Some remarks on adherence reactivity of autologous PHA--transformed lymphocytes on human glial tumor cells in vitro.

In 16 patients with primary supratentorial and in 1 with cerebellar tumor among them 5 multiforme glioblastomas, 3 malignant astrocytomas, 6 astrocytomas of other subtypes and 1 mixed glioma (oligo-astrocytoma) the peripheral blood was drawn and lymphocytes were separated from it. Out of the removed part of the tumors about 10 cultures in each case were prepared and cultivated at least 14 days. When the growth zone was well developed the cultures were used for further studies. All samples of the separated lymphocytes activated with PHA were cultivated for 72 h. So prepared lymphocytes were added to the tumor culture in vitro and observed for 24 h. After that time the not adhered lymphocytes were removed and the remaining tissue cultures with adhered lymphocytes were fixed and stained and the number of lymphocytes was counted. It was found that 1 h after the addition of lymphocytes the number of lymphocytes was very high, though a great part of them did not adhere to the tumor tissue. After 24 h the number of adhered lymphocytes was small or minute. Taking into consideration the results obtained it seems that the low efficiency of therapy of gliomas with autologous lymphocytes in vivo can result from the very weak direct contact with tumor cells. The influence of lymphocytes can be very limited so more as the tumor cells can secret biological active substances like PGE2, which counteract the cytotoxic activity of lymphocytes. For that reason the number of lymphocytes can be of significant value as counterbalance to that properties of the tumor cells. Taking into account even secretion of tumor cells of the same biological active substances such as PGE2 which counteract the cytotoxic activity of lymphocytes for the efficient activity of lymphocytes the number of them may be of significant value.