Safety and efficacy of low-dose intravenous immune globulin (IVIG) treatment for infants and children with immune thrombocytopenic purpura. Low-Dose IVIG Study Group.

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 higher-dose regimen of 1 g/kg/day for 2 days, in children with immune thrombocytopenic purpura (ITP).

PATIENTS AND METHODS

A total of 24 children received IVIG (Gammar i.v.). In Study 1, 10 centers enrolled 12 children 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 increased at least 30,000/cu mm over baseline) in 94% (16 of 17) of the evaluable patients in the low-dosage group. Platelet increases occurred rapidly: 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 551,000/cu mm. Adverse events (AEs) were most often mild, lasted less than 3 hours, and were usually those typically associated with immunoglobulin administration-headache, nausea, vomiting, and fever. There were two serious AEs-an anaphylactoid reaction in one patient in the 400 mg/kg group and aseptic meningitis in one patient in the 1 g/kg high-dosage group. Both patients recovered without sequelae and were responders. Although the incidence of AEs varied by dosage groups, this difference was not significant. However, the incidence of AEs was affected by age. AEs were significantly lower in patients younger than 5 years of age.

CONCLUSIONS

In this small, randomized trial, low-dose IVIG in 2-day regimens of 250, 400, or 500 mg/kg/day rapidly reversed thrombocytopenia just as effectively as 1 g/kg/day in infants and young children with ITP. Lower-dosage regimens are safe and well-tolerated; the incidence of AEs is lower in children younger than 5 years of age.