Microdissection combined with the polymerase chain reaction to identify potentiating viral co-infection in patients with HIV/AIDS with ocular infection

Background: In the presence of several coexisting infections, superimposed tissue necrosis or tissue metaplasia, it may be difficult to recognize standard histologic morphology on hematoxylin-eosin slides. Tissue microdissection combined with the polymerase chain reaction (PCR-MD) offers the advantages of high specificity and relative speed. The objective of this study was to describe the use of PCR-MD in identifying potentiating viral co-infection in patients with HIV/AIDS with retinitis and choroiditis. Methods: Eyes from two patients with HIV/AIDS with several ocular infections were studied by a variety of techniques, including standard histologic examination, immunochemistry, electron microscopy and in situ hybridization. PCR-MD was used to identify coexisting viral infections. Results: Histologic examination showed cytomegalovirus retinitis in both cases. Use of PCR-MD allowed the identification of Epstein-Barr virus within a zone of fulminant varicella-zoster virus retinitis in one patient. PCR-MD confirmed the presence of human herpesvirus 8 in the second patient, who had ocular lymphoma. Interpretation: PCR-MD can be used to demonstrate coexisting viral infection in ocular specimens from patients with unusually fulminant courses. Co-infections may contribute to the observed clinical course and should be considered in patients with rapid progression or unusual presentation