Methyl-donor supplementation in women with systemic lupus erythematosus with different nutritional status: the protocol for a randomised, double-blind, placebo-controlled trial.

INTRODUCTION

DNA hypomethylation in patients with systemic lupus erythematosus (SLE) has been recently documented in the literature. Low levels of DNA methylation have been observed globally and in genes associated with immune and inflammatory pathways in SLE's CD4+T lymphocytes. Given that certain micronutrients can either donate methyl groups within one-carbon metabolism pathways or serve as cofactors for enzymes involved in the DNA methylation process, this randomised, double-blind, placebo-controlled trial aims to investigate whether a 3-month supplementation of folic acid and vitamin B12 will modulate the DNA methylation profile in subcutaneous adipose tissue (primary outcome) of women with SLE and normal weight or excess body weight. As secondary objectives, we will assess gene expression, telomere length and phenotypic characteristics (ie, clinical parameters, body weight and composition, abdominal circumference, food intake and disordered eating attitude, physical activity, lipid profile, serum concentrations of leptin, adiponectin, and cytokines).

METHODS AND ANALYSIS: Patients will be classified according to their nutritional status by body mass index in normal weight or excess body weight. Subsequently, patients in each group will be randomly assigned to either a placebo or an intervention group (folic acid (400 mcg) and vitamin B12 (2000 mcg) supplementation). Endpoint evaluations will be conducted using both intention-to-treat and per-protocol analyses. This study has the potential to design new personalised nutritional approaches as adjunctive therapy for patients with SLE.

ETHICS AND DISSEMINATION: This study has been reviewed and approved by the Ethical Committee from Clinical Hospital of the School of Medicine of the University of Sao Paulo, Brazil (CAAE.: 47317521.8.0000.0068).

TRIAL REGISTRATION NUMBER: NCT05097365 (first version).