Pregnancy-associated plasma protein-A (PAPP-A) levels in patients with severe allergic asthma are reduced by omalizumab

J Asthma. 2018 Oct;55(10):1116-1121. doi: 10.1080/02770903.2017.1396471. Epub 2017 Dec 6.


Background: Remodeling is a crucial feature of severe asthma and may be associated with activation of the allergic cascade by immunoglobulin E (IgE). Omalizumab, an anti-IgE monoclonal antibody, effectively targets the severe allergic asthma phenotype. Pregnancy-associated plasma protein-A (PAPP-A) is an insulin-like growth factor binding protein-4 (IGFBP-4) protease, increasing local insulin-like growth factor (IGF)-1 concentrations, which in turn initiating a cascade involved in the regulation of cell growth, differentiation, and proliferation in various tissues. In the present study, we evaluated the effects of omalizumab on serum PAPP-A, IGFBP-4, and IGF-1 levels in subjects with severe allergic asthma.

Methods: We studied 36 asthmatic subjects and 36 healthy controls. An ultrasensitive enzyme-linked immunosorbent assay (ELISA) kit was used to measure serum PAPP-A levels, and routine commercial ELISA kits were employed to assess serum levels of IGF-1, IGFBP-4 in control subjects and asthmatic subjects before therapy (baseline) and after six months of omalizumab therapy in patients with severe asthma.

Results: Compared to control subjects, serum PAPP-A and IGFB-4 levels were significantly higher in asthmatic subjects (both p values < 0.001). However, the serum IGF-I levels of asthmatic subjects were similar to those of control subjects (p > 0.05). In asthma subjects, 6-month omalizumab treatment significantly decreased the serum PAPP-A (p < 0.001), IGF-I (p = 0.031), and IGFB4 (p = 0.025) levels.

Conclusion: PAPP-A level may be a useful biomarker for predicting airway remodeling in patients with severe asthma receiving omalizumab, and may also reflect the response to treatment.

Keywords: Allergy; asthma; inflammation; omalizumab; pregnancy-associated plasma protein A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma / drug therapy*
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunoglobulin E / drug effects
  • Insulin-Like Growth Factor I / drug effects*
  • Middle Aged
  • Omalizumab / pharmacology
  • Omalizumab / therapeutic use*
  • Pregnancy-Associated Plasma Protein-A / drug effects*
  • Respiratory Function Tests
  • Severity of Illness Index
  • Socioeconomic Factors


  • Omalizumab
  • Immunoglobulin E
  • Insulin-Like Growth Factor I
  • Pregnancy-Associated Plasma Protein-A