Circulating Extracellular Vesicles in Human Disease

To the Editor: Shah et al. (Sept. 6 issue) 1 provided a comprehensive review of the role of extracellular vesicles in human disease and of their clinical implications. In the article, the discussion of the nucleic acids contained in extracellular vesicles focused only on RNAs (e.g., messenger RNAs [mRNAs] and small noncoding RNAs). However, the DNA in extracellular vesicles is also important, and a large proportion of circulating cell-free DNA is localized in exosomes. 2 One study of pancreatic cancer has shown that the circulating level of exosomal DNA may be a better outcome predictor than circulating tumor-cell DNA. 3 The double-stranded DNA . . .