Detection of serum cross-reactive antibodies and memory response to SARS-CoV-2 in pre-pandemic and post-COVID-19 convalescent samples

Background A notable feature of COVID-19 is that children are less susceptible to severe disease. Children are known to experience more infections with endemic human coronaviruses (HCoVs) compared to adults. Little is known whether HCoV infections lead to cross-reactive anti-SARS-CoV-2 antibodies. Methods We investigated the presence of cross-reactive anti-SARS-CoV-2 IgG antibodies (to spike(S)1, S1-receptor-binding receptor (S1-RBD) and nucleocapsid protein(NP)), by enzyme-linked immunosorbent assays, and neutralizing activity by a SARS-CoV-2 pseudotyped virus neutralisation assay, in pre-pandemic sera collected from children(n=50) and adults(n=45), and compared with serum samples from convalescent COVID-19 patients(n=16). Results A significant proportion of children (up to 40%) had detectable cross-reactive antibodies to SARS-CoV-2 S1, S1-RBD and NP antigens, and the anti-S1 and -S1-RBD antibody levels correlated with anti-HCoV-HKU1 and -OC43 S1 antibody titers in pre-pandemic samples(p<0.001). There were marked increases of anti-HCoV-HKU1 and -OC43 S1 (but not anti-NL63 and -229E S-RBD) antibody titres in serum samples from convalescent COVID-19 patients(p<0.001), indicating an activation of cross-reactive immunological memory to β-coronavirus spike. Conclusions We demonstrated cross-reactive anti-SARS-CoV-2 antibodies in pre-pandemic serum samples from children and young adults. Promoting this cross-reactive immunity and memory response derived from common HCoV may be an effective strategy against SARS-COV-2 and future novel coronaviruses

The future of medical diagnostics: Review paper

While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, expressed as sensitivity and specificity, are reported in a number of studies suggests that they have a potential for cost effective, real-time, in situ diagnosis. We review the Third Scientific Meeting of the Head and Neck Optical Diagnostics Society held in Congress Innsbruck, Innsbruck, Austria on the 11th May 2011. For the first time the HNODS Annual Scientific Meeting was held in association with the International Photodynamic Association (IPA) and the European Platform for Photodynamic Medicine (EPPM). The aim was to enhance the interdisciplinary aspects of optical diagnostics and other photodynamic applications. The meeting included 2 sections: oral communication sessions running in parallel to the IPA programme and poster presentation sessions combined with the IPA and EPPM posters sessions. © 2011 Jerjes et al; licensee BioMed Central Ltd

Oral squamous cell cancer: early detection and the role of alcohol and smoking

Objective: Oral squamous cell carcinoma has a remarkable incidence worldwide and a fairly onerous prognosis, encouraging further research on factors that might modify disease outcome. Data sources: A web-based search for all types of articles published was initiated using Medline/Pub Med, with the key words such as oral cancer, alcohol consumption, genetic polymorphisms, tobacco smoking and prevention. The search was restricted to articles published in English, with no publication date restriction (last update 2010). Review Methods: In this review article, we approach the factors for a cytologic diagnosis during OSCC development and the markers used in modern diagnostic technologies as well. We also reviewed available studies of the combined effects of alcohol drinking and genetic polymorphisms on alcohol-related cancer risk. Results: The interaction of smoking and alcohol significantly increases the risk for aero-digestive cancers. The interaction between smoking and alcohol consumption seems to be responsible for a significant amount of disease. Conclusion: Published scientific data show promising pathways for the future development of more effective prognosis. There is a clear need for new prognostic indicators, which could be used in diagnostics and, therefore a better selection of the most effective treatment can be achieved

Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX fluorescence in detecting oral premalignancy

Background: Early detection of premalignant/malignant lesions in the oral cavity can certainly improve the patient’s prognosis. This study presents fluorescence imaging with the topical application of 5-aminolevulinic as a way to improve detection of various oral tissue pathologies. This procedure depends mainly on comparing the intensity of red and green fluorescence emitted from tissues during examination. Materials and methods: Seventy-one patients who presented with clinically suspicious oral leukoplakia were recruited for this study. Each of the patients was required to have 5-aminolevulinic acid in the form of mouth rinse prior to fluorescence imaging. Following this a surgical biopsy was acquired from the exact examination site. The results of the fluorescence spectroscopy have been compared with histopathology. Results: A Student’s t-test was applied to test the viability of the ratio between red and green fluorescence. The red-to-green ratio was found to increase significantly when the lesion was identified as dysplastic or carcinoma in situ. By applying a threshold line to discriminate between normal and dysplastic lesions; a sensitivity of 83–90% and specificity of 79–89% were obtained. Conclusion: Fluorescence spectroscopy combined with 5-aminolevulinic acid-induced protoporphyrin IX was found as a valuable tool in the diagnosis of oral premalignancy. This technique offers the potential to be advantageous over other non-optical techniques in terms of providing real-time diagnosis, in situ monitoring, cost effectiveness and more tolerated by patient compared to surgical biopsy.Eastman Dental Institute for Oral Healthcare Sciences, London, U

Photodynamic therapy down-regulates the invasion promoting factors in human oral cancer

Squamous cell carcinomas of the head and neck are characterized by their high tendency for invasion and metastasis. Several studies have identified the roles of matrix metalloproteinases (MMPs), vascular endothelial growth factors (VEGF) and urokinase plasminogen activators (uPA) in this process. Photodynamic Therapy (PDT) is an emerging treatment currently in clinical practice for the treatment of early cancer. Here we evaluate, in vitro, the influence of PDT on the expression of these molecules. A series of human keratinocyte cell lines derived from human oral squamous cell carcinomas (OSCC) were used as the PDT ‘targets’ in this study. Each cell line was subjected to sublethal dose of PDT. Activity of MMP-2, MMP-9, MMP-13, uPA and VEGF were evaluated at protein levels using zymography and ELISA on culture medium. For uPA, a chromogenic assay was performed. Gelatin zymography results revealed that, in control medium, MMP-9 and MMP-2 were secreted in proform. MMP-2 was highly expressed by H376 cells while VB6 and UP cells relatively show similar MMP-2 with comparatively low expression. For MMP-9, the latent type was highly expressed by VB6 cells and only slightly by H376, while activeMMP-9 was expressed by VB6 cell line only. Following PDT, both active and latent MMP- 2 and MMP-9 were down regulated by UP and VB6 cells ( p < 0.001), while H376 showed an increase in active-MMP-2. These observations were supported by ELISA. This study has demonstrated that, PDT causes the suppression of factors responsible for tumour invasion which may be of therapeutic value.UCL Eastman Dental Institute and University College London Hospitals, London, U

Relative Frequency of Oral Malignancies and Oral Precancer in the Biopsy Service of Jazan Province, 2009-2014

Background: The objective of this study was to report the types and relative frequency of oral malignancies and precancer in the Jazan region of Saudi Arabia during the period 2009-2014. Materials and Methods: Pathology reports were retrieved from the archives of Histopathology Department, King Fahd hospital in Jazan. Demographic data on tobacco habits, clinical presentation and histologic grading of oral precancer and cancer cases were transcribed from the files. Results: 303 (42.7%) oral pre-malignant and malignant cases were found out of 714 oral biopsy lesions. A pathology diagnosis of squamous cell carcinoma (85.1%) was most frequent, followed by premalignant lesions/epithelial dysplasia (8.6%), verrucous carcinoma (3.3%) and malignancy of other histological types (3%) such as ameloblastic carcinoma, salivary gland malignancy and sarcomas. Oral squamous cell carcinoma was predominant in females with a male to female ratio of 1:1.9. Patient age ranged from 22 to 100 years with a mean of 65±13.9. Almost 44.6% of oral cancer had occurred after 65 years of age. Only 16.3% cases were reported in patients younger than 50 years, predominantly females. The majority of female patients had the habit of using shammah with a long duration of usage for more than 45 years. Buccoalveolar mucosa (52.3%) was the common site of involvement followed by tongue/ floor of the mouth (47.7%) and clinically presented mostly as ulceration/swelling clinically. Moderately differentiated tumours (53.9%) were common followed by well differentiated (32.2%) and poorly differentiated tumours (5.8%). The prevalence of oral verrucous carcinoma (3.3%) was comparatively low with an equal distribution in both males and females. Both bucco-alveolar mucosa and tongue were predominantly affected. Oral precancer/epithelial dysplasia (8.6%) was common in females with a shammah habit. Bucco-alveolar mucosa was commonly involved and clinically presented mostly as white/red patches. Most cases were mild followed by moderate and severe dysplasia. Tumours of other histological types (3%) include 1 ameloblastic carcinoma, 3 malignant salivary gland tumours and 5 sarcomas. Conclusions: In this study, it was found that oral cancers reported in the pathology service to be a common occurrence. This study reconfirms previous reports of the high burden of oral cancer in this population This indicates that conventional preventive programs focused on oral cancer are in need of revision. In addition, further research into identifying new risk factors and molecular markers for oral cancer are needed for screening high risk individuals.</p