Interferon gamma expression and clinical features in patients with acute retinal necrosis syndrome

Background: Interferon gamma (IFN-γ) has been reported to play an important role during virus infections. The purpose of this study was to examine the relationship between IFN-γ expression and the clinical course of patients with acute retinal necrosis syndrome (ARN) associated with the varicella-zoster virus (VZV). Methods: Six patients with ARN were studied. The aqueous and/or vitreous were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay during the follow-up period. The presence of VZV genome was also determined by PCR. The results were correlated with the clinical data and features and compared with patients with other ocular diseases. Results: A statistically significant higher level of IFN-γ was detected in the aqueous and/or vitreous in eyes with ARN than in eyes with other ocular diseases. A statistically significant positive correlation was observed between the level of IFN-γ in the vitreous and the final visual acuity. IFN-γ was reduced to undetectable levels within 30 days after the initial eye symptoms. Three of five patients had severe inflammation initially, and the visual acuity gradually recovered with the disappearance of VZV and higher levels of IFN-γ. Conversely, the other 2 patients showed mild inflammation, had a slow decrease of visual acuity with persistent VZV, and lower levels of IFN-γ expression. Conclusion: Our results suggest that IFN-γ may be one of the factors that plays an important role in the clinical course of VZV-associated ARN.