Therapy with immunoglobulin in patients with acute myocarditis and cardiomyopathy: analysis of leukocyte balance.

Intravenous immunoglobulin (IVIG) therapy has been used to treat several autoimmune or inflammatory diseases. We conducted a clinical trial of immunoglobulin therapy for acute myocarditis. The study consisted of two projects: (1) a comparison of prognosis between patients treated with and those not treated with IVIG in a multi-center study; (2) analyses of inflammatory cytokines and blood cell profiles in a substudy. In (1), 15 patients were treated with IVIG (1-2 g/kg, over 2 days), whereas 26 were untreated. There was a statistically significant difference between the survival curves of the patients treated with IVIG and the survival curves of those not treated with IVIG. There was no significant difference between the IVIG-treated and untreated groups in terms of clinical parameters of the acute and chronic phases. In (2), 10 patients were treated with IVIG and 6 were untreated. In both groups, all of the data except for changes in the fraction of lymphocytes and the fraction of monocytes decreased due to the treatment or during the course. In patients in the IVIG group, the percentage of peripheral eosinophils was decreased and the percentage of peripheral monocytes was increased by this treatment when they were compared with the pretreatment data. Therefore, therapy with IVIG seems to be a promising treatment for acute myocarditis given that it improves the clinical course, which may be due to modulation of inflammatory cytokines and the peripheral leukocyte balance.