Interaction between polymorphisms of the Human Leukocyte Antigen and HPV-16 Variants on the risk of invasive cervical cancer

<p>Abstract</p> <p>Background</p> <p>Persistent infection with oncogenic types of human papillomavirus (HPV) is the major risk factor for invasive cervical cancer (ICC), and non-European variants of HPV-16 are associated with an increased risk of persistence and ICC. HLA class II polymorphisms are also associated with genetic susceptibility to ICC. Our aim is to verify if these associations are influenced by HPV-16 variability.</p> <p>Methods</p> <p>We characterized HPV-16 variants by PCR in 107 ICC cases, which were typed for <it>HLA-DQA1</it>, <it>DRB1 </it>and <it>DQB1 </it>genes and compared to 257 controls. We measured the magnitude of associations by logistic regression analysis.</p> <p>Results</p> <p>European (E), Asian-American (AA) and African (Af) variants were identified. Here we show that inverse association between <it>DQB1*05 </it>(adjusted odds ratio [OR] = 0.66; 95% confidence interval [CI]: 0.39–1.12]) and HPV-16 positive ICC in our previous report was mostly attributable to AA variant carriers (OR = 0.27; 95%CI: 0.10–0.75). We observed similar proportions of <it>HLA DRB1*1302 </it>carriers in E-P positive cases and controls, but interestingly, this allele was not found in AA cases (p = 0.03, Fisher exact test). A positive association with <it>DRB1*15 </it>was observed in both groups of women harboring either E (OR = 2.99; 95% CI: 1.13–7.86) or AA variants (OR = 2.34; 95% CI: 1.00–5.46). There was an inverse association between <it>DRB1*04 </it>and ICC among women with HPV-16 carrying the 350T [83L] single nucleotide polymorphism in the <it>E6 </it>gene (OR = 0.27; 95% CI: 0.08–0.96). An inverse association between <it>DQB1*05 </it>and cases carrying 350G (83V) variants was also found (OR = 0.37; 95% CI: 0.15–0.89).</p> <p>Conclusion</p> <p>Our results suggest that the association between HLA polymorphism and risk of ICC might be influenced by the distribution of HPV-16 variants.</p

Experience and Outcomes at a Specialized Clostridium difficile Clinical Practice

Objective: To report our experience with and outcomes among patients referred to a specialized Clostridium difficile clinical practice. Patients and Methods: We retrospectively identified consecutive patients referred for Clostridium difficile infection (CDI) management from January 1, 2013, through May 30, 2015. Data were collected for demographic characteristics, CDI history, final diagnoses, and management. Results: Overall, 211 patients (median age, 65 years; 66.4% women) were included. The most common indications for referral were recurrent CDI in 199 patients (94.3%), first CDI episode in 5 patients (2.4%), and chronic diarrhea in 7 patients (3.3%). After evaluation, the diagnoses were recurrent CDI in 127 patients (60.2%), resolved CDI in 36 patients (17.1%), first-episode CDI in 5 patients (2.4%), and non-CDI in 43 patients (20.4%). The most common non-CDI diagnoses were postinfection irritable bowel syndrome (PI-IBS) in 32 patients (15.2% overall), inflammatory bowel disease (n=3), small intestinal bacterial overgrowth (n=2), microscopic colitis (n=1), and asymptomatic C difficile colonization (n=2). Two patients had diabetic gastroparesis and food intolerances, and 1 had chronic constipation with overflow diarrhea. Of 127 patients with recurrent CDI, 30 (23.6%) received antibiotics; of these 30, 12 had antibiotic treatment failure and received fecal microbiota transplantation (FMT) for recurrent CDI. Among 97 patients (76.4%) who underwent FMT, 85 (87.6%) were cured after the first FMT, 5 were cured after the second FMT, and 7 were treated with antibiotics for FMT failure, with resolution of symptoms. Conclusion: A substantial proportion of patients referred for CDI subsequently received alternative diagnoses; PI-IBS was the most common. Patients being referred for recurrent CDI should be evaluated carefully for alternative diagnoses

Accessibility of Humic-Associated Fe to a Microbial Siderophore: Implications for Bioavailability

Microorganisms in aerobic, circum-neutral environments are challenged to acquire sufficient nutrient Fe due to low solubilities of Fe oxides. To overcome this challenge, many aerobic microbes produce low molecular weight (MW) organic ligands, or siderophores, with extremely high Fe-binding affinities. This research expands the existing understanding of siderophore-mediated Fe acquisition from minerals by examining the effects of the siderophore desferrioxamine B (DFOB) on Fe removal from aquatic humic substances (XAD-8-isolated) and other organic matter (OM) isolates (reverse osmosis, RO; and “transphilic”, XAD-4) from several rivers including the Suwannee River (GA, USA). Analysis of samples by asymmetrical flow field-flow fractionation (AsFlFFF) with in-line ICP–MS and UV–vis detectors showed that Fe was naturally abundant and primarily associated with intermediate to high MW OM. An excess of DFOB (relative to naturally present Fe) removed ∼75% of Fe and shifted the OM MW distribution to lower MWs, perhaps due to removal of “bridging” Fe, although additional mechanistic study of MW shifts is needed. Removal of other OM-associated metals (e.g., Al, Cu, Zn) by DFOB was minimal for all but a few samples. Fe bound to humic substances and other more “transphilic” organic components therefore should be considered readily bioavailable to aerobic, siderophore-producing microorganisms