500 Skin microbiota perturbations are clinical severity-dependent in hidradenitis suppurativa

Abstract

Hidradenitis Suppurativa (HS) is a prevalent and debilitating inflammatory skin disease. Previous studies have demonstrated skin microbiota perturbations in HS, but how these perturbations relate to disease severity is not understood. We aimed to understand the relationship between clinical disease severity and cutaneous dysbiosis in HS. We collected skin surface swabs from the inguinal crease of 12 HS patients and 5 age- and sex-matched healthy volunteers (HV). Demographic and clinical data, including clinical severity as measured by Hurley staging, were collected. The V1-V3 hypervariable region of the 16S ribosomal RNA gene was sequenced from purified genomic DNA and analyzed using a mothur-based pipeline. We used chi square tests to compare relative abundances of bacteria between HS subjects and HV, and Spearman correlation to examine relationships between clinical severity and bacterial relative abundance; p<0.05 was considered significant after adjusting for multiple comparisons using the false discovery rate method. Subjects had a mean age of 33.0 years (SD 11.6, women 58.3%, men 41.7%), and a range of clinical disease severity (Hurley I: 16.7%, II: 66.6%, III: 16.7%). Bacterial communities from HS subjects were distinct and clustered apart from those of HV on principal components analysis. The separation between the bacterial communities of HS subjects and HV increased with worsening clinical severity. The mean relative abundance of Cutibacterium acnes was reduced in HS subjects as compared with HV (HS 0.14 ± 0.04% vs HV 18.0 ± 15.3%, p<0.05). Lower relative abundances of Staphylococcus (Spearman ρ=-0.64, p<0.05) and Corynebacterium (ρ=-0.52, p<0.05) species, and higher relative abundances of mixed anaerobes (including Porphyromonas, Prevotella, and genera belonging to Clostridiales XI Incertae Sedis, ρ>0.53, p<0.05 for each comparison) were observed in HS subjects with worsening disease severity as compared with HV. Our findings indicate that worsening clinical severity is associated with increased skin microbiota perturbations in HS.