1.
Enhancing capillary blood collection: The influence of nicotinic acid and nonivamide.
Moro, C, Bass, J, Scott, AM, Canetti, EFD
Journal of clinical laboratory analysis. 2017;(6)
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Abstract
BACKGROUND Nicotinic acid and nonivamide are often applied topically during capillary blood collection to induce vasodilation. These molecules may have an influence on immune effector cell activity in nearby tissues. This study investigates whether the induction of flushing by nicotinic acid and nonivamide causes an inflammatory response that influences the composition of immune cells present in a capillary blood sample. METHODS Females aged between 18 and 30 years old provided capillary blood samples. Experimental samples were taken from an earlobe treated with nicotinic acid and nonivamide with controls obtained from the untreated earlobe. Immunophenotypic analyses were conducted using polychromatic flow cytometry to determine whether any changes occurred in leucocyte subpopulations (CD3, CD4, CD8, CD19, CD56, and CD14) and granulocytic functional-related surface antigen markers (CD11b, CD18, CD16b, and CD66b). RESULTS No significant differences were observed between experimental and control samples in the mean percent of parent for the lymphocyte, monocyte, or granulocyte subpopulations, or in the median fluorescence intensity of particular surface markers expressed on these leucocytes. CONCLUSION The topical application of nicotinic acid and nonivamide is a possible method to improve capillary blood collection for immunological assessments. The use of these agents may increase the safety and compliance of patients who suffer from needle phobia or are unable to provide venous blood samples.
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The effects of exogenous fatty acids and niacin on human monocyte-macrophage plasticity.
Montserrat-de la Paz, S, Rodriguez, D, Cardelo, MP, Naranjo, MC, Bermudez, B, Abia, R, Muriana, FJG, Lopez, S
Molecular nutrition & food research. 2017;(8)
Abstract
SCOPE Macrophage plasticity allows adapting to different environments, having a dual activity in inflammatory-related diseases. Our hypothesis is that the type of dietary fatty acids into human postprandial triglyceride-rich lipoproteins (TRLs), alone or in combination with niacin (vitamin B3), could modulate the plasticity of monocytes-macrophages. METHODS AND RESULTS We isolated TRLs at the postprandial peak from blood samples of healthy volunteers after the ingestion of a meal rich in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) or MUFAs plus omega-3 long-chain polyunsaturated fatty acids (LCPUFAs). Autologous monocytes isolated at fasting were first induced to differentiate into naïve macrophages. We observed that postprandial TRL-MUFAs, particularly in combination with niacin, enhance competence to monocytes to differentiate and polarise into M2 macrophages. Postprandial TRL-SFAs made polarised macrophages prone to an M1 phenotype. In contrast to dietary SFAs, dietary MUFAs in the meals plus immediate-release niacin primed circulating monocytes for a reduced postprandial pro-inflammatory profile. CONCLUSION Our study underlines a role of postprandial TRLs as a metabolic entity in regulating the plasticity of the monocyte-macrophage lineage and also brings an understanding of the mechanisms by which dietary fatty acids are environmental factors fostering the innate immune responsiveness in humans.
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The role of extended-release niacin on immune activation and neurocognition in HIV-infected patients treated with antiretroviral therapy - CTN PT006: study protocol for a randomized controlled trial.
Lebouché, B, Jenabian, MA, Singer, J, Graziani, GM, Engler, K, Trottier, B, Thomas, R, Brouillette, MJ, Routy, JP
Trials. 2014;:390
Abstract
BACKGROUND Approximately 30% of HIV-1-infected patients receiving antiretroviral therapy who achieve virologic control have unsatisfactory immune reconstitution, with CD4+ T-cell counts persistently below 350 cells/μL. These patients are at elevated risk for clinical progression to AIDS and non-AIDS events. CD4+ T-cell depletion following infection and persistent immune activation can partially explain this low CD4+ T-cell recovery. Recent data suggest a link between the tryptophan oxidation pathway, immune activation and HIV disease progression based on overstimulation of the tryptophan oxidation pathway by HIV antigens and by interferon-gamma. This overstimulation reduces levels of circulating tryptophan, resulting in inflammation which has been implicated in the development of neurocognitive dysfunction. Niacin (vitamin B3) is able to control the excess tryptophan oxidation, correcting tryptophan depletion, and therefore represents an interesting strategy to improve CD4 recovery.We aim to design a crossover proof-of-concept study to assess supplementation with an extended-release form of niacin (Niaspan FCT™) in combination with antiretroviral therapy, compared to antiretroviral therapy alone, on T-cell immune activation as defined by changes in the percentage of CD8+ CD38+ HLA-DR+ T-cells. METHODS/DESIGN This randomized, open-label, interventional crossover study with an immediate versus deferred use of Niaspan FCT for 24 weeks will assess its ability to reduce immune activation and thus increase CD4 recovery in 20 HIV-infected individuals with suboptimal immune responses despite sustained virologic suppression. A substudy evaluating neurocognitive function will also be conducted. DISCUSSION This randomized trial will provide an opportunity to evaluate the potential benefit of oral extended-release niacin, a drug that can indirectly increase tryptophan, to reduce immune activation and in turn increase CD4+ T-cell recovery. The study will also allow for the evaluation of the impact of Niaspan FCT on neurocognitive function in HIV-infected individuals with suboptimal immune responses despite sustained virologic suppression. TRIAL REGISTRATION This study was registered with ClinicalTrials.gov on 17 December 2013 (registration number: NCT02018965).