Abstract
The effect of amplicillin(AB-PC)on the measurement of circulating immune complex(CIC)by Clq solid-phase enzyme immunoassay(Clq SPEIA)was studied. The following results were obtained. 1)CIC levels in the sera significantly decreased by preincubation with 20mg/ml of AB-PC(p<0.01). 2)Aggregated human IgG(AHG)measured by Clq SPEIA after preincubation with 0, 0.2, 2 and 20mg/ml of AB-PC revealed the proportional decrease as the dose of AB-PC increased. 3)There was low avidity between AB-PC and Clq or AHG. Although the mechanism of inhibitory effect of AB-PC on Clq SPEIA is unknown, it is emphasized that Clq SPEIA may possibly result in a "false negative" reading in patients receiving massive ampicillin therapy.
