18 resultados para pro-oxidant activity
Resumo:
PURPOSE To analyze visual acuity (VA) outcomes before and after preplanned treatment regimen change in the VIEW studies at week 52 (W52). DESIGN Multiple post hoc analyses for retrospectively defined subgroups in 2 multicenter, multinational, double-masked trials. PARTICIPANTS Two thousand four hundred fifty-seven neovascular age-related macular degeneration (AMD) patients. METHODS Patients were randomized to treatment with 0.5 mg ranibizumab given monthly, a 0.5-mg or 2-mg intravitreal aflibercept injection given monthly, or 2 mg intravitreal aflibercept given every other month, after 3 initial monthly doses, up to W52. From W52 through W96, patients received their original dosing assignment using a capped pro re nata (PRN) regimen, with defined retreatment criteria based on VA and morphologic signs of disease activity and mandatory dosing at least every 12 weeks. MAIN OUTCOME MEASURES Best-corrected VA (BCVA) and optical coherence tomography assessments were mandatory at all visits from baseline to W96. Outcomes were changes in BCVA and central retinal thickness. Outcomes were evaluated in all patients who completed 2 years of the VIEW studies using the last observation carried forward method for missing data at interim visits. RESULTS After W52, approximately 20% of patients lost 5 Early Treatment Diabetic Retinopathy Study (ETDRS) letters or more across all treatment arms with PRN treatment. Patients who met the retreatment criterion of loss of 5 ETDRS letters or more in the first quarter of the PRN dosing phase did not recover; mean final VA loss across the 4 study arms was -4.4 to -5.8 letters. Outcomes of these patients up to W52 were indistinguishable from those of the overall population. There were no differences between groups in serious ocular adverse events or Anti-Platelet Trialists' Collaboration arterial thromboembolic events through W96. CONCLUSIONS These analyses suggest that there are subgroups of patients for whom VA outcomes in the second year of the VIEW studies were less stable than in the first year and for whom W52 seems to be an important inflection point. Although alternate reasons specific to the nature of the underlying AMD cannot be fully excluded, the switch in treatment regimen at W52 is a plausible explanation.
Resumo:
Correction of human myeloid cell function is crucial for the prevention of inflammatory and allergic reactions as well as leukaemia progression. Caffeine, a naturally occurring food component, is known to display anti-inflammatory effects which have previously been ascribed largely to its inhibitory actions on phosphodiesterase. However, more recent studies suggest an additional role in affecting the activity of the mammalian target of rapamycin (mTOR), a master regulator of myeloid cell translational pathways, although detailed molecular events underlying its mode of action have not been elucidated. Here, we report the cellular uptake of caffeine, without metabolisation, by healthy and malignant hematopoietic myeloid cells including monocytes, basophils and primary acute myeloid leukaemia mononuclear blasts. Unmodified caffeine downregulated mTOR signalling, which affected glycolysis and the release of pro-inflammatory/pro-angiogenic cytokines as well as other inflammatory mediators. In monocytes, the effects of caffeine were potentiated by its ability to inhibit xanthine oxidase, an enzyme which plays a central role in human purine catabolism by generating uric acid. In basophils, caffeine also increased intracellular cyclic adenosine monophosphate (cAMP) levels which further enhanced its inhibitory action on mTOR. These results demonstrate an important mode of pharmacological action of caffeine with potentially wide-ranging therapeutic impact for treating non-infectious disorders of the human immune system, where it could be applied directly to inflammatory cells.
Resumo:
BACKGROUND During pregnancy, many patients with rheumatoid arthritis (RA) experience disease improvement, whereas patients with ankylosing spondylitis often suffer from persistent active disease. Here we investigated whether pregnancy-related changes in disease activity were associated with changes in the proportion and function of γδT cells. METHODS The study population comprised 55 patients with RA, 31 patients with ankylosing spondylitis, and 35 healthy controls. Among these participants, 28 RA patients, 21 ankylosing spondylitis patients, and 23 healthy controls were investigated once before conception when possible, at each trimester of pregnancy, and at 8 weeks postpartum. Data were compared with age-matched non-pregnant patients to obtain disease-related background. In all subjects, peripheral Vδ1 and Vδ2 T cells were analyzed for cell frequencies, the activation marker CD69, the cytotoxicity markers NKG2D and NKG2A, and the intracellular cytokines tumor necrosis factor (TNF)α, interferon (IFN)γ, interleukin (IL)-17 and IL-10. RESULTS Pregnant patients showed a decreased Vδ2/Vδ1 ratio in the third trimester, which resulted from a slightly reduced proportion of Vδ2 cells. Changes in RA disease activity during pregnancy and postpartum were not associated with numerical proportions of γδT cells but with changes of the cell activation marker CD69 on Vδ1 and Vδ2 cells. Only RA patients showed reduced proportions of TNFα-positive Vδ1and Vδ2 cells and IFNγ-positive Vδ2 cells at the third trimester of pregnancy, a finding that was not apparent in the entire population of CD3 T cells. The proportions of IL-17-positive γδT cells and IL-10-positive γδT cells did not differ between pregnant and non-pregnant women of the different groups. CONCLUSIONS Changes of disease activity in pregnant RA patients were associated with functional changes in both γδT cell subsets. This reduced pro-inflammatory profile of γδT cells might contribute to the immunomodulation resulting in pregnancy-induced improvement of RA.