Table 4.
Ability of Assays to Distinguish NPC Cases from Non-Cases by Anti-EBV ELISA Serology Test - EBV Serology Reproducibility Study
| Assay | NPC Cases (N=20) | % Positivity (GMT among Positives) | P-value | ||
|---|---|---|---|---|---|
| Control Group 1 (2+)a (N=32) | Control Group 2 (1)a (N=25) | Control Group 3 (0)a (N=20) | |||
| EBNA IgA | 99.2% (420.5) | 52.6% (291.5) | 32.7% (140.3) | 11.7% (126.7) | <.0001b |
| VCAp18 IgA | 85.0% (228.9) | 72.1% (260.8) | 51.3% (207.6) | 20.0% (123.1) | <.0001b |
| EA ext IgA | 77.5% (191.0) | 24.7% (161.0) | 17.3% (143.4) | 12.5% (130.8) | <.0001c |
| EAp138 IgA | 43.3% (178.6) | 16.3% (149.8) | 12.7% (115.7) | 2.5% (110.3) | <.0001b |
| EAd IgA | 50.0% (256.9) | 12.6% (138.1) | 8.7% (123.8) | 5.0% (132.3) | <.0001c |
| Zebra IgA | 22.5% (220.9) | 18.4% (128.9) | 13.3% (143.4) | 15.8% (139.3) | 0.0026b |
| EA ext IgG | 100% (264.2) | 73.2% (161.8) | 64.7% (143.9) | 46.7% (131.9) | <.0001c |
| EAp138 IgG | 66.7% (236.9) | 36.3% (155.0) | 36.0% (142.4) | 31.7% (144.5) | <.0001b |
| EAd IgG | 76.7% (268.1) | 21.1% (193.0) | 25.3% (150.2) | 20.8% (145.4) | <.0001b |
| Zebra IgG | 85.5% (216.8) | 63.7% (190.2) | 66.7% (174.5) | 56.7% (182.2) | 0.0004b |
a
Controls grouped based on the number of positive results out of three anti-EBV antibody tests as described in the Methods
b
P-value for study group as fixed effect in mixed models also including as random effects, testing date, box, and repeated aliquots of the same person
c
Models including “testing date” as a random effect did not converge; “test day” (coded as 1 or 2) was included as a fixed effect instead.