Título

LOW-VOLUME MULTIPLEX PCR FOR ETIOLOGICAL DIAGNOSIS OF INFECTIOUS UVEITIS AND NON-USUAL HERPESVIRUS

Objetivo

To analyse the usefulness of low-volume direct multiplex PCR of intraocular fluid for the etiological diagnosis of uveitis.

Método

Thirty five patients with active uveitis were included in this study between July,21 and Sept,22. All patients had, in anterior chamber (AC), at least (2+) cells and signed the informed consent form. Samples were obtained by AC paracentesis (33 samples) or pars plana vitrectomy (2 samples). 20µl of sample was analysed using a direct multiplex qualitative polymerase chain reaction (PCR) assay, developed by Japanese researchers for uveitis diagnosis purpose. It detects herpes simplex virus 1 and 2; varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, human herpes virus 6, human T-lymphotropic virus, Treponema pallidum and Toxoplasma gondii) (Figure 1). This multiplex PCR was validated mainly in Japan.

Resultado

A total of 35 samples were collected from 35 patients with active uveitis. Uveitis were anterior in 16 patients (45.7%) and posterior in 15 patients (42.8%). It was the first acute episode in 11 patients, recurrent in 12 patients or chronic in 12 patients. Overall positivity was 25.7% (9/35 samples); among acute uveitis was 34.8% (8/23 samples). Herpes virus was detected in 4 samples: 2 for HHV6 (anterior uveitis), 1 for HSV2 (acute retinal necrosis) and 1 for EBV (neuroretinitis); T. gondii was detected in 4 samples (chorioretinitis) and T. pallidum in another sample (diffuse uveitis). The strip PCR changed the etiological diagnosis in two cases (5.7%; herpetic uveitis or syphilis to toxoplasmosis) and showed a unexpected herpesvirus as causative agent in another two cases. Detailed results are shown in Table 1.

Conclusão

For uveitis etiological diagnosis, direct strip PCR was able to demonstrate the infectious agent in one third of our sample with the unique characteristics of using very small sample volume, of testing for multiple pathogens all together and for a rapid results.