Storage of Gamma-Glutamyltransferase from Dried Serum Spots: Matrix for Field Based Studies

Background: Gamma-glutamyltransferase is recognised as a biomarker to assess the harms associated with alcohol misuse. The objective ways to measure GGT in areas lacking central lab facilities are desirable. This study aims to measure GGT from dried serum spots and its storage from dried serum spots. Method: The study was approved by the institutional ethical committee. One hundred and eighty (180) patients were included in the study. Their blood samples were collected. The serum samples were spotted onto filter paper (Whatman 903) dried and stored at 4°C. The GGT levels were measured on the day of collection and at various time periods to assess the effect of storage. All the analysis was performed on SPSS version 21. Result: The GGT levels measured from fresh serum GGT levels mean (SD) 286.5 (539.4) correlated well with their respective dried serum levels 287.18 (538.2) (P = 0.80). The mean recovery of GGT from dried serum was observed to be 103.3%. A sub-sample (n = 12) was stored at 4°C. The dried serum spots were found to be stable at the end of four weeks using repeated measure analysis of variance (ANOVA) (P = 0.39). Conclusion: This method has the potential to be used for epidemiological or field based studies to assess harms associated with alcohol use.

Diagnostic value of gamma-glutamyltransferase/aspartate aminotransferase ratio, protein induced by vitamin K absence or antagonist II, and alpha-fetoprotein in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND Researchers have investigated the diagnostic value of protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP) in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), and obtained abundant clinical diagnostic data. However, PIVKA-II and AFP have unsatisfactory specificity and sensitivity in the diagnosis of early-stage HBV-related HCC. Gamma-glutamyltransferase (γ-GT) and aspartate aminotransferase (AST) are common biomarkers for evaluating liver function, and we hypothesized that the γ-GT/AST ratio in combination with PIVKA-II and AFP would improve the diagnosis of early-stage HBV-related HCC. AIM To evaluate the diagnostic value of γ-GT/AST ratio alone or in combination with PIVKA-II and AFP in HBV-related HCC. METHODS Serum levels of γ-GT, AST, PIVKA-II, and AFP were detected and analysed in 176 patients with HBV-related HCC and in 359 patients with chronic hepatitis B. According to tumour size and serum level of HBV DNA, HBV-related HCC patients were divided into the following categories: Early-stage HCC patients, HCC patients, HBV DNA positive (HBV DNA+) HCC patients, and HBV DNA negative (HBV DNA-) HCC patients. Receiver-operating characteristic (ROC) curves were used to analyse and compare the diagnostic value of the single and combined detection of various biomarkers in different types of HBV-related HCC. RESULTS Tumour size was positively correlated with serum levels of PIVKA-II and AFP in HCC patients (r = 0.529, aP < 0.001 and r = 0.270, bP < 0.001, respectively), but there was no correlation between tumour size and the γ-GT/AST ratio (r = 0.073, P = 0.336). The areas under the receiver-operating characteristic curves (AUROCs) of the γ-GT/AST ratio in early-stage HCC patients, HBV DNA+ HCC patients and HBV DNA- HCC patients were not significantly different from that in the total HCC patients (0.754, 0.802, and 0.705 vs 0.779, respectively;P > 0.05). When PIVKA-II was combined with the γ-GT/AST ratio in the diagnosis of earlystage HCC, HCC, and HBV DNA+ HCC, the AUROCs of PIVKA-II increased, with values of 0.857 vs 0.835, 0.925 vs 0.913, and 0.958 vs 0.954, respectively. When AFP was combined with the γ-GT/AST ratio in the diagnosis of early-stage HCC, HCC, HBV DNA+ HCC, and HBV DNA- HCC, the AUROCs of AFP increased, with values of 0.757 vs 0.621, 0.837 vs 0.744, 0.868 vs 0.757, and 0.840 vs 0.828, respectively. CONCLUSION The γ-GT/AST ratio may be better than PIVKA-II and AFP in the diagnosis of early-stage HBV-related HCC, and its combination with PIVKA-II and AFP can improve the diagnostic value for HBV-related HCC.

Combination of serum gamma-glutamyltransferase and alkaline phosphatase in predicting the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis

BACKGROUND Gamma-glutamyltransferase(GGT) is one of the most important laboratory tests for the evaluation of liver damage. Through a long-term clinical observation of patients with secondary asymptomatic choledocholithiasis, we found that most patients had abnormal GGT serum levels.AIM To investigate the combination of serum GGT and alkaline phosphatase(ALP) in predicting the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis.METHODS In this retrospective cohort study, the clinical data of 829 patients with cholecystolithiasis admitted to the Third Affiliated Hospital of Zunyi Medical College from August 2014 to August 2017 were collected. Among these patients,151 patients had secondary asymptomatic choledocholithiasis and served as the observation group, and the remaining 678 cholecystolithiasis patients served as the control group. Serum liver function indexes were detected in both groups,and the receiver operating characteristic(commonly known as ROC) curves were constructed for markers showing statistical significances. The cutoff value,sensitivity, and specificity of each marker were calculated according to the ROC curves.RESULTS The overall incidence of asymptomatic choledocholithiasis secondary to cholecystolithiasis was 18.2%. The results of liver function indexes including serum aspartate aminotransferase, alanine aminotransferase, direct bilirubin and total bilirubin levels showed no significant differences between the two groups(P> 0.05). However, the serum GGT and ALP levels were significantly higher in the observation group than in the control group(P < 0.05). The ROC curve analysis showed that the area under the curve was 0.881(95%CI: 0.830-0.932), 0.647(95%CI: 0.583-0.711) and 0.923(0.892-0.953) for GGT, ALP, and GGT + ALP,respectively. The corresponding cut-off values of GGT and ALP were 95.5 U/L and 151.5 U/L, sensitivity were 90.8% and 65.1%, and specificity were 83.6% and59.8%, respectively. The sensitivity and specificity of GGT + ALP were 93.5% and85.1%, respectively.CONCLUSION An abnormally elevated serum GGT level has an important value in the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis.The combination of serum GGT and ALP has better diagnostic performance. As a convenient, rapid and inexpensive test, it should be applied in secondary asymptomatic choledocholithiasis routine screening.

Preoperative gamma-glutamyltransferase to lymphocyte ratio predicts long-term outcomes in intrahepatic cholangiocarcinoma patients following hepatic resection

BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a heterogeneous hepatobiliary cancer with limited treatment options.A number of studies have illuminated the relationship between inflammation-based prognostic scores and outcomes in patients with ICC.However,the use of reliable and personalized prognostic algorithms in ICC after resection is pending.AIM To assess the prognostic value of the gamma-glutamyltransferase to lymphocyte ratio(GLR)in ICC patients following curative resection.METHODS ICC patients following curative resection(2009-2017)were divided into two cohorts:The derivation cohort and validation cohort.The derivation cohort was used to explore an optimal cut-off value,and the validation cohort was used to further evaluate the score.Overall survival(OS)and recurrence-free survival(RFS)were analyzed,and predictors of OS and RFS were determined.RESULTS A total of 527 ICC patients were included and randomly divided into the derivation cohort(264 patients)and the validation cohort(263 patients).The two patient cohorts had comparable baseline characteristics.The optimal cut-off value for the GLR was 33.7.Kaplan-Meier curves showed worse OS and RFS in the GLR>33.7 group compared with GLR≤33.7 group in both cohorts.After univariate and multivariate analysis,the results indicated that GLR was an independent prognostic factor of OS[derivation cohort:hazard ratio(HR)=1.620,95%confidence interval(CI):1.066-2.462,P=0.024;validation cohort:HR=1.466,95%CI:1.033-2.142,P=0.048]and RFS[derivation cohort:HR=1.471,95%CI:1.029-2.103,P=0.034;validation cohort:HR=1.480,95%CI:1.057-2.070,P=0.022].CONCLUSION The preoperative GLR is an independent prognostic factor for ICC patients following hepatectomy.A high preoperative GLR is associated with worse OS and RFS.

Fractionation of gamma-glutamyltransferase in patients with nonalcoholic fatty liver disease and alcoholic liver disease

AIM To assess how serum gamma-glutamyltransferase(GGT) fractions vary in patients with alcoholic liver disease(ALD) and non-alcoholic fatty liver disease(NAFLD). METHODS Serum samples were obtained from 14 patients with biopsy-proven alcoholic liver diseases and 9 patients with biopsy proven non-alcoholic fatty liver disease. In addition to these biopsy-proven cases, 16 obese(body mass index > 25) patients without any history of alcohol consumption but with a fatty liver on ultrasound examination and with elevated GGT were included for an additional analysis. Serum GGT fractionation was conducted by high-performance gel filtration liquid chromatography and was separated into the four fractions, big-GGT, medium-GGT, small-GGT(s-GGT), and free-GGT(f-GGT).RESULTS The results were expressed as a ratio of each fraction including the total GGT(t-GGT). The s-GGT/t-GGT ratioswere lowest for the control group and highest for the ALD group. The differences between the control and NAFLD groups and also between the NAFLD and ALD groups were statistically significant. In contrast, the f-GGT/t-GGT ratios were highest in the control group and lowest in the ALD group, with the differences being statistically significant. As a result, the s-GGT/f-GGT ratios were markedly increased in the NAFLD group as compared with the control group. The increase of the s-GGT/t-GGT ratios, the decrease of the f-GGT/t-GGT ratios, and the increase of s-GGT/F-GGT ratios as compared with the control group subjects were also found in obese patients with clinically diagnosed fatty change of the liver.CONCLUSION Serum GGT fractionation by high-performance gel filtration liquid chromatography is potentially useful for the differential diagnosis of ALD and NAFLD.

Liver Enzymes Concentrations Are Closely Related to Pre-diabetes:Findings of the Shanghai Diabetes Study Ⅱ (SHDS Ⅱ)

Objective To investigate the relationship of liver enzymes with hyperglycemia in a large population in Shanghai and identify the association between liver enzymes and insulin resistance. Methods A total of 3 756 participants were enrolled. Each participant underwent an oral glucose tolerance test and completed a questionnaire. Anthropometric indices were recorded and serum samples were collected for measurement. Results Liver enzymes concentrations were independently associated with i-IGT, iFG＋IGT, and diabetes. With the increase of ALT and GGT concentrations, ORs for i-IGT, IFG＋tGT, and diabetes increased gradually. By comparing patients in the highest quartile of GGT concentrations or ALT concentrations with those in the lowest quartile （Q1）, ORs for iqGT, IFG＋IGT, or diabetes was significant after adjustment. Both ALT and GGT concentrations were linearly correlated with HOMA-IR and independently associated with HOMA-IR [ALT OR （95% Cl）： 2.56 （1.51-4.34） P=0.00; GGT OR （95% CI）： 2.66 （1.53-4.65） P=0.00]. Conclusion Serum ALT and GGT concentrations were closely related to pre-diabetes and diabetes in the Shanghai population and positively associated with insulin resistance.

Abnormal expression of hepatoma- derived γ-glutamyltransferase subtyping and its early alteration for carcinogenesis of hepatocytes

BACKGROUND: Although the hepatoma-specific band of gamma-glutamyltransferase ( GGT ) is a highly sensitive marker in diagnosis of hepatocellular carcinoma, the kine- tic expression and the early alterations of GGT in the deve- lopment of hepatoma remain unclear. In this study, we in- vestigated the expression and the alterations of GGT multi- ple molecular forms in hepatotumorigenesis. METHODS: The expression of GGT in a chemically in- duced hepatocarcinogenesis model was examined by giving 0. 05% of 2-fluoenylacetamide in diet for 12 weeks. The ex- pression levels of total RNA and GGT, and the changes of liver pathology, GGT multiple molecular forms and sugar- chain heterogeneity were investigated at the different stages of rat hepatoma development. RESULTS: Pathological examination and biochemical ana- lysis found that liver GGT was over-expressed and secreted into blood during canceration. Serum total GGT and liver GGT specific activities (IU/g) including soluble and mem- brane-combined GGT were significantly higher (P <0.05) in experimental groups than those in control group, respec- tively. A highly positive correlation was found between to- tal GGT activities and total RNA levels (r =0.90, P <0.05) of the liver. Both were higher six weeks later than before. Con A-non-reactive-GGT was increased consistantly dur- ing the development of rat hepatoma. GGT multiple mo- lecular forms in the liver and sera of experimental rats showed that fetal liver-type GGT bands were associated with the development of hepatoma. CONCLUSIONS: Fetal liver-type GGT in sera and the liver of rats is closely related to hepatotumorigenesis. It can be used as a sensitive enzymatic marker for the early diagnosis of liver cancer.

Repeatedly elevatedγ-glutamyltransferase levels are associated with an increased incidence of digestive cancers:A population-based cohort study

BACKGROUND The association between elevatedγ-glutamyltransferase(GGT)at a certain point and incident cancer has been suggested;however,no study has evaluated the association between repeatedly elevated GGT and cancer incidence.AIM To investigate the effects of repeatedly elevated GGT on the incidence of digestive cancers.METHODS Participants who had undergone health screening from 2009 to 2012 and 4 consecutive previous examinations were enrolled.GGT points were calculated as the number of times participants met the criteria of quartile 4 of GGT in four serial measurements(0-4 points).Multivariable Cox proportional hazard regression models were applied.RESULTS In total,3559109 participants were included;among them,43574 digestive cancers developed during a median of 6.8 years of follow-up.The incidence of total digestive cancers increased in a dose-response manner in men[adjusted hazard ratio(aHR)compared with those with 0 GGT points=1.28 and 95%confidence interval(CI)=1.24-1.33 in those with 1 point;aHR=1.40 and 95%CI=1.35-1.46 in those with 2 points;aHR=1.52 and 95%CI=1.46-1.58 in those with 3 points;aHR=1.88 and 95%CI=1.83-1.94 in those with 4 points;P for trend<0.001].This trend was more prominent in men than in women and those with healthy habits(no smoking,no alcohol consumption,and a low body mass index)than in those with unhealthy habits.CONCLUSION Repeatedly elevated GGT levels were associated with an increased risk of incident digestive cancer in a dose-responsive manner,particularly in men and those with healthy habits.Repeated GGT measurements may be a good biomarker of incident digestive cancer and could help physicians identify high-risk populations.

Association of Serum Antioxidant Enzymes and Nervous Tissue Markers in Hypertensive Patients

Background and Purpose: Hypertension has serious effects on cerebral blood vessels. Oxidative stress seems to be implicated in blood pressure elevation, through increased reactive oxygen species and/or decreased antioxidant capacity. Recently blood markers indicating damage to the central nervous system were reported to be increased in hypertensive patients. However, it is unknown whether antioxidant capacity is related to these changes. This study was designed to explore if the concentration of blood markers for nervous tissue damage was associated to antioxidant capacity in hypertensive patients. Methods: Twenty hypertensive patients and 23 healthy controls were studied. They were paired by age, sex, ethnicity, or risk factors. Serum neuron specific enolase (NSE) and S100 calcium binding protein B (S100B) were measured as nervous tissue damage markers, as well as the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase and gamma-glutamyltransferase). Results: Serum neuronal specific enolase (NSE) and S100 calcium binding protein B (S100B) concentrations determined by immunoassay were significantly increased in patients vs. controls. The activities of antioxidant enzymes measured by spectrophotometry showed that plasmatic catalase and erythrocytic glutathione peroxidase were significantly increased in patients, but erythocytic catalase was decreased. Gamma-glutamyltransferase activity was significantly correlated with S100B in hypertensive patients, while erythrocytic catalase activity was decreased in subjects with higher NSE levels. Conclusion: This preliminary investigation suggested that antioxidant status might be modulated through changes in antioxidant enzymatic activity in hypertensive patients. The association of some of these changes with peripheral markers of damage to the central nervous system could indicate that the increased levels of these proteins in hypertension are partly related to oxidative stress.