Background: Apoptotic (natural or programmed) cell death of lymphocytes contributes to an immune decline of HIV-infected persons. Active fragments of thymopoietin may reduce apoptosis and slow down this progress of immune decline.
Material/Methods: In vitro studies were performed in order to investigate the apoptosis-reducing effect of a new active thymopoietin fragment, Thymocartin (Arg-Lys-Asp-Val). Separated peripheral blood lymphocytes of 10 asymptomatic HIV-positive and 7 HIV-negative persons were cultured. Unstimulated, IL-2-stimulated and IL-2-stimulated plus 0.1 and 0.001 µg/ml Thymocartin-treated cells were investigated for apoptosis by morphological (HE, Apop-Tag), flow cytometric and agarose DNA fragmentation methods.
Results: Unstimulated lymphocytes of HIV-positive persons showed higher apoptotic activity than those of HIV-negative persons. IL-2-stimulation increased the apoptotic rate in 7 HIV-positive and 1 HIV-negative individuals. Thymocartin reduced the apoptotic activity in 8 HIV-positive and 1 HIV-negative case.
Conclusions: Thymocartin reduces the apoptotic activity in lymphocytes of HIV-positive patients in vitro. This compound may have the same effect in vivo and may prolong the asymptomatic period of HIV-infected patients.

Keywords: HIV-infection, thymocartin