Persistent measles virus infection oftheintestine: confirmation byimmunogold electron microscopy

Thisstudysought toinvestigate persistent measles virusinfection oftheintestine: a novelprotocol forimmunogold electron microscopy wasdeveloped using a polyclonalanti-measles nucleoprotein antibody on reprocessed, formalinfixed paraffin wax embeddedtissue sections. Antibody binding wasdetected using both immunoperoxidase andlight microscopy ontissue sections, and10nm goldconjugated secondary antibody andelectron microscopy on ultrathin sections. The techniques were validated usingboth measlesinfected verocells andhuman tissues withestablished measles infection: theseincluded brainaffected bysubacute sclerosing panencephalitis and acute measlesappendicitis. Thetechnique was applied subsequently to sixuntreated casesofgranulomatous Crohn'sdisease, andtwocasesofileocaecal tuberculosis, a granulomatous control. Mumps primary antibody - appliedto both mumps infected verocells, andmeaslesinfected vero cellsand tissuesstudiedby immunoperoxidase, andmeasles antibody on mumps infected cellsstudiedby immunoperoxidase and immunogoldwere usedas specificity controls: the primary antibodies identified their respective target antigen andthere wasno antibody crossreactivity. Measlesvirus nucleocapsids labelled withgoldconjugated antibody inbothinfected cells and tissues, including fociofgranulomatous inflammation in fiveof sixcasesof Crohn'sdisease: inthefifth case,the granulomacouldnotbe identified in ultrathin section. Inone ofthetuberculosis cases, a lowlevel ofsignal was notedwhilethesecond casewasnegative. Labelling adopted acharacteristic pattern inallinfected tissues, strengthening the specificity ofthesefindings. Thisstudy provides thefirst direct confirmation of persistent measlesvirusinfection ofthe intestine. 1995; 36:564-569)