Eosinophil to lymphocyte ratio may predict OCS reduction and change in quality of life (AQLQ) resulting from asthma biological treatment.

Objectives: Simple clinical parameters that could be helpful in choice of monoclonal antibodies and prediction of their effectiveness are being sought. The aim was to assess if neutrophil-to-lymphocyte, eosinophil-to-lymphocyte and platelet-to-lymphocyte ratios may predict outcomes of biologic therapy for severe asthma.

Methods: Retrospective, single-center study including severe asthma patients treated with three different biologics. The blood ratios were assessed at initiation of treatment (point 0) and after six months (point 1). The chi-square test was used to analyze differences in nominal variables. Quantitative variables were compared by Student's t-test, Mann-Whitney U or Wilcoxon signed-rank tests.

Results: 53 patients with severe asthma were included, among them 21 patients (40%) treated with omalizumab and 32 patients (60%) with mepolizumab or benralizumab. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios did not change during six-month-course of biological treatment. Eosinophil-to-lymphocyte ratio was higher at the point 0 (p = 0.016) in the group treated with anti-eosinophils than in the omalizumab group and lower at the point 1 (p = 0.006). In the anti-eosinophil group this ratio decreased between points 0 and 1 (p < 0.001). In the omalizumab group there was an inverse correlation between the initial ratio and oral corticosteroid dose reduction (r_s = -0,67). In the a/eos group there were significant correlations between initial ratio and age (r_s = 0.36), and ACQ (r_s = -0.4) and ACQ (r_s = 0.41) measured at the point 1.

Conclusions: Pretreatment eosinophil-to-lymphocyte ratio may predict oral corticosteroid dose reduction resulting from omalizumab treatment and change in quality of life and asthma control resulting from anti-IL-5 and IL-5R treatment.