Brenda Alvarado-Sánchez

Immune effects of therapy with Adalimumab in patients with rheumatoid arthritis

The aim of this study was to assess the effect of Adalimumab on different immune parameters in patients with RA. Adalimumab was administered (40 mg every other week for 26 weeks) to eight patients with RA that were refractory to conventional drug therapy. Peripheral blood samples were obtained at days 0, 15 and 180 of Adalimumab therapy, and the following immune parameters were assessed: Number, phenotype, and function of regulatory T lymphocytes. The induction of apoptosis of immune cells and the in vitro and in vivo reactivity towards M. tuberculosis were also analysed. All patients responded to Adalimumab (ACR response 50–70), and a modest but significant increase in the number and function of regulatory T cells was observed at day 15 of anti‐TNF‐α therapy. In addition, an increased percent of apoptotic cells was detected in the peripheral blood at day 15 of Adalimumab therapy. Unexpectedly, most of these effects were not further observed at day 180. However, two patients showed a persistent and marked reduction in the reactivity to M. tuberculosis. Although we have found that Adalimumab affects the number and function of regulatory T lymphocytes, and the apoptosis of immune cells, these effects are transient and its possible causal relationship with the therapeutic activity of this biological agent remains to be determined. Nevertheless, the down‐regulatory effect of Adalimumab on the reactivity to M. tuberculosis could be related to an enhanced risk of tuberculosis reactivation.

Obesity is the main determinant of insulin resistance more than the circulating pro-inflammatory cytokines levels in rheumatoid arthritis patients

BACKGROUND Systemic blockade of TNF-α in Rheumatoid arthritis with insulin resistance seems to produce more improvement in insulin sensitivity in normal weight patients with Rheumatoid arthritis than in obese patients with Rheumatoid arthritis, suggesting that systemic-inflammation and obesity are independent risk factors for insulin resistance in Rheumatoid arthritis patients. OBJECTIVES To evaluate the insulin resistance in: normal weight patients with Rheumatoid arthritis, overweight patients with Rheumatoid arthritis, obese Rheumatoid arthritis patients, and matched control subjects with normal weight and obesity; and its association with major cytokines involved in the pathogenesis of the disease. METHODS Assessments included: body mass index, insulin resistance by Homeostasis Model Assessment, ELISA method, and enzymatic colorimetric assay. RESULTS Outstanding results from these studies include: (1) In Rheumatoid arthritis patients, insulin resistance was well correlated with body mass index, but not with levels of serum cytokines. In fact, levels of cytokines were similar in all Rheumatoid arthritis patients, regardless of being obese, overweight or normal weight (2) Insulin resistance was significantly higher in Rheumatoid arthritis with normal weight than in normal weight (3) No significant difference was observed between insulin resistances of Rheumatoid arthritis with obesity and obesity (4) As expected, levels of circulating cytokines were significantly higher in Rheumatoid arthritis patients than in obesity. CONCLUSIONS Obesity appears to be a dominant condition above inflammation to produce IR in RA patients. The dissociation of the inflammation and obesity components to produce IR suggests the need of an independent therapeutic strategy in obese patients with RA.

Antioxidant activity, antimicrobial and effects in the immune system of plants and fruits extracts

ABSTRACT Nowadays, medicinal plants, and fruits and vegetables with antioxidant and antimicrobial activity are increasingly studied. In this review, the impact of the medicinal plant extracts on the immune system was discussed. The first part described the phenomenon of oxidative stress, followed by the mechanisms involved in the antioxidant activity and finally discussed on the evaluation of the antioxidant activity of plants and fruits. The second part revised the works that discuss about the antimicrobial activity of plants and fruits extracts, emphasizing in the factors that influence the evaluation of such characteristic. Finally, in the third part, studies on the effect of the plant extracts over the immune response were discussed, describing the results of the enhancer effects, as well as those of the suppressing ones. This work allowed us to discern the necessity of a wider research on the chemical composition of the natural extracts, in order to establish a correlation with the effects observed in health.

Candida and Candidiasis

Candida species comprehend a wide group of opportunistic pathogens that usually form a part of the microbiota on human linings. Under specific conditions such as immune depression, tissue invasion and infection may occur. Candida infections are ranked as the sixth most common cause of nosocomial infections according to studies by the Centers for Disease Control and Prevention, thus constituting a serious public health problem. Candida albicans has been the most studied member of this species; nevertheless, non-albicans species have risen as emergent pathogens in many regions across the globe. This text presents an outlook of Candida and its infections, including the historical aspects of the fungus, epidemiology and clinical manifestations of the infection, diagnostic techniques as well as treatment guidelines.