Low CD25 in ALK+ Anaplastic Large Cell Lymphoma Is Associated with Older Age, Thrombocytopenia, and Increased...

Anaplastic lymphoma kinase (ALK)-positive (+) anaplastic large cell lymphoma (ALCL) is known to express CD25, but its significance has not been well studied.

In the present study, we identified 54 ALK+ ALCL patients with CD25 results available and investigated the significance of CD25 expression levels.

Forty-two (78%) cases had high CD25 expressions, whereas low CD25 expressions were found in 12 (22%) cases. Compared with ALK+ ALCL patients with CD25-high neoplasms, patients with CD25-low neoplasms were older (median: 40 years vs. 29 years, p = 0.01) and more often had thrombocytopenia (40% vs. 0%, p = 0.02). Between CD25-low and CD25-high groups, other clinical features were similar to each other (all p > 0.05). CD25-low ALK+ ALCL cases showed higher frequency of surface CD3 (100% vs. 3%, p = 0.001) and CD8 (57% vs. 14%, p = 0.03). Fourteen of 47 (30%) ALK+ ALCL patients died (median follow-up time, 33.8 months; range, 0.3-382.8 months): 5 of 9 (56%) patients with CD25-low neoplasms and 9 of 38 (24%) patients with CD25-high neoplasms. Univariate analysis showed: (1) the OS of patients with CD25-low ALK+ ALCL was shorter than that of patients with CD25-high ALK+ ALCL (median: 72.2 months vs. undefined, p = 0.02); and (2) young (<30 years) patients with high CD25 expression had the best prognosis, with a long-term OS rate of 89%. However, in multivariate analysis, low CD25 expression did not significantly impact OS.

most cases of ALK+ ALCL highly express CD25 which is a potential target for therapy. ALK+ ALCL with low CD25 expression is associated with older patient age and increased frequency of thrombocytopenia and surface CD3 and CD8 expression.