Patients receiving etoposide within four weeks after diagnosis had a good prognosis as five of the seven patients survived compared to one of 13 not treated with etoposide or treated late (chi-square test for survival, P = 0.0095). The Kaplan-Meier analysis showed the 2.5-year survival of 85.7 +/- 13.2% in the early etoposide-treated patients, compared to 10.3 +/- 9.4% in the remaining patients (log-rank test, P = 0.0141). Thus, early etoposide treatment is effective in treating EBV-HLH in young adults as well as in children.

No abstract

Interleukin (IL)-13 is an immunoregulatory cytokine secreted predominantly by activated T-helper type 2 (Th2) cells, and it has been identified as crucial in developing allergic inflammatory responses. Its diverse functions are mediated by a complex receptor system including IL-4 receptor alpha (IL-4Ralpha; CD124) and two other cognate cell surface proteins, IL-13Ralpha1 (CD213a1) and IL-13Ralpha2 (CD213a2). IL-13Ralpha1 forms a heterodimer with IL-4Ralpha that is a signaling IL-13 receptor. In contrast, IL-13Ralpha2 has been thought to be a decoy receptor due to its short cytoplasmic tail. IL-13Ralpha2 exists on the cell membrane, intracellularly, and in soluble form. Recent reports revealed that membrane IL-13Ralpha2 may have some signaling capabilities, and soluble IL-13Ralpha2 is a critical endogenous modulator for IL-13 responses. The receptor has more complicated functions than a simple decoy receptor. In this review, we describe the isoforms of IL-13Ralpha2 and discuss newly revealed functions of IL-13Ralpha2.

IL-13, a critical cytokine for allergic inflammation, exerts its effects through a complex receptor system including IL-4Rα, IL-13Rα1, and IL-13Rα2. IL-4Rα and IL-13Rα1 form a heterodimeric signaling receptor for IL-13. In contrast, IL-13Rα2 binds IL-13 with high affinity but does not signal. IL-13Rα2 exists on the cell surface, intracellularly, and in soluble form, but no information is available regarding the relative distributions of IL-13Rα2 among these compartments, whether the compartments communicate, and how the relative expression levels impact IL-13 responses. Herein, we investigated the distribution of IL-13Rα2 in transfected and primary cells, and we evaluated how the total level of IL-13Rα2 expression impacted its distribution. Our results demonstrate that the distribution of IL-13Rα2 is independent of the overall level of expression. The majority of the IL-13Rα2 protein existed in intracellular pools. Surface IL-13Rα2 was continually released into the medium in a soluble form, yet surface expression remained constant supporting receptor trafficking to the cell surface. IL-13Rα2 inhibited IL-13 signaling proportionally to its level of expression, and this inhibition could be overcome with high concentrations of IL-13.