Identifying SE in Initial Asthma Screening May Help Promote Precision Medicine

Data from a new study are pointing to a certain toxin that could help drive precision medicine in asthma.

The retrospective findings showed that searching for Staphylococcus aureus and its enterotoxins (SE) when initially screening patients can help with identifying a targeted treatment option by improving phenotyping and predicting comorbidities.

“Perspectively, these data could be interesting for new biological therapies indication and patient selection,” explained the researchers. “In fact, recent approaches have demonstrated that Staphylococcus aureus, regardless of enterotoxins production, may damage the airway epithelial cells, thus inducing the release of the alarmins IL-25, IL-33 and thymic stromal lymphopoietin (TSLP), which in turn can activate the type-2 innate lymphoid cells (ILC2) involved in IL-5 mediated eosinophilic inflammation.”

Overall, 1 in 4 of the 249 patients included in the study were positive for staphylococcal enterotoxin B (SEB)-IgE. According to the researchers, the prevalence was similar to that found in a previous large-scale study, which identified a 29.3% prevalence. Patients who had SEB-IgE sensitization tended to be younger and have an earlier disease onset.

Compared with SEB-IgE­–negative patients and the cohort as a whole, patients who were positive for SEB-IgE had a weak and negative correlation between FEV₁% and BEC, indicating that BEC is not correlated with the severity of asthma.

Based on these findings, the researchers argued that SE-IgE sensitization should be considered as an independent risk factor for the development of asthma.

SEB-IgE was positively associated with chronic rhinosinusitis (CRS) (OR = 2.65; 95% CI, 1.22–5.71) and with CRS with nasal polyps (CRSwNP) (OR = 1.98; 95% CI, 1.08–3.52). Data also showed a meaningful association between SEB-IgE and being female, which is consistent with previous research. There were no significant associations observed between SEG-IgE sensitization and atopy, exacerbations, or corticosteroid dosages. The researchers observed a suggested increase in the risk of SEB-IgE sensitization for smokers (OR = 1.9; 95% CI, 0.98–3.60).

“There was not enough statistical data to point out the presence of a significant association between smoking status and SEB-IgE sensitization,” described the group. “The latter finding also agrees with previous data, where statistical significance if reached only after thresholding the population according to the number of cigarette packs/year (>15 for statistical significance), highlighting a dose-dependent relationship between the two variables.”

While the study was not set up to assess responses to treatment, the researchers noted that not all patients responded the same to different biologics. Certain patients, particularly those with nasal polyposis, did not have notable responses to anti–IL-5 treatments such as mepolizumab. The researchers wrote that these patients may be SE-IgE positive rather than IL-5 positive with CRSwNP, which would explain their lack of response to anti–IL-5 treatment.

Reference

Caruso C, Colantuono S, Ciasca G, et al. Different aspects of severe asthma in real life: Role of Staphylococcus aureus enterotoxins and correlation to comorbidities and disease severity. Allergy. Published online August 3, 2022. doi: 10.1111/all.15466