Ten-Week Sucralose Consumption Induces Gut Dysbiosis and Altered Glucose and Insulin Levels in Healthy Young Adults.

Sucralose consumption alters microbiome and carbohydrate metabolism in mouse models. However, there are no conclusive studies in humans. Our goals were to examine the effect of sucralose consumption on the intestinal abundance of bacterial species belonging to Actinobacteria, Bacteroidetes, and Firmicutes and explore potential associations between microbiome profiles and glucose and insulin blood levels in healthy young adults. In this open-label clinical trial, volunteers randomly drank water, as a control (n = 20), or 48 mg sucralose (n = 20), every day for ten weeks. At the beginning and the end of the study, participants were subjected to an oral glucose tolerance test (OGTT) to measure serum glucose and insulin every 15 min for 3 h and provided fecal samples to assess gut microbiota using a quantitative polymerase chain reaction. Sucralose intake altered the abundance of Firmicutes without affecting Actinobacteria or Bacteroidetes. Two-way ANOVA revealed that volunteers drinking sucralose for ten weeks showed a 3-fold increase in Blautia coccoides and a 0.66-fold decrease in Lactobacillus acidophilus compared to the controls. Sucralose consumption increased serum insulin and the area under the glucose curve compared to water. Long-term sucralose ingestion induces gut dysbiosis associated with altered insulin and glucose levels during an OGTT.

The Combined Use of Cytokine Serum Values with Laboratory Parameters Improves Mortality Prediction of COVID-19 Patients: The Interleukin-15-to-Albumin Ratio.

Laboratory parameters display limited accuracy in predicting mortality in coronavirus disease 2019 (COVID-19) patients, as with serum albumin. Emerging evidence suggests that cytokine serum values may enhance the predictive capacity of albumin, especially interleukin (IL)-15. We thus investigated whether the use of the IL-15-to-albumin ratio enables improving mortality prediction at hospital admission in a large group of COVID-19 patients. In this prospective cross-sectional study, we enrolled and followed up three hundred and seventy-eight patients with a COVID-19 diagnosis until hospital discharge or death. Two hundred and fifty-five patients survived, whereas one hundred and twenty-three died. Student's T-test revealed that non-survivors had a significant two-fold increase in the IL-15-to-albumin ratio compared to survivors (167.3 ± 63.8 versus 74.2 ± 28.5), a difference that was more evident than that found for IL-15 or albumin separately. Likewise, mortality prediction considerably improved when using the IL-15-to-albumin ratio with a cut-off point > 105.4, exhibiting an area under the receiver operating characteristic curve of 0.841 (95% Confidence Interval, 0.725-0.922, p < 0.001). As we outlined here, this is the first study showing that combining IL-15 serum values with albumin improves mortality prediction in COVID-19 patients.

Efficacy and safety of canakinumab in the treatment of adult-onset Still's disease: A systematic review.

BACKGROUND: Adult-onset Still's disease (AOSD) is a rare inflammatory disease, typically characterized by spiking fever, skin rash, and arthralgia or arthritis. Its conventional treatment includes NSAIDs and corticosteroids, and DMARDs as second-line therapy. Frequently, IL-1 inhibitors are also required, mainly in patients refractory to traditional therapy. Canakinumab is a monoclonal antibody that binds IL-1ß with high affinity and specificity, making it appropriate for therapeutic purposes in AOSD. OBJECTIVE: The aim of this systematic review was to identify and compile the current data on the efficacy and safety of canakinumab in the treatment of AOSD. METHODS: Following the guidelines established by the PRISMA statement, we searched Scopus, Web of Science, Pubmed, and Cochrane Library for relevant literature up to March 2021. The inclusion criteria comprised: randomized controlled trials, pooled analyses, observational studies, case series, and case reports. RESULTS: Seventeen studies published from 2012 to 2021 were evaluated; 11 of these correspond to case series or case reports, four observational studies, one placebo-controlled phase II trial, and one analysis of pooled systemic juvenile idiopathic arthritis data. In general, out of a total of 99 patients, 68.7% of these presented a complete remission of the systemic and arthritic manifestations at the end of the observation period, while 16.2% of the patients showed a partial improvement of the symptoms and the remaining (15.1%) did not show clinical improvement or were excluded. Moreover, 210 adverse events were reported in 69 patients during canakinumab treatment, of which the majority correspond to respiratory tract infections, arthralgia, disease flares, abdominal pain, nausea, and diarrhea, whereas the most common severe adverse events included macrophage activation syndrome and serious infections. Also, a corticosteroid-sparing effect was observed in a large percentage of patients. CONCLUSION: More studies with solid evidence are needed to support the efficacy of canakinumab in AOSD, although its use is encouraged by the increasing favorable results reported and the efficacy of other IL-1 inhibitors. It was also associated with an acceptable safety profile, similar to expected in IL-1 inhibitor therapy. However, future studies with well-defined endpoints are warranted to examine further the usefulness of canakinumab in AOSD.

Venom components of the scorpion Centruroides limpidus modulate cytokine expression by T helper lymphocytes: Identification of ion channel-related toxins by mass spectrometry.

The study of the effector mechanisms of T helper cells has revealed different phenotypic characteristics that can be manipulated for designing new therapeutic schemes in different pathological scenarios. Ion channels are significant targets in T lymphocyte modulation since they are closely related to their effector activity. Remarkably, some toxins produced by scorpions specifically affect the function of these membrane proteins. For that reason, these toxins are important candidates in the search for new immunomodulators. Here, the effect of two venom fractions of the scorpion Centruroides limpidus was assessed on T lymphocyte proliferation and cytokine production. The venom fractions ClF8 and ClF9 were separated by reversed-phase high-performance liquid chromatography (RP-HPLC) and cultured at 25 and 35 µg/ml with murine T lymphocytes. The results indicate that the fraction ClF8 increased both production and secretion levels of IFN-γ, IL-4, IL-17A and IL-10 by CD4+ T cells at 24 h. In contrast, fraction ClF9 only promoted the secretion of IL-17A and IL-10 at its highest concentration (35 µg/ml). Both fractions did not show any effect on T cell proliferation. Subsequent analyses by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed seventeen toxins in the fraction ClF8 and five toxins in the fraction ClF9, most of them with voltage-gated sodium (NaScTx) and potassium (KScTx) channels as molecular targets. These toxins might probably interact with ion channels involved in T lymphocyte activity. Our findings suggest that the difference in composition between the two fractions could be related to the observed effects, and the components identified could be isolated to search for possible immunomodulatory molecules.

Marine peptides as immunomodulators: Californiconus californicus-derived synthetic conotoxins induce IL-10 production by regulatory T cells (CD4+Foxp3+).

Context: CD4+ T lymphocytes are able to differentiate into distinct subtypes according to several immunological scenarios, including T helper (Th)1, Th2, Th17 and regulatory T (Treg) cells. CD4+ T cells are phenotypically flexible and have specific ion channels, such as the nicotinic acetylcholine receptors (nAChR) that could be modulated by peptides produced by marine snails, known as conotoxins. Their effect on T lymphocytes has not been explored and emerging evidence suggests that these peptides may have immunomodulatory activities. Objective: This study investigated the effect of two Californiconus californicus-derived synthetic conotoxins on the proliferation and differentiation of T lymphocyte subpopulations Th1, Th2, Th17 and Treg. Methods: Cells from lymph nodes of BALB/c mice were cultured in the presence of conotoxins cal14.1b and cal14.2c (5.5 µM), during 96 h. Cell proliferation and intracellular cytokine production (IFN-γ, IL-4, IL-17 and IL-10) were analyzed by flow cytometry. Results and Discussion: cal14.1b and cal14.2c increased intracellular IL-10 production in Treg (CD3+CD4+Foxp3+) cells and decreased intracellular IL-17 production (CD3+CD4+) after 72 h of culture. Conotoxins did not show any effect on T cell proliferation nor Th1/Th2 balance. Conclusion: These results suggest that synthetic conotoxins exert immunomodulatory activity, especially by regulating specific functions on T lymphocytes.