Abstract
Purpose: :
To compare the cytokine patterns in the aqueous and/or vitreous of patients with CMV retinitis in immunocompetent and immunosuppressed patients
Methods: :
4 patients with clinical CMV retinitis were studied. 16 Cytokines (interleukin [IL]-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, MCP-1, MIP-1β, GM-CSF, G-CSF, TNF- and IFN-γ) and CMV viral load in the aqueous and/or vitreous of these patients were examined by enzyme-linked immunosorbent assay and real time-polymerase chain reaction (RT-PCR) test respectively during the follow-up period when an anterior chamber or vitreous tap was required clinically. The results were correlated with the clinical course of the CMV retinitis and also compared to cytokines in other posterior uveitis.
Results: :
Patient 1 and 2 were healthy, HIV negative, with normal CD4 and CD 8 counts and no history of immunosuppression. Both patients had only a small patch of CMV retinitis in the peripheral retina. Patient 3 who was HIV positive with decreased CD4 counts, had a slightly larger area of CMV retinitis in the peripheral retina compared to Patient 1 and 2. Patient 4 who had extensive involvement of the macula, was HIV negative but was on immunosuppressive therapy. High levels of IL6, IL7, IL8, IL 10, MCP-1, MIP-1β, TNF- and IFN-γ were seen in both immune-competent and immunosuppressed patients. These were significantly higher when compared to inflammation in other posterior uveitis conditions such as Behcets Disease and Vogt-Koyanagi-Harada disease. A particularly high level of cytokines was seen in Patient 4, however this correlated with the severity of clinical disease rather than to viral load. The viral load did not appear to correlate with degree of retinitis.
Conclusions: :
Various immunoregulatory cytokines are involved in the host defense of CMV retinitis. Both TH1 and TH2 cytokines as well as macrophage and monocyte responses appear to be involved. These responses in our series were independent of the immune status of the patient. However, the degree of retinitis could be correlated to the amount of cytokines released
Keywords: cytokines/chemokines • cytomegalovirus • retinitis