Real-time PCR in infectious uveitis as an alternative diagnosis

Abstract

Purpose: Uveitis is a major visual impairment disease affecting parts or the entire uveal tract and occasionally the sclera, the cornea or the optic nerve. The disease is a major cause of ocular morbidity and blindness in immunocompetent and immunocompromised patients. In this work we analyzed the sensitivity and specificity of realtime PCR to detect the etiological agent from blood, plasma, vitreous and aqueous humor and compared with the diagnostic hypothesis. Methods: Twenty-seven patients (13 male) were studied and Real-time PCR method was used for the detection of herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), Mycobacterium tuberculosis (TB) and Toxoplasma gondii (Toxo) in the aqueous humor as well as in the vitreous, blood and plasma. Results: Our results showed the presence of Toxo, CMV, VZV or HSV-2 in 19.2% of aqueous humor samples, and in 30% of vitreous humor samples. In plasma and blood samples, only CMV was detected (11.1% and 3.7%, respectively). Conclusion: Real-time PCR was able to detect and to confirm diagnostic hypothesis in uveitis. Our data also confirms that vitreous humor is the best source for molecular diagnosis of infectious uveitis but indicates aqueous humor samples that are easier to obtain may also be appropriate to be tested by Real-time PCR. Keywords

Outcome of polymerase chain reaction (PCR) analysis in 100 suspected cases of infectious uveitis

“…Patients with uveitis of infectious and non-infectious etiologies often share similar clinical signs and symptoms at presentation, representing diagnostic challenges, especially when serology is unable to establish the diagnosis [8]. Having an early definitive laboratory-proven diagnosis is very advantageous in starting timely appropriate effective treatment.…”

Aqueous humor polymerase chain reaction in uveitis – utility and safety

“…On these grounds recent reports even question its utility and discourage its practice in anterior uveitis [5, 8]. Recent reports discourage aqueous PCR for the diagnosis of infectious uveitis or favour PCR of vitreous over aqueous [5, 9, 10]. …”

Detection ofToxoplasma gondiiDNA in peripheral blood and aqueous humor of patients with Toxoplasmic active focal necrotizing retinochoroiditis using real-time PCR

“…The use of real-time PCR as a diagnostic tool for infectious uveitis has been demonstrated by many groups (11,(19)(20)(21) . In this study, qPCR identified T. gondii infection in 37.21% of the aqueous humor samples, confirming the clinical hypothesis of toxoplasmic active focal necrotizing retinochoroiditis.…”

“…Polymerase chain reaction (PCR) can detect microorganism DNA and is a rapid method with high sensitivity and specificity that has been used to detect T. gondii DNA in different biological samples (8,9) . With the recent advances in molecular biology, the use of real-time PCR makes quantitative measurement of T. gondii DNA possible in patients with ocular toxoplasmosis (10)(11)(12) . Rapid recogni- tion of specific infections is important for adequate management of uveitis (13) .…”