Antibodies to the R component of Epstein-Barr virus-induced early antigens in Burkitt's lymphoma exceeding in titer antibodies to Epstein-Barr capsid antigen.

African patients with Burkitt's lymphoma (BL) may show antibodies to the R (restricted) component of the Epstein-Barr (EB) virus-induced early antigens that appear to match in titer the antibodies to EB viral capsid antigen (VCA) as determined with the aid of acetone-fixed smears of EB3 cells. Virus-producing EB3 cells, however, contain the R component as well as VCA so that the correct anti-VCA titers in such cases remain in doubt. Since the R component, but not VCA, was found to be denatured by methanol fixation, the parallel use of acetone- and methanol-fixed EB3 cell smears permitted the determination of the correct anti-VCA titer. Our results showed that the anti-R titers of BL patients can in fact be up to eightfold higher than the anti-VCA titers. Anti-R titers equaling or exceeding anti-VCA titers have been encountered thus far only in BL.