Correlation between clinical diagnosis and PCR analysis of serum, aqueous, and vitreous samples in patients with inflammatory eye disease

ABSTRACT

PURPOSE: To study the applicability (sensitivity, specificity) of polymerase chain reaction (PCR) tests in the detection of cytomegalovirus (CMV), herpes virus (HSV) and varicella zoster (VZV), Epstein-Barr virus (EBV), Mycobacterium sp and Toxoplasma gondii in the diagnosis of patients with or without AIDS, with presumably infectious uveitis, using serum, aqueous humor and vitreous humor samples. METHODS: Twenty individuals with uveitis of presumed infectious origin were evaluated. Sixteen of them had AIDS, four were immunocompetent individuals. We also evaluated 4 normal controls who underwent vitrectomy surgery. Clinical evaluation of the patients was performed together by three clinicians. PCR evaluations of the serum, aqueous, and vitreous humor were performed in a masked fashion by the laboratory staff. RESULTS: Twelve patients had a clinical diagnosis of CMV retinitis. Of these 6 (50 percent) had a positive PCR for CMV in the vitreous, three (25 percent) had a positive PCR for CMV in the serum, and none were positive in the aqueous. Five patients had a clinical diagnosis of acute retinal necrosis (ARN). Three (60 percent) of these had positive PCR for HSV/VZV in the vitreous. One of these patients had a positive PCR reaction for both EBV and HSV/VZV in the vitreous samples. One patient with cutaneous herpes zoster had a positive PCR reaction for HSV/VZV in the serum. Four patients had a presumed diagnosis of ocular toxoplasmosis, one patient (25 percent) had a positive PCR for Toxoplasma gondii in the serum, 3 (75 percent) had positive results in the aqueous, and 2 (50 percent) had positive results in the vitreous. One patient with presumed ocular tuberculosis had a positive PCR reaction both in the serum and in the vitreous samples. Finally, none of the four control individuals revealed any positive PCR reaction. CONCLUSION: PCR is an auxiliary diagnostic procedure that should be evaluated together with ophthalmological aspects...

RESUMO

OBJETIVOS: Avaliar a aplicabilidade (especificidade, sensibilidade) do teste da reação da cadeia de polimerase (PCR) na detecção de citomegalovírus (CMV), herpes vírus e varicela zoster (HSV, VZV), Epstein-Barr vírus (EBV), Mycobacterium sp e Toxoplasma gondii no diagnóstico de pacientes com ou sem AIDS, com uveíte infecciosa presumível, utilizando amostras de humor aquoso, humor vítreo e soro. MÉTODOS: Vinte pacientes com uveíte infecciosa presumível foram estudados. Dezesseis destes apresentavam AIDS e quatro eram imunocompetentes. Foram utilizados quatro pacientes como grupo controle que se submeteram a vitrectomia. A avaliação clínica foi feita conjuntamente com três oftalmologistas. O exame do PCR do soro, aquoso e vítreo foi feito sem o conhecimento da hipótese diagnóstica pela equipe do laboratório. RESULTADOS: Doze pacientes tinham o diagnóstico clínico de retinite por CMV. Deste subgrupo 6 (50 por cento) eram PCR positivo para CMV no vítreo, 3 (25 por cento) eram PCR positivos para CMV no soro e nenhum destes foi positivo no aquoso. Cinco pacientes tinham o diagnóstico clínico de necrose aguda de retina (ARN). Três (60 por cento) destes eram PCR positivos para HSV/VZV no vítreo. Um destes pacientes era PCR positivo tanto para EBV e HSV/VZV na amostra do vítreo. Um destes pacientes com herpes zoster cutâneo era PCR positivo para HSV/VZV no soro. Quatro pacientes tinham o diagnóstico de toxoplasmose ocular presumida, um paciente (25 por cento) era PCR positivo para Toxoplasma gondii no soro, 3 (75 por cento) eram positivos no aquoso e 2 (50 por cento) eram positivo no vítreo. Um paciente com tuberculose ocular presumível era PCR positivo tanto no soro quanto no vítreo. Nenhum dos pacientes do grupo controle era PCR positivo em qualquer amostra. CONCLUSÃO: O exame do PCR é procedimento diagnóstico auxiliar que deve ser utilizado conjuntamente com os aspectos clínicos.