Effect of Indomethacin and Thymostimulin on Natural Killer Activity of Thalassemic Patients and Normal Subjects

Abstract

To evaluate whether indomethacin (IM) and thymostimulin (TP-1) could revert the alterations of natural killer cytotoxicity (NKC) observed in patients and carriers of Thalassemia Major (TM), 14 TM patients, 10 TM carriers, 16 normal controls, and 4 polytransfused patients were studied. In vitro, IM induced an increase in NKC of normal controls and TM carriers (Δ CI: + 5.98±2.49 and + 9.77±6.82 respectively), but not in TM patients (-0.32±1.45) or other polytransfused recipients. The addition of IM to Concanavalin A (Con A) also resulted in an increase of NKC in normal controls and TM carriers, similar to that induced by each substance separately in normal controls, or by IM alone in TM carriers. Similarly, TP-1 (50 μg/ml) induced increases of NKC in normal subjects (+ 4.66±3.62), but not in TM patients (-1.1±2.43). The impairment in NKC observed in TM and polytransfused patients, and the absence of response to Con A in both, TM patients and carriers, do not seem to be mediated by an excessive production of prostaglandins. The lack of response not only to Con A, but also to TP-1 could indicate a quantitative or qualitative defect in T cells, that affects NKC regulation, or a deficient response of NK cells to modulators produced by T lymphocytes.