IgA responses to EBV EBNA1 and viral capsid antigens have long been used as a diagnostic tool for nasopharyngeal carcinoma [38] . In addition to nasopharyngeal carcinoma, IgA responses to VCA and to EBNA1 are frequently elevated in lymphoma patients and in individuals who are HIV-1 positive [39] . IgA responses to EBV proteins were examined at a 1:1000 dilution for 15 of the HIV-positive KS patients, 10 healthy individuals, and 10 HIV-positive lymphoma patients. Seven EBV antigens were consistently recognized by IgA across these patient groups, namely, EBNA1, the helicase BBLF4, the viral IL10 BCRF1, the uracil DNA glycoslyase BKRF3, the early protein BRRF1, the tegument protein BRRF2 [40] , and the latency membrane protein LMP2A ( Figure 6 ). The most intense IgA response detected was to EBNA1, which appeared to be recognized even more readily by IgA than IgG. All 25 normal and HIV-positive KS plasma tested recognized EBNA1 at a 1:1000 dilution, whereas in 4 of these samples there was no recognition of EBNA-1 by IgG even at a 1:100 dilution. However, the IgA response to the functionally equivalent protein in KSHV, LANA, was very different. Of 14 HIV-positive KS plasma samples that had IgG responses to LANA at a 1:10 000 dilution, only 2 had IgA responses at a 1:1000 dilution (data not shown). In 1 previous study, IgA antibody to KSHV LANA was detected in saliva but not in serum [41] .