Effect of thymopentin on the mortality and immune response after an experimental herpes simplex infection in mice

Immunomodulation with thymopentin: in vitro studies

Immunomodulation is interpreted as a temporary alert in a certain part of the immune system. The activation of immune competent cells is presented as a possible basic mechanism of this phenomenon. In the absence of a primary stimulus, immunomodulation remains physiologically silent, but it results in a modified immune response if the corresponding targets are being stimulated. For practical reasons it is suggested that distinctions be made between preventive and regulative immunomodulation. The PWM-induced IgG production of PBMCs was used as a model for the demonstration of the modulatory effect of thymopentin in vitro. Depending on the concentration of thymopentin used in the cultures, this pentapeptide can either stimulate or inhibit the induced IgG production. It also influences PGE2 production and catabolism in the cultures stimulated with PWM. Indomethacin abolishes the modulatory effect of thymopentin on IgG production in this model. It is suggested that the possibility of interactions between an immune modulator and therapeutic approaches which can influence the proportions or functions of the corresponding target cells be considered.

Prevention of recurrences in frequently relapsing herpes labialis with thymopentin. A randomized double-blind placebo-controlled multicenter study

The present randomized, placebo-controlled double-blind multicenter study included a population of 36 subjects with frequent recurrences (at least once a month) of herpes labialis. Most of the patients had failed to respond adequately to previous treatment with other therapeutic tools, including acyclovir. Either 50 mg of thymopentin or of placebo was administered 3 times a week, by the subcutaneous route, for 6 weeks. Subsequently, the patients were observed for nearly 6 months on the average. The results achieved with thymopentin for the individual parameters were significantly superior to those obtained with placebo; thus significant improvement was seen in patients on thymopentin in the duration of the longest symptomfree period (prolonged from 2.1 weeks to 20.9 weeks, p = 0.000), in the number of relapses (reduced from 1.6 to 0.4 episodes/month, p = 0.001), and in the total duration of herpes symptoms per month (shortened from 2.0 to 0.3 weeks, p = 0.000). Placebo treatment also resulted in considerable improvement (p less than 0.05 or 0.01), but was significantly inferior to the improvement obtained with thymopentin. The longest symptomfree period in the placebo group was prolonged from 2.4 to 11.2 weeks. The number of relapses per month was reduced from 1.4 to 0.8, and the total duration of herpes symptoms per month from 2 to 0.9 weeks. The results of intergroup analyses, in which the observed parameters and the improvement achieved in either group were compared, significantly favored thymopentin treatment. The effect of thymopentin was in all but one parameters superior to that of placebo and highly significant (p less than 0.01).