Study: Metabolic Analysis Could Indicate Skin Involvement in SLE

A new report highlights the role of the metabolome in the mechanism of skin involvement among patients with systemic lupus erythematosus (SLE).

The study also suggests that gas chromatography-mass spectrometry (GC-MS) assays can be used to detect skin involvement and better understand an individual patient’s disease.

Corresponding author Zhouwei Wu, PhD, of the Shanghai Jiao Tong University School of Medicine, and colleagues noted that SLE is a complex autoimmune disease with multiple organs involved. However, the skin is the second-most-common organ affected by the disease.

Writing in Clinical, Cosmetic, and Investigational Dermatology, the authors noted that metabolic profiling has been used to successfully identify biomarkers in a number of different diseases, including SLE. They therefore wanted to investigate whether metabolic profiling might lend insights into the presence or absence of a specific feature of some cases of SLE: skin involvement.

“We aimed to identify the disturbed metabolic features and provide novel insights into the pathogenesis of skin lesion in SLE patients, as well as [find] potential biomarkers,” they wrote.

Wu and colleagues conducted GC-MS assessments of serum metabolism from 11 patients who had SLE and skin lesions, 10 patients with SLE without skin involvement, and 16 healthy controls. They used 3 databases to conduct their metabolism profile analysis.

The analysis identified 14 “differential metabolites” that were either increased or decreased in the group with skin lesions compared with the non-lesion group.

“Levels of L-alpha-aminobutyric acid, acrylic acid, glycine, L-aspartic, indole lactic acid, L-tyrosine, nicotinic acid, glucosamine, O-phosphoethanolamine, and rhamnose were increased in [the skin lesion] group,” they wrote. “In addition, levels of dehydroascorbic acid, gluconic acid lactone, and putrescine were decreased in [the lesion] group.”

They added that beta-alanine and L-threonine were decreased in both cohorts of patients with SLE compared with the healthy controls.

Of the metabolites identified, L-alpha-aminobutyric acid, dehydroascorbic acid, glycine, and L-tyrosine had areas under receiver operating characteristic (ROC) curves suggesting they have diagnostic potential for patients with skin involvement.

“In addition, the combined model of L-alpha-aminobutyric acid and dehydroascorbic acid provided better diagnostic accuracy,” Wu and colleagues wrote.

The investigators said they believe their study to be the first to focus on changes in metabolomics in patients with SLE and skin involvement.

The authors said their findings, and other studies like it, suggest that individual and combined metabolites may be meaningful biomarkers to diagnose a number of diseases beyond SLE.

Wu and colleagues noted several limitations to their study. They said their sample size was relatively small, meaning there will need to be additional studies on a larger scale to validate their results. They also suggested that future studies use control groups with other inflammatory or autoimmune diseases in order to ensure that the findings are actually related to SLE, and not a related disease.

Still, the investigators said their findings point not only to the potential for metabolic diagnostic tools, but also to new avenues to understand how medications affect diseases like SLE.

“These results open a new avenue to investigate the mechanism of SLE skin involvement, and might provide potential targets for treating skin lesions and prevent systemic flare,” they concluded.

Reference:

Xie Y, Liu B, and Wu Z. Identification of serum biomarkers and pathways of systemic lupus erythematosus with skin involvement through GC/MS-based metabolomics analysis. Clin Cosmet Investig Dermatol. Published online January 18, 2022. doi:10.2147/CCID.S345372