title: Pulse interleukin-2 with famotidine induces CD56+ lymphocytes in the peripheral blood of patients with metastatic melanoma or kidney cancer.
abstract: Increased lymphokine-activated killer (LAK) cell numbers and cytotoxicity against tumor cell lines have been seen in patients receiving high-dose continuous and bolus infusion interleukin-2 (IL-2) regimens. LAK are CD56 positive on flow cytometry. Daily intravenous doses of IL-2 of 18-21.6 MIU/m(2) over 15-30 minutes ("pulses") have been developed to attempt to lessen the toxicity of this therapy. It has been previously shown that the patients with metastatic melanoma or kidney cancer may be treated safely with pulse IL-2 daily for 5 days preceded by intravenous famotidine. Cycles were repeated every 21 days. Because LAK numbers have not been previously described with this regimen, the present study has examined CD56 numbers via peripheral blood flow cytometry in 11 patients with samples scheduled at baseline, after two cycles, and after four cycles. Eight (8) patients had melanoma and 3 had kidney cancer. Median CD56 counts after two cycles was significantly higher than baseline (p = 0.001). Similarly, CD56 counts at 2 months later were also greater than baseline (p = 0.009). There was no difference between median values after two cycles versus after four cycles. Patients who were clinical responders had a median CD56 count of 650 after two cycles when compared with nonresponders who had a median CD56 count of 290 (p = 0.005). CD56 counts are significantly elevated in patients treated with pulse IL-2 with famotidine and clinical responders have significantly higher CD56 than nonresponders.
authors.affiliation: Department of Medical Oncology, Loma Linda University School of Medicine, Loma Linda, California 92354, USA. wquan@llu.edu
authors.forename: Walter D Y
authors.initials: WD
authors.lastname: Quan
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Gagnon
authors.forename: Paul R
authors.initials: PR
authors.lastname: Walker
authors.forename: Francine M
authors.initials: FM
authors.lastname: Quan
mesh_terms: D019002:CD56 Antigen / Q000276:immunology* / Q000378:metabolism; D015738:Famotidine / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D007376:Interleukin-2 / Q000008:administration & dosage*; D007680:Kidney Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008545:Melanoma / Q000097:blood / Q000188:drug therapy* / Q000276:immunology
chemical_list: D019002:CD56 Antigen; D007376:Interleukin-2; C522918:NCAM1 protein, human; D015738:Famotidine