Epithelial-Cell-Derived Cytokines in Patients with Obesity before and after Bariatric Surgery

Abstract/Purpose: Epithelial signals such as interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) are stimulators of group 2 innate lymphoid cells (ILCs2) that are integral regulators of adipose tissue type 2 immunity. The purpose of this study was to assess cytokines activating ILCs2 in the serum of patients with obesity and the effect of bariatric surgery on these parameters.

In a single-center prospective study, serum IL-25, IL-33, TSLP, and ST2L levels were assayed at the baseline and at 6 months after bariatric surgery and correlated with anthropometric changes and metabolism parameters.

Mean age and median of body mass index (BMI) of study participants were 41.9 years ± 11 and 45.6 kg/m2 (range 36.3-56.3), respectively. Six months after surgery, excess weight loss percentage was 43.1 ± 10.2%. Serum TSLP was significantly lower in patients with obesity both before and after surgery than in healthy controls. TSLP values before operation were significantly correlated to glycated hemoglobin percentage and BMI. Serum IL-25, IL-33, and ST2L levels were comparable to controls both before and after operation.

Decreased serum levels of TSLP may be a characteristic trait for obesity however nonmodifiable by body mass surgical reduction in short time observation. Low serum levels of TSLP are related to disturbances in glucose metabolism and BMI.