Indomethacin-induced, monocyte-dependent restoration of local graft-versus-host reaction among cells from cancer patients.

Peripheral blood mononuclear cells from 16 of 17 cancer patients known to have a negative local graft-versus-host (GVH) reaction (T-cell function deficiency) were pharmacologically immunorestored by treatment with indomethacin. The restorative effect of the indomethacin was exerted directly on nonadherent lymphocytes. This process of desuppression required for its completion the presence of glass-adherent monocytes. The immune restorative effect of indomethacin in terms of local GVH reaction did not appear to be mediated by inhibition of prostaglandin synthesis. Pharmacologic immune restoration may be an important therapeutic modality in cancer patients.