Imatinib Treatment in PDGFRA‐Negative Childhood Hypereosinophilic Syndrome

Abstract

We report a 4-year-old female who presented with severe hypereosinophilia (215.7 K/μl) and end-organ dysfunction. Extensive evaluation including whole exome sequencing was performed, revealing no causative mutation. Initial treatment with corticosteroids, leukapheresis, and hydroxyurea decreased her absolute eosinophil count (AEC), although it remained elevated. Despite the absence of a PDGFRA mutation, an imatinib trial resulted in normalization of her AEC. Imatinib was discontinued after sustained normal counts for 1 month. AECs have remained normal for more than 1 year off therapy. This provides support for consideration of imatinib in the treatment of hypereosinophilia even in the absence of a known tyrosine kinase mutation.

Hypereosinophilia and severe bone disease in an African child: an unexpected diagnosis

“…Aside from prominent general symptoms, our patient also presented distinctive features, such as arthritis8 and bone pain, only sporadically described in HES 11 12. She had an apparently worse course than the previously described FP-child with bone pain,7 developing multiple focal lesions.…”

An Almost Fatal Case of the Hypereosinophilic Syndrome: A Dilemma Between Vasculitis or Clonal Disorder

“…Some genetic changes may still be discovered, and our patient might present with one of these. Imatinib that was given to our patient only for a short period may be effective in some forms of M-HES, hydroxyurea decreases the eosinophil count by cytotoxicity so it is not specific to the HES subtypes, mepolizumab acts as an anti-IL5 and is effective in both clonal and reactive eosinophilia, cyclophosphamide is a chemoimmunotherapy that is particularly effective in the context of EGPA [7,[13][14][15]. Since our patient received all of these therapies in a short timing, we cannot be sure which of them were actually effective.…”