This study tested whether circulating exosomes from post-herpetic neuralgia (PHN) patients can drive sensory neuron dysfunction independent of direct varicella zoster virus (VZV) infection, using human nociceptive neurons exposed to exosomes from controls, acute herpes zoster (HZ) patients, or PHN patients.
PHN patient-derived exosomes recapitulated and amplified a pro-inflammatory neuronal phenotype in uninfected neurons — suppressing neurite outgrowth (via predicted ELAVL4 inhibition), inducing MMP-9 secretion, upregulating substance P, and downregulating canonical nociceptive ion channels — without causing cytotoxicity. Complement C3b and HSPA5 were enriched on PHN exosomes by proteomic profiling.
This is an *in vitro* mechanistic study; no animal model or clinical intervention data are presented, limiting direct translation. Sample sizes for patient exosome donors are not reported. Causal roles of specific exosome cargo (e.g., C3b, HSPA5) were not experimentally confirmed through gain/loss-of-function studies.
No immediate clinical practice change is warranted, but circulating exosome cargo (notably complement C3b and HSPA5) represent novel mechanistic targets for future PHN therapeutic development. Clinicians should be aware that neuronal dysfunction in PHN may persist via acellular, virus-independent signaling long after viral clearance.
