Cytokine response after severe respiratory syncytial virus bronchiolitis in early life

J Allergy Clin Immunol. 2008 Oct;122(4):726-733.e3. doi: 10.1016/j.jaci.2008.07.010. Epub 2008 Aug 28.


Background: Immune response after viral infection usually involves T(H)1-mediated response; however, severe respiratory syncytial virus (RSV) infection appears to be associated with the development of asthma, a T(H)2-predominant phenotype.

Objective: To understand the early and subsequent immunologic response to a serious RSV infection in children over time.

Methods: A total of 206 previously healthy infants hospitalized with severe RSV bronchiolitis were enrolled in a prospective cohort called the RSV Bronchiolitis in Early Life study. Peripheral blood T cells were obtained immediately after RSV infection and at 2, 4, and 6 years of age, stimulated with phorbol 12-myristate 13-acetate and ionomycin, and analyzed for IL-2, IL-4, IL-13, and IFN-gamma by flow cytometry and real-time PCR.

Results: Of the children, 48% (n = 97) developed asthma (physician-diagnosed), and 48% (n = 97) had eczema by age 6 years; 32% (n = 48 of 150) developed allergic sensitization by 3 years of age. Children with asthma had lower IL-13 expression at 6 years of age than those without (P = .001). IFN-gamma, IL-2, and IL-4 levels did not differ by asthma or eczema status during follow-up (all P > .05). Allergic sensitization was not associated with differences in cytokine levels during follow-up (all P > .05).

Conclusion: Severe RSV infection early in life is associated with a high incidence of asthma and eczema. Contrary to expectations, subsequent immunologic development in those who developed asthma, eczema, or allergic sensitization was not associated with a T(H)2 phenotype in the peripheral blood.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Asthma / etiology
  • Asthma / immunology
  • Bronchiolitis, Viral / complications
  • Bronchiolitis, Viral / immunology*
  • Carcinogens / pharmacology
  • Cells, Cultured
  • Child, Preschool
  • Cytokines / immunology*
  • Eczema / etiology
  • Eczema / immunology
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Ionomycin / pharmacology
  • Ionophores / pharmacology
  • Male
  • Prospective Studies
  • Respiratory Syncytial Virus Infections / complications
  • Respiratory Syncytial Virus Infections / immunology*
  • Respiratory Syncytial Viruses / immunology
  • Tetradecanoylphorbol Acetate / pharmacology
  • Th1 Cells / immunology*
  • Th2 Cells / immunology*


  • Carcinogens
  • Cytokines
  • Ionophores
  • Ionomycin
  • Tetradecanoylphorbol Acetate