Platelet mtDNA content and leukocyte count influence whole blood mtDNA content.

Changes in whole blood (WB) mitochondrial DNA (mtDNA) content are associated with health and disease. Platelet-derived mtDNA can confound WB mtDNA content measurements. From a sample of 44 volunteers, we show that platelet mtDNA content and platelet:leukocyte ratio are both dependent predictors of WB mtDNA content, but that platelet count itself is not. Furthermore, when platelet:leukocyte ratio increased by <2-fold ex vivo, the effect on WB mtDNA content was minimal. Altogether, this study clarifies the contribution of platelet mtDNA content rather than platelet count on WB mtDNA content measurements, and identifies defined parameters for future research on WB mtDNA content.