Correlation between Total Serum Free Light Chain Immunoglobulins in Respiratory and Food Allergies.

Objectives: Tetrameric Ig are produced and secreted by plasma cells, but they also produce and secrete Ig-free light chains (FLC κandυ). Studies in animal models of allergic disease suggest the existence of an IgE-independent hypersensitivity response involving antigen-induced mast cell activation mediated by FLCs. FLCs are increased during mucosal immune responses and are possibly involved in the pathogenesis of various atopic and non-atopic diseases. We aimed to explore the relation between serum FLC and IgE in patients with high levels of specific IgE for food and respiratory allergens. Material and Methods: 37 subjects with food allergy, 27 subjects with respiratory allergy and controls were selected and serum was collected for determination of κand υFLCs, total IgE by ELISA. Specific food and respiratory allergens were detected using Improvio C Blotting. Results: Serum FLCs were found significantly increased in respiratory and food allergic patients. In cow's milk allergic patients, no increase in specific IgE was detected, while serum FLCs were found increased. No correlation between FLC and total serum IgE was found. Conclusions: We show that FLCs are significantly augmented in patients with high total and allergen-specific IgE. No significant correlation between FLC and allergen-specific IgE was found indicating an IgE-independent production of FLCs. Interestingly; total FLC levels in cow's milk allergic subjects are raised even in the absence of elevated allergen-specific IgE, which suggests that detection of FLC may be a complementary biomarker for allergy. [ABSTRACT FROM AUTHOR]