Lipoperoxidation and T‐cell leukemia of childhood. Effects of indomethacin

Serum thiobarbituric acid (TBA) reactivity for lipoperoxidation products was assessed at diagnosis in children with T‐cell and common acute lymphocytic leukemia (ALL) and T‐lymphoblastic lymphoma. Comparisons were made among these groups and with healthy controls. Mean TBA reactivity (μmol malondialdehyde/L serum) was increased (P < 0.01) in the T‐cell leukemia group versus common ALL and T‐lymphoblastic lymphoma patients and controls, respectively. The increase in lipoperoxidation products in T‐cell ALL appeared to bear a positive relation to peripheral leukocyte counts, and was accompanied by increased serum prostaglandin E₂ (PGE₂) levels in most representative cases. Indomethacin added to a childhood T‐cell ALL line (SUP‐T3), at a concentration known to inhibit prostaglandin synthesis in vitro (i.e., 3 μg/mL), effected significant increases in the numbers of natural killer (NK; Leu‐11⁺ and Leu‐19⁺) cells (P < 0.01) and B‐lymphocytes (P < 0.05), and significant decreases in cell viability (P < 0.01). Indomethacin may be a useful agent for enhancing the antileukemic immune response in T‐cell ALL.