Two subtypes of EBV, type 1 and type 2 (also called A and B), were originally defined on the basis of differences in the EBNA2 gene [30] . In this set, 10/35 sera showed discordant responses to the 2 EBNA2 proteins with either a different sensitivity of detection (1:100 vs 1:10 000) or recognition of only 1 of the 2 EBNA2 proteins. It is likely that these individuals are infected with only 1 of the 2 EBV subtypes. Note that 9/10 discordant sera had preferential recognition of type 1 EBNA2, which is consistent with the greater prevalence of type 1 EBV in clinical samples from the United States. Positivity to both proteins would represent recognition of common epitopes or reflect concurrent infection with both virus subtypes. In contrast to the antibody responses to KSHV proteins, the profiles of antibody responses to EBV proteins in these plasma samples were similar in the KS and lymphoma-carrying HIVpositive populations ( Figure 4B ). There was no significant difference in either the intensity of the positive signals or the number of antigens being recognized at a 1:10 000 serum dilution. Thus, the presence of KSHV-associated disease did not appear to have any impact on humoral responses to EBV antigens in the setting of concurrent HIV-1 infection. Again, the broader antigenic response to EBV compared with KSHV is striking. The W1 exon of EBV BamHI-W encodes 22 amino acids that form part of the EBNA-LP protein [33, 34] . The protein encoded by the entire EBV BamHI-W ORF (BWRF1) and the EBNA-LP protein were both printed on the array. We noted that 23/24 (95%) of the specimens that recognized EBNA-LP also recognized the protein encoded by BWRF1, implying that the common 22 amino acids contribute significantly to antibody recognition of EBNA-LP.