Background: Some studies have proposed that varicella zoster virus (VZV) may cause giant cell arteritis (GCA) based on high rates of VZV antigen in temporal artery biopsies (TAB). We aimed to clarify this possible link by assessing clinical, serological and biopsy markers of acute infection in acute GCA patients.
Methods: Between July 2016 and April 2017, 24 patients acutely suspected of having GCA were clinically evaluated for active and past VZV infection. All were tested for VZV IgM and IgG and treated with corticosteroids while awaiting TAB. Patients were followed clinically for at least three months. Biopsies were cut into a minimum of four sections and stained using a mouse derived antibody against VZV antigen. Antigen detection was assessed by two experienced, blinded immunohistochemistry researchers.
Results:Mean patient age was 68 and 71% were female. Seven (29%) had inflammatory change on biopsy; four had mural inflammation and three had limited periadventitial small vessel vasculitis (SVV). 11 (46%) were assessed as having definite or probable (>= 50% chance) GCA at two-week follow-up. None had clinical features of active zoster at enrolment. Six (25%) reported a history of zoster, 22 (92%) chickenpox and none had received the adult zoster vaccine. One patient developed zoster ophthalmicus after commencing corticosteroids with subsequent ipsilateral biopsy showing SVV. All 24 biopsies stained negative for VZV antigen by immunohistochemistry. VZV IgM was negative in all 23 tested patients.
Conclusions: These interim clinical, serological and biopsy results do not support a convincing link between VZV and GCA.