Lymphocytic infiltration of bladder after local cellular immunotherapy.

Background: This is a case report of a patient who received cellular immunotherapy, in the form of local injections of autologous stimulated lymphocytes (ASL) into individual tumors in the urinary bladder. A major consideration in cellular immunotherapy being the ability of immune cells to reach all target areas, we hypothesized that direct delivery of effector cells into individual bladder tumors might assure such access.

Methods: ASL were generated by exposing the patient's PBL to phytohemagglutinin and culturing them in the presence of IL-2 to expand the population. ASL were injected into the base of individual bladder tumors three times at intervals of 3 weeks.

Results: The patient died of a myocardial infarct, unrelated to cell therapy, 20 days after the third injection. An autopsy was performed. Histological sections of the bladder showed extensive lymphocytic infiltration of virtually the entire organ.

Discussion: No conclusions about the therapeutic efficacy of local immunotherapy using ASL are possible. Nevertheless, the observations reported, taken together with reports of therapeutic efficacy of other immunotherapy regimens in the management of bladder cancer, suggest that ready access of stimulated lymphocytes to all regions of the organ may account, in part, for the relatively high rate of therapeutic success reported for various immunotherapy regimens for this malignancy.