Thymopentin treatment in patients with chemotherapy-resistant lepromatous leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae; it is chiefly involving the skin and peripheral nerves. In lepromatous leprosy there are widespread loose infiltrates with M. leprae multiplying extensively in the skin macrophages and Schwann cells of peripheral nerves. Such patients reveal a decrease of circulating T helper cells, which is still more pronounced in the cutaneous lesions. Due to the ever increasing bacterial resistance to classical dapsone and combined chemotherapy as well, an immunomodulatory approach seemed reasonable: Eight patients with long-lasting (5-40 years) disease who had become resistant to combined chemotherapy were treated with thymopentin, 50 mg s.c., 3 times weekly for 5 weeks and thereafter combined with dapsone and clofazimine for 5 months. During the trial a statistically significant increase in E-rosette-forming cells (p less than 0.05) was observed, along with a steady improvement of the bacterial status of the nasal mucus. Although the skin lesions did not disappear within the observation period of the study, it is important to realize that long-term improvement of such lesions is always initiated by clearance of bacilli from the nasal mucus, hence, thymopentin treatment appears to be a promising approach to chemotherapy-resistant lepromatous lepra.