The effect of thymopentin treatment on the relapse rate in frequently relapsing herpes simplex virus infections.

Twenty-four patients suffering from longstanding severe recurrent herpes simplex, who had not responded to prior therapy, were treated with s.c. thymopentin injections 50 mg, three times weekly, over a period of six weeks. They were followed up at weekly intervals over this period and then six weeks later. Moreover, the longest relapse-free period observed in the year after the treatment was recorded in the investigator's documentation. Thirteen of the 14 patients with labial herpes simplex and 10 of the 13 patients with genital herpes simplex improved markedly as shown by a decrease in the relapse rate of at least 50%, shorter episodes of relapse and improvement of symptoms such as pain and itching. Fourteen of these 27 patients experienced no relapse for a period longer than four months after cessation of the therapy. No serious side-effects were observed. Laboratory examinations before, during and after thymopentin did not reveal significant alterations except for an increase in the T-helper/T-suppressor ratio. The effect of thymopentin is assumed to be due to T-helper cell activation resulting in enhanced interleukin-2 production with subsequent proliferation of cytotoxic T lymphocytes and natural killer cells which are capable of producing immune interferon.