Are serum immunoglobulin concentrations a predictive biomarker of response to anti-IL5/IL5Rα therapies?

Respir Med Res. 2022 May:81:100882. doi: 10.1016/j.resmer.2021.100882. Epub 2022 Jan 1.


Background: Approval of biologics has recently revolutionized T2 severe asthma management. However, predictive biomarkers remain highly needed to improve patient's selection.

Objective: This study aims to determine whether serum immunoglobulins (Igs) levels might be predictive biomarkers of response to anti-interleukin-5 (IL5)/IL5Rα therapies.

Methods: Severe asthma patients eligible for mepolizumab or benralizumab were included herein. Serum immunoglobulin quantification was performed at baseline before mepolizumab or benralizumab initiation. After a 6-month treatment of mepolizumab or benralizumab, patients presented a second serum immunoglobulin quantification. The treatment response was evaluated by the GETE (Global Evaluation of Treatment Effectiveness) score at 6 months.

Results: A total of 50 patients were included. Median age was 56 [IQR 48.8-65.3] and 50% were females. Compared to baseline, a significant increase in IgG was observed at 6 months (9.2 [7.8-10.2] g/l vs 10.1 [8.8-11.1] g/l, p = 0.04). The area under the ROC curve was 0.58 [95%IC 0.40-0.77] for blood eosinophil count (p = 0.37), 0.75 [95%IC: 0.58-0.92] for serum IgG concentration (p = 0.009) for predicting the treatment response. According to the Youden index, serum IgG concentration ≥ 9.2 g/l predicts the response to anti-IL5 therapies with a sensitivity of 76.9% and a specificity of 75.7%.

Conclusion: Baseline serum IgG concentrations may be a useful tool to predict the response to anti-IL5/IL5Rα therapies but should be confirmed in larger clinical trials. Interestingly, anti-IL5/IL5Rα therapies are associated with a significant increase in serum IgG concentrations at 6 months.

Keywords: Asthma; Benralizumab; Biomarkers; IgG; Mepolizumab.

MeSH terms

  • Asthma* / diagnosis
  • Asthma* / drug therapy
  • Biomarkers
  • Eosinophils
  • Female
  • Humans
  • Immunoglobulin G / therapeutic use
  • Interleukin-5 Receptor alpha Subunit / immunology
  • Interleukin-5* / immunology
  • Male
  • Middle Aged


  • Biomarkers
  • IL5RA protein, human
  • Immunoglobulin G
  • Interleukin-5
  • Interleukin-5 Receptor alpha Subunit