Epstein‐Barr virus genomes are found predominantly in IgA‐positive B cells in the blood of healthy carriers

B lymphocytes have been identified as the main reservoir of latent Epstein‐Barr virus (EBV) in healthy virus carriers. We have established a semi‐quantitative PCR method to estimate the EBV genome load in the blood B‐cell subpopulation in healthy individuals. EBV DNA was detected in subfractionated IgM‐, IgG‐ and IgA‐positive B cells. Between 80% and 90% of the viral DNA was found in the IgA‐positive compared with the IgA‐negative fraction. Int. J. Cancer 83:50–54, 1999. © 1999 Wiley‐Liss, Inc.