Abstract

Recent studies have shown that, when used in early stage disease, interferon-alpha (IFN-alpha) can produce a fall in the number of malignant cells in the peripheral blood of patients with B-CLL. In this study, we investigated the effect of IFN-alpha on natural killer (NK) cell and lymphokine-activated cell (LAK) activity in patients with B-CLL. In vitro, IFN-alpha (500 U/ml for 18 hours) induced LAK activity in patients with B-CLL (27.7 +/- 9.9%, n = 20), and IL-2 (500 U/ml for 5 days) produced similar activity (35.9 +/- 8.8%, n = 7). Despite the induction of LAK activity by IFN-alpha and IL2 in patients with B-CLL, the malignant cells remained resistant to both allogeneic and autologous LAK effectors. NK activity in patients with B-CLL is also low (23.1 +/- 7.2%, n = 20), and B-CLL cells were resistant to NK cell activity. In cold target competition assays, CLL cells did not compete with labelled K562 or Daudi targets in the NK and LAK assays, suggesting that the malignant cells are not recognised by the effector cells, and this may be related to low level of expression of the adhesion receptors, LFA-1 and ICAM-1. Finally, CLL cells were also resistant to antibody dependent cell mediated cytotoxicity, but were susceptible to antibody dependent complement mediated lysis. These results suggest that it is unlikely that the effects of IFN-alpha in B-CLL are due to the enhancement of NK or LAK activity.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.