Clinical relevance of FLT3 receptor protein expression in Indian patients with acute leukemia.
OBJECTIVE
FLT3 is a receptor tyrosine kinase that plays an important role in the pathogenesis of leukemia. The present study aimed to evaluate the role of FLT3 protein in patients with acute leukemia.


METHODS
FLT3 protein was quantified by flow cytometry on leukemic blasts using CD135 antibody in 160 patients with acute leukemia.


RESULTS
We demonstrated FLT3 protein expression (>20%) in 82% of acute myeloid leukemia (AML), 60% of B-lineage acute lymphoblastic leukemia (B-ALL), 23% of T-lineage acute lymphoblastic leukemia (T-ALL) and 80% of biphenotypic leukemia. Further, FLT3 expression was seen to be significantly higher in AMLM2, M4, and M5 than in AMLM3. In B-ALL, FLT3 was found to be higher in pro-B-ALL and lower in early B-ALL. A CD34 expression >20% was associated with FLT3 positive B-ALL. When correlated with disease status, all patients in the relapsed AML group had FLT3 > 20% at diagnosis. Unlike AML, the relapsed group of B-ALL showed a lower incidence of FLT3 than the remission group.


CONCLUSIONS
In summary, our data imply that there is frequent overexpression of the FLT3 protein in AML and B-ALL patients of Indian origin. In future, the FLT3 protein level may be used to select patients for whom FLT3 inhibitor therapy may be indicated.
Immunohistochemistry and Flowcytometry Division, The Gujarat Cancer and Research Institute, New Civil Hospital Compound, Asarwa, Ahmedabad, India. ihcgcri@hotmail.com
Hemangini H
HH
Vora
Shilin N
SN
Shukla
Birwa V
BV
Brahambhatt
Shalvi H
SH
Mehta
Nupur A
NA
Patel
Sonia K
SK
Parikh
Kruti N
KN
Shah
Pankaj M
PM
Shah
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult; D051941:fms-Like Tyrosine Kinase 3 / Q000378:metabolism*
C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3