Sequential evaluation of cutaneous delayed hypersensitivity responses to recall and to lymphoid cell line antigens in Burkitt's lymphoma.

Delayed cutaneous hypersensitivity reactions to standard recall antigens (candidin, mumps and PPD), to crude membrane extracts of a cell line derived from Burkitt's lymphoma (Raji) and to cell line derived from normal lymphocytes (F265) were sequentially evaluated in 44 patients with Burkitt's lymphoma. Sixteen patients (36%) manifested delayed hypersensitivity responses to the standard antigens and seven (16%) to the Raji membrane extract at presentation. Following successful chemotherapy, there was prompt and significant improvement of reactivity to both the standard and Raji antigens (p greater than 0.001), suggesting that the initial impairment of delayed hypersensitivity was most likely related to tumor burden. By 9 months after treatment, all patients in sustained remission expressed reactivity to Raji and 21 of 22 to the standard antigens. None of the patients skin-tested with the F265 extract at presentation gave a positive response and only one subsequently expressed reactivity after remission was induced. On relapse, reactivity to the standard antigens was more readily lost (4 of 11) then reactivity to the Raji extract (1 of 7). Pretreatment delayed hypersensitivity to the standard antigens also correlated better with long-term survival than to pretreatment responses to Raji. It remains to be determined whether the antigens expressed in the Raji extract are indeed tumor-specific or related to Epstein-Barr virus.