DEMONSTRATION OF COXSACKIE-VIRUS RNA IN FORMALIN-FIXED TISSUE-SECTIONS FROM CHILDHOOD MYOCARDITIS CASES BY INSITU HYBRIDIZATION AND THE POLYMERASE CHAIN-REACTION

This is a combined study using in situ hybridization and the polymeras e chain reaction to investigate the presence of Coxsackie virus RNA in formalin-fixed tissue from cases of childhood myocarditis. Of the ten cases studied, two were positive by both methods. The virus RNA was p redominantly located in areas showing an inflammatory cell infiltrate and myofibre necrosis. These findings suggest that direct lytic infect ion of myocytes by virus is responsible for myocarditis in these cases , rather than an autoimmune process, which has been suggested previous ly. The findings in one case, where the virus showed a marked sub-endo cardial distribution, may have implications for the aetiology of endoc ardial fibroelastosis by confirming a viral tropism for this location. The techniques used in this study are easily repeatable and can be di rectly applied to look for viruses in a number of other diseases where a viral aetiology is suspected.