SSPE: immunohistochemical demonstration of measles virus antigen(s) in paraffin sections.

We used the indirect immunoperoxidase method to study formalin-fixed, paraffin-embedded brain sections of four autopsied subacute sclerosing panencephalitis (SSPE) patients. Specific reactions with measles virus antigens was noted in all cases. Positive staining was observed in neurons and glia cells and both nucleus and cytoplasm were usually stained in these positive cells. Electron microscopy revealed intranuclear and intracytoplasmic nucleocapsids stained with electron-dense reaction products. Our findings suggest that for immunoperoxidase studies of SSPE formalin-fixed, paraffin-embedded material can be used.