Staph Nasal Carriage: A Link With Lupus? The skin microbiome now implicated in disease pathogenesis

"It should be considered that glucocorticoid treatment could determine skin abnormalities. In particular, permeability barrier homeostasis and stratum corneum integrity and cohesion could be modified by glucocorticoid treatment," the researchers explained. They also offered potential explanations for why carriage of S. aureus might contribute to lupus pathogenesis, stating that its presence "seems to induce an inflammatory response by exposing staphylococcal superantigen, molecular mimicry, causing increased toll-like receptor signaling in leukocytes, and inducing neutrophil extracellular traps." Carriage also could lead to T-cell activation, they suggested. "Data from the literature demonstrated that staphylococcal enterotoxins could bind directly the major histocompatibility complex class II of antigen-presenting cells. The presentation to T cells leads to massive nonspecific activation of the immune system, by stimulating around 20% of the naive T-cell population." The commensal S. aureus can be found intermittently in the anterior nares in approximately one-third of the population. Its presence has been associated with atopic dermatitis, and studies have considered a possible association with other skin disorders such as acne vulgaris and rosacea. In addition, a study in patients with rheumatoid arthritis found carriage rates of 50% compared with 33% in controls, and another study found an association between carriage and disease development and relapse in granulomatosis with polyangiitis. http://www.medpagetoday.com/Rheumatology/Lupus/59487?xid=NL_breakingnews_2016-08-03&eun=g721819d0r