Humoral immunity to viral and bacterial antigens in lymphoma patients 4-10years after high-dose therapy with ABMT. Serological responses to revaccinations according to EBMT guidelines

The aim of this study was to investigate the late effects of ABMT on the im mune system with regard to protective Immoral immunity against common antig ens and responses to recall antigens (vaccines). The vaccines were given ac cording to EBMT guidelines from 1995. The protocol included 35 patients wit h malignant lymphoma in CR 4-10 years after ABMT, and 35 controls. The resu lts show that prior to ABMT the proportion of patients with protective immu nity against poliomyelitis, tetanus and diphtheria was similar to that of c ontrols. At study entry 4-10 years after ABMT, the proportion of patients w ith protective immunity against poliomyelitis and diphtheria was reduced, w hile all patients maintained protection against tetanus. A significant decr ease in geometric mean antibody concentrations or titres was observed again st all three antigens during this period. Serum levels of antibodies agains t different pneumococcal serotypes were lower in the patients than in the c ontrols prior to vaccination. The responses to pneumococcal vaccination, wh ich is considered to be a T cell-independent vaccine, were studied. Unlike controls, a minority of patients achieved protective levels of antibodies a fter a single vaccination. Despite persistent levels of protective antibodi es in many patients post ABMT, secondary booster responses after one vaccin ation with T cell-dependent vaccines (tetanus, diphtheria and polio) were a bsent. In conclusion, this study shows that post ABMT, a full re-vaccinatio n program was necessary to mount responses comparable to those observed aft er a single vaccination in controls.