Viral glycoproteins in herpesviridae granulomas

Granulomatous reactions after varicella zoster virus (VZV) and herpes simplex virus (HSV) infections are rare, and their pathogenesis remains unclear. We studied by immunohistochemistry and in situ hybridization early granulomatous reactions after VZV and HSV infections. In the five cases studied, the VZV glycoproteins gp I and gp II were present in cells abutted to altered vessels, but the corresponding genome sequences were disclosed in similar locations in only one of these cases. In an immunocompromised patient with diffuse HSV eruption, HSV I antigens were present in cells of the reticular dermis, while viral nucleic acids were not evident. Immunophenotyping of the granulomas showed strong Mac 387 and CD68 positive labelings of macrophages/monocytes, without any involvement of Factor XIIIa-positive cells. These findings suggest that the major viral envelope glycoproteins, rather than complete viral particles could trigger granuloma formation following HSV and VZV skin infections.