Activation status of peripheral blood neutrophils and the complement system in adult rheumatoid arthritis patients undergoing combined therapy with infliximab and methotrexate.

We examined the functional activity of peripheral blood neutrophils and the complement system activation status in patients with rheumatoid arthritis (RA) undergoing infliximab/methotrexate combined therapy. We studied female RA patients under treatment with infliximab (3-5 mg/kg) and methotrexate (15-25 mg/week) who presented inactive (i-RA; n = 34, DAS-28 ≤ 2.6) or at least moderately active disease (a-RA; n = 29, DAS-28 > 3.2), and age-matched healthy women (n = 38). We measured the levels of reactive oxygen species (ROS) generation (chemiluminescence assay) and membrane expression of FcγRIIa/CD32, FcγRIIIb/CD16, CR1/CD35, and CR3/CD11b receptors (ELISA assay) in neutrophils. We also determined the hemolytic activity of the alternative and classical pathways of the complement system (spectrophotometry), serum levels of C5a and Bb (ELISA assay), and serum chemotactic activity (Boyden chamber). Compared with the control group, i-RA and a-RA patients exhibited: (1) increased neutrophil ROS production and membrane expression of FcγRIIa/CD32, FcγRIIIb/CD16, and CR1/CD35, indicating neutrophil activation; and (2) increased serum chemotactic activity and decreased activity of the alternative complement pathway, indicating systemic complement system activation. The levels of C-reactive protein in a-RA patients were augmented, compared with i-RA patients. Although infliximab/methotrexate combined therapy induced disease remission according to the DAS-28 criteria, both i-RA and a-RA patients still exhibited significant levels of systemic activation of neutrophils and the complement system.

Effects of the Consumption of Milk Biofortified with Selenium, Vitamin E, and Different Fatty Acid Profile on Immune Response in the Elderly.

SCOPE: Nutrition is a major contributing factor for immunocompetence. The aim was to assess the immune status of older people after consuming milk produced by lactating cows fed with one of the following diets: control diet (C), C + vitamin E + selenium (C + A), C + sunflower oil (C + O), and C + sunflower oil + vitamin E + selenium (A + O). METHODS AND RESULTS: Sixty elderly people received one of these biofortified milks for 12 weeks. Immune response was assessed by measurement of the expression of COX-1, COX-2, MCP-1, PPAR (δ, α, and ß/δ) genes, neutrophil production of oxygen reactive species induced by immune complexes, neutrophil phagocytosis and lytic activity of the alternative pathway of the complement system, and cytokine levels. Variables were assessed before and after treatment. Our findings showed stability of some inflammatory mediators (complement activity and neutrophils burst) in treatment groups, except complement activity in C + A, and an increase of these markers in C, especially reactive oxygen species production and phagocytic activity. TNF-α was significantly increased in all groups. In C + A, IL-4 and IL-2 increased after treatment, and in the group that received the milk produced by cows fed with "O" diet, CCL20 and IL-27 increased. CONCLUSION: Overall, as compared to C, milk biofortification was associated with stabilization of the activity of alternative complement pathway and the neutrophils burst, and modulated different cytokines levels.

Flavonols modulate the effector functions of healthy individuals' immune complex-stimulated neutrophils: a therapeutic perspective for rheumatoid arthritis.

Rheumatoid arthritis (RA) patients usually exhibit immune complex (IC) deposition and increased neutrophil activation in the joint. In this study, we assessed how four flavonols (galangin, kaempferol, quercetin, and myricetin) modulate the effector functions of healthy individuals' and active RA patients' IC-stimulated neutrophils. We measured superoxide anion and total reactive oxygen species production using lucigenin (CL-luc)- and luminol (CL-lum)-enhanced chemiluminescence assays, respectively. Galangin, kaempferol, and quercetin inhibited CL-lum to the same degree (mean IC50=2.5 µM). At 2.5 µM, quercetin and galangin suppressed nearly 65% CL-lum of active RA patients' neutrophils. Quercetin inhibited CL-luc the most effectively (IC50=1.71±0.36 µM). The four flavonols diminished myeloperoxidase activity, but they did not decrease NADPH oxidase activity, phagocytosis, microbial killing, or cell viability of neutrophils. The ability of the flavonols to scavenge hypochlorous acid and chloramines, but not H2O2, depended on the hydroxylation degree of the flavonol B-ring. Therefore, at physiologically relevant concentrations, the flavonols partially inhibited the oxidative metabolism of IC-stimulated neutrophils without affecting the other investigated effector functions. Using these compounds to modulate IC-mediated neutrophil activation is a promising safe therapeutic strategy to control inflammation in active RA patients.