Table 1.
Demographic and immunological variables of the study population (© Mayo Clinic 2010)
| Variable | Median (IQR)a |
|---|---|
| Age at enrollment, years | 15.0 (13.0, 17.0) |
| Median age at first rubella immunization, months (IQRa) | 15.0 (15.0,16.0) |
| Median age at second rubella immunization, years (IQRa) | 11.0 (5.0,12.0) |
| Median time from second rubella immunization to enrollment, years (IQR) | 5.8 (3.8,7.4) |
| Gender, [N (%)] | |
| Males | 396 (53.7) |
| Race, [N (%)] | |
| White | 672 (91.1) |
| Antibody, IU/mL | 34.4 (19.2, 63.7) |
| Inflammatory cytokine responseb, pg/mL | |
| IL-6 (n=713) | 3,681.0 (3,160.0, 4,052.0) |
| TNF-α (n=713) | 29.7 (−7.0, 89.2) |
| GM-CSF (n=711) | 28.0 (23.6, 32.6) |
| Th1 cytokine responseb, pg/mL | |
| IL-2 (n=713) | 17.6 (7.7, 30.5) |
| IFN-γ (n=713) | 8.5 (3.0, 23.4) |
| IL-12p40 (n=711) | 0.0 (−7.1, 7.2) |
| Th2 cytokine responseb, pg/mL | |
| IL-4 (n=691) | 0.3 (−0.3, 1.0) |
| IL-5 (n=691) | 0.5 (0.0, 1.1) |
| IL-10 (n=713) | 4.2 (2.3, 6.7) |
All results are in median (IQR interquartile range within 1st quartile–3rd quartile)
Unless indicated otherwise
Response is defined as the subject-specific median rubella-stimulated response (measured in triplicate) minus the median unstimulated response (also measured in triplicate). Negative values indicated that unstimulated responses were, on average, higher than the response to stimulation
IL-12p40 and GM-CSF were assayed at 18 h, IL-4, IL-5, IL-6, and IL-10 at 24 h, IFN-γ at 2 days and IL-2 at 8 days in response to in vitro stimulation with rubella virus at MOI of 5. TNF-α was also assayed at 8 days in response to in vitro stimulation with rubella virus at MOI of 0.05. PHA (5 μg/mL) was used as a positive control.
The limits of detection for cytokines, based on the lowest standard, were 4.7 pg/mL (IL-6, GM-CSF, IFN-γ, and TNF-α), 7.8 pg/mL (IL-2, IL-4, IL-5, and IL-10) and 31.3 pg/mL (IL-12p40).