Serological Biomarkers in Systemic Lupus Erythematosus

Abstract

BackgroundSystemic lupus erythematosus (SLE) is a multi-system autoimmune disease characterised by autoantibody production and variable clinical features, ranging from mild to severe disease. Patients with SLE are at increased risk of developing accelerated atherosclerosis. Biomarkers have potential utility in SLE as markers of disease or predictors of future clinical events and mortality.ObjectiveThe aim of this thesis was to identify serological biomarkers predictive for erosive arthritis (EA), cardiovascular events (CVEs), mortality and subclinical atherosclerosis in SLE.MethodsIn chapters 2 to 4, study subjects were SLE patients from Bath. Anti-cyclic citrullinated peptide antibodies (ACPA) and HLA-DR and -DQ were studied for markers of EA, and anticardiolipin (aCL) and lipoprotein profiles for markers of CVEs and mortality. In chapters 5 and 6, study subjects were women with SLE from Manchester. B-mode ultrasound scans of subjects' carotid arteries were performed at baseline and follow-up time-points to detect atherosclerotic plaque. Baseline IgG and IgM antiphospholipid (aPL) antibodies and CV risk factors were studied for markers of subclinical atherosclerosis. Clinical data collected for all studies included SLE features and auto-antibody profiles.ResultsACPA was identified as a marker of a SLE phenotype with EA - "rhupus". Patients with major erosive arthritis were HLA-DQB1*0302 carriers. Increased aCL GPL levels and total cholesterol : high density lipoprotein-C (TC : HDL-C) ratio were markers for future CVEs, and increased TC : HDL ratio, aCL GPL and lipoprotein(a) concentrations were markers for increased mortality. Lower HDL-C concentrations and anti-annexin A5 (anti-AnxA5) GPL were markers of carotid plaque progression.ConclusionThis thesis identified new markers for EA, subclinical atherosclerosis and future CVE and mortality risk in SLE. Strategies to incorporate these new CV markers into clinical CV risk assessments may assist in distinguishing the subset of SLE patients most at risk of developing accelerated atherosclerosis.

Date of Award	18 Sept 2013
Original language	English
Awarding Institution	University of Bath
Supervisor	Neil McHugh (Supervisor) & Dylan Thompson (Supervisor)