Aids-associated herpes simplex virus retinitis: Clinical description and use of a polymerase chain reaction-based assay as a diagnostic tool

Purpose: To describe two patients with AIDS who developed a rapidly progressive, bilateral retinitis due to herpes simplex virus (HSV), one with HSV-1 and a second with HSV-2. A polymerase chain reaction (PCR)-based assay used to detect and distinguish HSV-1 and HSV-2 DNA in vitreous samples from these patients is also presented. Methods: The presentation and clinical course of the two patients with AIDS and a rapidly progressive, bilateral retinitis are described. A novel PCR-based assay and DNA restriction analysis for detecting and distinguishing HSV-1 and HSV-2 DNA in vitreous samples was used to confirm the diagnosis in both patients. Previously described PCR-based as says for cytomegalovirus and herpes zoster virus DNA were negative. The diagnosis was supported in both patients by the occurrence of a herpes simplex-like encephalitis, and in one patient by a positive vitreous culture. Results: Both patients developed a rapidly progressive, bilateral outer retinal necrosis associated with intraretinal hemorrhages and a diffuse vasculitis . The HSV-1-associated vasculitis affected primarily the retinal arterioles, with marked capillary drop-out and occlusion of larger arcade vessels. In contrast, the HSV-2-associated vasculitis was limited to the retinal veins, and was associated with an exudative retinal detachment. Vision was lost despite aggressive therapy in both patients. The PCR-based assay used to detect HSV DNA was run on vitreous from 164 inflamed and uninflamed control samples with no false positive results, a specificity of 100%. Conclusions: HSV can be the sole cause of a rapidly progressing, necrotizing retinitis in patients with AIDS. Combined PCR and restriction analysis of vitreous samples from such patients is a useful and highly specific means of diagnosing HSV-1 and HSV-2 retinitis.