Genome-wide association and polygenic risk score estimation of type 2 diabetes mellitus in Kinh Vietnamese-A pilot study.

A genome-wide association study (GWAS) is a powerful tool in investigating genetic contribution, which is a crucial factor in the development of complex multifactorial diseases, such as type 2 diabetes mellitus. Type 2 diabetes mellitus is a major healthcare burden in the Western Pacific region; however, there is limited availability of genetic-associated data for type 2 diabetes in Southeast Asia, especially among the Kinh Vietnamese population. This lack of information exacerbates global healthcare disparities. In this study, 997 Kinh Vietnamese individuals (503 with type 2 diabetes and 494 controls) were prospectively recruited and their clinical and paraclinical information was recorded. DNA samples were collected and whole genome genotyping was performed. Standard quality control and genetic imputation using the 1000 Genomes database were executed. A polygenic risk score for type 2 diabetes was generated in different models using East Asian, European, and mix ancestry GWAS summary statistics as training datasets. After quality control and genetic imputation, 107 polymorphisms reached suggestive statistical significance for GWAS (≤5 × 10-6) and rs11079784 was one of the potential markers strongly associated with type 2 diabetes in the studied population. The best polygenic risk score model predicting type 2 diabetes mellitus had AUC = 0.70 (95% confidence interval = 0.62-0.77) based on a mix of ancestral GWAS summary statistics. These data show promising results for genetic association with a polygenic risk score estimation in the Kinh Vietnamese population; the results also highlight the essential role of population diversity in a GWAS of type 2 diabetes mellitus.

Ultra-Deep Sequencing of Plasma-Circulating DNA for the Detection of Tumor- Derived Mutations in Patients with Nonmetastatic Colorectal Cancer.

Identification of tumor-derived mutation (TDM) in liquid biopsies (LB), especially in early-stage patients, faces several challenges, including low variant-allele frequencies, interference by white blood cell (WBC)-derived mutations (WDM), benign somatic mutations and tumor heterogeneity. Here, we addressed the above-mentioned challenges in a cohort of 50 nonmetastatic colorectal cancer patients, via a workflow involving parallel sequencing of paired WBC- and tumor-gDNA. After excluding potential false positive mutations, we detected at least one TDM in LB of 56% (28/50) of patients, with the majority showing low-patient coverage, except for one TDM mapped to KMT2D that recurred in 30% (15/30) of patients.

Evaluation of a Liquid Biopsy Protocol using Ultra-Deep Massive Parallel Sequencing for Detecting and Quantifying Circulation Tumor DNA in Colorectal Cancer Patients.

The identification and quantification of actionable mutations are critical for guiding targeted therapy and monitoring drug response in colorectal cancer. Liquid biopsy (LB) based on plasma cell-free DNA analysis has emerged as a noninvasive approach with many clinical advantages over conventional tissue sampling. Here, we developed a LB protocol using ultra-deep massive parallel sequencing and validated its clinical performance for detection and quantification of actionable mutations in three major driver genes (KRAS, NRAS and BRAF). The assay showed a 92% concordance for mutation detection between plasma and paired tissues and great reliability in quantification of variant allele frequency.

Characterization of SCCA-IgM as a biomarker of liver disease in an Asian cohort of patients.

Viral hepatitis infection is a major global issue and a leading cause of liver disease and associated deaths. Over time, patients infected with hepatitis B (HBV) or C virus (HCV) develop cirrhosis and, eventually, hepatocellular carcinoma (HCC). For this reason, they need to be constantly monitored. Current Asian guidelines recommend the determination of serum alpha-fetoprotein (AFP) together with liver ultrasounds every six months to detect HCC nodules. However, both methods have several limitations, and other biomarkers have been studied for monitoring cirrhosis, including SCCA-IgM, an immune-complex formed by Squamous Cell Carcinoma Antigen and IgM. To date, SCCA-IgM has been validated as a novel biomarker for liver diseases only in European populations. The aim of our study was to analyze SCCA-IgM as a biomarker to monitor cirrhosis evolution in an Asian cohort of patients and to compare its performance to that of AFP. We analyzed the concentration of AFP and SCCA-IgM in serum samples obtained from a group of Asian adult patients with cirrhosis or HCC and a control group of patients admitted for gastrointestinal disorders. In untreated patients and similarly to AFP, SCCA-IgM levels were significantly higher in patients with cirrhosis compared to those with HCC. In addition, SCCA-IgM, but not AFP serological levels, were significantly lower in HCC patients who were treated with surgical resection compared to those who received a different therapy.

Mycoplasma genitalium prevalence, co-infection and macrolide resistance-associated mutations in Southern Vietnam.

Mycoplasma genitalium is an emerging sexually transmitted infection, with increasing rates of macrolide resistance and some ways of treatments being recommended by many countries. This study aimed to investigate the prevalence of M. genitalium infection, M. genitalium co-infection with other sexually transmitted organisms, and the frequency of macrolide antibiotic resistance genotypes identified in urethral specimens collected from male and urethral, vaginal and cervical specimens from female who visited the STIs clinic of HCMC Hospital of Dermato-Venereology, Vietnam. The results obtained positive samples for C. trachomatis was 8.46%, N. gonorrhoeae was 6.28%, and M. genitalium was 5.95%. Fifty-five out of 90 M. genitalium samples were found to have mutations in the 23S rRNA gene associated with macrolide resistance (61.11%). M. genitalium/C. trachomatis co-infection was 6.19%, and M. genitalium/N. gonorrhoeae was 1.22%. The percentage of M. genitalium carrying the macrolide resistance mutant gene co-infected with C. trachomatis accounted for 37.50%. The high prevalence of the M. genitalium mutations associated with macrolide resistance showed the importance of M. genitalium testing.

Invasive Fungal Rhinosinusitis: The First Histopathological Study in Vietnam.

BACKGROUND: Invasive fungal rhinosinusitis (IRFS) is a rare but highly fatal disease. The two primary groups of pathogens, Mucorales and Aspergillus, require different treatments and have distinct prognoses. PURPOSE: This study aimed to analyze the histopathological features of IFRS. METHODS: We conducted a retrospective study involving 57 IFRS cases. Demographic and comorbid characteristics were obtained from clinical records. Two pathologists independently examined the histopathological features using H&E, PAS, and GMS-stained slides. Fungal groups were identified with PCR under the guidance of histopathology. RESULTS: The mean age of IFRS was 58.9 ± 13.4. The male-to-female ratio was 1.4:1. 100% of cases had diabetes comorbidity. Mucorales, Aspergillus, and other fungi were found in 61.4%, 33.3%, and 5.3% of cases, respectively. No Aspergillus and Mucorales co-infections were detected. Histopathology and PCR results were strongly concordant in classifying pathogens (Cohen's kappa = 84.2%, 95% CI 60.1% - 100%, p < 0.001). Mucormycosis exhibited higher rates of extensive necrosis and vascular invasion, and lower rates of pigment and spore presence than the non-Mucormycosis group (p < 0.001, p = 0.01, p = 0.02, p = 0.03, respectively). Extensive necrosis and vascular invasion were statistically significantly correlative (OR = 13.03, 95% CI 2.62-64.75, p = 0.002). CONCLUSIONS: IFRS predominantly affects older adults and males. Histopathology is a reliable method for differentiating between Mucorales and Aspergillus. When extensive necrosis is detected, it is critical to investigate for vascular invasion carefully. The vascular invasion, degree of necrosis, pigments, and spores are valuable factors for distinguishing fungal agents of IFRS.

Design and generation of mRNAs encoding conserved regions of SARS-CoV-2 ORF1ab for T cell-mediated immune activation.

Aim: To generate mRNAs encoding conserved regions within SARS-CoV-2 ORF1ab which can induce strong T-cell responses to overcome the immune invasion of newly emergent variants. Methods: We selected two conserved regions with a high density of T-cell epitopes using immunoinformatics for mRNA synthesis. The ability of testing mRNAs to activate T cells for IFN-γ production was examined by an ELISpot assay and flow cytometry. Results: Two synthesized mRNAs were successfully translated in MDA-MB-231 cells and had comparable potency to the spike mRNA to induce CD4+ and CD8+ T-cell responses in peripheral blood mononuclear cells in 29 out of 34 participants. Conclusion: This study provides a proof-of-concept for the use of SARS-CoV-2 conserved regions to develop booster vaccines capable of eliciting T-cell-mediated immunity.

The Coexistence of Hepatitis B Surface Antigen and Anti-HBs in Patients With Chronic HBV Infection: Prevalence and Related Factors.

Background and Aims: The prevalence of coexistence of HBsAg and anti-HBs in chronic hepatitis B virus (HBV)-infected patients is different between studies. The mutations on the S gene were proved as the cause of this coexistence. This study determined the frequency and factors associated with coexistence of HBsAg and anti-HBs in chronic HBV-infected patients. Methods: This cross-sectional study was conducted at University Medical Center at Ho Chi Minh City, Vietnam, from April 2014 to December 2020. HBeAg, HBsAg, and anti-HBs were measured by chemiluminescent immunoassay. Mutations on the HBV small S gene from amino acids 1-227 were detected using Sanger sequencing on 177 patients. Results: A total of 521 chronic HBV-infected patients were enrolled, including 350 males (62.7%), 17.1% with hepatic fibrosis of ≥ F3 and 9.8% with hepatocellular carcinoma (HCC). The coexistence of HBsAg and anti-HBs was detected in 9.8%, with 17.9% among genotype C compared to 7.4% in genotype B, P = .001. The coexistence group had lower levels of HBsAg titers (P = .052). There were significantly higher rates of coexistence in the group with HCC (19.6% vs 8.7%, P = .013). The existence of point mutations on the major hydrophilic region and the "a" determinant region of HBV was more frequently detected in the HBsAg and anti-HBs coexistence group (P = .043 and P = .008, respectively). Conclusion: The coexistence of HBsAg and anti-HBs was detected more frequently in the HBV genotype C group. The coexistence status was related to lower HBsAg titers, mutations on the major hydrophilic region, and/or the "a" determinant and exposed significant relation with HCC.

Mutations in the HBV PreS/S gene related to hepatocellular carcinoma in Vietnamese chronic HBV-infected patients.

BACKGROUND: Chronic hepatitis B virus (CHB) infection is a major health problem and leading cause of hepatocellular carcinoma (HCC) worldwide. Several point and deletion mutations on the PreS/S gene have been intensively considered associated with HCC. This study aimed to describe the characteristics of HBV PreS/S mutations in Vietnamese CHB-infected patients and their association with HCC. METHODS: This cross-sectional study was conducted from 02/2020 to 03/2021, recruited Vietnamese CHB-infected patients with HBV-DNA >3 log10-copies/mL and successful PreS/S gene sequencing. Mutations were detected by direct Sanger sequencing. RESULTS: 247 CHB-infected patients were recruited, characterized by 68.8% males, 54.7% HBV genotype B, 57.5% HBeAg positive, 23.1% fibrosis score ≥F3 and 19.8% HCC. 61.8% amino acid replacements were detected throughout the PreS1/PreS2/S genes. The most common point-mutations included N/H51Y/T/S/Q/P (30.4%), V68T/S/I (44.9%), T/N87S/T/P (46.2%) on PreS1 gene; T125S/N/P (30.8%), I150T (42.5%) on PreS2 gene; S53L (37.7%), A184V/G (39.3%), S210K/N/R/S (39.3%) on S gene. The rates of case(s) with any point-mutation on the Major Hydrophylic Region (MHR) and the "a" determinant region were 63.6% and 39.7%, respectively. Most of S point-mutations were presented with low rates such as T47A/E/V/K (9.3%), P120S/T (8.5%), G145R (2%). On multivariable analysis, males (OR = 4.51, 95%CI 1.78-11.4, p = 0.001), age≥40 (OR = 5.5, 95%CI 2.06-14.68, p = 0.001), W4P/R/Y on PreS1 (OR = 11.56, 95%CI 1.99-67.05, p = 0.006) and 4 S point-mutations as: T47A/E/V/K (OR = 3.67, 95%CI 1.19-11.29, p = 0.023), P120S/T (OR = 3.38, 95%CI 1.09-10.49, p = 0.035), S174N (OR = 29.73, 95%CI 2.12-417.07, p = 0.012), P203R (OR = 8.45, 95%CI 1.43-50.06, p = 0.019) were associated with HCC. CONCLUSIONS: We detected 61% amino acid changes on PreS/S regions in Vietnamese CHB patients. One point-mutation at amino acid 4 on PreS1 gene and 4 point-mutations at amino acids 47, 120, 174, and 203 on S gene were associated with HCC. Further investigations are recommended to further clarify the relationship and interaction between mutations in HBV genome and HCC progression.

Liquid biopsy uncovers distinct patterns of DNA methylation and copy number changes in NSCLC patients with different EGFR-TKI resistant mutations.

Targeted therapy with tyrosine kinase inhibitors (TKI) provides survival benefits to a majority of patients with non-small cell lung cancer (NSCLC). However, resistance to TKI almost always develops after treatment. Although genetic and epigenetic alterations have each been shown to drive resistance to TKI in cell line models, clinical evidence for their contribution in the acquisition of resistance remains limited. Here, we employed liquid biopsy for simultaneous analysis of genetic and epigenetic changes in 122 Vietnamese NSCLC patients undergoing TKI therapy and displaying acquired resistance. We detected multiple profiles of resistance mutations in 51 patients (41.8%). Of those, genetic alterations in EGFR, particularly EGFR amplification (n = 6), showed pronounced genome instability and genome-wide hypomethylation. Interestingly, the level of hypomethylation was associated with the duration of response to TKI treatment. We also detected hypermethylation in regulatory regions of Homeobox genes which are known to be involved in tumor differentiation. In contrast, such changes were not observed in cases with MET (n = 4) and HER2 (n = 4) amplification. Thus, our study showed that liquid biopsy could provide important insights into the heterogeneity of TKI resistance mechanisms in NSCLC patients, providing essential information for prediction of resistance and selection of subsequent treatment.