sCD48 is elevated in non-allergic but not in allergic persistent rhinitis.

Background: CD48 is a costimulatory receptor of the immune response. Interactions between CD48 and CD244 (2B4) on mast cells and eosinophils suggest that these cells can act synergistically in the 'allergic effector unit' to promote inflammation. This report explores the role of CD48 in persistent allergic (PAR) and non-allergic rhinitis (NAR).

Methods: In this study, serum was obtained from 70 subjects (45 female, 64%; mean age, 36; range 18-70 years) to estimate the levels of sCD48 and two eosinophils-related parameters, ECP and eotaxin-1/CCL11. Twenty patients with PAR, 15 patients with NAR, and 35 healthy controls were included. The intensity of rhinitis symptoms was estimated by the Total Nasal Symptom Score. We also assessed the fractional exhaled nitric oxide bronchial and nasal fractions (FeNO) and neutrophil to lymphocyte (NLR) and eosinophil to lymphocyte (ELR) ratios.

Results: Significantly higher sCD48 serum levels were observed in the NAR group than in the PAR and control groups, and significant correlations were found between the serum level of sCD48 and the number and percentage of eosinophils. ECP and eotaxin-1/CCL11 serum levels were also found to be significantly higher in the NAR group.

Conclusions: CD48 may be involved in eosinophilic pathophysiological reactions in non-allergic rhinitis.