Serum-specific IgE and Allergen Immunotherapy in Allergic Children

Mariangela Tosca; Michela Sivestri; Andrea Accogli; Giovanni Arturo Rossi; Giorgio Ciprandi

Disclosures

Immunotherapy. 2014;6(1):29-33. 

In This Article

Discussion

This preliminary retrospective study reported that serum-sIgE measurement before starting SLIT might also be useful to identify AIT responders in allergic children. In fact, the present experience could confirm a previous report that demonstrated a baseline sIgE level >10 kU/l as reliable cut-off for discriminating AIT-responder patients.[8] Overall, children with high sIgE perceived AIT efficacy, whereas children with low sIgE, such as <10 kU/l, perceived slight AIT benefit. In fact, there was a strong relationship between sIgE levels and perception of AIT efficacy. However, AIT efficacy was also supported by more traditional clinical parameters, such as VAS for nasal symptoms and ACT for asthma control.

This topic is intriguing, as it is clinically relevant to have an available biomarker able to predict AIT response. However, very few studies addressed this issue and the outcomes were conflicting.

Di Lorenzo and colleagues reported that high sIgE/total IgE ratios were able to predict AIT responders.[5] This study was well conducted, but only monoallergic patients were recruited. Even though, it is well known that polysensitization is more prevalent than monosensitization. For this reason, a real-life study was performed to confirm this outcome also in polysensitized patients.[8] On the contrary, Fujimura and colleagues reported opposite findings; patients with low sIgE/total IgE ratios achieved better AIT benefit than patients with high ratio.[6] However, this study reported the start of clinical improvement only after the second AIT treatment year. These data seem to be conflicting with:

  • The response to AIT is usually prompt;

  • High specific IgE are associated with severe symptoms;

  • Patients with severe symptoms achieve optimal response to AIT.[13]

We believe that to only consider the sIgE level, instead of the ratio between sIgE/total IgE levels, may be easier and may allow the avoidance of confounding factors depending on high total IgE values owing to extra-allergic causes.

Conversely, the present study has some limitations; it was retrospective, open and had a limited number of patients. The primary outcome was based on patient's perception, which is a subjective parameter, even though more traditional clinical parameters (nasal VAS and ACT) were also considered. In addition, the definition of a responder (such as a VAS ≥6) was arbitrary and not validated. Thus, it should be followed by rigorous trials conducted prospectively on larger cohorts to confirm these preliminary findings.

processing....