiency in ALDH2 activity, and this particular polymorphism is prevalent among people of Mongoloid descent. It seems reasonable to expect that people with the ALDH2*2 variant would be more vulnerable to stress and diseases because ALDH2 defends the human body against toxic aldehydes. However, it has been suggested that people with the ALDH2*2 variant are protected by alternative stress-defending systems. The ALDH2*2 variant has been reported to be associated with many different kinds of diseases, although the mechanisms underlying these associations have not yet been elucidated. ALDH2 polymorphism has a significant impact on human health; further studies are therefore required to determine the practical implications of this polymorphism in the fields of preventive and clinical medicine.

Alcohol Dehydrogenase-1B (rs1229984) and Aldehyde Dehydrogenase-2 (rs671) Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men

BACKGROUND

Elevated serum triglyceride (TG) and high-density-lipoprotein cholesterol (HDL-C) levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype) and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype) modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively) in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics.

METHODS

The population consisted of 1806 Japanese alcoholic men (≥40 years) who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission.

RESULTS

High serum levels of TG (≥150 mg/dl), HDL-C (>80 mg/dl), and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl) were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI) affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval) for a high TG level (2.22 [1.67-2.94] and 1.39 [0.99-1.96], respectively), and decreased the OR for a high HDL-C level (0.37 [0.28-0.49] and 0.51 [0.37-0.69], respectively). The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45-0.80]). The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl) and HDL-C (≥100 mg/dl).

CONCLUSIONS

The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast-metabolizing ADH1B was associated with lower serum LDL-C levels.

Fanconi anemia: a model disease for studies on human genetics and advanced therapeutics

Fanconi anemia (FA) is characterized by bone marrow failure, malformations, and chromosome fragility. We review the recent discovery of FA genes and efforts to develop genetic therapies for FA in the last five years. Because current data exclude FANCM as an FA gene, 15 genes remain bona fide FA genes and three (FANCO, FANCR and FANCS) cause an FA like syndrome. Monoallelic mutations in 6 FA associated genes (FANCD1, FANCJ, FANCM, FANCN, FANCO and FANCS) predispose to breast and ovarian cancer. The products of all these genes are involved in the repair of stalled DNA replication forks by unhooking DNA interstrand cross-links and promoting homologous recombination. The genetic characterization of patients with FA is essential for developing therapies, including hematopoietic stem cell transplantation from a savior sibling donor after embryo selection, gene therapy, or genome editing using genetic recombination or engineered nucleases. Newly acquired knowledge about FA promises to provide therapeutic strategies in the near future.

Ethanol reduces lifespan, body weight, and serum alanine aminotransferase level of aldehyde dehydrogenase 2 knockout mouse

BACKGROUND

The aldehyde dehydrogenase 2 (Aldh2) knockout mouse is an animal model of a polymorphism at the human ALDH2 locus (ALDH2*2). To detect differences in the basic phenotype of this animal model, lifespan, body weight (BW), and serum alanine aminotransferase (ALT) level were evaluated.

METHODS

Aldh2(+/+) , Aldh2(+/-) , and Aldh2(-/-) mice were maintained, from 10 weeks of age, on standard solid food, with liquid supplied as ethanol (EtOH) solution at a concentration of 0 to 20% (forced EtOH consumption).

RESULTS

For animals provided with water (without EtOH), mice of the distinct genotypes exhibited no difference in lifespan, with the mean values ranging from 90 to 96 weeks for female mice and 97 to 105 weeks for male mice. For animals provided with EtOH, there was a dose-dependent reduction of lifespan in Aldh2(-/-) mice with p for trend <0.001. For example, the mean lifespans of the Aldh2(-/-) females in the 0, 3, 10, and 20% groups were 95, 85, 70, and 29 weeks, respectively. No influence on lifespan was found for Aldh2(+/+) and Aldh2(+/-) mice. BW and ALT level of Aldh2(-/-) mice were significantly lower than those of Aldh2(+/+) mice when the mice were treated with EtOH. While multiple regression analysis suggested that the BW and ALT level in Aldh2(-/-) mice correlated with lifespan, adjustment for EtOH concentration revealed that this correlation was not significant (i.e., reflected EtOH dependence).

CONCLUSIONS

Aldh2(-/-) mice were unchanged in terms of their basic phenotype under standard laboratory conditions. However, chronic EtOH administration (forced consumption) in these mice resulted in dose-dependent reductions in lifespan, BW, and serum ALT level.