Liquid-based cytological and immunohistochemical study of nasopharyngeal swab from persons under investigation for SARS-CoV-2 infection.

INTRODUCTION: We describe cytologic and immunohistologic findings in virus transport medium on cases under investigation of SARS-CoV-2 infection. METHODS: Cytologic findings in cases under investigation of SARS-CoV-2 infection from one hundred consecutive nasopharyngeal swab were reviewed. Immunohistochemistry and SARSCoV-2 RT-PCR determination were performed to detect virus. RESULTS: No viral inclusions were noted in squamous cells obtained from virus transport medium. Immunohistochemical study with monoclonal antibody against SARS-CoV-2 viral nucleoprotein showed positivity in squamous cells. No positivity was present in others cellular components. CONCLUSIONS: SARS-CoV-2 predominantly localizes squamous cells in cytology samples of patients with RT-PCR positive determination of SARSCoV-2. The results of the current study support the notion that the nasopharyngeal region is the anatomical station that SARS-CoV-2 infects first, and the infection can lead to the migration of the virus into the lower airways.

Study of Liquid-Based Cytology Using Next-Generation Sequencing as a Liquid Biopsy Application in Patients with Advanced Oncological Disease.

In patients with advanced cancer, it is necessary to detect driver mutations and genetic arrangements. If a mutation is found, targeted therapy may become an option. However, in most patients with advanced cancer, obtaining material can be challenging, and these determinations must be made based on small biopsies or cytologic samples. We analyzed the ability of liquid-based cytology to determine the mutational status in patients with advanced cancer by next-generation sequencing. We studied cytologic samples from 28 patients between 1 January 2018 and 31 December 2022. All samples were processed by next-generation sequencing using the Oncomine® Precision and Comprehensive Assay Panels for Solid Tumors. Eleven male and 17 female patients with a median age of 63.75 years were included. Clinical stage IV was predominant in 21 patients. Eleven patients died, and 17 survived. The DNA and RNA concentrations were 10.53 ng/µL and 13 ng/µL, respectively. Eleven patients showed actionable mutations, and 17 showed other genomic alterations. Liquid-based cytology can be used as a component of liquid biopsy, as it allows the identification of actionable mutations in patients with advanced oncological disease. Our findings expand the utility of liquid biopsy from different body fluids or cell aspirates.

Retrospective Analysis of Vaccination Status and Predominant Viral Variants in Patients Hospitalized with COVID-19 in Reus, Spain.

SARS-CoV-2 infection in already-vaccinated individuals is still possible and may require hospitalization. The aim of the present study was to evaluate the clinical evolution of patients with COVID-19 admitted to a public hospital. The outcomes were assessed in relation to the predominant viral variant and the vaccination status. This retrospective study was performed on 1295 COVID-19-positive patients who attended a 352-bed university hospital between 2021 and 2022. Clinical variables and vaccination status were recorded. Of the patients, 799 had not been vaccinated (NV, 61.7%), 449 were partially vaccinated (PV, 34.7%), and 47 were completely vaccinated (CV, 3.6%). The mean age of the CV patients was significantly higher than that of PV and NV. Additionally, they had higher percentages of chronic diseases. The outcomes depended on age but not on vaccination status. There were 209 patients admitted during the Omicron-infection period, of whom 70 (33.5%) were NV, 135 (64.6%) were PV, and 4 (1.9%) were CV. In conclusion, correct vaccination greatly reduces the risk of acquiring severe COVID-19. Partial vaccination does not guarantee protection of the population. This highlights the need for continuous vaccination promotion with all recommended doses, while also investigating alternative treatments for those patients who do not respond to the vaccines.

Usefulness of the Urine Methylation Test (Bladder EpiCheck®) in Follow-Up Patients with Non-Muscle Invasive Bladder Cancer and Cytological Diagnosis of Atypical Urothelial Cells-An Institutional Study.

Urothelial bladder cancer is a heterogeneous disease and one of the most common cancers worldwide. Bladder cancer ranges from low-grade tumors that recur and require long-term invasive surveillance to high-grade tumors with high mortality. After the initial contemporary treatment in non-muscle invasive bladder cancer, recurrence and progression rates remain high. Follow-up of these patients involves the use of cystoscopies, cytology, and imaging of the upper urinary tract in selected patients. However, in this context, both cystoscopy and cytology have limitations. In the follow-up of bladder cancer, the finding of urothelial cells with abnormal cytological characteristics is common. The main objective of our study was to evaluate the usefulness of a urine DNA methylation test in patients with urothelial bladder cancer under follow-up and a cytological finding of urothelial cell atypia. In addition, we analyzed the relationship between the urine DNA methylation test, urine cytology, and subsequent cystoscopy study. It was a prospective and descriptive cohort study conducted on patients presenting with non-muscle invasive urothelial carcinoma between 1 January 2018 and 31 May 2022. A voided urine sample and a DNA methylation test was extracted from each patient. A total of 70 patients, 58 male and 12 female, with a median age of 70.03 years were studied. High-grade urothelial carcinoma was the main histopathological diagnosis. Of the cytologies, 41.46% were cataloged as atypical urothelial cells. The DNA methylation test was positive in 17 urine samples, 51 were negative and 2 were invalid. We demonstrated the usefulness of a DNA methylation test in the follow-up of patients diagnosed with urothelial carcinoma. The methylation test also helps to diagnose urothelial cell atypia.

Immunocytochemical Assessment of ACE2 and TMPRSS2 in Nasopharyngeal Swabs from SARS-CoV-2 Patients.

BACKGROUND: SARS-CoV-2 is a positive-sense single-stranded RNA virus. It is enveloped by four structural proteins. The entry of the virus into the host cells is mediated by spike protein binding to the angiotensin converting enzyme 2 (ACE2) and proteolytic cleavage by transmembrane protease serine 2 (TMPRSS2). In this study, we analyzed the expression of the ACE2 receptor and TMPRSS2 in cases under investigation for SARS-CoV-2 infection. METHODS: The study was carried out using the viral transport medium of consecutive nasopharyngeal swabs from 300 people under examination for SARS-CoV-2 infection. All samples underwent the SARS-CoV-2 transcriptase-mediated amplification assay (Procleix® SARS-CoV-2) to detect the virus. Immunocytochemistry was used in each sample to detect the presence of the SARS-CoV-2 nucleoprotein, the ACE2 receptor, and TMPRSS2. RESULTS: An immunocytochemical study with monoclonal antibody against SARS-CoV-2 viral nucleoprotein showed positivity in squamous cells. ACE2 were not detected in the squamous cells obtained from the nasopharyngeal samples. CONCLUSIONS: SARS-CoV-2 predominantly localizes to squamous cells in cytology samples of patients with positive transcriptase-mediated amplification SARS-CoV-2 assay results. The immunocytochemical negativity for ACE2 evidenced in the present study could be related to the cellular heterogeneity present in the nasopharyngeal smear samples and could be related to variations at the genomic level. Our results suggest that SARS-CoV-2 might be present in the nasopharyngeal region because viral cell junctions are weaker. This facilitates viral concentration, infective capacity and migration to specific organs, where SARS-CoV-2 infects target cells by binding to their receptors and then entering.

Utility of ctDNA Liquid Biopsies from Cancer Patients: An Institutional Study of 285 ctDNA Samples.

Liquid biopsy has improved significantly over the last decade and is attracting attention as a tool that can complement tissue biopsy to evaluate the genetic landscape of solid tumors. In the present study, we evaluated the usefulness of liquid biopsy in daily oncology practice in different clinical contexts. We studied ctDNA and tissue biopsy to investigate EGFR, KRAS, NRAS, and BRAF mutations from 199 cancer patients between January 2016 and March 2021. The study included 114 male and 85 female patients with a median age of 68 years. A total of 122 cases were lung carcinoma, 53 were colorectal carcinoma, and 24 were melanoma. Liquid biopsy was positive for a potentially druggable driver mutation in 14 lung and colorectal carcinoma where tissue biopsy was not performed, and in two (3%) lung carcinoma patients whose tissue biopsy was negative. Liquid biopsy identified nine (45%) de novo EGFR-T790M mutations during TKI-treatment follow-up in lung carcinoma. BRAF-V600 mutation resurgence was detected in three (12.5%) melanoma patients during follow-up. Our results confirm the value of liquid biopsy in routine clinical oncologic practice for targeted therapy, diagnosis of resistance to treatment, and cancer follow-up.

Study of the Plasma and Buffy Coat in Patients with SARS-CoV-2 Infection-A Preliminary Report.

The pandemic caused by the SARS-CoV-2 infection affects many aspects of public health knowledge, science, and practice around the world. Several studies have shown that SARS-CoV-2 RNA in plasma seems to be associated with a worse prognosis of COVID-19. In the present study, we investigated plasma and buffy RNA in patients with COVID-19 to determine its prognostic value. A prospective study was carried out in patients hospitalized for COVID-19, in which RNA was analyzed in plasma and the buffy coat. Morphological and immunohistochemical studies were used to detect the presence of SARS-CoV-2 in the buffy coat. In COVID-19 patients, the obtained RNA concentration in plasma was 448.3 ± 31.30 ng/mL. Of all the patients with positive plasma tests for SARS-CoV-2, 46.15% died from COVID-19. In four cases, tests revealed that SARS-CoV-2 was present in the buffy coat. Abnormal morphology of monocytes, lymphocytes and neutrophils was found. An immunohistochemical study showed positivity in mononuclear cells and platelets. Our results suggest that SARS-CoV-2 is present in the plasma. This facilitates viral dissemination and migration to specific organs, where SARS-CoV-2 infects target cells by binding to their receptors. In our study, the presence of plasma SARS-CoV-2 RNA was correlated with worse prognoses.