Cytokine analysis of aqueous humor in HIV patients with cytomegalovirus retinitis

Abstract

Purpose: Cytomegalovirus retinitis (CMVR) is the most common opportunistic ocular infection in patients with AIDS. Comprehensive analysis of aqueous humor for immunologic factors has yet to be performed in patients with CMVR. This study aims to perform comprehensive immune factor analysis of aqueous humor in CMVR patients to determine the presence of any characteristic immunological profile in the aqueous humor.

Methods: Comparative prospective analysis of aqueous humor was performed across three groups: (1) AIDS patients with CMVR (CMVR group) (n=20), (2) HIV-positive patients without CMVR (HIV group) (n=6) and (3) patients undergoing cataract surgery with no underlying ocular infection or inflammation (control group) (n=11). At least 100μl of aqueous humor was drawn from all subjects and fractionated prior to analysis for 41 cytokines, chemokines and growth factors with the FlexMAP 3D (Luminex®) platform using the Milliplex Human Cytokine® kit.

Results: Three distinct immunologic signatures were observed in the aqueous humor of the three groups. Statistically significant differences (p<0.05) were observed across the three groups with the HIV group having lower levels and CMVR group having raised levels for the following factors: IP-10, fractalkine, PDGF-AA, G-CSF, Flt-3L and MCP-1.

Conclusion: Aqueous humor though clinically quiescent in CMVR revealed a unique immunologic signature consistent with a combined Th-1 and monocyte-macrophage mediated response. Subsequent longitudinal analysis of aqueous cytokine levels of CMVR through the course of treatment would allow better understanding of the immunopathogenetic mechanisms of CMVR. This may also be used to better prognosticate the disease, predict complications and allow better assessment of treatment response and individualization of treatment in the future.

Keywords: Aqueous humor; Chemokine; Cytokine; Cytomegalovirus retinitis; HIV.