Patients with Henoch-Schönlein purpura nephritis (HSPN) vs healthy individuals were found to have significant differences in their gut microbiota, including lower diversity, overrepresentation of pathogenic bacteria, and reduced proportion of beneficial bacteria, according to study results published in BMC Nephrology.
HSPN is a form of Henoch-Schönlein purpura (also called immunoglobulin [Ig] A vasculitis) with kidney involvement, which is the most common cause of mortality in patients with HSPN. The cause of HSPN is still unknown, but immune factors are thought to play a role. Dysbiosis in the intestinal tract is linked to immune-mediated diseases and may be involved in the pathogenesis of kidney diseases, such as HSPN.
This study, the first of its kind, was conducted by researchers to evaluate the gut microbiota in patients with HSPN compared with healthy control participants.
The study population included patients who were newly diagnosed with HSPN (prior to initiation of immunosuppressive therapy) and age- and sex-matched healthy control individuals. Microbiota composition was analyzed in fecal samples using 16S ribosomal RNA gene sequencing. Statistical analyses were performed to compare differences between the groups, including alpha and beta diversity testing. Receiver operating characteristic (ROC) with area under curves (AUC) was used to evaluate the strength of classifying HSPN from healthy control individuals.
A total of 26 patients with HSPN and 26 control participants were include in the study. The overall gut microbiota was quite different between the HSPN and control groups. Patients with HSPN had lower diversity, significantly higher proportions of pathogenic bacteria including g-Bacteroides (P =.016), g-Escherichia-Shigella (P =.021) and g-Streptococcus (P =.012), and a lower proportion of g-Prevotella_9 (P =.016). The AUC from the ROC curve analysis was 0.86, indicating that the differential taxonomic abundance could be used to classify patients with HSPN from healthy control participants.
The relative abundance of gut microbiota was also associated with disease severity. Specifically, the percentage of g-Streptococcus was significantly higher in patients with hematuria and hypoalbuminemia (P <.05).
Limitations of the study were the cross-sectional study design that did not include interventions, such as probiotics or antibiotics, and did not account for the complex relationship between gut microflora and kidney disease. Randomized controlled trials are needed to verify these study results.
The researchers concluded, “Intestinal mucosal streptococcal infection might cause the occurrence of HSPN and be closely related to its severity. A microbial-based management of HSPN might be a potential direction of HSPN in the future.”
Tan J, Zhong Z, Tang Y, Qin W. Intestinal dysbiosis featuring abundance of Streptococcus associates with Henoch-Schönlein purpura nephritis (IgA vasculitis with nephritis) in adult. BMC Nephrology. Published online January 3, 2022. doi:10.1186/s12882-021-02638-x