Multiplex detection of herpesviruses in tear fluid using the "stair primers" PCR method: prospective study of 93 patients

Abstract

Human herpesviruses can infect the eye and be excreted subsequently in tears. The aim of the present study was to use a multiplex PCR to detect herpesviruses (HSV-1, -2, VZV, CMV, EBV, HHV-6) in tears from normal subjects and from patients with pathological conditions (acute herpes, zoster, papillary conjunctivitis, and dry eye). Schirmer test strips were used to collect tear fluid from 93 patients, sampling both eyes. DNA was then extracted from the 186 samples by chromatography, and viral DNA amplified using a commercialised multiplex "stair primer" method. Thirty-four samples (18.3%) contained Taq inhibitors. The multiplex test gave positive results for HSV and VZV in tear fluid from patients with acute dendritic keratitis (3 patients) and acute ocular zoster (4 patients) and was, therefore, considered effective in testing samples from patients with acute lesions. HSV-1 and HSV-2 were found in two samples from patients with metaherpetic corneal scarring. Among 28 cases of dry eye, two were positive for HHV-6, the latter being associated with EBV in one patient. HHV-6 was also found in 4 out of 54 cases of papillary conjunctivitis. This raised occurrence of HHV-6 in dry eye or papillary conjunctivitis, suggests new clinical patterns for HHV-6 latency or reactivation. Detection of EBV in 1 out of 80 healthy eyes confirms previous evidence that lacrimal glands constitute potentially a site for latent-phase EBV.