World J Mens Health.  2022 Apr;40(2):316-329. 10.5534/wjmh.210003.

CD4+/CD8+ Ratio and Growth Differentiation Factor 8 Levels in Peripheral Blood of Large Canine Males Are Useful Parameters to Build an Age Prediction Model

  • 1Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
  • 2Institute of Animal Molecular Biotechnology, Korea University, Seoul, Korea.
  • 3Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju, Korea.
  • 4Military Working Dog Training Center, Chuncheon, Korea.


To build an age prediction model, we measured CD4+ and CD8+ cells, and humoral components in canine peripheral blood.
Materials and Methods
Large Belgian Malinois (BGM) and German Shepherd Dog (GSD) breeds (n=27), aged from 1 to 12 years, were used for this study. Peripheral bloods were obtained by venepuncture, then plasma and peripheral blood mononuclear cells (PBMCs) were separated immediately. Six myokines, including interleukin (IL)-6, IL-8, IL-15, leukemia inhibitory factor (LIF), growth differentiation factor 8 (GDF8), and GDF11 were measured from plasma and CD4+/CD8+ T-lymphocytes ratio were measured from PBMC. These parameters were then tested with age prediction models to find the best fit model.
we found that the T-lymphocyte ratio (CD4+/CD8+) was significantly correlated with age (r=0.46, p=0.016). Among the six myokines, only GDF8 showed a significant correlation with age (r=0.52, p=0.005). Interestingly, these two markers showed better correlations in male dogs than females, and BGM breed than GSD. Using these two age biomarkers, we could obtain the best fit in a quadratic linear mixed model (r=0.77, p=3×10 -6 ).
Age prediction is a challenging task because of complication with biological age. Our quadratic linear mixed model using CD4+/CD8+ ratio and GDF8 level showed a meaningful age prediction.


Age prediction model; Aging; CD4-CD8 ratio; Dogs; Myostatin
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