Serum tumor marker CA19-9 in the follow-up of patients with cystic echinococcosis

Ratiometric electrochemical immunosensor for the detection of CA199 based on the ratios of NiCo@Fc-MWCNTs-LDH and 3D-rGOF@Ag/Au complexes

Carbohydrate antigen 199 (CA199) is the most sensitive marker reported for pancreatic cancer, and it is a difficult task to develop a highly sensitive assay for CA199. During the experiment, a ratiometric electrochemical immunosensor for quantitative analysis of CA199 was prepared for NiCo@Fc-MWCNTs-LDH as the electrode sensing surface and 3D-rGOF@Ag/Au as the label of Ab2. NiCo@Fc-MWCNTs-LDH not only provide the required signal for the immunosensor, but also have a layered structure to obtain a large specific surface area, which can provide more sites for the placement of biological molecules. rGOF has the advantages of large specific surface area and high porosity, which can adsorb Ag electrochemical probe through redox reaction. The modification of gold nanoparticles can not only enhance the electrical conductivity of nano-composites, but also immobilize more biomolecules to improve the sensitivity of electrochemical sensors. With the beefing up of CA199 concentration, the oxidation peak current of Ag increases and the oxidation peak current of Fc-COOH decreases. The ratio (y = IAg/IFc-COOH) of two different signals was linear with the logarithm of CA199 concentration in a certain value range. Under optimal conditions, the immunosensor showed excellent performance in the concentration range of 0.0001 U/mL to 10 U/mL, and the detection limit was 5.55 × 10-4 U/mL. The strategy could clearly discriminate between matched and mismatched targets, demonstrating high specifificity. This approach further detects CA199 in human plasma to differentiate pancreatic cancer patients from healthy individuals with high accuracy. This method also provided a new idea for the ultrasensitive quantitative detection of other biomarkers.

Preoperatively elevated RDW-SD and RDW-CV predict favorable survival in intrahepatic cholangiocarcinoma patients after curative resection

BACKGROUND

Recent studies suggest red blood cell distribution width (RDW) was a prognostic factor in various types of cancer patients, although the results are controversial. The objective of this study was to investigate the significance of RDW in patients with intrahepatic cholangiocarcinoma (ICC) after radical resection.

METHOD

The relationship between the preoperative serum RDW value and clinic pathological characteristics was analyzed in 157 ICC patients between January 2012 and June 2018 who underwent curative resection. X-tile software was used to determine 40.2 fl, 12.6% as the optimal cut-off value for RDW-SD and RDW-CV respectively. 153 patients were classified into the low RDW-SD (≤ 40.2, n = 53) group and the high RDW-SD (> 40.2, n = 104) group, low RDW-CV (≤ 12.6, n = 94) group and the high RDW-CV (> 12.6, n = 63). Based on the RDW-SD combined with RDW-CV (SCC), classified into SCC = 0, 1 and 2 group. Kaplan-Meier survival analysis and Cox proportional hazard models were used to examine the effect of RDW on survival.

RESULTS

Kaplan-Meier curve analysis showed that Patients with RDW-SD > 40.2 were significantly associated with better OS (P = 0.004, median OS: 68.0 months versus 17.0 months). Patients with RDW-CV > 12.6 were significantly associated with better OS (p = 0.030, median OS: not reach versus 22.0 months). Compared with a SCC = 0 or SCC = 1, SCC = 2 was significantly associated with better OS (p < 0.001, median OS: not reach versus 33.0 months versus 16, respectively). In the multivariate analysis, RDW-SD > 40.2 fl (HR = 0.446, 95% CI: 0.262-0.760, p = 0.003), RDW-CV > 12.6% (HR = 0.425, 95%CI: 0.230-0.783, p = 0.006), SCC = 2 (HR = 0.270, 95%CI: 0.133-0.549, p < 0.001) were associated with favorable OS. The multivariate analysis showed RDW-SD, RDW-CV and SCC level were not independent prognostic factors for DFS.

CONCLUSIONS

Preoperative low levels of RDW are associated with poor survival in ICC after curative resection. This provides a new way for predicting the prognosis of ICC patients and more targeted intervention measures.

Novel redox species polyaniline derivative-Au/Pt as sensing platform for label-free electrochemical immunoassay of carbohydrate antigen 199

A novel electrochemical redox-active nanocomposite was synthesized by a one-pot method using N,N'-diphenyl-p-phenylediamine as monomer, and HAuCl4 and K2PtCl4 as co-oxidizing agents. The as-prepared poly(N,N'-diphenyl-p-phenylediamine)-Au/Pt exhibited admirable electrochemical redox activity at 0.15 V, excellent H2O2 electrocatalytic ability and favorable electron transfer ability. Based on these, the evaluation of the composite as sensing substrate for label-free electrochemical immunosensing to the sensitive detection of carbohydrate antigen 199 was described. This technique proved to be a prospective detection tool with a wide liner range from 0.001 U mL(-1) to 40 U mL(-1), and a low detection limit of 2.3 × 10(-4) U mL(-1) (S/N = 3). In addition, this method was used for the analysis of human serum sample, and good agreement was obtained between the values and those of enzyme-linked immunosorbent assay, implying the potential application in clinical research. Importantly, the strategy of the present substrate could be extended to other polymer-based nanocomposites such as polypyrrole derivatives or polythiophene derivatives, and this could be of great significance for the electrochemical immunoassay.

Comparative assessment of ELISAs using recombinant saposin-like protein 2 and recombinant cathepsin L-1 from Fasciola hepatica for the serodiagnosis of human Fasciolosis

Two recombinant Fasciola hepatica antigens, saposin-like protein-2 (recSAP2) and cathepsin L-1 (recCL1), were assessed individually and in combination in enzyme-linked immunosorbent assays (ELISA) for the specific serodiagnosis of human fasciolosis in areas of low endemicity as encountered in Central Europe. Antibody detection was conducted using ProteinA/ProteinG (PAG) conjugated to alkaline phosphatase. Test characteristics as well as agreement with results from an ELISA using excretory–secretory products (FhES) from adult stage liver flukes was assessed by receiver operator characteristic (ROC) analysis, specificity, sensitivity, Youdens J and overall accuracy. Cross-reactivity was assessed using three different groups of serum samples from healthy individuals (n = 20), patients with other parasitic infections (n = 87) and patients with malignancies (n = 121). The best combined diagnostic results for recombinant antigens were obtained using the recSAP2-ELISA (87% sensitivity, 99% specificity and 97% overall accuracy) employing the threshold (cut-off) to discriminate between positive and negative reactions that maximized Youdens J. The findings showed that recSAP2-ELISA can be used for the routine serodiagnosis of chronic fasciolosis in clinical laboratories; the use of the PAG-conjugate offers the opportunity to employ, for example, rabbit hyperimmune serum for the standardization of positive controls.

To improve the serodiagnosis of human fasciolosis caused by Fasciola hepatica, we comparatively evaluated the accuracy of two different enzyme-linked immunosorbent assays (ELISAs) based on the use of two published recombinant antigens. The best performance was achieved with the recombinant F. hepatica saposin-like protein-2 antigen (recSAP2). Although the F. hepatica E/S antigen exhibited a slightly higher diagnostic sensitivity, the higher specificity performance of recSAP2 renders this antigen very suitable for application in low endemic areas, especially when coupled to an easy and standardized production facility as compared to the relatively complex production procedure for an E/S antigen. Conclusively, the recSAP2-ELISA can be used as a routine individual serodiagnostic test for human fasciolosis, especially when backed up by a compatible clinical history together with other serodiagnostic technique for other helminth infections of the liver, e.g. alveolar or cystic echinococcosis.

Carbohydrate antigen 19-9 is extremely elevated in polycystic liver disease

BACKGROUND/AIMS

Carbohydrate antigen 19-9 (CA19-9) is used as a biomarker to differentiate benign from malignant gastrointestinal disorders. We examined the value of CA19-9 measurement in polycystic livers after observing high CA19-9 cyst fluid levels in a benign polycystic liver case.

METHODS

We determined CA19-9 levels in serum (n=120) and hepatic cyst fluid (n=81), from patients with polycystic livers (n=109) and simple hepatic cysts (n=24). Further, we analysed CA19-9 expression in normal and polycystic liver tissue (n=17).

RESULTS

Cyst fluid CA19-9 levels from both polycystic livers and simple hepatic cysts were extremely high (median 91 000 U/ml, range 14-15 870 000 U/ml; median 85 000 U/ml, range 332-1 744 000 U/ml respectively). Serum CA19-9 levels were significantly higher in polycystic liver patients (median 30 U/ml, range 0-1200 U/ml) compared with patients with simple hepatic cysts (median 10 U/ml, range 3-200 U/ml, P=0.0011). Serum CA19-9 levels correlated with those in cyst fluid (r=0.3979, P=0.0399), polycystic liver volume (r=0.3870, P=0.0025) and the size of the largest cyst (simple cysts group; r=0.5319, P=0.0280). Cyst epithelia showed strong CA19-9 expression. Evacuation of cyst fluid in four patients resulted in a dramatic decrease in the serum CA19-9 levels (60-95%).

CONCLUSIONS

CA19-9 levels are high in the cyst fluid and serum of polycystic liver disease patients due to production and secretion by cyst epithelia. It does not reflect malignancy in these patients and may be of value as a biomarker for intervention efficiency assessment.