A recent publication in eBioMedicine revealed a higher presence of Corynebacterium simulans (C. Simulans) in the severe-moderate Psoriasis Area and Severity Index (PASI) groups, correlating with interferon-induced host genes. The study, utilizing data from the Microbes in allergy and autoimmunity related to the skin (MAARS) cohort, conducted a multi-omics investigation into host-microbe interactions in psoriasis. This research also identified two distinct clusters of psoriasis characterized by varying levels of disease severity.
The study enrolled 116 individuals with plaque-type psoriasis and 102 healthy controls, excluding those with autoimmune conditions or recent antibiotic, phototherapy, biologics, or immunosuppressive therapy. Skin biopsies and microbiome samples were collected from active psoriasis lesions and nearby non-lesional areas on the lower back, along with samples from healthy controls. Microbiome DNA underwent shotgun metagenomic sequencing, and RNA from biopsies was analyzed via weighted gene correlation network analysis (WGCNA) to explore taxonomic and functional aspects of the microbiome.
Transcriptome analysis revealed significant differences between psoriatic lesions and non-lesional samples, with WGCNA identifying six gene modules associated with inflammation-related pathways. Positive correlations were found between PASI scores and certain host genes, highlighting their roles in antiviral responses. Protein-protein interaction (PPI) networks identified interferon-associated networks across both groups, underscoring their involvement in psoriasis pathogenesis.
Microbiome analysis identified 13 enriched microbial species across varying PASI categories, with C. simulans notably elevated in moderate and severe cases. This bacterium correlated positively with immune cells like CD4 T cells and dendritic cells, implicating its role in psoriasis severity. Functional differences in microbiome features between psoriatic lesions, non-lesions, and healthy skin were notable, revealing distinct clusters of microbial gene families associated with psoriatic conditions. Hierarchical clustering highlighted microbial metabolic pathways and host gene expressions linked to immune responses and cellular reactions to stimuli, offering insights into potential therapeutic targets for managing psoriasis.
Psoriasis, an immune-mediated inflammatory disorder influenced by genetic factors and characterized by T-helper 1 (Th1)/Th17 T cell activity, is prevalent in India, affecting 0.44% to 2.8% of the population. Typically manifesting in individuals during their third or fourth decade of life, it disproportionately impacts males over females. This condition significantly diminishes quality of life for patients and their families, posing substantial physical, emotional, and social challenges. Globally, psoriasis affects approximately 125 million people, representing 2-3% of the world’s population, as reported by the World Psoriasis Day Consortium.
In conclusion, this study has revealed significant correlations between host genes, microbial profiles, and the severity of psoriasis, particularly emphasizing the influence of antiviral responses and C. simulans. The identification of two distinct clusters within psoriatic conditions, characterized by unique host and microbial traits, underscores the heterogeneity of the disease. These findings suggest promising opportunities to enhance psoriasis treatment by targeting both the microbiota and employing immunomodulatory therapies. Integrating microbiome analysis into routine clinical practice holds potential to optimize psoriasis management strategies and ultimately improve patient outcomes.
Reference
- Yang Y, Olah P, Radai Z, Maia G, Salava A, Salo V, et al. Exploratory multi-omics analysis reveals host-microbe interactions associated with disease severity in psoriatic skin. eBioMedicine [Internet]. 2024 Jul 1 [cited 2024 Jun 29];105. Available from: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(24)00257-3/fulltext
- Research on psoriasis in India: Where do we stand? – PMC [Internet]. [cited 2024 Jun 29]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5761022/
- Get the Facts About Psoriasis and Psoriatic Arthritis [Internet]. [cited 2024 Jun 29]. Available from: https://www.psoriasis.org/psoriasis-statistics/