SAFETY AND EFFICACY OF LOW-DOSE INTRAVENOUS IMMUNE GLOBULIN (IVIG) TREATMENT FOR INFANTS AND CHILDREN WITH IMMUNE THROMBOCYTOPENIC PURPURA

Purpose: This report presents pooled data from two multicenter studies conducted to assess the efficacy, safety, and tolerance of lower-dose intravenous immune globulin (IVIG) regimens of 250 mg/kg/day, 400 mg/ kg/day, and 500 mg/kg/day for 2 days, compared to an established highe r-dose regimen of 1 g/kg/day for 2 days, in children with immune throm bocytopenic purpura (ITP). Patients and Methods: A total of 24 childre n received IVIG (Gammar(R) I.V.). In Study 1, 10 centers enrolled 12 c hildren between 5 and 12 years old who received IVIG at either 400 mg/ kg/day or 1 g/kg/day for 2 days. In Study 2, five centers enrolled 12 infants and children younger than 5 years old who received IVIG at 250 mg/kg/day or 500 mg/kg/day for 2 days. Both studies were prospective and randomized. Results: IVIG treatment was effective (platelets incre ased at least 30,000/cu mm over baseline) in 94% (16 of 17) of the eva luable patients in the low-dosage group. Platelet increases occurred r apidly: by 48 hours, total platelet counts ranged from 32,000/cu mm to 256,000/cu mm, and peak platelet counts reached 38,000/cu mm to 551,0 00/cu mm. Adverse events (AEs) were most often mild, lasted less than 3 hours, and were usually those typically associated with immunoglobul in administration-headache, nausea, vomiting, and fever. There were tw o serious AEs-an anaphylactoid reaction in one patient in the 400 mg/k g group and aseptic meningitis in one patient in the 1 g/kg high-dosag e group. Both patients recovered without sequelae and were responders. Although the incidence of AEs varied by dosage groups, this differenc e was not significant. However, the incidence of AEs was affected by a ge. AEs were significantly lower in patients younger than 5 years of a ge. Conclusions: In this small, randomized trial, low-dose IVIG in 2-d ay regimens of 250, 400, or 500 mg/kg/day rapidly reversed thrombocyto penia just as effectively as 1 g/kg/day in infants and young children with ITP. Lower-dosage regimens are safe and well-tolerated; the incid ence of AEs is lower in children younger than 5 years of age.