Fig. 1.

Serum Sample Selection concurrent with and prior to IBD diagnosis for PREDICTS subjects.

Legend: Sample A was the first sample available following the initial medical encounter in which an IBD diagnosis was made. In the absence of this sample, the last sample prior to that medical encounter was selected. Samples B and C represent the serum samples stored from the three preceding biennial (e.g. every two years) HIV screening test. Sample D represented the earliest serum sample available in the repository.