Inflammatory Bacteriome and Oral Squamous Cell Carcinoma.

Results from microbiome studies on oral cancer have been inconsistent, probably because they focused on compositional analysis, which does not account for functional redundancy among oral bacteria. Based on functional prediction, a recent study revealed enrichment of inflammatory bacterial attributes in oral squamous cell carcinoma (OSCC). Given the high relevance of this finding to carcinogenesis, we aimed here to corroborate them in a case-control study involving 25 OSCC cases and 27 fibroepithelial polyp (FEP) controls from Sri Lanka. DNA extracted from fresh biopsies was sequenced for the V1 to V3 region with Illumina's 2 × 300-bp chemistry. High-quality nonchimeric merged reads were classified to the species level with a prioritized BLASTN-based algorithm. Downstream compositional analysis was performed with QIIME (Quantitative Insights into Microbial Ecology) and linear discriminant analysis effect size, while PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was utilized for bacteriome functional prediction. The OSCC tissues tended to have lower species richness and diversity. Genera Capnocytophaga, Pseudomonas, and Atopobium were overrepresented in OSCC, while Lautropia, Staphylococcus, and Propionibacterium were the most abundant in FEP. At the species level, Campylobacter concisus, Prevotella salivae, Prevotella loeschii, and Fusobacterium oral taxon 204 were enriched in OSCC, while Streptococcus mitis, Streptococcus oral taxon 070, Lautropia mirabilis, and Rothia dentocariosa among others were more abundant in FEP. Functionally, proinflammatory bacterial attributes, including lipopolysaccharide biosynthesis and peptidases, were enriched in the OSCC tissues. Thus, while the results in terms of species composition significantly differed from the original study, they were consistent at the functional level, substantiating evidence for the inflammatory nature of the bacteriome associated with OSCC.

Viral infections associated with oral cancers and diseases in the context of HIV: a workshop report.

Human herpesviruses (HHVs) and human papillomavirus (HPV) are common in the general population and, in immunocompetent people, are mostly carried asymptomatically. However, once an individual becomes immunocompromised by age, illness or HIV infection these dormant viruses can manifest and produce disease. In HIV-positive patients, there is an increased risk of disease caused by HHVs and HPV infections and cancers caused by the oncoviruses Epstein-Barr Virus, HHV-8 and HPV. This workshop examined four questions regarding the viruses associated with oral cancers and disease in the HIV-positive and -negative populations, the immune response, and biomarkers useful for accurate diagnostics of these infections and their sequalae. Each presenter identified a number of key areas where further research is required.

Successful treatment of iatrogenic multicentric Castleman's disease arising due to recrudescence of HHV-8 in a liver transplant patient.

We describe the case of a 59-year-old HIV-negative male who developed multicentric Castleman's disease (MCD) 1 year postliver transplantation due to recrudescence of a pretransplant human herpesvirus-8 (HHV-8) infection. He presented with fevers, dry cough, weight loss and drenching night sweats. Routine investigations were all unremarkable. Computerized axial tomography (CT) scans showed splenomegaly and intra-abdominal lymphadenopathy, confirmed by positron emission tomography. Cervical lymph node biopsies were consistent with MCD. The presence of HHV-8 was confirmed on immunohistochemistry. Peripheral blood HHV-8 quantitative polymerase chain reaction (qPCR) monitoring showed a threefold decrease in viremia in the first week of treatment with ganciclovir but had little impact on clinical symptoms. Reducing immunosuppression and switching to rituximab resolved clinical symptoms and produced a negative HHV-8 qPCR result. Retrospective molecular testing of sera collected pre- and immediately posttransplantation confirmed preexisting HHV-8 in the host. This is the first reported case of an HIV-negative postliver transplant patient developing MCD that manifested as posttransplant lymphoproliferative disorder due to recrudescence of HHV-8. We propose (1) the introduction of the term iatrogenic Castleman's disease (CD) for this and similar cases, (2) rituximab should be considered as a treatment option for CD and (3) consideration be given to a change to the World Health Organization classification of CD to incorporate such cases.

Comparison of salivary collection and processing methods for quantitative HHV-8 detection.

OBJECTIVES: Saliva is a proved diagnostic fluid for the qualitative detection of infectious agents, but the accuracy of viral load determinations is unknown. Stabilising fluids impede nucleic acid degradation, compared with collection onto ice and then freezing, and we have shown that the DNA Genotek P-021 prototype kit (P-021) can produce high-quality DNA after 14 months of storage at room temperature. Here we evaluate the quantitative capability of 10 collection/processing methods. METHODS: Unstimulated whole mouth fluid was spiked with a mixture of HHV-8 cloned constructs, 10-fold serial dilutions were produced, and samples were extracted and then examined with quantitative PCR (qPCR). Calibration curves were compared by linear regression and qPCR dynamics. RESULTS: All methods extracted with commercial spin columns produced linear calibration curves with large dynamic range and gave accurate viral loads. Ethanol precipitation of the P-021 does not produce a linear standard curve, and virus is lost in the cell pellet. DNA extractions from the P-021 using commercial spin columns produced linear standard curves with wide dynamic range and excellent limit of detection. CONCLUSION: When extracted with spin columns, the P-021 enables accurate viral loads down to 23 copies µl(-1) DNA. The quantitative and long-term storage capability of this system makes it ideal for study of salivary DNA viruses in resource-poor settings.

Oral lesions, HIV phenotypes, and management of HIV-related disease: Workshop 4A.

The workshop considered 5 questions related to oral lesions, HIV phenotypes, and the management of HIV-related disease, with a focus on evidence and challenges in resource-poor settings. First, are oral lesions unique with respect to geographic location or phenotype? Second, how useful would an oral lesion index be to predict HIV in resource-poor countries with no access to CD4 counts or viral load? Third, what are the latest methods and delivery modes for drugs used to treat oral lesions associated with HIV? Fourth, what is the role of the oral health care worker in rapid diagnostic testing for HIV? Fifth, what ethical and legal issues are to be considered when managing the HIV patient? The consensus of the workshop was the need for additional research in 4 key areas in developing countries: (1) additional investigation of comorbidities associated with HIV infection that may affect oral lesion presentation and distribution, especially in pediatric populations; (2) the development of region-specific algorithms involving HIV oral lesions, indicating cumulative risk of immune suppression and the presence of HIV disease; (3) well-designed clinical trials to test new therapies for oral lesions, new treatments for resistant oral fungal and viral diseases, effectiveness of therapies in children, and new drug delivery systems; and (4) the role of the oral health care worker in rapid diagnostic testing for HIV in various regions of the world.

Mucosal fluids and biomarkers of clinical disease: workshop 3B.

Diagnostic tests for a range of oral and systemic diseases using fluids sampled from the mouth are under intense investigation and are increasingly being used. Methods exist for identification of HIV antibody and nucleic acid and for other viral infections of the mouth, such as Kaposi sarcoma herpes virus or human herpesvirus-8, which may coexist with HIV. A number of commercial test kits are available, with variable evidence of sensitivity, specificity, and utility. There is intense research on sophisticated but potentially facile handheld in-office devices for many disease markers. Challenges to their uptake require well-designed studies on their practical reliability and utility, with appropriate controls. A range of ethical, social, and political issues need to be addressed in such studies.