New approach to determine the healthy immune variations by combining clustering methods

Area of Science:

• Immunology
• Systems Biology
• Human Health

Background:

• Immune-mediated inflammatory diseases exhibit diverse presentations and severity.
• Understanding healthy immune system variability is crucial for disease research.
• Characterizing immune cell composition and influencing factors is a key challenge.

Purpose of the Study:

• To characterize global immune cell composition in healthy individuals.
• To identify intrinsic and environmental factors influencing immune cell variability.
• To determine if immune cell variability forms distinct clusters or a continuum.

Main Methods:

• Analysis of blood samples from two independent cohorts (389 and 208 healthy subjects).
• Measurement of twelve immune cell types and biological parameters.
• Application of three complementary clustering approaches to assess immune cell variability.

Main Results:

• Confirmed significant inter-individual variability in immune cell counts (large coefficients of variation).
• Immune cell makeup was organized as a continuum, not as distinct clusters, across both cohorts.
• Identified age, gender, BMI, cortisol, season, and CMV infection as factors influencing immune cell variability.

Conclusions:

• The healthy human immune system exhibits continuous variability rather than discrete clusters.
• Established a framework using complementary clustering for analyzing immune cell inter-individual variability.
• Highlighted specific intrinsic and environmental factors impacting immune cell composition in healthy populations.