Elevated serum levels of soluble interleukin-2 receptor: a marker of
disease activity in the hypereosinophilic syndrome
L Prin, J Plumas, V Gruart, S Loiseau, D Aldebert, JC Ameisen, A Vermersch, P Fenaux, O Bletry and M Capron
C.I.B.P., Institut Pasteur, Lille, France.
We report here the presence of very high serum levels of the soluble
interleukin-2 receptor (sIL-2R) in patients with blood hypereosinophilia
with or without detectable markers of malignancy or signs of visceral
involvement. The highest sIL-2R levels were observed in 16 eosinophilic
patients with T-cell lymphoma (3,440 to 79,500 U/mL). Elevated levels of
sIL-2R were also present (1,330 to 22,500 U/mL) in sera from 38 patients
with the hypereosinophilic syndrome (HES) without detectable T-cell
lymphoma. In this group of patients, the highest levels were noted in the
patients with the malignant form of HES. Significantly lower levels were
measured in sera of patients with hypereosinophilia associated with
parasitic diseases, allergic disorders, or other miscellaneous diseases.
Elevated serum sIL-2R levels were not closely paralleled by changes in the
number of CD25- positive peripheral blood mononuclear cells as assessed by
flow cytometric analysis. However, expression of IL-2R messenger RNA was
detected in blood mononuclear cells collected from HES patients. In eight
eosinophilic patients with T-cell lymphoma, the serum sIL-2R levels were
significantly correlated with the eosinophil counts, and with the total
number of blood hypodense eosinophils. alpha-Interferon (alpha-IFN) therapy
resulted in both a dramatic clinical improvement and a rapid decrease in
sIL-2R levels and blood hypereosinophilia. Similar beneficial effects of
alpha-IFN were noted in patients with malignant HES who lacked a detectable
T-cell lymphoma. Our data indicate that HES is associated with elevated
serum IL-2R levels. The highest levels were observed in the most severe
forms of HES with hematologic markers of malignancy or evident visceral
involvement. Serum levels of sIL-2R might represent a useful indicator for
the management of HES patients. In addition, the respective changes of sIL-
2R and blood eosinophilia might reflect distinct processes of mononuclear
cell activation affecting the eosinophil lineage.
Volume 78,
Issue 10,
pp. 2626-2632,
11/15/1991
Copyright © 1991 by The American Society of Hematology
