DIMINISHED MONOCYTIC HLA-DR EXPRESSION AND EX-VIVO CYTOKINE SECRETIONCAPACITY IN PATIENTS WITH GLIOBLASTOMA - EFFECT OF TUMOR EXTIRPATION

Severe immunodysregulation on lymphocyte level has been described in p atients with glioblastoma and is likely involved into its unfavorable prognosis. Although the major importance of monocytic cells for immuno regulation is well established, only very limited data exist regarding the monocyte status in glioblastoma patients. Here we demonstrate a m arkedly diminished monocytic HLA-DR expression and ex vivo cytokine se cretion capacity (TNF-alpha, IL-1 beta, IL-10) as signs for monocyte d eactivation in glioblastoma patients but not in patients with astrocyt oma. As known in immunocompromised patients from other reasons, monocy te deactivation indicate global immunodepression associated with an en hanced risk of infectious complications. Interestingly, tumor resectio n resulted in partial recovery from the monocytic deactivation. This s uggests that the glioblastoma itself contributed to this phenomenon. H owever, IL-IO and the active forms of transforming growth factor-beta 2 and -beta 1, which are produced by glioblastoma cells and known to i nhibit monocyte function, were not detectable in plasma in our patient s. Moreover. low levels of the adrenocorticotropic hormone and cortiso l excluded hypothalamo-pituitary-adrenal axis involvement. So, further investigations are necessary to clarify the mechanism. The demonstrat ed severe glioblastoma-associated monocytic deactivation may contribut e to its unfavorable prognosis. Therefore, monocytes may represent tar get cells for new adjuvant immunotherapies in glioblastoma. (C) 1998 E lsevier Science B.V.