GAMMA-GLOBULIN TREATMENT OF ACUTE MYOCARDITIS IN THE PEDIATRIC POPULATION

Background Myocardial damage in myocarditis is mediated, in part, by immunological mechanisms. High-dose intravenous gamma-globulin (MG) is an immunomodulatory agent that is beneficial in myocarditis secondary to Kawasaki disease, as well as in murine myocarditis. Since 1990, the routine management of presumed acute myocarditis at Children's Hospital, Boston, and Children's Hospital, Los Angeles, has included administration of high-dose MG. Methods and Results We treated 21 consecutive children presenting with presumed acute myocarditis with MG, 2 g/kg, over 24 hours, in addition to anticongestive therapies. A comparison group comprised 25 recent historical control patients meeting identical eligibility criteria but not receiving MG therapy. Left ventricular function was assessed during five time intervals: 0 to 7 days, 1 to 3 weeks, 3 weeks to 3 months, 3 to 6 months, and 6 to 12 months. At presentation, the IVIG and non-MG groups had comparable left ventricular enlargement and poor fractional shortening. Compared with the non-IVIG group, those treated with MG had a smaller mean adjusted left ventricular end-diastolic dimension and higher fractional shortening in the periods from 3 to 6 months (P=.008 and P=.033, respectively) and 6 to 12 months (P=.072 and P=.029, respectively). When adjusting for age, biopsy status, intravenous inotropic agents, and angiotensin-converting enzyme inhibitors, patients treated with MG were more likely to achieve normal left ventricular function during the first year after presentation (P=.03). By 1 year after presentation, the probability of survival tended to be higher among IVIG-treated patients (.84 versus .60, P=.069). We observed no adverse effects of MG administration. Conclusions These data suggest that use of high-dose IVIG for treatment of acute myocarditis is associated with improved recovery of left ventricular function and with a tendency to better survival during the first year after presentation.