Comparison of EBV neutralization tests based on abortive infection or transformation of lymphoid cells and their relation to membrane reactive antibodies (anti-MA).

Abstract

AbstractEpstein‐Barr virus (EBV)‐neutralizing (N) antibodies were determined in human sera by three techniques based on (1) early antigen (EA) synthesis in lymphoblasts (NEA); (2) inhibition of colony formation by lymphoblasts (NICF); and (3) cordblood lymphocyte transformation (NLT). A good correlation was noted between the NEA and NICF titres of 41 sera so tested (r = 0.73). The correlation between NEA or NICF and NLT titres was less pronounced (r = 0.54 and 0.56), possibly because only 22 sera were tested by the last method. Limited to concordant sera, i.e. sera with either both high or both low titres of antibodies to EB viral capsid antigens (VCA) and to EBV‐determined cell membrane antigens (MA), the N titres determined by the three methods showed a good correlation with anti‐MA titres (r = 0.83, 0.80 and 0.68, respectively) as did the few discordant sera with high anti‐MA but low anti‐VCA titres. However, some discordant sera with low anti‐MA and high anti‐VCA titres also showed substantial N titres. The mean anti‐VCA titres were equal in the concordant and discordant groups (553), the anti‐MA (BT) titres were 25 and ⩽ 1.4, respectively, whereas the neutralization titres were 209 (NEA), 204 (NICF) and 523 (NLT) in the concordant, as compared to 128, 74 and 99 in the discordant group. These findings support the view that lymphoblast transformation and EA induction and inhibition of lymphoblast colony formation are induced by the same type of viral particle.