[Viral diseases of the outer eye--rapid diagnosis by immunohistochemistry]

Rapid diagnosis of viral diseases of the outer eye was attempted by means of immunohistochemical methods. Specimens were obtained with a nitrocellulose membrane, used as a blotter of immunoblotting test. An impression of the corneal or conjunctival surface was obtained by anesthetizing the eye and lightly pressing the membrane against the tissues. In some cases, scraping materials were taken on a slide glass. Viral antigens in the specimens were detected by peroxidase-antiperoxidase (PAP) method, ABC system (Vectastain), or immunofluorescence. Four common diseases were studied. Dendritic corneal lesions caused by herpes simplex virus (HSV) were impressed on the membrane, and exhibited exact duplicates of lesions which were composed of PAP-positive epithelial cells. Under a high magnification, pathologic changes such as margination of chromatin, intranuclear inclusion bodies, and multinucleated giant cells were observed. Of 27 cases of epithelial herpetic keratitis, 25 showed positive results. The impression can permit examination of a minute lesion, therefore, is superior to scraping. Dendritic lesions caused by varicella-zoster virus (VZV) have a characteristic morphology different from those of HSV. Impressions showed the virus antigen, when treated with fluorescein-labeled anti-VZV monoclonal antibody. Appearance of such a dendrite in disorders of unknown cause indicates the etiology. Conjunctival impressions of adenovirus (Adv) conjunctivitis examined by the PAP method revealed Adv-antigen containing cells. Of 64 cases analyzed, 24 PAP-positive cases were compared with the 35 culture-proven cases. The sensitivity of PAP method was 69%, and the specificity was 97%. The detection rate varied according to serotype, and was especially low (33%) in type 3. Guinea pig antisera with high titers against enterovirus type 70 (EV70) and a variant of coxsackievirus A type 24 (CA24v), the causative viruses of acute hemorrhagic conjunctivitis (AHC), were obtained. Using these sera as the primary antibody, the antigen of each virus was localized in the cytoplasm of infected HeLa cells by either ABC, or immunofluorescence. Conjunctival cells from patients with EV70 AHC were antigen-positive for 3 days after the onset of disease. Though epidemics of CA24v AHC have only been experienced in Okinawa, sporadic cases have been observed in other districts of Japan.