Impact of renin-angiotensin system inhibitors on clinical outcomes and ventricular remodelling after transcatheter aortic valve implantation: rationale and design of the RASTAVI randomised multicentre study.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) as a treatment in severe aortic stenosis (AS) is an excellent alternative to conventional surgical replacement. However, long-term outcomes are not benign. Renin-angiotensin system (RAS) blockade has shown benefit in terms of adverse remodelling in severe AS and after surgical replacement. METHODS AND ANALYSIS: The RAS blockade after TAVI (RASTAVI) trial aims to detect if there is a benefit in clinical outcomes and ventricular remodelling with this therapeutic strategy following the TAVI procedure. The study has been designed as a randomised 1:1 open-label study that will be undertaken in 8 centres including 336 TAVI recipients. All patients will receive the standard treatment. The active treatment group will receive ramipril as well. Randomisation will be done before discharge, after signing informed consent. All patients will be followed up for 3 years. A cardiac magnetic resonance will be performed initially and at 1 year to assess ventricular remodelling, defined as ventricular dimensions, ejection fraction, ventricular mass and fibrosis. Recorded events will include cardiac death, admission due to heart failure and stroke. The RASTAVI Study will improve the management of patients after TAVI and may help to increase their quality of life, reduce readmissions and improve long-term survival in this scenario. ETHICS AND DISSEMINATION: All authors and local ethics committees have approved the study design. All patients will provide informed consent. Results will be published irrespective of whether the findings are positive or negative. TRIAL REGISTRATION NUMBER: NCT03201185.

Human Invariant Natural Killer T Cells Respond to Antigen-Presenting Cells Exposed to Lipids from Olea europaea Pollen.

BACKGROUND: Allergic sensitization might be influenced by the lipids present in allergens, which can be recognized by natural killer T (NKT) cells on antigen-presenting cells (APCs). The aim of this study was to analyze the effect of olive pollen lipids in human APCs, including monocytes as well as monocyte-derived macrophages (Mϕ) and dendritic cells (DCs). METHODS: Lipids were extracted from olive (Olea europaea) pollen grains. Invariant (i)NKT cells, monocytes, Mϕ, and DCs were obtained from buffy coats of healthy blood donors, and their cell phenotype was determined by flow cytometry. iNKT cytotoxicity was measured using a lactate dehydrogenase assay. Gene expression of CD1A and CD1D was performed by RT-PCR, and the production of IL-6, IL-10, IL-12, and TNF-α cytokines by monocytes, Mϕ, and DCs was measured by ELISA. RESULTS: Our results showed that monocytes and monocyte-derived Mϕ treated with olive pollen lipids strongly activate iNKT cells. We observed several phenotypic modifications in the APCs upon exposure to pollen-derived lipids. Both Mϕ and monocytes treated with olive pollen lipids showed an increase in CD1D gene expression, whereas upregulation of cell surface CD1d protein occurred only in Mϕ. Furthermore, DCs differentiated in the presence of human serum enhance their surface CD1d expression when exposed to olive pollen lipids. Finally, olive pollen lipids were able to stimulate the production of IL-6 but downregulated the production of lipopolysaccharide- induced IL-10 by Mϕ. CONCLUSIONS: Olive pollen lipids alter the phenotype of monocytes, Mϕ, and DCs, resulting in the activation of NKT cells, which have the potential to influence allergic immune responses.