Impaired release of colony stimulating activity by monocytes from Hodgkin's disease in response to phorbol myristate acetate activation

We assessed the humoral effect of resting and phorbol esters preincubated monocytes from Hodgkin's disease patients (HDMo) and healthy subjects (nMo), on granulocyte progenitors (CFU-dG) growth using a double diffusion chamber technique. The release of colony stimulating activity and indomethacin-dependent inhibitors by resting HDMo and nMo was found to be cell-concentration dependent. However, phorbol myristate acetate preincubated HDMo (PMA-HDMo) in contrast to nMo at low concentrations (2.5 x 10(4] were unable to increase the CFU-dG growth stimulation. On the other hand, at a higher cell number (5 x 10(4], phorbol treated HDMo stimulated the myeloid colony formation, whereas nMo suppressed the CFU-dG proliferation. Further enhancement of HDMo and nMo concentrations induced a pronounced inhibition of CFU-dG-derived colony formation, caused by an increased PGE2 production. After incubation with the cyclooxygenase inhibitor-indomethacin, PMA-HDMo showed considerably more granulocyte colony formation than nMo. Our results suggest that the observed abnormalities in the function of HDMo could be associated with an excessive production of PGE2 and a general dysfunction of these cells in Hodgkin's disease.