Enhancement of interleukin-2 and γ-interferon productionin vitro on cord blood lymphocytes andin vivo on primary cellular immunodeficiency patients with thymic extract (Thymostimulin)

Cord blood mononuclear cells (MNC) were isolated from 20 normal full-term newborns. These MNC were preincubated with either 50, 100, or 200 µg/ml Thymostimulin or without Thymostimulin. The interleukin-2 (IL-2) and -interferon (-IFN) production, cytotoxicity, and lymphoproliferation and IL-2 receptor (Tac) expression were all significantly increased after Thymostimulin treatment. For evaluation of thein vivo effect, two combined-imimunodeficiency patients defective on the thymic level, one with progressive BCG infection, and one with DiGeorge syndrome were used. Before Thymostimulin treatment, the patient's MNC did not produce sufficient amounts of IL-2 and -IFN. The cytotoxicity and lymphoproliferation were also low. After Thymostimulin treatment, the IL-2 and -IFN production, cytotoxicity, and lymphoproliferative response were enhanced. These results suggest that Thymostimulin may be beneficial in the clinical treatment of primary cellular immunodeficiency. The improved immune reactivity including cytotoxicity and enhanced IL-2 and -IFN production in the Thymostimulin treatment also indicates that there may be a beneficial effect on the combination of chemotherapy and Thymostimulin.