Researchers Identify Link Between Gut and Lupus
Individuals with systemic lupus erythematosus (SLE) may have specific strains of gut commensal bacteria that can contribute to the immune pathogenesis of lupus nephritis, according to a new study.
“Our study strongly suggests that in some patients, bacterial imbalances may be driving lupus and its associated disease flares,” senior study investigator Dr Gregg Silverman from NYU School of Medicine, said in an institution-issued press release. “Our results also point to leakages of bacteria from the gut as a possible immune system trigger of the disease and suggest that the internal gut environment may therefore play a more critical role than genetics in renal flares of this all too often fatal disease.”
IF YOU LIKE THIS, READ MORE...
More Diverse Clinical Trials Can Lead to Improved Outcomes in Lupus
In Systemic Lupus Erythematosus, Monoclonal Antibody Can Improve Disease Activity
Previous research has indicated that individuals with lupus often have restricted gut microbiome diversity and general patterns of dysbiosis. However, few patients with active disease have been previously characterized.
To assess whether there is a transmissible agent in the development of lupus, the researchers evaluated fecal and blood samples of 61 women with SLE seen at NYU Langone Medical Center and Bellevue Hospital in New York City. In addition, 17 healthy women acted as controls and their samples were also analyzed.
In evaluating the fecal 16S rRNA samples for associations with host immunity, the microbiome in patients with SLE had decreased species richness diversity compared with the controls. Participants with high SLE disease activity had greater reductions in taxonomic complexity.
Ruminococcus gnavus was found at a 5-fold greater rate among participants with SLE than among the control group. The fecal samples of participants with SLE also showed increases in sIgA-coated-R. gnavus bacteria.
Participants with active nephritis had the highest levels of serum anti-R. gnavus strain-restricted antibodies.
This new research could lead to the development of simple blood tests to detect antibodies to leaked bacteria, which could be beneficial to diagnosis and progression of lupus, even in early stages of disease, according to the press release.
“We speculate that leakage of RG bacterial components contributes to nephritogenic autoantibody responses,” the researchers concluded. “To pursue these questions, it will be important to characterize the diversity and genetic features of RG strains and to understand when these strains colonize and expand in patients with lupus. In part, these investigations may lead to development of a biomarker assay that aids both earlier diagnosis and better prognostic determinations.”
—Colleen Murphy
References:
- Azzouz D, Omarbekova A, Heguy A, et al. Lupus nephritis is linked to disease-activity associated expansions and immunity to a gut commensal [published online February 19, 2019]. Ann Rheum Dis. http://dx.doi.org/10.1136/annrheumdis-2018-214856.
- Lupus Strongly Linked to Imbalances in Gut Microbiome. Accessed February 19, 2019. https://nyulangone.org/press-releases/lupus-strongly-linked-to-imbalances-in-gut-microbiome.