A pilot study of intraperitoneal recombinant interleukin-2 and ex vivo activated intracavitary lymphocytes in patients with malignant peritoneal spread: I. Clinical aspects

A novel approach to adoptive immunotherapy is described in this study. Of 13 patients with malignant effusions, nine were treated by intraperitoneal (IP) instillation of intracavitary lymphocytes (ICL), activated ex vivo by recombinant interleukin-2 (rIL-2, Cetus Co., Emeryville, CA) with escalating doses of IP rIL-2 and four by IP rIL-2 alone. ICL and rIL-2 were administered by repeated peritoneal punctures. Patients were divided into two groups: group I of six patients, who received activated ICL with low doses of IP rIL-2 (total dose not exceeding 6 X 10(5) units) and group II of seven patients, in whom escalating higher doses of rIL-2 were administered IP with or without activated ICL, in doses ranging from 10(6) up to 16 X 10(6) units, total dose. Total dose of ICL given ranged from 2 X 10(8) to 2 X 10(9) in both groups. The main objectives of this pilot study was to establish the feasibility of treatment by ex vivo activated ICL and IP rIL-2, to assess the toxicity associated with such a treatment, to escalate doses of rIL-2 to a maximal tolerable dose, and to look for clinical responses. The first two goals were achieved: such a treatment approach is feasible and is not associated with severe toxicity. The side effects observed during this study were usually mild in group I patients and more pronounced in group II patients. These included transient fever, chills, nausea, cellulitis at the puncture site, and one case of peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Depletion of B cells rejuvenates the peripheral B‐cell compartment but is insufficient to restore immune competence in aging

Aging is associated with increasing prevalence and severity of infections caused by a decline in bone marrow (BM) lymphopoiesis and reduced B‐cell repertoire diversity. The current study proposes a strategy to enhance immune responsiveness in aged mice and humans, through rejuvenation of the B lineage upon B‐cell depletion. We used hCD20Tg mice to deplete peripheral B cells in old and young mice, analyzing B‐cell subsets, repertoire and cellular functions in vitro, and immune responsiveness in vivo. Additionally, elderly patients, previously treated with rituximab healthy elderly and young individuals, were vaccinated against hepatitis B (HBV) after undergoing a detailed analysis for B‐cell compartments. B‐cell depletion in old mice resulted in rejuvenated B‐cell population that was derived from de novo synthesis in the bone marrow. The rejuvenated B cells exhibited a "young"‐like repertoire and cellular responsiveness to immune stimuli in vitro. Yet, mice treated with B‐cell depletion did not mount enhanced antibody responses to immunization in vivo, nor did they survive longer than control mice in "dirty" environment. Consistent with these results, peripheral B cells from elderly depleted patients showed a "young"‐like repertoire, population dynamics, and cellular responsiveness to stimulus. Nevertheless, the response rate to HBV vaccination was similar between elderly depleted and nondepleted subjects, although antibody titers were higher in depleted patients. This study proposes a proof of principle to rejuvenate the peripheral B‐cell compartment in aging, through B‐cell depletion. Further studies are warranted in order to apply this approach for enhancing humoral immune responsiveness among the elderly population.