A meta-analysis of structural MRI studies of the brain in systemic lupus erythematosus (SLE)

Abstract

ObjectiveA comprehensive search of published literature in brain volumetry was conducted in three autoimmune diseases – Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA), and Ulcerative Colitis (UC) with the intention of performing a meta-analysis of published data. Due to lack of data in RA and UC the reported meta-analysis was limited to SLE.MethodsThe MEDLINE database was searched for studies from 1988 through March 2022. A total of 175 papers met the initial inclusion criteria and 16 were included in a random effects meta-analysis. The reduction in the number of papers included in the final analysis is primarily due to the lack of overlap in measured and reported brain regions.ResultsA significantly lower volume was seen in patients with SLE in the hippocampus, corpus callosum and total gray matter volume measurements as compared to age and sex matched controls. There were not enough studies to perform a meta-analysis for RA and UC; instead we include a summary of published volumetric studies.ConclusionsThe meta-analyses revealed structural brain abnormalities in patients with SLE suggesting that lower global brain volumes are associated with disease status. This volumetric difference was seen in both the hippocampus and corpus callosum and total gray matter volume measurements. These results indicate both gray and white matter involvement in SLE and suggest there may be both localised and global reductions in brain volume.KEY MESSAGESWhat’s already known on this topicCentral nervous system effects of lupus are common, however, agreement on principally affected neuroanatomical regions is lacking.What this study addsThis study combines the volumetric neuroimaging data from previously published SLE literature in a meta-analysis. The hippocampus, corpus callosum and total gray matter volume in patients with SLE is smaller than in age and sex matched controls. Additionally, a summary of published data in RA and UC is provided.How this study might affect research, practice or policyThis is the first meta-analysis on neuroimaging studies of volume differences in SLE. The regions identified can inform further research on disease progression and therapy evaluation targeted at brain volumetric changes in SLE.These results provide specific regions of interest to further explore in the central treatment and management of SLE. While these regions are shown to be directly affected, additional brain regions may be implicated. Further research to understand the potential link between these volumetric measurements and behavioural/cognitive changes observed in patients with lupus is warranted.