Cytokine expression patterns associated with systemic adverse events following smallpox immunization.

Area of Science:

• Immunology
• Virology
• Biochemistry

Background:

• Vaccinia virus vaccination, used for smallpox immunization, frequently causes systemic adverse events such as fever, lymphadenopathy, and rash.
• These events indicate a significant systemic inflammatory response despite cutaneous inoculation.

Purpose of the Study:

• To identify the specific cytokine and chemokine profiles associated with systemic adverse events following vaccinia virus vaccination.
• To develop a predictive model for adverse event status based on serum cytokine levels.

Main Methods:

• Utilized a protein microarray to quantify 108 serum cytokines and chemokines in 74 vaccine recipients before and 1 week after immunization.
• Employed machine-learning methods and statistical analysis to identify key soluble factors differentiating individuals with and without adverse events.
• Constructed a decision-tree model based on the identified cytokine signature.

Main Results:

• Identified a distinct signature of 6 cytokines that accurately discriminate between individuals experiencing systemic adverse events and those who do not.
• The key discriminating cytokines include granulocyte colony-stimulating factor, stem cell factor, monokine induced by interferon-gamma (CXCL9), intercellular adhesion molecule-1, eotaxin, and tissue inhibitor of metalloproteinases-2.
• This signature reflects specific inflammatory response pathways.

Conclusions:

• The identified cytokine signature provides a molecular basis for understanding systemic adverse events after vaccinia virus vaccination.
• Suggests a significant role for fibroblast-derived cytokines in mediating these inflammatory responses.
• Highlights potential biomarkers for predicting and managing vaccine-related adverse events.