Immunological alterations induced by adjuvant treatment of postoperative colon carcinoma Duke's B or C with levamisole in combination with 5-FU.

BACKGROUND: Postoperative 5-FU combined with levamisole increases 5 year survival in colon cancer patients (Duke C) by 30% (1). In order to investigate the potential immunological mechanism, we determined lymphocyte subtypes and markers of immune activation in 22 patients before and during one year of postoperative adjuvant treatment. METHODS: Before and regularly during treatment, according to the scheme described by Moertel (1), major lymphocyte subsets were quantified by flow cytometry. Serum neopterin, soluble IL2-receptors, beta 2-microglobulin, TNF-alpha and interferon-gamma were determined by Elisa. RESULTS: The CD4/CD8 ratio increased significantly after levamisole was added to the treatment, as did the levels of soluble IL2-receptors. The percentages of T-cells expressing the interleukin 2 receptor followed a similar trend. The levels of neopterin tended to decrease during the combined treatment course. This was paralleled by a progressive fall in the proportion of T-cells expressing HLA-DR. CONCLUSIONS: The treatment induced significant and consistent alterations in major immunological mediators and lymphocyte subtypes. It remains to be established whether these changes are related to the therapeutic effect.

A simple and rapid flow cytometric method to measure lymphocyte activation in HIV+ subjects. Diminished response to pokeweed mitogen in early disease.

It was our objective to investigate the effect of asymptomatic infection with HIV on the expression of lymphocyte activation markers after stimulation with mitogens. Whole blood cultures were made of HIV+ and HIV- subjects (29 asymptomatic HIV-1-infected subjects and 33 apparently healthy normal volunteers). At various times after stimulation with concanavalin A (Con A), anti-CD3 and pokeweed mitogen (PWM), the expression of activation markers (CD25 and HLA-DR) and the blastogenesis were quantified by flow cytometry. The flow cytometric quantification of the expression of activation markers and blastogenesis in whole blood cultures provided an easy and safe alternative to thymidine incorporation to assess lymphocyte responses in HIV+ subjects. Activation showed a tendency to be lower in the HIV+ subjects with all three stimulants. This difference with HIV- subjects was statistically significant only for stimulation with PWM after 4 days. Further investigations should be undertaken to show whether this functional impairment is related to disease progression and whether it can be influenced by effective therapy.

The effects of short-term treatment with levamisole on cytokines in volunteers and cancer-patients.

In search for clues to the potential immunomodulating mechanism of action of levamisole which might be used as monitoring parameters, we have determined a variety of cytokines in the peripheral blood of volunteers and carcinoma patients before and after a single or a 3-day-treatment with 150 mg/day. In cancer patients no changes could be detected 4 days after a 3-day-treatment course in the levels of TNF-alpha, IL-1beta, IL-2 or IL-6. In a placebo-controlled volunteer study the same treatment did not affect the levels of beta2-microglobulin, IL-1beta, IL-1alpha, IL-2 or IL-6. However, 24hr after the last treatment the concentration of neopterin was slightly but significantly increased and the concentration of soluble IL-2 receptors decreased. A single treatment failed to produce such an effect. It is suggested that the measurement of neopterin and soluble IL-2 receptors may provide useful information in future trials.