Glycomics: a new taste of cirrhosis marker

Tissue N-linked glycosylation as potential prognostic biomarker for biochemical recurrence-free survival

PURPOSE

Only few biomarkers have been evaluated for their prognostic value following radical prostatectomy. We explored if tissue N-glycosylation shows prognostic properties for biochemical recurrence (BCR)-free survival.

MATERIALS AND METHODS

Tissue N-glycosylation profile was determined from 82 prostate cancer (PCa) patients and prognostic features were compared to clinical and biochemical parameters for BCR-free survival.

RESULTS

Majority presented with Gleason score 3 + 4 (41%), extensive local disease (62%) and without pelvic lymph nodes invasion (83%). Several parameters (low T stage, low Gleason score, low EAU risk groups for BCR, absence of positive surgical margins, high ratio of fucosylated triantennary structures on total of multiantennary structures [3AFc/MA], low ratio of fucosylated biantennary with core-branched N-acetylglucosamine on total of biantennary structures, and high ratio of triantennary structures on total of multiantennary structures) proved to have a univariate beneficial effect on BCR-free survival. Multivariate analysis proved positive surgical margins and 3AFc/MA to be independent prognosticators.

CONCLUSIONS

Tissue N-glycans are a powerful prognostic tool and can be an asset in PCa as the ratio of 3AFc/MA is independently associated with BCR-free survival. This could be of clinical use in guiding patients following radical prostatectomy, e.g. referral to adjuvant radiotherapy. Further elaboration of this biomarker is warranted.

Immunological measurement of aspartate/alanine aminotransferase in predicting liver fibrosis and inflammation

BACKGROUND/AIMS

Enzymatic analysis of aspartate/alanine aminotransferase (AST/ALT) does not exactly represent the progression of liver fibrosis or inflammation. Immunoassay for AST (cytoplasmic [c] AST/mitochondrial [m] AST) and ALT (ALT1/ALT2) has been suggested as one alternatives for enzymatic analysis. The objective of this study was to evaluate the efficacy of immunoassay in predicting liver fibrosis and inflammation.

METHODS

A total of 219 patients with chronic hepatitis B (CHB) who underwent hepatic venous pressure gradient (HVPG) and liver biopsy before antiviral therapy were recruited. Serum samples were prepared from blood during HVPG. Results of biochemical parameters including enzymatic AST/ALT and immunological assays of cAST, mAST, ALT1, and ALT2 through sandwich enzyme-linked immunosorbent assay (ELISA) immunoassay with fluorescence labeled monoclonal antibodies were compared with the results of METAVIR stage of live fibrosis and the Knodell grade of inflammation.

RESULTS

METAVIR fibrosis stages were as follows: F0, six (3%); F1, 52 (24%); F2, 88 (40%); F3, 45 (20%); and F4, 28 patients (13%). Mean levels of AST and ALT were 121 ± 157 and 210 ± 279 IU/L, respectively. Mean HVPG score of all patients was 4.7 ± 2.5 mmHg. According to the stage of liver fibrosis, HVPG score (p < 0.001, r = 0.439) and ALT1 level (p < 0.001, r = 0.283) were significantly increased in all samples from patients with CHB. ALT (p < 0.001, r = 0.310), ALT1 (p < 0.001, r = 0.369), and AST (p < 0.001, r = 0.374) levels were positively correlated with Knodell grade of inflammation.

CONCLUSION

ALT1 measurement by utilizing sandwich ELISA immunoassay can be useful method for predicting inf lammation grade and fibrosis stage in patients with CHB.

Diagnostic accuracy of hepatic venous pressure gradient measurement in the prediction of stage 1 compensated liver cirrhosis in patients with chronic hepatitis B

OBJECTIVE

Hepatic venous pressure gradient (HVPG) of 6-10 mmHg has been accepted as a hemodynamic parameter of stage 1 compensated liver cirrhosis (LC). The diagnostic accuracy of HVPG in the prediction of stage 1 compensated LC has been investigated in patients with chronic hepatitis B (CHB).

METHODS

A total of 219 patients with CHB who underwent HVPG and liver biopsy were enrolled. The diagnostic accuracy of two methods was compared. Risk factors associated with the diagnosis of stage 1 compensated LC on the basis of the findings of HVPG, biopsy, and both HVPG and biopsy were evaluated.

RESULTS

The HVPG score was correlated positively with the stage of biopsy (r=0.439). The sensitivity/specificity of HVPG for predicting stage 1 compensated LC were 78/81% in 6 mmHg, respectively. A total of 57 (26%), 28 (13%), and 20 (9%) patients were diagnosed with stage 1 compensated LC on the basis of the findings of HVPG, biopsy, and both HVPG and biopsy (P>0.05), respectively. Platelet/age (-0.77-0.01×platelet+0.03×age), albumin/platelet (5.05-1.19×albumin-0.01×platelet), and platelet (0.24-0.01×platelet) were found to be risk factors (logit model) for the diagnosis of stage 1 compensated LC on the basis of the findings of HVPG, biopsy, and both HVPG and biopsy.

CONCLUSION

HVPG showed a positive correlation with biopsy, and platelet was found to be a common risk factor for the diagnosis of stage 1 compensated LC in patients with CHB.

Diagnostic accuracy of biomarkers measured in the hepatic vein and peripheral vein in the prediction of advanced fibrosis in patients with chronic viral hepatitis

OBJECTIVES

The accuracies of biomarkers checked in the hepatic vein (HV) and peripheral vein (PV) were compared in the prediction of advanced fibrosis (AF) of liver.

METHODS

Patients with chronic viral hepatitis (n=101) who underwent hepatic venous pressure gradient, liver biopsy, and paired HV-PV samples (6 biomarkers: hyaluronic acid [HA], haptoglobin, matrix metalloproteinase-2 [MMP2], tissue inhibitor of metalloproteinases-1 [TIMP1], procollagen III N-terminal peptide [PIIINP], and apolipoprotein-A1 [Apo-A1]) were enrolled.

RESULTS

Differences were displayed between the HV and PV in the predictive logit-models for predicting AF (-3.13+0.017×MMP2-0.019×haptoglobin and -0.270+0.007×HA-0.018×haptoglobin, respectively). In the area under the receiver operating characteristic curves, PIIINP (0.74/0.68, p=0.03), MMP2 (0.72/0.63, p=0.04), HA (0.79/0.76, p=0.94), Apo-A1 (0.56/0.48, p=0.73), and predictive logit-model (0.81/0.78, p=0.68) showed higher diagnostic value in the HV sample.

CONCLUSIONS

While most biomarkers were correlated better with hepatic fibrosis in HV than in PV, individually and in predictive logit-models, they were inadequate to determine the degree of advanced fibrosis.

A rapid mass spectrometric strategy for the characterization of N- and O-glycan chains in the diagnosis of defects in glycan biosynthesis

Glycosylation of proteins is a very complex process which involves numerous factors such as enzymes or transporters. A defect in one of these factors in glycan biosynthetic pathways leads to dramatic disorders named congenital disorders of glycosylation (CDG). CDG can affect the biosynthesis of not only protein N-glycans but also O-glycans. The structural analysis of glycans on serum glycoproteins is essential to solving the defect. For this reason, we propose in this paper a strategy for the simultaneous characterization of both N- and O-glycan chains isolated from the serum glycoproteins. The serum (20 microL) is used for the characterization of N-glycans which are released by enzymatic digestion with PNGase F. O-glycans are chemically released by reductive elimination from whole serum glycoproteins using 10 microL of the serum. Using strategies based on mass spectrometric analysis, the structures of N- and O-glycan chains are defined. These strategies were applied on the sera from one patient with CDG type IIa, and one patient with a mild form of congenital disorder of glycosylation type II (CDG-II) that is caused by a deficiency in the Cog1 subunit of the complex.

Exploiting flow injection system with mini-immunoaffinity chromatographic column for chondroitin sulfate proteoglycans assay

A flow injection (FI) system with a mini-immunoaffinity chromatographic column was used to perform on-line assays of specific proteoglycans. The 300-microL mini-column contained beads coupled with monoclonal antibodies against the specific sulfation pattern of chondroitin sulfate proteoglycans, which have been reported to be a potential biomarker for cancer. The amount of these proteoglycans present was estimated indirectly from their protein content using the Bradford assay, which is an alternative to a direct carbohydrate assay. The system developed was tested by assaying for chondroitin sulfate proteoglycans in sera from patients with various cancers and comparing the results to those obtained for sera from healthy people. The results indicated that this approach could be used as a cost-effective alternative system for determining the amount of these specific biomarker proteoglycans. The column could be reused at least 90 times, with each run consisting of 200 microL of serum sample diluted twofold; an analysis rate of 30 min per run was achieved, as compared to 4 h for a batch procedure.

Do we still need a liver biopsy? Are the serum fibrosis tests ready for prime time?

Liver biopsy has been in use for more than a century for diagnosis and staging of acute and chronic liver diseases. Several serum markers and panels offer the opportunity to assess the extent of liver disease noninvasively and spare some patients the risks associated with percutaneous liver biopsy, but only a few of the noninvasive serum markers allow the determination of different stages of fibrosis on a continuum similar to that achieved with liver biopsy. This article reviews the results of recent published and preliminary studies on serum markers, focusing on their comparison with liver biopsy and their clinical utility.