Table 2.

Rate ratio of NPC for specific EBV biomarker profiles in high-risk families

VariableaNo. of subjectsPerson-years FUNo. of NPC casesbRate of NPC/100,000 person-yearsRate ratio (95% CI) overall (n = 14)Rate ratio (95% CI) first 5 y of follow-up (n = 10)
Entire follow-up period2,44415,519.21490.2
VCA IgA (IF)
 Negative1,37210,122.2769.2
 Positive (>1:10 dilution of serum)4883,6164110.61.6 (0.34–6.3)2 (0.30–12)
VCA IgA (ELISA)
 Negative2,28514,591.41389.1
 Positive (OD405 > 0.50)103570.91175.22 (0.046–13)2.6 (0.060–19)
EBNA1 IgA
 Negative2,00812,518.3755.9
 Positive (OD405 > 0.20)3802,6447264.84.7 (1.4–16)11.9 (2.7–71)
DNase
 Negative2,02312,974.21077.1
 Positive (>400 neutralizing units)2751,783.73168.22.2 (0.39–8.5)2.1 (0.21–11)
Number of marker positivity
01,4318,574558.3
Any9576,588.39136.62.3 (0.71–8.9)3.2 (0.73–19)
17355,024.3599.51.7 (0.39–7.4)1.8 (0.24–13)
2+2221,563.94255.84.4 (0.87–20)7.7 (1.3–52)

aThere were 3 cases with missing VCA IgA by IF and 1 case with missing DNase biomarker values.