Identification of bacterial DNA in the peripheral blood of patients with active hidradenitis suppurativa.

Bacterial translocation may have a role in the pathogenesis of several inflammatory conditions. A prospective analytical case-control study was designed to assess the presence of bacterial DNA in the peripheral blood of patients with hidradenitis suppurativa (HS). An age- and gender-matched control population was recruited from healthy blood donors. Demographic and HS-related data were also collected. We took fasting blood samples from each participant and determined the presence of bacterial DNA (including bacterial species identification) and levels TNF-α, IL-1β, and IL-17A. We included 50 patients with HS and 50 healthy controls. Bacterial DNA was present in 17 (34.0%) cases vs. 2 (4.0%) controls (P < 0.001); 14/17 (82.4%) bacterial species identified in HS patients were Gram-negative bacilli, especially Escherichia coli. The presence of bacterial DNA in patients with HS was associated with elevated levels of TNF-α (P < 0.001), IL-1β (P = 0.01) and IL-17 (P < 0.001); however, it was not associated with disease severity or disease location. BactDNA in the peripheral blood of patients with active HS is more common that in healthy controls, and it is associated with higher levels of proinflammatory cytokines. We hypothesized that BT from the skin/intestinal lumen may play a relevant role in the pathogenesis of HS.