Irrelevance of Panton-Valentine leukocidin in hidradenitis suppurativa: results from a pilot, observational study

Panton-Valentine leukocidin (PVL) appears to be a virulence factor which, among others, can exacerbate the pathogenicity ofStaphylococcus aureusinfections, especially inducing severe necrotic, deep-seated skin infections, abscesses, and recurrences.These peculiarities have some overlaps with hidradenitis suppurativa (HS). Our main aim was to assess ifS. aureusproducingPVL could have some role in influencing clinical features and/or course of HS, specifically in the suppuration and recurrence oflesions. This pilot, mono-centric, observational study included all adult subjects affected with HS consecutively referring to ourHS clinic over a 3-month period. Clinically evident suppuration and at least 2 weeks wash out from any antibiotic were the maininclusion criteria. Purulent material from HS skin lesions was collected with swabs in order to isolate micro-organisms, withspecific regard toS. aureus.Detection of PVL was performed by real-time quantitative PCR (RT-qPCR). We also analyzedpurulent material from suppurative skin lesions other than HS, as a control. Thirty HS patients were included; 29 purulent lesions(96.7%) harbored at least one bacterial species. Five (16.7%) swab samples were positive forS. aureus, none of which waspositive for PVL genes. Among the 30 purulent disorders included as controls, 8 (26.3%) were positive forS. aureus;ofthese,4strains (50%) expressed LPV. The study results seem to exclude the pathogenetic involvement ofS. aureusproducing PVL inHS; as a result, PVL does not seem to represent a potential target in the future development of HS treatments