Do exosomes contribute to diseases?

Yes, exosomes can contribute to diseases. 

Exosomes play a key role in intercellular communication by transferring their cargo of proteins, RNA, lipids and other molecules from parent cells to recipient cells. Along with these molecules, exosomes have also been found to carry cargo associated with various diseases. During the intercellular communication process, exosomes may potentially communicate bad information, contributing to an associated disease.