FIG. 2.

Distribution frequency of EBV IgA ELISA values in the Indonesia panel for combination [EBNA1+VCA p18] antigen (A) and EA extract (A). Shown are the mean OD₄₅₀ values and 25th and 75th percentiles of OD₄₅₀ values for IgA reactivity in both ELISAs, using Indonesian serum panels consisting of healthy blood donors (n = 199) and NPC patients (n = 151). The cutoff values of both tests were 0.35 for IgA [EBNA1+VCA p18] and 0.22 for IgA EA. IgA reactivities to the [EBNA1+VCA p18] and EA ELISAs showed mean OD₄₅₀ values of 0.19 and 0.16 for healthy EBV carriers (HC), and NPC patients had mean OD₄₅₀ values of 1.48 and 1.39, respectively. These differences were highly significant (P < 0.0001).