Human bio plex pro assays

The serum samples were tested for IL-1β, IL-2, IL-5, IL-10, IL-13, IFN-γ, and TNF-α using Human Bio-Plex Pro Assays (Bio-Rad, Hercules, CA) (Jiang et al., 2014 (link)) on a Bio-Plex 200 platform (Bio-Rad, Hercules, CA, United States). Bio-Plex Manager software version 6.0 was used for data analysis.

Sera from 127 infants at 6 months of age and were tested for IL-1β, IL-6 TNF-α, IL-4, and IL-10 using the Human Bio-Plex Pro Assays (Bio-Rad, Hercules, CA). Inflammation-related cytokines were measured on every child for which there was 6-month sera available. We chose to test 6-month sera based on the following rationale. First, we wanted to pick an early time point as to enable useful prediction of outcomes, leaving room for potential interventions. Second, we wanted to choose a time at which the majority of children will have suffered at least one infection so that we could discern differences in their cytokine profiles. 12.5 μl of serum was diluted to a 1:3 ratio using the diluent from the kit per the manufacturer’s recommended protocol. The standard positive control included in assay kits was used to generate a standard curve for each target. Standard curves were used to determine the approximate concentrations of all 5 targets for each sample. The Bio-Plex 200 platform was used for detection and Bio-Plex Manager software version 6.0 was used for data analysis.