Detection of varicella zoster virus antigen and DNA in two cases of cerebral amyloid angiopathy.

Objective: Varicella zoster virus (VZV) vasculopathy and cerebral amyloid angiopathy (CAA) have similar clinical presentations: both affect cerebrovasculature in the elderly, produce hemorrhage, and can have a protracted course of cognitive decline and other neurological deficits. The cause of CAA is unknown, but amyloid-beta (Aβ) is found within arterial walls. Recent studies show that VZV induces Aβ and amylin expression and an amyloid-promoting environment. Thus, we determined if VZV was present in CAA-affected arteries.

Methods: Two subjects with pathologically-verified CAA were identified postmortem and frontal lobes analyzed by immunohistochemistry for arteries containing VZV, Aβ, and amylin and H&E for pathological changes. VZV antigen detection was confirmed by PCR for VZV DNA in the same region.

Results: In both CAA cases, sections with cerebral arteries containing VZV antigen with corresponding VZV DNA were identified; VZV antigen co-localized with Aβ in media of arteries with histological changes characteristic of CAA. Amylin was also seen in the intima of a VZV-positive artery in the diabetic subject. Not all Aβ-containing arteries had VZV, but all VZV-positive arteries contained Aβ.

Conclusions: VZV antigen co-localized with Aβ in some affected arteries from two CAA cases, suggesting a possible association between VZV infection and CAA.