Varicella-zoster virus encephalitis in acquired immunodeficiency syndrome: report of four cases

Four patients with acquired immunodeficiency syndrome, a 27-year-old female intravenous drug abuser and three males (two drug addicts aged 27 and 33 years and a 40-year-old homosexual) presented with a rapidly progressive encephalopathy. Two had generalized varicella-zoster virus skin infection, one had had a regressive thoracic zoster rash 7 months previously and one had no history of cutaneous eruption. Neuropathological examination revealed, in each case, multifocal necrotic changes with numerous, intranuclear Cowdry type A inclusion bodies in glial cells, endothelial cells, macrophages and neurons, within and around the lesions. These inclusion bodies were stained positively for varicella-zoster virus by immunocytochemistry and contained herpes virus nucleocapsids by electron microscopy. Molecular biology using the polymerase-chain-reaction method demonstrated viral genome. In one case, zoster-induced non-inflammatory vasculopathy involved medium sized leptomeningeal vessels and was associated with circumscribed areas of cortico-subcortical infarction. In another case, varicella-zoster virus encephalitis was associated with human immunodeficiency virus encephalitis and a secondary cerebral lymphoma. Multinucleated giant cells expressing human immunodeficiency virus proteins in their cytoplasm, were found in the lymphomatous deposits and in the varicella-zoster virus necrotic lesions. In these latter lesions, Cowdry type A inclusion bodies could be seen in the nuclei of some multinucleated giant cells confirming previous observations of MGCs co-infected by HIV and CMV, and supporting the hypothesis that DNA viruses interact with HIV, thus increasing its effect.