Furthermore, we demonstrate a novel translocation in this tumor, the t(5;9)(q31;p24), that possibly led to fusion of the interleukin-3 (IL3) (5q31) and JAK2 (9p24) genes and may explain the concomitant appearance of eosinophilia and ALL.
Our data support a role for GM-CSF and IL-3 in the eosinophilia characteristic of CHS and show that IL-5 mRNA expression is not a prominent feature of nonallergic inflammation.
The data suggest that activation of the IL-3 gene by the enhancer of the immunoglobulin heavy chain gene may play a central role in the pathogenesis of this leukemia and the associated eosinophilia.