We studied 16 patients with primary disorders of humoral immunity to determine the practicality of infusing intravenous gamma globulin at rates of infusion and concentrations higher than the 4 mg/kg/min and 6% currently recommended. In the first portion of the study, the concentration of Sandoglobulin was increased from 6% to 12%. In the second portion, the flow rate was increased to 5 mg/kg/min, and if no reactions occurred, the time of each successive infusion was decreased by 10 minutes until infusions were completed in 15 to 20 minutes or vasomotor reactions occurred. Thirteen of the 16 patients completed the study; six patients achieved reaction-free rates greater than 15 mg/kg/min, and the other patients achieved rates ranging from 7.1 to 12 mg/kg/min. Seven patients had infusion times less than 30 minutes, with four patients completing infusions in 15 minutes. In the 13 patients who completed the study, there were 14 reactions in 159 infusions, mostly fever and chills, and often at the end or after the infusion. Only one infusion could not be completed because of an adverse reaction. Three patients were not able to complete the study because of adverse reactions; there were seven reactions in 11 infusions in these three patients, although none of the reactions were considered serious. Overall, in this study, most immunodeficient patients (13/16) were able to tolerate infusion rates of Sandoglobulin two to 10 times higher than the standard rates now recommended. The maximal rate of infusion must be individualized, but for carefully selected patients, infusions of 400 mg/kg can be completed in 1 hour or less.(ABSTRACT TRUNCATED AT 250 WORDS)