Fig. 4

Parallelism of PK study samples with or without heat pre-treatment. Three ADA-positive PK study samples with suspected parallelism issues (problematic ADA-positive samples) were selected. Additionally, three more ADA-positive PK study samples and 3 ADA-negative PK study samples were selected randomly (analyte NNC9204-1177). For each sample, the difference between the measured concentration at 10, 30, or 100 times dilution was plotted as fold change, relative to the lowest dilution, against the dilution factor. These measurements were done with a traditional ECL assay and an ECL assay with heat pre-treatment. a, d The randomly selected ADA-negative samples show parallelism according to the parallelism acceptance criterion with and without heat pre-treatment. b, e The same is true for the randomly selected ADA-positive samples. c, f The ADA-positive samples that were suspected to have parallelism issues (problematic ADA-positive) showed no parallelism in two out of three samples according to the parallelism acceptance criterion when analyzed with a traditional ECL assay; however, heat pre-treatment abolished this lack of parallelism. ^#Overall CV > 30.0%