B-cell acute lymphoblastic leukaemia (B-ALL) harbouring
immunoglobulin heavy chain (IGH) gene rearrangements encompasses a clinically
and molecularly heterogeneous group of haematological malignancies. Among
these, the subset presenting with hypereosinophilia represents a particularly
underrecognised diagnostic challenge, frequently resulting in significant
delays to appropriate treatment. The paradigmatic example is B-ALL with
t(5;14)(q31.1;q32.3)/IGH::IL3, in which dysregulated interleukin-3 (IL-3)
expression driven by the IGH enhancer leads to pronounced reactive eosinophilia
that may entirely dominate the clinical picture. The leukaemic blast burden at
presentation may be deceptively low, and the eosinophilia—reactive rather than
clonal—can divert clinical attention towards primary eosinophilic disorders, myeloid
neoplasms with eosinophilia, or common reactive causes including parasitic
infection and atopy. Beyond the IGH::IL3 fusion, other IGH partner genes,
including CRLF2, EPOR, and DUX4, create signalling environments that may
further potentiate eosinophil recruitment and bone marrow expansion. Accurate
diagnosis requires the integration of peripheral blood film morphology,
multiparameter flow cytometric immunophenotyping, conventional cytogenetics,
fluorescence in situ hybridisation (FISH), and, increasingly, next-generation
sequencing (NGS) or transcriptomic profiling. Treatment of the underlying
leukaemia with standard multi-agent B-ALL chemotherapy regimens remains the
definitive approach, resolving the associated eosinophilia as the leukaemic
clone is suppressed. Emerging immunotherapeutic agents and targeted kinase
inhibitors are reshaping the treatment landscape for molecularly defined B-ALL
subtypes. This comprehensive review synthesises current knowledge of the
molecular pathogenesis, clinical presentation, diagnostic challenges, and
therapeutic strategies for this underrecognised entity, with the dual aim of
heightening clinical awareness and reducing diagnostic delay.
Author(s) Details
Sonagara Nikhilkumar
Mavjibhai
Military Hospital, Jaipur, Rajasthan, India.
Rushang Mukeshbhai
Dave
Shantabaa Medical College and General Hospital, Amreli, Gujarat, India.
Chinmay Shrikrishna
Pendharkar
181 Military Hospital, Tenga, Arunachal Pradesh, India.
Please see the book here :- https://doi.org/10.9734/bpi/msup/v7/7288
No comments:
Post a Comment