Protective effect of recombinant alpha interferon on coxsackievirus B3 myocarditis in mice.

The effects of recombinant human leukocyte interferon alpha-A/D on experimental myocarditis caused by coxsackievirus B3 were investigated. Four-week-old male C3H/He mice were inoculated intraperitoneally with 10(5.5) 50% tissue culture infective dose (TCD50) in 0.1 ml of coxsackievirus B3 (Nancy strain). Interferon alpha-A/D, 10(4) U/gm/day, was administered subcutaneously daily, starting 1 day before (group 1) or on the day of (group 2) infection. Animals were killed on day 7. The infectivity of myocardial virus was significantly lower in group 1 (0.7 +/- 0.1 log10TCD50/mg, p less than 0.005) and in group 2 (2.5 +/- 1.2 log10TCD50/mg, p less than 0.005) than in control mice (4.4 +/- 0.9 log10TCD50/mg). Results of histologic examination showed extensive myocardial necrosis and cellular infiltration in all mice in the untreated group, but significantly less severe necrosis and infiltration in the treated groups. Thus, interferon alpha-A/D, when given before and simultaneously with virus, effectively inhibited replication of myocardial virus and reduced the inflammatory response and myocardial damage in an experimental model of viral myocarditis.