OBJECTIVETo evaluate the effect of intravenous immunoglobulin (IVIG) and vitamin C on the progression of experimental autoimmune myocarditis(EAM).

METHODSFifty-two Balb/c mice were randomized into six groups: The blank group received no treatment, the remaining 5 groups were immunized with 100mug emulsified porcine myosin at d 1 and d 7. Different agents were injected from d 1, SVitC group:150 mg/kg*d(-1)vitamin C; LVitC group: 300 mg/kg*d(-1)vitamin C; IVIG group: 1 g/kg*d(-1)IVIG; IVIG+VitC group: 1 g/kg*d(-1)IVIG and 150 mg/kg*d(-1)vitamin C; The control group same volume of normal saline. All mice were sacrificed at d 21, and serum TNF-alpha levels were detected with enzyme linked immunosorbent assay (ELISA). The ratio of heart to body weight(C/W), spleen to body weight(S/W) and kidney to body weigh(R/W) were calculated. The spleens and heart were examined pathologically and/or immunohistochemically.

RESULTCompared with those of control group, inflammatory cells infiltration in the myocardium and calcification in the pericardiume in SVitC and LVitC groups were extenuated. There were inflammatory cells infiltrating in the myocardium sparely and no calcification in the pericardium in IVIG and IVIG+VitC groups. The size of spleens enlarged especially in IVIG and IVIG+VitC groups. White and red pulps of spleens were hyperplastic microscopically. The C/W of treatment groups decreased significantly compared with that of control group. The S/W of therapy groups and control group was significantly higher than that of blank group; and the S/W of IVIG and IVIG + VitC groups was significantly higher than that of SVitC and LVitC groups. The R/W in each groups had no significant difference. The TNF-alpha level in SVitC and LVitC groups was a little lower than that in control group; TNF-alpha level in IVIG and IVIG+VitC groups was significantly lower than that of control group. Wide fluorescence stripe was found along extracellular matrix surrounding the damaged cardiomyocytes of control group. Both density and intensity of fluorescence in SVitC and LVitC groups were lower than those of control group. There were much wider fluorescence stripe and strengthened intensity in IVIG and IVIG + VitC groups. The myofilaments were in wild disorder and sarcomere had severe breakage in control group. Moreover, chondriosome hypertrophy and vacuolar degeneration were found. The damage lessened in SVitC and LVitC groups. Both myofilaments and sarcomeres in IVIG and IVIG + VitC groups were almost normal, and the chondriosome was normal.

CONCLUSIONIVIG and vitamin C have some protective and therapeutic effect on the progression of EAM by decreasing pathological damage of myocardium and depressing TNF-alpha production, and IVIG combined with vitamin C is more effective.