Table 2.

NPC risk, according to a combined measure of anti-EBNA1 IgA and anti-gp350 antibodies

Total (N)Incident case (N)Disease-free control (N)OR (95% CI)
EBNA1 IgA negativea293261.00 (referent)
EBNA1 IgA positive4117246.1 (1.6–23.6)
 Elevated anti-gp350b6151.7 (0.15–20.2)
 Not elevated anti-gp3503516197.3 (1.9–28.7)
  • aSeropositivity for EBNA1 IgA defined as defined previously (11).

  • bElevated anti-gp350 antibody level defined as upper median of the anti-gp350 distribution in participants.