Interferon levels in human pulmonary tumors are lower than plasma levels
Bocci, V.; Carraro, F.; Naldini, A.; Borrelli, E.; Biagi, G.; Gotti, G.; Giomarelli, P.P.
Journal of Biological Regulators and Homeostatic Agents 4(4): 153-156
1990
ISSN/ISBN: 0393-974X PMID: 2096600 Document Number: 348184
It is uncertain whether interferon levels in the interstitial fluid of tumors are equivalent to interferon plasma levels and we have investigated this problem in human pulmonary tumors by infusing human recombinant interferon .alpha.A and natural interferon .beta. for about three hours before surgery. By determining the hematocrit and hemoglobin content it was possible to calculate interferon values (International Units/g wet tissue) present in the interstitial fluid of tumor and lung samples, simultaneously. In 14 patients (epidermoids, n = 9 and adenocarcinomas, n = 5) interferon levels in tumor and "normal" lung expressed as percentages of interferon plasma levels were: 9.5 .+-. 3.9 and 29.8 .+-. 6.9 for recombinant interferon .alpha. A and 3,1 .+-. 0.4 and 10.1 .+-. 2.4 for natural interferon .beta., respectively. Differences for both interferons are statistically significantly (P < 0.05). To our knowledge these are the first data indicating that interferon levels in pulmonary tumor interstitial fluid are markedly lower than those in normal lung and although they do not clarify the main factor responsible for the decrease, they explain at least in part the neglibible therapeutic activity of interferons in these tumors and emphasize the need for new approaches for improving the therapeutic index of interferons.