[Protective and therapeutic effects of intravenous-immunoglobulin on viral myocarditis]

This study was conducted to determine whether the administration of domestically manufactured intravenous-immunoglobulin (IVIG) could prevent or alleviate myocarditis in mice. Male BALB/c mice were randomized into two groups for protection group (P) and therapy group (T), and each of the two groups was subdivided into 4 groups (1, 2, 3 and c). A 7-day protocol with daily IVIG dosage of 200 mg/kg, 500 mg/kg and 1 g/kg for groups, P1, T1, P2, T2 and P3, T3 respectively was designed. In the experiment, the mice were inoculated with Coxsackie virus B3. The prevention groups (P1, P2, P3) received IVIG in the week immediately after the inoculation; the therapy groups (T1, T2, T3) received IVIG in the second week after the inoculation. All the animals were observed for 14 days. The results showed that all mice in groups P2 and P3 survived and the pathological studies revealed no myocarditis change. By the end of observation, however, 7 mice in the control group (Pc) died with severe myocarditis changes while one mouse in group P1 died with only slight inflammatory lesions in the heart. The survival rates of groups P1, P2 and P3(95%, 100% and 100%) differed significantly from the control (65%) statistically (P < 0.05). Similarly, the results of computed image analysis demonstrated that a significant difference existed between the cardiac lesions of groups P1 and Pc in severity (P < 0.05). The survival rates were 80.0%, 93.3%, 93.3% and 53.3% for groups T1, T2, T3 and Tc respectively (P < 0.05 for T2, T3 v. s. control), yet the hearts and heart/body weight ratios of T2 and T3 were significantly smaller than those of control, pathological study was supportive which showed slight (T2 and T3) or mild (T1) lesions of the heart in comparison with the control. These results demonstrate that Chinese made IVIG has definite protective and therapeutic effects on the mice infected with CVB3.