P. Lissoni et al., INVIVO BIOLOGICAL RESULTS OF THE ASSOCIATION BETWEEN INTERLEUKIN-2 AND INTERLEUKIN-3 IN THE IMMUNOTHERAPY OF CANCER, European journal of cancer, 29A(8), 1993, pp. 1127-1132
The concomitant generation of macrophage-mediated suppressive events,
as documented by the increase in neopterin and soluble interleukin-2 (
IL-2) receptor (SIL-2R), and the enhanced production of cortisol, woul
d represent the most investigated phenomena responsible for the reduce
d anticancer efficacy of IL-2 immunotherapy in humans. Based on our pr
eliminary experimental studies suggesting a modulatory role of IL-3 on
immune and endocrine effects induced by IL-2, a study was performed t
o evaluate the influence of IL-3 on biological effects of IL-2 cancer
immunotherapy. We have evaluated 12 immunotherapeutic courses with IL-
3 plus IL-2, which were performed in 6 patients with metastatic non-sm
all cell lung cancer. The results were compared to those seen in 22 co
urses with IL-2 alone, carried out in 12 patients with metastatic non-
small cell lung cancer. IL-3 was given intravenously at a daily dose o
f 1 mug/kg/b.w. at 6 p.m. for 14 consecutive days, starting 7 days bef
ore IL-2. IL-2 was given subcutaneously at a dose of 3 million IU twic
e/daily for 5 days/week for 3 weeks. The increase in serum levels of t
he specific macrophage marker neopterin, induced by IL-2, was complete
ly blocked by IL-3. The IL-2-induced SIL-2R rise was significantly low
er during IL-3 plus IL-2 than under IL-2 alone. The increase in cortis
ol levels in response to IL-2 was neutralised by IL-3. The increase in
lymphocyte, T lymphocyte, natural killer (NK) cell, activated T lymph
ocyte and eosinophil mean number was significantly higher during IL-3
plus IL-2 than during IL-2 alone. Episodes of fever, asthenia, anorexi
a, vomiting, anaemia and thrombocytopenia were significantly more freq
uent in patients receiving IL-2 alone than in those treated with IL-3
and IL-2. This preliminary study would suggest that IL-3 may improve t
he tolerability of IL-2 immunotherapy and enhance the biological antit
umour properties of IL-2 by neutralising cortisol increase and macroph
age-mediated suppressive events, with a following potential amplificat
ion of Il-2 anticancer efficacy.