Imbalance of serum IL-10 and TGF-β in patients with pollen food syndrome

BackgroundPollen food syndrome is one of the main causes of food allergies in adults. However, the intrinsic immunological mechanisms remain unclear.MethodsForty pollinosis sufferers [23 with a food allergy (PSFA) and 17 without a food allergy (PS)] and 17 non-atopic healthy controls were included in this study. The PSFA group was subdivided into an oral allergy syndrome group, a systemic reaction group, and an anaphylactic reaction group according to their symptoms after eating the suspected foods. Serum IL-10 and TGF-β levels of all participants were determined by ELISA. Clinical characteristics of the patients were also evaluated.ResultsThere were no significant differences in age, sex, pollen-associated symptoms, duration of respiratory disease, and positive parental history of atopy between the PSFA and PS groups. Compared to healthy controls, serum IL-10 levels of both the PSFA group and PS group were significantly lower (p ≤ 0.01), but TGF β levels were significantly higher in the PSFA group (35.3 ± 5.6 ng/ml vs. 31.2 ± 6.6 ng/ml, respectively; p = 0.037). Within the PSFA group, IL-10 levels in the anaphylactic reaction subgroup were significantly lower compared to oral allergy syndrome subgroup (1.87 ± 0.47 pg/ml vs. 1.40 ± 0.30 pg/ml, respectively; p = 0.027). More severe food allergy symptoms were associated with lower serum IL-10 levels. In contrast, the highest serum levels of TGF-β were found in patients from the anaphylactic reaction subgroup.ConclusionsWith the exception of a defect in regulatory cells represented by the reduction of IL-10, other potential immunological mechanisms (e.g., Th17 or IL-23 together with TGF-β) may be involved in the development of pollen food syndrome.