D1.213 - Staphylococcus aureus enterotoxins in allergic rhinitis: impact on disease severity and molecular sensitization profile

S. aureus enterotoxins (SE) play a dual role as allergens and superantigens, causing polyclonal T-cell activation and chronic inflammation. The relationship between S. aureus carriage, SE sensitization, and allergic rhinitis (AR) severity remains incompletely understood. This investigation evaluated S. aureus carriage, SE sensitization profile, and associations with allergen sensitization patterns in AR patients.

Retrospective analysis of 56 patients with AR, 53 non-allergic rhinitis patients included bacterial culture, skin prick-tests determination of sIgE to components or extracts using ImmunoCAP, specific IgE to SE (SEA, SEB, SEC, TSST) and total IgE assessment. Patients were divided into groups: AR+SE (n=22), AR-SE (n=34), NAR+SE (n=16), NAR-SE (n=37).

S. aureus carriage was detected in 64.2% of patients, but SE sensitization in only 34.9%, confirming that carriage alone is insufficient. Multiple SE sensitization (≥2 types) was significantly more common in AR+SE than NAR+SE patients, indicating pronounced immune dysregulation caused by superantigens in AR.

The AR+SE group demonstrated a more severe phenotype: higher total IgE (202 vs. 89.9 kU/L, p<0.05), increased polysensitization to ≥5 allergens (27.3% vs. 5%), persistent rhinitis (63.6% vs. 35.3%), and asthma comorbidity (13.6%). Ragweed sensitization was equally high in both groups (68.2% and 64.7%). However, component diagnostics revealed median IgE to Amb a 1 were 3.0 times higher in AR+SE (37.65 vs. 12.75 kU/L). Sensitization to perennial allergens showed a tendency toward sensitization to epidermal allergens: (cat 36.4% vs. 11.8%, dog 22.7% vs. 5.9%), house dust mites (18.2% vs. 8.8%). Molecular analysis confirmed elevated specific IgE in AR+SE: Fel d 1 increased 6.2 times (15.47 vs. 2.48 kU/L), Can f 5 increased 3.0 times (12.56 vs. 4.17 kU/L). While D.pteronyssinus molecule profile showed heterogeneous patterns with trend towards higher Der p 2 levels.

SE sensitization is associated with severe AR phenotype characterized by persistent course, significant polysensitization to perennial allergens, and elevated IgE levels (total and specific). SE sensitization may be an additional marker of AR severity and disease progression risk. These findings require further study, highlight the need for individualized treatment strategies, including local immune modulation and inclusion of bacterial lysates in complex therapy for AR patients sensitized to SE.