Influence of Warfarin Therapy on Prothrombin Production and Its Posttranslational Modifications

Overcoming cross-reactivity of antibodies against human lactate dehydrogenase

Lactate dehydrogenase subunit A (LD-A) plays an important role in cancer regulation and therapy. We attempted to develop an enzyme-linked immune-solvent assay (ELISA) for LD-A in human serum. However, commercial antibodies against LD-A exhibited cross-reactivity with an unknown protein. The unknown protein was purified and characterized by protein sequencing and Western blotting. In addition, we attempted to prepare a specific antibody for the ELISA using partially synthesized peptides of LD-A as immunogens. The epitope position in LD-A was carefully selected based on bioinformatics analysis. Peptide sequencer elucidated a ten amino acid sequence of the purified protein at the N-terminal. A BLAST search revealed that this sequence perfectly matched that at the N-terminus of the IgG heavy chain (H-chain). Furthermore, we demonstrated that twelve commercially available antibodies targeting LD-A or LD-B (subunit B) primarily cross-reacted with IgG or its H-chain, with only one specific antibody for each subunit. As the specific antibody against LD-A is no longer commercially accessible, we successfully produced two kinds of specific antibodies using partially synthesized LD-A peptides as immunogens. In conclusion, we have successfully produced specific antibodies against LD-A. Moreover, our findings underscore the utility of bioinformatics tools for determining the optimal positions of immunizing peptides.

Current status and new directions for hepatocellular carcinoma diagnosis

Liver cancer ranks as the sixth most common cancer globally, with hepatocellular carcinoma (HCC) accounting for approximately 75%-85% of cases. Most patients present with moderately advanced disease, while those with advanced HCC face limited and ineffective treatment options. Despite diagnostic efforts, no ideal tumor marker exists to date, highlighting the urgent clinical need for improved early detection of HCC. A key research objective is the development of assays that target specific pathways involved in HCC progression. This review explores the pathological origin and development of HCC, providing insights into the mechanistic rationale, clinical statistics, and the advantages and limitations of commonly used diagnostic tumor markers. Additionally, it discusses the potential of emerging biomarkers for early diagnosis and offers a brief overview of relevant assay methodologies. This review aims to summarize existing markers and investigate new ones, providing a basis for subsequent research.

Vitamin K insufficiency and the prophylaxis strategy in term healthy infants: A multicentre study

BACKGROUND/AIM

Late vitamin K deficiency bleeding (VKDB) during early infancy is a serious problem worldwide. Vitamin K (VK) deficiency commonly occurs in newborns who are exclusively breastfed. Protein Induced by VK Absence (PIVKA-II) has been identified as an early indicator of subclinical VK deficiency in neonates, surpassing prothrombin time. To assess PIVKA-II levels at 48 h, 1 and 3 months of age in full-term newborns who were exclusively breastfed and received varying VKDB prophylaxis regimens.

METHODS

A prospective observational study was conducted in four hospitals, enrolling 105 newborns. PIVKA-II levels were measured using a sandwich-type enzyme-linked immunosorbent assay.

RESULTS

At 48 h of age, there was no significant difference in PIVKA-II concentrations between newborns who received intramuscular administration of 1 mg of phylloquinone (VK1) and those who received oral administration of 2 mg of VK1 at birth. At 1 and 3 months of life, infants who received any supplementation regimen between 2 and 14 weeks exhibited significantly lower PIVKA-II concentrations compared to infants who received only 1 mg of intramuscular VK1 at birth. The prophylaxis involving a dose of 1 mg of intramuscular VK1 at birth followed by oral administration of 150 μg/day of VK1 from the 2nd to the 14th week of life showed the lowest PIVKA-II blood concentrations.

CONCLUSIONS

Oral supplementation of VK1 after discharge significantly reduced PIVKA-II concentrations in exclusively breastfed term infants. These findings suggest the importance of oral VK1 supplementation in exclusively breastfed infants during their first 3 months of life to avoid the risk of VK insufficiency.

Meta-analysis of the GALAD model for diagnosing primary hepatocellular carcinoma

BACKGROUND

Ever since the GALAD (gender-age-Lens culinaris agglutinin-reactive alpha-fetoprotein-alpha-fetoprotein-des-gamma-carboxy prothrombin) logistic regression model was established to diagnose hepatocellular carcinoma (HCC), there has been no high-level evidence that evaluates and summarizes it.

OBJECTIVE

This meta-analysis was performed to assess the diagnostic ability of the GALAD model.

METHODS

The following databases were systematically searched for original diagnostic studies on HCC: PubMed, Embase, Medline, the Web of Science, Cochrane Library, China National Knowledge Infrastructure Wanfang (China), Wiper and the Chinese BioMedical Literature Database. After screening the search results according to our criteria, the Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to evaluate the methodologic qualities, and statistical software were used to output the statistics.

RESULTS

Ultimately, 10 studies were included and analyzed. The results revealed the pooled sensitivity and specificity of the GALAD model to be 0.86 (95% confidence interval [CI]: 0.82, 0.90) and 0.90 (95% CI: 0.87, 0.92), respectively, for all-stage HCC. The area under the curve (AUC) was 0.94. For early-stage HCC, the pooled sensitivity and specificity of the GALAD model were 0.83 (95% CI: 0.78, 0.87) and 0.81 (95% CI: 0.78, 0.83), respectively. The AUC was 0.90.

CONCLUSION

This meta-analysis confirmed that the GALAD model has excellent diagnostic performance for early-stage and all-stage HCC and can maintain high sensitivity and specificity in early-stage HCC. Therefore, the GALAD model is qualified for screening early-stage canceration from chronic liver disease.

Development and validation of a diagnostic model for AFP-negative hepatocellular carcinoma

PURPOSE

AFP appears to be negative in about 30% of overall hepatocellular carcinoma (HCC). Our study aimed to develop a nomogram model to diagnose AFP-negative HCC (AFPN-HCC).

PATIENTS AND METHODS

The training set included 294 AFPN-HCC patients, 159 healthy objects, 63 patients with chronic hepatitis B(CHB), and 64 patients with liver cirrhosis (LC). And the validation set enrolled 137 healthy controls objects, 47 CHB patients and 45 patients with LC. LASSO, univariate, and multivariable logistic regression analysis were performed to construct the model and then transformed into a visualized nomogram. The receiver operating characteristic (ROC) curves, the calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were further used for validation.

RESULTS

Four variables including age, PIVKA-II, platelet (PLT) counts, and prothrombin time (PT) were selected to establish the nomogram. The area under the curve (AUC) of the ROC to distinguish AFPN-HCC patients was 0.937(95% CI 0.892-0.938) in training set and 0.942(95% CI 0.921-0.963) in validation set. We also found that the model had high diagnostic value for small-size HCC (tumor size < 5 cm) (AUC = 0.886) and HBV surface antigen-positive AFPN-HCC (AUC = 0.883).

CONCLUSIONS

Our model was effective for discrimination of AFPN-HCC from patients with benign liver diseases and healthy controls, and might be helpful for the diagnosis for AFPN-HCC.

Measuring serum prothrombin in patients treated with warfarin or direct oral anticoagulants

BACKGROUND

Warfarin therapy influences generation of γ-carboxyglutamyl (Gla) residues in prothrombin, causing reduced coagulation activity. It will leave such inactive prothrombin in serum after clot formation, resulting in serum prothrombin constituting total inactive prothrombin in these patients.

METHODS

An ELISA was developed to measure biologically inactive prothrombin in serum, and applied to serum from warfarin therapy causing a decrease in Gla residues or direct oral anticoagulant (DOAC) therapy as its contrast.

RESULTS

The concentrations of serum prothrombin in both the warfarin and DOAC groups were higher than those in the healthy group (p < 0.01 and p < 0.001, respectively). When serum in the previous three groups was treated with barium carbonate to exclude prothrombin, which lost several Gla residues, the prothrombin concentration in the DOAC group decreased to the same level as that in the healthy group, indicating that prothrombin was obtained at a high level only in the warfarin group (p < 0.01).

CONCLUSIONS

Warfarin and DOAC led to increase in serum prothrombin concentration. The reason is that DOAC decreases prothrombin recruitment during fibrin clot formation, while warfarin leads to the accumulation of inactive prothrombin, which have a decreased number of Gla residues.