Fucosylation Index Research Articles

Development of an AlphaLISA assay to quantify serum core-fucosylated E-cadherin as a metastatic lung adenocarcinoma biomarker

Lung cancer is the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer is a heterogeneous condition with variability in prognosis and in individual response to treatment. Thus, the identification of patients with a high risk of metastasis or relapse after surgery would allow better management. There is increasing evidence that glycosylation plays a significant role in biological processes including oncogenic transformation and metastasis. We set up a platform to screen and identify serum glycoproteins as metastasis biomarkers of lung cancer. Concanavalin A affinity chromatography was used to enrich glycoproteins from pooled serum of lung adenocarcinoma patients. The captured glycoproteins were separated with 2-D DIGE combined with nano-LC-MS/MS and identified by database searching. Some differentially expressed cancer-related glycoproteins, such as α-1-antitrypsin, complement C3c, haptoglobin, and E-cadherin, were identified. These glycoproteins were evaluated by Western blotting and Aleuria aurantia lectin staining and several, including E-cadherin, showed increased core-fucosylation during lung cancer progression. We then measured the fucosylation index (FI) of E-cadherin in 154 lung adenocarcinoma patients. In addition, a homogeneous proximity-based AlphaLISA assay to measure the FI of E-cadherin was established. The present study indicates that the FI of E-cadherin could be a potential prognostic marker of metastatic lung adenocarcinoma.

Impact of elevation of total bilirubin level and etiology of the liver disease on serum N-glycosylation patterns in mice and humans

The GlycoFibroTest and GlycoCirrhoTest are noninvasive alternatives for liver biopsy that can be used as a follow-up tool for fibrosis patients and to diagnose cirrhotic patients, respectively. These tests are based on the altered N-glycosylation of total serum protein. Our aim was to investigate the impact of etiology on the alteration of N-glycosylation and whether other characteristics of liver patients could have an influence on N-glycosylation. In human liver patients, no specific alteration could be found to make a distinction according to etiological factor, although alcoholic patients had a significant higher mean value for the GlycoCirrhoTest. Undergalactosylation did not show a significantly different quantitative alteration in the cirrhotic and noncirrhotic population of all etiologies. Importantly, patients with an elevation of total bilirubin level (>2 mg/dl) had a strong increase of glycans modified with alpha1-6 fucose. The fucosylation index was therefore significantly higher in fibrosis/cirrhosis and hepatocellular carcinoma patients with elevated total bilirubin levels irrespective of etiology. Furthermore, in a multiple linear regression analysis, only markers for cholestasis significantly correlated with the fucosylation index. In mouse models of chronic liver disease, the fucosylation index was uniquely significantly increased in mice that were induced with a common bile duct ligation. Mice that were chronically injected with CCl(4) did not show this increase. Apart from this difference, common changes characteristic to fibrosis development in mice were observed. Finally, mice induced with a partial portal vein ligation did not show biological relevant changes indicating that portal hypertension does not contribute to the alteration of N-glycosylation.

Prognostic Significance of Simultaneous Measurement of Three Tumor Markers in Patients With Hepatocellular Carcinoma

We conducted a prospective study to evaluate the significance of simultaneous measurement of 3 currently used tumor markers in the evaluation of tumor progression and prognosis of patients with hepatocellular carcinoma (HCC). Three tumor markers for HCC, alpha-fetoprotein (AFP), Lens culinaris agglutinin A-reactive fraction of AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP), were measured in the same serum samples obtained from 685 patients at the time of initial diagnosis of HCC. Positivity for AFP >20 ng/dL, AFP-L3 >10% of total AFP, and/or DCP >40 mAU/mL was determined. In addition, tumor markers were measured after treatment of HCC. Of the 685 patients, 337 (55.8%) were positive for AFP, 206 (34.1%) were positive for AFP-L3, and 371 (54.2%) were positive for DCP. In a comparison of patients positive for only 1 tumor marker, patients positive for AFP-L3 alone had a greater number of tumors, whereas patients positive for DCP alone had larger tumors and a higher prevalence of portal vein invasion. When patients were compared according to the number of tumor markers present, the number of markers present clearly reflected the extent of HCC and patient outcomes. The number of markers present significantly decreased after treatment. Tumor markers AFP-L3 and DCP appear to represent different features of tumor progression in patients with HCC. The number of tumor markers present could be useful for the evaluation of tumor progression, prediction of patient outcome, and treatment efficacy.

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Our previous results showed that the fucosylation index (FI) was considered to be a useful prognostic factor in patients with hepatocellular carcinoma (HCC). On the other hand, serum concentrations of α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) were regarded as prognostic indicators. However, the relationship among FI, AFP, and DCP as prognostic factors remained unknown. The aim of this study was to elucidate the correlation among these three prognostic factors. One hundred and seventy-six patients with HCC from 1990 to 1998, who showed increment of serum AFP concentrations more than 30 ng/ml before treatment, were examined in the present study. FI was determined in these patients by crossed immunoaffino-electrophoresis in the presence of Lens culinaris agglutinin. FI of AFP was defined as the percentage of the L. culinaris agglutinin (LCA)-reactive species in total AFP (same as L3 fraction). Serum concentrations of DCP were also measured. Enrolled patients with HCC underwent transcatheter arterial embolization, chemoembolization, percutaneous ethanol injection, and/or percutaneous microwave coagulation therapy. The current patients status was the one which was confirmed at the end of March 2001. Analysis by the Cox’s proportional hazards model showed that FI, AFP, and DCP were significant prognostic factors. When the tentative demarcation levels of FI, AFP, and DCP were set at 18%, 200 ng/ml, and 0.06 arbitrary units (AU)/ml, respectively, the following results for the prognostication of patients with HCC were obtained. First, the survival rates in the groups with one out of the three optional markers over the demarcation level were significantly lower than the survival rates of other groups, whose optional one marker was equal to or less than the demarcation level, respectively. Next, the survival rates in the groups in which two out of three optional markers were over the demarcation levels were lower than the survival rates of other groups, whose optional two markers were equal to or less than the demarcation levels, with high significance. On the contrary, there was absence or attenuation of statistically significant differences in the survival rates between the groups in which two of the three optional markers showed no accordant results (high FI and low AFP versus low FI and high AFP, low FI and high DCP versus high FI and low DCP, high DCP and low AFP versus low DCP and high AFP). Finally, we compared the survival rates between the HCC groups, whose optional one marker was over the demarcation level and whose remainders were equal to or less than the demarcation levels and another HCC group whose optional one marker was equal to or less than the demarcation level and whose remainders were over the demarcation levels to reconfirm the weight of each prognostic factor. These comparisons together with Cox’s analysis showed that the weight of each prognostic factor in the survival rates is consecutively ordered as DCP, FI, and AFP. The present study indicates that measurements of FI, AFP, and DCP from the sera before the initial treatment improve prognostic estimates and appraisal of the therapeutic outcome in patients with HCC.

Studies on the correlation among the fucosylation index, concentration of α-fetoprotein and des-γ-carboxy prothrombin as prognostic indicators in hepatocellular carcinoma

Our previous results showed that the fucosylation index (FI) was considered to be a useful prognostic factor in patients with hepatocellular carcinoma (HCC). On the other hand, serum concentrations of α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) were regarded as prognostic indicators. However, the relationship among FI, AFP, and DCP as prognostic factors remained unknown. The aim of this study was to elucidate the correlation among these three prognostic factors. One hundred and seventy-six patients with HCC from 1990 to 1998, who showed increment of serum AFP concentrations more than 30 ng/ml before treatment, were examined in the present study. FI was determined in these patients by crossed immunoaffino-electrophoresis in the presence of Lens culinaris agglutinin. FI of AFP was defined as the percentage of the L. culinaris agglutinin (LCA)-reactive species in total AFP (same as L3 fraction). Serum concentrations of DCP were also measured. Enrolled patients with HCC underwent transcatheter arterial embolization, chemoembolization, percutaneous ethanol injection, and/or percutaneous microwave coagulation therapy. The current patients status was the one which was confirmed at the end of March 2001. Analysis by the Cox’s proportional hazards model showed that FI, AFP, and DCP were significant prognostic factors. When the tentative demarcation levels of FI, AFP, and DCP were set at 18%, 200 ng/ml, and 0.06 arbitrary units (AU)/ml, respectively, the following results for the prognostication of patients with HCC were obtained. First, the survival rates in the groups with one out of the three optional markers over the demarcation level were significantly lower than the survival rates of other groups, whose optional one marker was equal to or less than the demarcation level, respectively. Next, the survival rates in the groups in which two out of three optional markers were over the demarcation levels were lower than the survival rates of other groups, whose optional two markers were equal to or less than the demarcation levels, with high significance. On the contrary, there was absence or attenuation of statistically significant differences in the survival rates between the groups in which two of the three optional markers showed no accordant results (high FI and low AFP versus low FI and high AFP, low FI and high DCP versus high FI and low DCP, high DCP and low AFP versus low DCP and high AFP). Finally, we compared the survival rates between the HCC groups, whose optional one marker was over the demarcation level and whose remainders were equal to or less than the demarcation levels and another HCC group whose optional one marker was equal to or less than the demarcation level and whose remainders were over the demarcation levels to reconfirm the weight of each prognostic factor. These comparisons together with Cox’s analysis showed that the weight of each prognostic factor in the survival rates is consecutively ordered as DCP, FI, and AFP. The present study indicates that measurements of FI, AFP, and DCP from the sera before the initial treatment improve prognostic estimates and appraisal of the therapeutic outcome in patients with HCC.

Diagnostic Accuracy of α1-Acid Glycoprotein Fucosylation for Liver Cirrhosis in Patients Undergoing Hepatic Biopsy

Increased fucosylation of serum glycoproteins has previously been reported in patients with liver disease. We analyzed alpha(1)-acid glycoprotein (AGP) fucosylation in serum samples from patients investigated for suspected liver disease to evaluate its value as a biochemical marker for liver cirrhosis. We used a novel lectin immunoassay adapted to the AutoDELFIA system to analyze AGP fucosylation in 261 consecutive patients admitted for liver biopsy at Malmö University Hospital in Southern Sweden. The results were compared with histopathologic findings. In addition, AGP fucosylation was compared with other biochemical markers described as useful in the diagnosis of liver cirrhosis. The biochemical markers were compared by ROC curve analysis. AGP fucosylation was significantly (P <0.05) higher in patients with liver cirrhosis (n = 65) than in healthy controls (n = 72), patients with normal histology (n = 29), patients with steatosis only (n = 38), patients with viral or chronic hepatitis without cirrhosis (n = 71), and patients with other liver diseases without histologic signs of cirrhosis (n = 58). By calculating the AGP fucosylation index (AGP-FI = AGP fucosylation/AGP serum concentration), we obtained a high diagnostic accuracy. The areas under the ROC curves for AGP-FI were 0.83 and 0.74 for men and women, respectively, compared with 0.82 for hyaluronic acid and 0.77 for the aspartate aminotransferase/alanine aminotransferase ratio in both men and women. AGP fucosylation appears to be useful in identifying patients with liver cirrhosis among patients investigated for liver disease. The lectin immunoassay showed satisfactory reproducibility and is suitable for routine use in a clinical laboratory.

The fucosylation index of serum α-fetoprotein as useful prognostic factor in patients with hepatocellular carcinoma in special reference to chronological changes

Aim of this study was to establish fucosylation index (FI) of α-fetoprotein (AFP) before and after initial treatment as a useful prognostic factor in patients with hepatocellular carcinoma (HCC). One hundred ninety-seven patients with HCC from 1990 to 2000, in whom an increment of serum AFP concentrations more than 30 ng/ml was observed before treatment, were examined in the present study. Enrolled patients with HCC underwent transcatheter arterial embolization, chemoembolization, percutaneous ethanol injection and/or percutaneous microwave coagulation therapy. The current patients status was confirmed as of the end of March 2001. FI was determined by crossed immunoaffinoelectrophoresis in the presence of Lens culinaris agglutinin (LCA). FI of AFP was defined as the percentage of the LCA-reactive species in total AFP (same as L3 fraction). When the tentative discriminating line of FI was set at 18%, the mean survival rate in the HCC group, whose FI-1 (before treatment) was higher than 18% (high FI), was significantly lower than that in another HCC group, whose FI-1 was equal to or less than 18% (low FI) by the generalized Wilcoxon test and the log rank test ( P<0.0001). There were statistical significant differences of survival rate when FI-2 (2 months after treatment) and FI-3 (at the time of HCC recurrence or 2 years after treatment in the case of no recurrence) were introduced in the same analysis. Additionally, statistical significant differences of survival rates were obtained between HCC groups with high and low FI-1 when the patient stage was limited to II, III, IVA or IVB. The HCC group, FI-1, FI-2 and FI-3 of which were persistently equal to or less than 18%, showed considerably better prognosis than the group, whose FI-1, FI-2 and FI-3 were persistently higher than 18%. The univariate analysis in the prognostic factor by the Cox's proportional hazards model showed that FI-1, FI-2 and FI-3 were independent prognostic factors. The present study indicates that measuring FI from the sera before and after the treatment serves as a new prognostic indicator and may improve prognostic estimates and appraisal of therapeutic outcome in patients with HCC.

Plasma fucosyltransferase activity in patients with hepatocellular carcinoma, with special reference to correlation with fucosylated species of alpha-fetoprotein

Background/Aims: Our previous results showed that the percentage of fucosylated species of alpha-fetoprotein (AFP) in total AFP, fucosylation index, was a very useful diagnostic tool to distinguish AFP due to hepatocellular carcinoma from AFP due to non-neoplastic liver diseases. On the other hand, α1–6 fucosyl-transferase (αFT) catalyzes the addition of fucose from GDP-fucose through an α1–6 linkage to the reducing end of N-acetylglucosamine residue of N-linked oligosaccharides of glycoproteins. However, the biological and clinical significance of αFT in patients with hepatocellular carcinoma is not fully understood. In the present study, we measured αFT activity to elucidate the enzymatic background of fucosylated species of AFP in hepatocellular carcinoma.Methods: Plasma samples from 84 cases of hepatocellular carcinoma, 40 of liver cirrhosis, 40 of chronic hepatitis and 30 of normal controls, and 26 paired samples of hepatocellular carcinoma and surrounding noncancerous tissues were enrolled in the present study. αFT activity was measured by high performance liquid chromatography with a synthesized fluorescencelabeled glycopeptide with an asialoagalactobiantennary sugar chain as a substrate in the presence of GDP-fucose.Results: Plasma αFT activities (mean±SD, pmol/ml/h) in patients with hepatocellular carcinoma, liver cirrhosis, chronic hepatitis and normal controls were 435±271, 490±290, 590±209 and 380±133, respectively. αFT levels in hepatocellular carcinoma and chronic liver diseases were increased compared with that in normal controls. A statistically significant positive correlation was observed between plasma αFT activity and fucosylation index of AFP (r=0.34, p=0.0032) in 60 patients with hepatocellular carcinoma, in which increments of serum AFP were observed. When the tentative cutoff value of fucosylation index was set at 18%, which corresponded to the cutoff value to discriminate between hepatocellular carcinoma and non-neoplastic liver diseases in our previous study, the plasma αFT activity in hepatocellular carcinoma patients whose fucosylation index was more than 18% (n=32, 523±324 pmol/ml/h) was higher than that in hepatocellular carcinoma patients whose fucosylation index was equal to or less than 18% (n=28, 383±229) (p=0.055). An increment of the plasma levels of αFT occurred in accordance with an advancement of hepatocellular carcinoma stages. Tissue αFT activity in hepatocellular carcinoma (175±178 pmol/mg/h) was higher than those in surrounding noncancerous liver (144±134) and in normal liver (79±19). The mean αFT activities in well-, moderately- and poorly-differentiated hepatocellular carcinoma were 38±0.7, 177±182 and 219±189, respectively, and they tended to increase with dedifferentiation in hepatocellular carcinoma tissues.Conclusions: The present study indicates that αFT is responsible for the formation of the fucosylated species of AFP in hepatocellular carcinoma and suggests that the measurement of αFT provides a possible aid in the evaluation of the degree of advancement in patients with hepatocellular carcinoma.

The fucosylation index of α‐fetoprotein as a possible prognostic indicator for patients with hepatocellular carcinoma

BACKGROUND The aim of this study was to elucidate the usefulness of measuring the fucosylation index (FI) of α-fetoprotein (AFP) before the initiation of therapy as a new prognostic indicator for patients with hepatocellular carcinoma (HCC). METHODS One hundred twelve patients with HCC who underwent transcatheter arterial embolization, chemoembolization, and/or percutaneous ethanol injection were examined in the current study. FI was determined by crossed immunoaffinoelectrophoresis in the presence of Lens culinaris agglutinin. RESULTS When the tentative discriminating value of FI was set at 18%, the mean survival rate for the group whose FI was higher than 18% was significantly lower than that for the group whose FI was equal to or less than 18%, according to the generalized Wilcoxon test (P = 0.0117) and the log rank test (P = 0.0183). The survival rate for HCC patients with AFP concentrations of more than 200 ng/mL was also significantly lower than that for patients with AFP in the range of 21-200 ng/mL, according to the generalized Wilcoxon test (P = 0.0017) and the log rank test (P = 0.0018). When FI was combined with AFP concentration, a highly significant difference was observed between the group with FI >18% and AFP >200 ng/mL and another group with FI ≤18% and AFP ≤200 ng/mL, as determined by the generalized Wilcoxon test (P < 0.0001) and the log rank test (P = 0.0003). An analysis of multiple covariates in the prognostic factors with the Cox proportional hazards model showed that FI was one of the independent prognostic factors. CONCLUSIONS The current study indicates that measuring FI from sera before the initiation of treatment serves as a new prognostic factor and may improve prognostic estimates and appraisal of therapeutic outcomes for patients with HCC. Cancer 1998;83:2076-2082. © 1998 American Cancer Society.

The fucosylation index of ?-fetoprotein as a possible prognostic indicator for patients with hepatocellular carcinoma

The aim of this study was to elucidate the usefulness of measuring the fucosylation index (FI) of alpha-fetoprotein (AFP) before the initiation of therapy as a new prognostic indicator for patients with hepatocellular carcinoma (HCC). One hundred twelve patients with HCC who underwent transcatheter arterial embolization, chemoembolization, and/or percutaneous ethanol injection were examined in the current study. FI was determined by crossed immunoaffino-electrophoresis in the presence of Lens culinaris agglutinin. When the tentative discriminating value of FI was set at 18%, the mean survival rate for the group whose FI was higher than 18% was significantly lower than that for the group whose FI was equal to or less than 18%, according to the generalized Wilcoxon test (P = 0.0117) and the log rank test (P = 0.0183). The survival rate for HCC patients with AFP concentrations of more than 200 ng/mL was also significantly lower than that for patients with AFP in the range of 21-200 ng/mL, according to the generalized Wilcoxon test (P = 0.0017) and the log rank test (P = 0.0018). When FI was combined with AFP concentration, a highly significant difference was observed between the group with FI >18% and AFP >200 ng/mL and another group with FI < or =18% and AFP < or =200 ng/mL, as determined by the generalized Wilcoxon test (P < 0.0001) and the log rank test (P = 0.0003). An analysis of multiple covariates in the prognostic factors with the Cox proportional hazards model showed that FI was one of the independent prognostic factors. The current study indicates that measuring FI from sera before the initiation of treatment serves as a new prognostic factor and may improve prognostic estimates and appraisal of therapeutic outcomes for patients with HCC.

Sequential study of serum glycoprotein fucosylation in acute hepatitis

Background: α-Fetoprotein is a useful diagnostic marker in hepatocellular carcinoma, during which its serum level increases and its glycan structure is hyperfucosylated. Normally-expressed glycoproteins (α1-antitrypsin and transferrin) are also hyperfucosylated in hepatocellular carcinoma. α-fetoprotein serum levels are also increased in conditions associated with hepatic regeneration, such as acute hepatitis. We conducted a longitudinal study of the α1–6 fucosylation pattern of serum α-fetoprotein in ten patients with acute hepatitis and compared it to that of transferrin and α1-antitrypsin. Methods: Protein levels were measured by using immunochemical assays. Crossed affinoimmunoelectrophoresis in the presence of Lens culinaris agglutinin was performed for each protein, and the fucosylation index, corresponding to the agglutinin reactive fraction, was determined. The results were compared to those in 25 healthy donors and five newborns. Results: α-Fetoprotein was hyperfucosylated and remained stable throughout the course of the disease. In contrast, serum transferrin and α1-antitrypsin gradually became hyperfucosylated during the course of acute hepatitis. The transferrin and α1-antitrypsin fucosylation indexes correlated with each other, but not with the α-fetoprotein fucosylation index. No correlation was found between α-fetoprotein, α1-antitrypsin and transferrin fucosylation indexes and the corresponding glycoprotein serum levels. Conclusions: Hyperfucosylation of α-fetoprotein is not specific to hepatocellular carcinoma. Increased α1–6 fucosylation should not be considered solely as a tumour marker, but might also reflect cell proliferation. The study of α1–6 hyperfucosyation process of normally-expressed glycoproteins awaits further investigation, to test its usefulness as a new marker of liver regeneration during the follow-up of acute hepatitis.

Carbohydrate-based measurements on alpha-fetoprotein in the early diagnosis of hepatocellular carcinoma.

Serum alpha-fetoprotein (AFP) is a useful marker for the diagnosis of hepatocellular carcinoma (HCC), although this protein also increases moderately in benign liver diseases. The serum concentration of AFP in HCC at the time of initial diagnosis is now lower than before because of advancements in techniques for imaging the liver. The AFP concentration alone cannot distinguish between HCC and benign liver diseases, especially when it is less than 1000 ng ml-1. These circumstances lead to the need to discriminate between these diseases. This has been achieved by determining the carbohydrate structures of AFP by its reactivity with Lens culinaris agglutinin (LCA). The percentage of LCA-reactive species of AFP is significantly higher in HCC than in benign liver diseases. The fucosylation of the sugar chain at the innermost N-acetylglucosamine is the molecular basis of this variation. Therefore, the term 'fucosylation index' has been introduced to express the percentage of LCA-reactive species of AFP. This index is useful for the diagnosis of HCC even if the carcinoma is at an early stage. Furthermore, it can predict the development of HCC in the follow-up of chronic liver diseases. Thus, the qualitative and quantitative measurements of carbohydrate in AFP provide us with very valuable information for the differential diagnosis of various liver diseases.

Fucosylation Index of α-Fetoprotein, a Possible Aid in the Early Recognition of Hepatocellular Carcinoma in Patients with Cirrhosis

We report here on three patients with cirrhosis for whom an early recognition of hepatocellular carcinoma was made possible by the measurement of the degree of fucosylation (fucosylation index) of alpha-fetoprotein. Increased levels of this index associated with a moderate increment of serum concentration of alpha-fetoprotein were observed in three patients with cirrhosis who showed no indication of hepatocellular carcinoma by several imaging modalities. Four years after the onset of an increase in the fucosylation index, small hepatocellular carcinoma with a tumor diameter less than 2 cm was revealed in case 1. In cases 2 and 3, small hepatocellular carcinomas were detected 24 mo and 9 mo, respectively, after the first sign of the increase in the index. However, the development to hepatocellular carcinoma was not detected in five patients with cirrhosis in whom continuous increments of serum concentration of alpha-fetoprotein with low levels of fucosylation index were observed during the prospective follow-up from 3 to 9 yr. These findings indicated that the fucosylation index of alpha-fetoprotein can be used as an aid in an early recognition of hepatocellular carcinoma, especially in patients with cirrhosis during the follow-up process in which the moderate increment of serum concentration of alpha-fetoprotein is noted.

Fucosylation index of α-fetoprotein, a possible aid in the early recognition of hepatocellular carcinoma in patients with cirrhosis

We report here on three patients with cirrhosis for whom an early recognition of hepatocellular carcinoma was made possible by the measurement of the degree of fucosylation (fucosylation index) of α-fetoprotein. Increased levels of this index associated with a moderate increment of serum concentration of α-fetoprotein were observed in three patients with cirrhosis who showed no indication of hepatocellular carcinoma by several imaging modalities. Four years after the onset of an increase in the fucosylation index, small hepatocellular carcinoma with a tumor diameter less than 2 cm was revealed in case 1. In cases 2 and 3, small hepatocellular carcinomas were detected 24 mo and 9 mo, respectively, after the first sign of the increase in the index. However, the development to hepatocellular carcinoma was not detected in five patients with cirrhosis in whom continuous increments of serum concentration of α-fetoprotein with low levels of fucosylation index were observed during the prospective follow-up from 3 to 9 yr. These findings indicated that the fucosylation index of α-fetoprotein can be used as an aid in an early recognition of hepatocellular carcinoma, especially in patients with cirrhosis during the follow-up process in which the moderate increment of serum concentration of α-fetoprotein is noted. (HEPATOLOGY 1993;17:50–52.)

The usefulness of simultaneous determinations of glucosaminylation and fucosylation indices of alpha-fetoprotein in the differential diagnosis of neoplastic diseases of the liver

The degrees of glucosaminylation (glucosaminylation index) and fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples of 351 patients with hepatocellular carcinoma (HCC), 47 with carcinoma metastatic to the liver from digestive organs, five with mixed cholangiocellular and HCC, and 176 with benign liver diseases. The glucosaminylation index of AFP in patients with carcinoma metastatic to the liver (42 +/- 23%, mean +/- SD) was significantly higher than that in patients with HCC (5 +/- 7%, P less than 0.001) or that in patients with benign liver diseases (2 +/- 4%, P less than 0.001). The fucosylation indices of AFP in patients with carcinoma metastatic to the liver, with HCC, and with benign liver diseases were 76 +/- 25%, 42 +/- 30%, and 4 +/- 6%, respectively. Thus, the fucosylation indices of AFP were high in two neoplastic liver diseases (carcinoma metastatic to the liver and HCC) and low in benign liver diseases, whereas the glucosaminylation indices were high in carcinoma metastatic to the liver but low in HCC and benign liver diseases. When the values of 30% and 80% were used as the level of the glucosaminylation and fucosylation indices, respectively, to discriminate carcinoma metastatic to the liver from HCC, 40 of 47 patients with carcinoma metastatic to the liver (85%) were able to be discriminated from HCC (sensitivity). The specificity, the positive predictive value, and the overall accuracy were 86% (302/351), 45% (40/40 + 47 + 3 - 2) and 86% (40 + 302/47 + 351), respectively. These data suggest that the combined information in these two indices provides a potent criterion for the diagnosis of neoplastic diseases of the liver.

Transferrin glycosylation in hypoxia

The aim of this study was to examine the effect of reduced O2 tension on the glycosylation of transferrin. Rats were placed in a hypobaric chamber (380 mmHg) that corresponded to an altitude of 5486 m above sea level for 21 days. The animals responded with marked increases in hematocrit (from 44 to 76%) and cardiac weight, and with reductions in the concentration of plasma transferrin averaging 15%. Analyses of their plasma transferrin by serial anion-exchange and lectin affinity chromatography revealed no changes in the extent of glycan branching. However, there was a moderate rise in the proportion of fucosylated transferrin molecules (fucosylation index) and a slight decrease in the transferrin fraction bearing a tetrasialylated biantennary glycan. The fucosylation index correlated positively with plasma transferrin concentrations in the test animals, but not in the controls. In contradistinction to the situation with transferrin, hypoxic rats exhibited a reduced fucosylation index of immunoglobulin G.

The fucosylation index of alpha-fetoprotein and its usefulness in the early diagnosis of hepatocellular carcinoma

The serum concentration and degree of fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples from 258 patients with hepatocellular carcinoma (HCC) and 114 patients with benign liver diseases. When the serum AFP concentration was below 1000 ng/ml, it could not be used as a measure to distinguish between HCC and benign liver diseases. However, the fucosylation index of AFP proved useful for such a purpose. The sensitivity of the analysis using the fucosylation index in total patients with HCC was 69%; the specificity was 96% in benign liver diseases, and the accuracy of this test was 77%. When HCC patients who were grouped according to tumor size (5 cm, 3 cm, and 2 cm in diameter) were analyzed, they all had a fucosylation index significantly higher than that in benign liver disease patients. The mean fucosylation index in 28 patients with a serum AFP concentration below 1000 ng/ml and a tumor diameter less than 3 cm was 26 +/- 30%. Corresponding values for 16 patients with an AFP concentration below 400 ng/ml and a tumor size less than 3 cm and for 8 patients with a concentration below 400 ng/ml and a tumor size less than 2 cm were 32 +/- 31% and 27 +/- 27%, respectively. These values were higher, with statistical significance, than those in patients with benign liver diseases. These data indicate that the measurement of the fucosylation index of AFP is useful for the early diagnosis of HCC.