Serum alanine aminotransferase level in relation to hepatitis B and C virus infections among blood donors

Enzymatic characterization of D-lactate dehydrogenase and application in alanine aminotransferase activity assay kit

D-lactate dehydrogenase (D-LDH) is widely used for the clinical detection of alanine aminotransferase (ALT) activity. It is a key enzyme in ALT detection kits, and its enzymatic properties directly determine sensitivity and accuracy of such kits. In this study, D-lactate dehydrogenase (WP_011543503, ldLDH) coding sequence derived from Lactobacillus delbrueckii was obtained from the NCBI database by gene mining. LdLDH was expressed and purified in Escherichia coli, and its enzyme activity, kinetic parameters, optimum temperature, and pH were characterized. Furthermore, stabilizers, including sugars, polyols, amino acids, certain salts, proteins, and polymers, were screened to improve stability of ldLDH during freeze-drying and storage. Finally, a kit based on ldLDH was tested to determine whether the enzyme had potential clinical applications. The results showed that ldLDH had a specific activity of 1,864 U/mg, K_m value of 1.34 mM, optimal reaction temperature of 55°C, and an optimal pH between 7.0 and 7.5. When sucrose or asparagine was used as a stabilizer, freeze-dried ldLDH remained stable at 37°C for > 2 months without significant loss of enzymatic activity. These results indicated that ldLDH possesses high activity and stability. Test results using the ALT assay kit prepared with ldLDH were consistent with those of commercial kits, with a relative deviation <5%. These results indicated that ldLDH met the primary requirements for ALT assays, laying a foundation for the development of new ALT kits with potential clinical applications.

Prevalence of elevated alanine aminotransferase levels in adult participants from a community-based study from northern part of India

Alanine aminotransferase (ALT) is a cytosolic enzyme specific to hepatocytes, and its elevated level in the peripheral blood denotes liver cell injury. Detection of persistently elevated ALT levels during routine health check-up in asymptomatic or symptomatic individuals provides a window of opportunity to explore the causes of liver cell damage and for the timely institution of appropriate treatment. This was a retrospective study using a subset of the data from a previous community-based prospective study done for the estimation of the prevalence of celiac disease (CD) in India,  during which estimation of ALT levels in the blood samples of participants was also carried out. Of the 11,053 individuals (4399 [39.8%] males; mean age 37.9 ± 13.3 years) screened, 6209 consented to provide blood samples for testing for CD. Of these, assessment of serum ALT levels was done in 6083 (2235 [36.7%] males) patients. ALT was elevated above the upper limit of normal (ULN) (> 40 IU/L) in 1246 (20.5%) of the participants and > 1.5 times (> 60 IU/L) in 329 (5.4%) participants. The ALT levels were elevated more frequently in men as compared to women (29.4% vs. 15.3%, p < 0.001). There was a significant positive correlation (Pearson correlation coefficient [r] = 0.25, p < 0.0001) between ALT levels and body mass index (BMI). With increasing age, there was a significant decrease in the proportion of subjects with ALT ≥ 1.5× ULN (p < 0.001). Our results suggest that a high proportion (20.5%) of individuals otherwise considered healthy have values of ALT level in the serum above the "normal" range/cut-off suggesting likely ongoing underlying liver damage. There is a need for measures to evaluate and, if found, treat the underlying cause for the same.

Heat shock protein A1B 1267 polymorphism is highly associated with risk and prognosis of hepatocellular carcinoma: a case-control study

We conducted a case-control study to elucidate the role of heat shock protein A1B (HSPA1B) 1267 single nucleotide polymorphism (SNP) on the risk and prognosis of hepatocellular carcinoma (HCC). Subjects enrolled included 150 pairs of sex- and age-matched HCC patients and unrelated controls. Genomic DNA was typed for HSPA1B1267 SNP using polymerase chain reaction with restriction fragment length polymorphism. The frequencies of the HSPA1B P2/P2 genotype and the HSPA1B P2 allele in HCC patients were higher than in unrelated controls (each p = 0.0001). Multivariate analysis identified the following independent risk factors for HCC: HSPA1B P1/P2 genotype (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.07-5.11), HSPA1B P2/P2 genotype (OR, 12.06; 95% CI, 4.43-32.79), hepatitis B surface antigen (HBsAg) (OR, 25.95; 95% CI, 11.88-56.68), and antibodies to hepatitis C virus (anti-HCV) (OR, 70.43; 95% CI, 21.89-226.64). There was an additive interaction between HSPA1B P2 allele carriers and the presence of either HBsAg (synergy index = 2.48) or anti-HCV (synergy index = 1.52). However, as HSPA1B1267 SNP is a silent mutation, it is a surrogate genetic marker for increasing risk of HCC. Our findings indicate that patients with chronic hepatitis B/hepatitis C virus infection who harbor this SNP represent a high-risk group for HCC. They should receive more intensive surveillance for early detection of HCC. Moreover, patients with the HSPA1B P2 allele had significantly longer survival (p = 0.002).The limitations of this study include the unknown functional significance of the HSPA1B1267 polymorphism, the relatively small sample size, the fact that this was not a prospective study of cases and controls, and the questionable generalizability of the findings given the specific ethnic composition of the population studied.

Clinical significance of activity of ALT enzyme in patients with hepatitis C virus

AIM: To investigate serum alanine aminotransferase (ALT) levels in relation to the clinical, biochemical, ultrasonographic and histological characteristics of patients with hepatitis C virus.

METHODS: Duration of disease, HCV-RNA, liver steatosis, and the hepatitis activity index (HAI) were correlated with serum ALT in 36 patients with HCV. ALT values were also investigated in 16 control subjects without any liver diseases.

RESULTS: In bivariate analyses, ALT levels correlated with duration of HCV infection (P < 0.01), HCV-RNA (P < 0.05), and the HAI (P < 0.01). Among the components of the HAI, ALT concentrations were significantly associated with periportal bridging/necrosis (P < 0.01) and fibrosis (P < 0.05). In multivariate analysis, periportal bridging/necrosis (β = 0.508; P < 0.01), duration of HCV infection (β = 0.413; P < 0.01), and HCV-RNA (β = 0.253; P < 0.05) were independently associated with ALT activity. The normal ALT activity for men and women was < 23 IU/L and < 22 IU/L, respectively.

CONCLUSION: In patients with HCV, alterations in the liver tissue as reflected by ALT elevation are mainly associated with periportal bridging/necrosis, viral load and duration of disease. A cut-off value < 23 IU/L distinguished with high diagnostic accuracy healthy controls from patients with HCV.

Dietary amino acid taurine ameliorates liver injury in chronic hepatitis patients

The effect of dietary amino acid taurine on the liver function of chronic hepatitis patients was investigated. The 24 chronic hepatitis patients with 2-5 times over normal activities of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) were selected and equally divided into taurine treatment and control groups. In taurine treatment group, each patient took 2 g taurine 3 times a day for three months, and then stopped treatment for 1 month. Patients taking placebo without taurine for 4 months served as a control group. ALT and AST activities and levels of cholesterol, triglyceride and thiobarbituric acid relative substances of serum plasma in the taurine group were all decreased at the end of three month treatment. The study suggested that dietary amino acid taurine may ameliorate liver injury for chronic hepatitis patients.

A community-based epidemiological study of elevated serum alanine aminotransferase levels in Kinmen, Taiwan

AIM: To explore any gender-related differences in prevalence of and condition-associated factors related to an elevated serum alanine aminotransferase (ALT) level amongst residents of Kinmen, Taiwan.

METHODS: A total of 11 898 of a potential 20 112 regional residents aged 30 years or more completed a related questionnaire that was carried out by the Yang-Ming Crusade between 1991 and 1994 inclusively, with blood samples being collected by public nurses. The overall questionnaire response rate was 59.3% (52.4% for males and 66.0% for females).

RESULTS: The prevalence of an elevated serum ALT level for this sub-population was found to be 7.2%, the prevalence revealing a statistically significant decrease with increasing population age (P<0.0001). Males exhibited a greater prevalence of elevated serum ALT level than did females (9.4% vs 5.3%, P<0.0001). Using multiple logistic regression analysis, in addition to male gender, a younger age, greater waist circumference, presence of type-2 diabetes and hyperuricemia were the significant factors associated with an elevated serum ALT level for both males and females. Gender-related differences as regards associated factors were also revealed. For males, obesity was significantly related to an elevated serum ALT level (OR = 1.28, 95%CI: 1.00-1.66) but this was not so for females (OR = 1.09, 95%CI: 0.84-1.42). Hypertriglyceridemia (OR = 1.80, 95%CI: 1.36-2.39) and hyperuricemia (OR = 1.61, 95%CI: 1.03-2.52) were significantly related to elevated serum ALT levels only for females.

CONCLUSION: Several gender-related differences were noted pertaining to the prevalence of and relationship between obesity, hypertriglyceridemia and hyperuricemia and elevated serum ALT level in the present study.

Normal serum aminotransferase concentration and risk of mortality from liver diseases: prospective cohort study

OBJECTIVE

To examine the relation between the normal range of serum aminotransferase concentration and mortality from liver disease.

DESIGN

Prospective cohort study.

SETTING

Korea Medical Insurance Corporation study with eight years' follow up.

PARTICIPANTS

94,533 men and 47,522 women aged 35-59 years.

MAIN OUTCOME MEASURE

Mortality from liver diseases according to death certificate.

RESULTS

There was a positive association between the aminotransferase concentration, even within normal range (35-40 IU/l), and mortality from liver disease. Compared with the concentration < 20 IU/l, the adjusted relative risks for an aspartate aminotransferase concentration of 20-29 IU/l and 30-39 IU/l were 2.5 (95% confidence interval 2.0 to 3.0) and 8.0 (6.6 to 9.8) in men and 3.3 (1.7 to 6.4) and 18.2 (8.1 to 40.4) in women, respectively, The corresponding risks for alanine aminotransferase were 2.9 (2.4 to 3.5) and 9.5 (7.9 to 11.5) in men and 3.8 (1.9 to 7.7) and 6.6 (1.5 to 25.6) in women, respectively. According to receiver operating characteristic curves the best cut-off values for the prediction of liver disease in men were 31 IU/l for aspartate aminotransferase and 30 IU/l for alanine aminotransferase.

CONCLUSION

People with slightly increased aminotransferase activity, but still within the normal range, should be closely observed and further investigated for liver diseases.

Habitual betel quid chewing as a risk factor for cirrhosis: a case-control study

Betel quid chewing, part of traditional Taiwanese culture, is common in 10%-20% of the human population worldwide. In this case-control study we assessed the independent and interactive role of habitual betel quid chewing and chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on risk of cirrhosis. Subjects enrolled included 210 pairs of sex- and age-matched cirrhotic patients and healthy controls. Information on risk factors was obtained through serologic examination of hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV), and a standardized personal interview with a structured questionnaire. Univariate analysis indicated that betel quid chewing, HBsAg+, anti-HCV+, alcohol drinking, and smoking are significant risk factors for cirrhosis. Multivariate analysis indicated that betel quid chewing (odds ratio [OR], 3.56), HBsAg (OR 20.37), and anti-HCV (OR 31.43) are independent risk factors for cirrhosis. Most betel quid chewers habitually drink alcohol. Although our analysis indicates that betel quid chewing acts independently from alcohol as a risk factor for cirrhosis, the confounding effect of alcohol cannot be excluded entirely by our study. There was an additive effect of the interaction between betel quid chewing and the presence of either HBsAg or anti-HCV. Moreover, a higher risk of cirrhosis was associated with longer duration of betel quid chewing and greater amount of betel quid consumed (each p for trend <0.0001). In conclusion, betel quid chewing appears to be an independent risk factor for cirrhosis. There is an additive interaction between betel quid chewing and chronic HBV/HCV infection.

Multiple viral infections in a group of intravenous drug users: hepatitis B virus exposure is the risk factor

OBJECTIVE

Infection with hepatotropic viruses is associated with a variable degree of liver disease, and there is evidence that more severe lesions are related to the association with another viral infection. The aim of this investigation is to establish the relationship between different viral infections occurring in the same individual and the presence and progression of liver disease.

DESIGN

The study population comprises 754 intravenous (IV) drug abusers exposed to hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) or cytomegalovirus (CMV). All individuals were followed for an average of 2 years. Liver disease was assessed by liver function tests, 99m-technetium (99mTc) liver scintigraphy, and also by liver biopsy in a subset (n = 136) of patients. The different viral patterns and presence of disease were analysed by logistic regression, and the risk factors were calculated. Contingency tables of patients with single or associated infections were drawn up to evaluate progression of liver disease.

RESULTS

Association of HIV with at least one other viral infection was constant. Surface antigens of HBV (HBsAg) were always associated with HIV (n = 19); in this group, 18 patients had signs of liver disease. A past infection with HBV, as revealed by the presence of at least antibodies against the surface antigen (HBsAb) and antibodies against the core antigen of HBV (HBcAb), was detected in 463 patients (61.4%). The overall prevalence of HCV antibodies was 63.91% (n = 482). In 96.8% of the 406 patients tested, HCV-RNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR). The majority of patients with high alanine transaminase (ALT) had anti-HBV antibodies in the presence of HCV (56.1%). At the end of follow-up, all of these patients showed signs of active liver disease, and scoring was significantly worse than in patients with either HBV or HCV alone. An infection/reactivation of CMV was found in patients previously exposed to HBV and with increased ALT values.

CONCLUSIONS

Data emerging from this study reveal the association of HCV or CMV, or both, with a previous HBV infection, as demonstrated by HBsAb and HBcAb, and rapid progression of the disease in this group of patients. A previous HBV infection therefore appears to be an important risk factor for subsequent viral-related liver disease.

Betel quid chewing as a risk factor for hepatocellular carcinoma: a case-control study

The role of betel quid chewing in the aetiology of hepatocellular carcinoma (HCC) was evaluated in a case-control study including 263 pairs of age- and sex-matched HCC patients and healthy controls. Serum hepatitis B surface antigen (HBsAg), and antibodies to hepatitis C virus (anti-HCV) were determined, and standardized personal interview conducted using a structured questionnaire. Multivariate analysis indicated that betel quid chewing (odds ratio (OR), 3.49; 95% confidence interval (CI), 1.74-6.96), HBsAg (OR, 16.69; 95% CI, 9.92-28.07), anti-HCV (OR, 38.57; 95% CI, 18.15-81.96), and educational duration of less than 10 years (OR, 1.71; 95% CI, 1.05-2.78) are independent risk factors of HCC. In addition, there was an additive interaction between betel quid chewing and chronic infection with either hepatitis B virus (synergy index, 5.37) or hepatitis C virus (synergy index, 1.66). Moreover, risk on HCC increased as duration of betel quid chewing increased, or amount of betel quid consumed (each P for trend < 0.0001).

Immunoglobulin- and hepatitis B surface antigen-specific circulating immune complexes in chronic hepatitis B virus infection

For assessing the role of circulating immune complexes (CIC) in chronic hepatitis B virus (HBV) infection, CICs containing IgM, IgG, and HBsAg were determined by C1q and conglutinin (K) assays in 216 patients with chronic HBV infection and 54 healthy controls. The concentration of each type of CIC in patients is higher than in controls (P = 0.0001). CIC is a common feature of chronic HBV infection with 95.8% of cases having at least one abnormal test result. At least one type of HBsAg-CIC is positive in 54.2% of patients. HBsAg-CIC positivity is associated with HBeAg positivity (P = 0.0001), higher aminotransferase levels (P < 0.002), and younger age (P = 0.001). IgG-CIC or IgM-HBsAg-CIC correlates with higher aminotransferase activity (P = 0.001). In conclusion, HBsAg-CIC correlates with HBV replication. IgG-CIC and/or IgM-HBsAg-CIC correlate with disease activity. Immune-mediated injury may play a role in the pathogenesis of chronic HBV infection.

Clinical relevance of transforming growth factor-beta 1 in the urine of patients with hepatocellular carcinoma

To assess the clinical relevance of transforming growth factor-beta 1 (TGF-beta 1) in the urine of patients with hepatocellular carcinoma (HCC), TGF-beta 1 was measured, by radioimmunoassay, in 140 patients with HCC, 50 cirrhotic patients, 30 patients with chronic active hepatitis, and 50 healthy controls. The results indicate that there were significantly increased urinary TGF-beta 1 levels in patients with HCC. Raised TGF-beta 1 levels were associated, in a dose-related fashion, with increased risk for development of HCC (odds ratio, 1.05, 95% confidence interval, 1.03-1.07). HCC patients with raised TGF-beta 1 levels had shorter survival than those with normal TGF-beta 1 levels (p = 0.038). TGF-beta 1 levels decreased after successful anticancer therapy (p < 0.0001). There was an inverse correlation between TGF-beta 1 and serum alpha-fetoprotein (AFP) (r = -0.199, p < 0.04). Receiver operating characteristics (ROC) curve analysis indicated that parallel determination of TGF-beta 1 and AFP significantly increased the sensitivity and diagnostic accuracy, with a high specificity. In conclusion, raised urinary TGF-beta 1 was associated with HCC development. It is a predictor of poor prognosis, and a tumor marker for diagnosis and therapeutic follow-up of HCC.

Effect of hepatitis C and B virus infection on risk of hepatocellular carcinoma: a prospective study

To assess whether there is an additive effect between chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the development of hepatocellular carcinoma (HCC), 400 consecutive cirrhotic patients were followed prospectively with periodic abdominal ultrasound examination and measurement of serum alpha-fetoprotein (AFP) level every 4 months. During a follow-up of 1185 person-years, 80 (20%) patients developed HCC, with an annual incidence of 6.8%. The annual incidence was 2.0% in patients negative for hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV), 6.6% in patients with HBsAg alone, 7.0% in patients with anti-HCV alone and 13.3% in patients co-infected with HBV and HCV. There was a positive linear trend in the annual incidence of HCC among patients without either marker, patients with single viral infection and patients with dual viral infection (P[for trend] < 0.0001). Cox's proportional hazard model indicated that HCV/HBV co-infection [hazard ratio (HR), 6.41; 95% confidence interval (CI), 1.80-22.80], anti-HCV alone (HR, 3.74; 95% CI, 1.07-13.07) and HBsAg alone (HR, 4.06; 95% CI, 1.23-13.34) were independently risk factors of HCC. In conclusion, there is an additive and independent effect modification of HCV and HBV infection on HCC development.