GAMMA-GLOBULIN TREATMENT OF ACUTE MYOCARDITIS IN THE PEDIATRIC POPULATION

Background Myocardial damage in myocarditis is mediated, in part, by i mmunological 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 Hospit al, Boston, and Children's Hospital, Los Angeles, has included adminis tration 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 g roup comprised 25 recent historical control patients meeting identical eligibility criteria but not receiving MG therapy. Left ventricular f unction was assessed during five time intervals: 0 to 7 days, 1 to 3 w eeks, 3 weeks to 3 months, 3 to 6 months, and 6 to 12 months. At prese ntation, the IVIG and non-MG groups had comparable left ventricular en largement and poor fractional shortening. Compared with the non-IVIG g roup, those treated with MG had a smaller mean adjusted left ventricul ar end-diastolic dimension and higher fractional shortening in the per iods 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, biop sy status, intravenous inotropic agents, and angiotensin-converting en zyme inhibitors, patients treated with MG were more likely to achieve normal left ventricular function during the first year after presentat ion (P=.03). By 1 year after presentation, the probability of survival tended to be higher among IVIG-treated patients (.84 versus .60, P=.0 69). We observed no adverse effects of MG administration. Conclusions These data suggest that use of high-dose IVIG for treatment of acute m yocarditis is associated with improved recovery of left ventricular fu nction and with a tendency to better survival during the first year af ter presentation.