Background: Following the results of the MANDARA trial, this real-life study aimed at comparing the effectiveness and safety profile of mepolizumab versus benralizumab in a European EGPA cohort. Methods: We conducted a retrospective observational comparative study including EGPA patients, who received mepolizumab or benralizumab at the asthma dose. Patients were matched 1:1 by sex, age, BVAS and oral corticosteroid (OCS) dosage at the treatment initiation (T0). Complete response (CR) and partial response (PR), disease activity, OCS, pulmonary parameters, eosinophil count, relapses, and safety outcomes were also compared at 3, 6 and 12 months. Results: Patients treated with mepolizumab or benralizumab (n=88 each) were matched: 57% were females, median age was 54 years (IQR 45-60), median OCS dose 10 (7.5-12.5) and 10 (7-13) mg/day, median BVAS 4 (2-7) and 3 (2-8), respectively. 45.4% of patients in the mepolizumab group and 51.1% in the benralizumab group achieved CR or PR at T3, with CR steadily increasing during follow-up for both treatments. At T12, a higher CR rate was found in the benralizumab group (48.1% vs 32.4%, p=0.005). No differences in BVAS, OCS, and respiratory parameters were observed between groups at the different timepoints. Throughout the follow-up, both treatments reduced eosinophil count, although a deeper reduction was found in the benralizumab group at all timepoints (p<0.0001). Safety profile was comparable between patient groups. Conclusion: Mepolizumab and benralizumab showed comparable overall effectiveness and safety in EGPA. However, benralizumab achieved a higher CR rate at T12, and a deeper peripheral eosinophil reduction.

Background: Increasing evidence are available about the presence of increased serum concentration of Immunoglobulin (Ig) Free Light Chains (FLCs) in both atopic and non-atopic inflammatory diseases, including severe asthma, providing a possible new biomarker of disease, disease severity and also an alternative approach to the treatment. Methods: We analyzed clinical and laboratory data, including FLCs, obtained from a cohort of 79 asthmatic subjects, clinically classified into different GINA steps. A control group of 40 age-matched healthy donors (HD) was considered. Particularly, HD have been selected according to the absence of monoclonal components (in order to exclude paraproteinemias), were tested for total IgE (that were in the normal ranges) and were negative for aeroallergens specific IgE. Moreover, no abnormality of common inflammatory markers (i.e. erythrocyte sedimentation rate, C-reactive protein) was detectable. Results: FLC-k levels were significantly increased in the asthmatic population, compared to the control group. Despite the absence of statistically significant differences in FLC-λ levels, the FLC-k/FLC-λ ratio displayed remarkable differences between the two groups. A positive correlation between FLC-κ and FLC-λ levels was found. FLC- λ level displayed a significant negative correlation with the FEV1 value. Moreover, the FLC-κ /FLC- λ ratio was negatively correlated with the SNOT-22 score and a positive correlation was observed between FLCs and Staphylococcus Aureus IgE enterotoxins sensitization. Conclusions: Our findings confirmed the role of FLCs in asthma as a potential biomarker in an inflammatory disease characterized by different endotypes and phenotypes. In particular, FLC-κ and FLC-k/FLC-λ ratio could be a qualitative indicator for asthma, while FLC-λ levels could be a quantitative indicator for disease severity.