by
Lesley S. Park;
Janet P. Tate;
Keith Sigel;
David Rimland;
Kristina Crothers;
Cynthia Gibert;
Maria C. Rodriguez-Barradas;
Matthew Bidwell Goetz;
Roger J. Bedimo;
Sheldon T. Brown;
Amy C. Justice;
Robert Dubrow
Objective: Utilizing the Veterans Aging Cohort Study, the largest HIV cohort in North America, we conducted one of the few comprehensive comparisons of cancer incidence time trends in HIV-infected (HIV+) versus uninfected persons during the antiretroviral therapy (ART) era.
Design: Prospective cohort study.
Methods: We followed 44 787 HIV+ and 96 852 demographically matched uninfected persons during 1997–2012. We calculated age-, sex-, and race/ethnicity-standardized incidence rates and incidence rate ratios (IRR, HIV+ versus uninfected) over four calendar periods with incidence rate and IRR period trend P values for cancer groupings and specific cancer types.
Results: We observed 3714 incident cancer diagnoses in HIV+ and 5760 in uninfected persons. The HIV+ all-cancer crude incidence rate increased between 1997–2000 and 2009–2012 (P trend = 0.0019). However, after standardization, we observed highly significant HIV+ incidence rate declines for all cancer (25% decline; P trend <0.0001), AIDS-defining cancers (55% decline; P trend <0.0001), nonAIDS-defining cancers (NADC; 15% decline; P trend = 0.0003), and nonvirus-related NADC (20% decline; P trend <0.0001); significant IRR declines for all cancer (from 2.0 to 1.6; P trend <0.0001), AIDS-defining cancers (from 19 to 5.5; P trend <0.0001), and nonvirus-related NADC (from 1.4 to 1.2; P trend = 0.049); and borderline significant IRR declines for NADC (from 1.6 to 1.4; P trend = 0.078) and virus-related NADC (from 4.9 to 3.5; P trend = 0.071).
Conclusion: Improved HIV care resulting in improved immune function most likely contributed to the HIV+ incidence rate and the IRR declines. Further promotion of early and sustained ART, improved ART regimens, reduction of traditional cancer risk factor (e.g. smoking) prevalence, and evidence-based screening could contribute to future cancer incidence declines among HIV+ persons.
Severe asthma in children is characterized by sustained symptoms despite treatment with high doses of inhaled corticosteroids or oral corticosteroids. Children with severe asthma may fall into 2 categories, difficult-to-treat asthma or severe therapy-resistant asthma. Difficult-to-treat asthma is defined as poor control due to an incorrect diagnosis or comorbidities, or poor adherence due to adverse psychological or environmental factors. In contrast, treatment resistant is defined as difficult asthma despite management of these factors. It is increasingly recognized that severe asthma is a highly heterogeneous disorder associated with a number of clinical and inflammatory phenotypes that have been described in children with severe asthma. Guideline-based drug therapy of severe childhood asthma is based primarily on extrapolated data from adult studies. The recommendation is that children with severe asthma be treated with higher-dose inhaled or oral corticosteroids combined with long-acting β-agonists and other add-on therapies, such as antileukotrienes and methylxanthines. It is important to identify and address the influences that make asthma difficult to control, including reviewing the diagnosis and removing causal or aggravating factors. Better definition of the phenotypes and better targeting of therapy based upon individual patient phenotypes is likely to improve asthma treatment in the future.
by
Maritza J. Romero;
Lin Yao;
Supriya Sridhar;
Anil Bhatta;
Huijuan Dou;
Ganesan Ramesh;
Michael W. Brands;
David M. Pollock;
Ruth B. Caldwell;
Stephen D. Cederbaum;
Clarence Head;
Zsolt Bagi;
Rudolf Lucas;
Robert W. Caldwell
RATIONALE: Diabetic nephropathy (DN) is a major cause of end-stage renal disease, associated with endothelial dysfunction. Chronic supplementation of l-arginine (l-arg), the substrate for endothelial nitric oxide synthase (eNOS), failed to improve vascular function. l-Citrulline (l-cit) supplementation not only increases l-arg synthesis, but also inhibits cytosolic arginase I, a competitor of eNOS for the use of l-arg, in the vasculature. AIMS: To investigate whether l-cit treatment reduces DN in streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice and rats and to study its effects on arginase II (ArgII) function, the main renal isoform. METHODS: STZ-C57BL6 mice received l-cit or vehicle supplemented in the drinking water. For comparative analysis, diabetic ArgII knock out mice and l-cit-treated STZ-rats were evaluated. RESULTS: l-Citrulline exerted protective effects in kidneys of STZ-rats, and markedly reduced urinary albumin excretion, tubulo-interstitial fibrosis, and kidney hypertrophy, observed in untreated diabetic mice. Intriguingly, l-cit treatment was accompanied by a sustained elevation of tubular ArgII at 16 weeks and significantly enhanced plasma levels of the anti-inflammatory cytokine IL-10. Diabetic ArgII knock out mice showed greater blood urea nitrogen levels, hypertrophy, and dilated tubules than diabetic wild type (WT) mice. Despite a marked reduction in collagen deposition in ArgII knock out mice, their albuminuria was not significantly different from diabetic WT animals. l-Cit also restored nitric oxide/reactive oxygen species balance and barrier function in high glucose-treated monolayers of human glomerular endothelial cells. Moreover, l-cit also has the ability to establish an anti-inflammatory profile, characterized by increased IL-10 and reduced IL-1β and IL-12(p70) generation in the human proximal tubular cells. CONCLUSION: l-Citrulline supplementation established an anti-inflammatory profile and significantly preserved the nephron function during T1D.
by
Adam Penn-Nicholson;
Hennie Geldenhuys;
Wivine Burny;
Robbert van der Most;
Cheryl Liane Day;
Erik Jongert;
Philippe Moris;
Mark Hatherill;
Opokua Ofori-Anyinam;
Willem Hanekom;
Anna Bollaerts;
Marie-Ange Demoitie;
Angelique Kany Kany Luabeya;
Evi De Ruymaeker;
Michele Tameris;
Didier Lapierre;
Thomas J. Scriba
Background: Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01 E was evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless of Mycobacterium tuberculosis (M.tb) infection status. Methods: In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01 E or placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. Results: No serious adverse events were recorded. M72/AS01 E induced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective of M.tb infection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses in M.tb-infected participants, suggesting natural infection acts as a prime to vaccination. Conclusions: The clinically acceptable safety and immunogenicity profile of M72/AS01 E in adolescents living in an area with high TB burden support the move to efficacy trials.
by
Kaustuv Nayak;
Lichen Jing;
Ronnie M. Russell;
D. Huw Davies;
Gary Hermanson;
Douglas M. Molina;
Xiaowu Liang;
David R. Sherman;
William W. Kwok;
Junbao Yang;
John Kenneth;
Syed F. Ahamed;
Anmol Chandele;
Murali Kaja;
David M. Koelle
Elicitation of CD4 IFN-gamma T cell responses to Mycobacterium tuberculosis (MTB) is a rational vaccine strategy to prevent clinical tuberculosis. Diagnosis of MTB infection is based on T-cell immune memory to MTB antigens. The MTB proteome contains over four thousand open reading frames (ORFs). We conducted a pilot antigen identification study using 164 MTB proteins and MTB-specific T-cells expanded in vitro from 12 persons with latent MTB infection. Enrichment of MTB-reactive T-cells from PBMC used cell sorting or an alternate system compatible with limited resources. MTB proteins were used as single antigens or combinatorial matrices in proliferation and cytokine secretion readouts. Overall, our study found that 44 MTB proteins were antigenic, including 27 not previously characterized as CD4 T-cell antigens. Antigen truncation, peptide, NTM homology, and HLA class II tetramer studies confirmed malate synthase G (encoded by gene Rv1837) as a CD4 T-cell antigen. This simple, scalable system has potential utility for the identification of candidate MTB vaccine and biomarker antigens.
Upon recognition of specific molecular patterns on microbes, host cells trigger an innate immune response, which culminates in the production of type I interferons, proinflammatory cytokines and chemokines, and restricts pathogen replication and spread within the host. At each stage of this response, there are stimulatory and inhibitory signals that regulate the magnitude, quality, and character of the response. Positive regulation promotes an antiviral state to control and eventually clear infection, whereas negative regulation dampens inflammation and prevents immune-mediated tissue damage. An overexuberant innate response can lead to cell and tissue destruction, and the development of spontaneous autoimmunity. The retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), RIG-I and melanoma differentiation-associated gene 5 (MDA5), belong to a family of cytosolic host RNA helicases that recognize distinct nonself RNA signatures and trigger innate immune responses against several RNA viruses by signaling through the essential adaptor protein mitochondrial antiviral signaling (MAVS). The RLR signaling pathway is tightly regulated to maximize antiviral immunity and minimize immune-mediated pathology. This review highlights contemporary findings on negative regulators of the RLR signaling pathway, with specific focus on the proteins and biological processes that directly regulate RIG-I, MDA5 and MAVS signaling function.
by
Julie A. Womack;
Terrence E. Murphy;
Harini Bathulapalli;
Kathleen M. Akgun;
Cynthia Gibert;
Ken M. Kunisaki;
David Rimland;
Maria Rodriguez-Barradas;
H. Klar Yaggi;
Amy C. Justice;
Nancy S. Redeker
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P. Todd Korthuis;
David A. Fiellin;
Kathleen A. McGinnis;
Melissa Skanderson;
Amy C. Justice;
Adam J. Gordon;
Donna Almario Doebler;
Steven M. Asch;
Lynn E. Fiellin;
Kendall Bryant;
Cynthia L. Gibert;
Stephen Crystal;
Matthew Bidwell Goetz;
David Rimland;
Maria C. Rodriguez-Barradas;
Kevin L. Kraemer
HIV-infected patients with substance use experience suboptimal health outcomes, possibly because of variations in care. OBJECTIVES: To assess the association between substance use and the quality of HIV care (QOC) received. RESEARCH DESIGN: Retrospective cohort study. SUBJECTS: HIV-infected patients enrolled in the Veterans Aging Cohort Study. MEASURES: We collected self-report substance use data and abstracted 9 HIV quality indicators (QIs) from medical records. Independent variables were unhealthy alcohol use (AUDIT-C score ≥4) and illicit drug use (self-report of stimulants, opioids, or injection drug use in past year). Main outcome was the percentage of QIs received, if eligible. We estimated associations between substance use and QOC using multivariable linear regression. RESULTS: The majority of the 3410 patients were male (97.4%) and black (67.0%) with a mean age of 49.1 years (SD = 8.8). Overall, 25.8% reported unhealthy alcohol use, 22% illicit drug use, and participants received 81.5% (SD = 18.9) of QIs. The mean percentage of QIs received was lower for those with unhealthy alcohol use versus not (59.3% vs. 70.0%, P < 0.001) and those using illicit drugs vs. not (57.8% vs. 70.7%, P < 0.001). In multivariable models, unhealthy alcohol use (adjusted β-2.74; 95% confidence interval:-4.23 to-1.25) and illicit drug use (adjusted β-3.51; 95% CI:-4.99 to-2.02) remained inversely associated with the percentage of QIs received. CONCLUSIONS: Although the overall QOC for these HIV-infected Veteran patients was high, gaps persist for those with unhealthy alcohol and illicit drug use. Interventions that address substance use in HIV-infected patients may improve the QOC received.
The anaerobic gastrointestinal pathogen Clostridium difficile must form a metabolically dormant spore to survive in oxygenic environments and be transmitted from host to host. The regulatory factors by which C. difficile initiates and controls the early stages of sporulation in C. difficile are not highly conserved in other Clostridium or Bacillus species. Here, we investigated the role of two conserved oligopeptide permeases, Opp and App, in the regulation of sporulation in C. difficile. These permeases are known to positively affect sporulation in Bacillus species through the import of sporulation-specific quorum-sensing peptides. In contrast to other spore-forming bacteria, we discovered that inactivating these permeases in C. difficile resulted in the earlier expression of early sporulation genes and increased sporulation in vitro. Furthermore, disruption of opp and app resulted in greater virulence and increased the amounts of spores recovered from feces in the hamster model of C. difficile infection. Our data suggest that Opp and App indirectly inhibit sporulation, likely through the activities of the transcriptional regulator SinR and its inhibitor, SinI. Taken together, these results indicate that the Opp and App transporters serve a different function in controlling sporulation and virulence in C. difficile than in Bacillus subtilis and suggest that nutrient availability plays a significant role in pathogenesis and sporulation in vivo. This study suggests a link between the nutritional status of the environment and sporulation initiation in C. difficile.