title: Immunophenotypic analysis of T-acute lymphoblastic leukemia. A CD5-based ETP-ALL perspective of non-ETP T-ALL.
abstract: T-cell antigens [CD5,CD1a,CD8] define early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). To understand immature T-ALL of which ETP-ALL is part, we used these antigens to subcategorize non-ETP T-ALL for examining expression of myeloid/stem cell antigens (M/S) and clinical features. Using CD5 (+/-) to start categorization, we studied 69 routinely immunophenotyped patients with T-ALL. CD5(-) was a homogenous (CD8,CD1a)(-) M/S(+) ETP-ALL group (n = 9). CD5(+) cases were (CD8,CD1a)(-) pre-T-ALL (n = 22) or (CD8,CD1a)(+) (n = 38) thymic/cortical T-ALL; M/S(+) 20/22 (90.91%) in former and 22/38 (57.89%) in latter (P = 0.007). ETP- and pre-T-ALL together (CD1a(-) ,CD5(-/+) immature T-ALL group) were nearly always M/S(+) (29/31; 93.55%). In multivariate analysis, only ETP-ALL predicted poor overall survival (P = 0.02). We conclude (i) CD5 negativity in T-ALL almost always means ETP-ALL. CD1a and CD8 negativity, as much as CD5, marks immaturity in T-ALL, and the CD5(+/-) /CD1a(-) /CD8(-) immature T-ALL group needs further study to understand the biology of the T-ALL-myeloid interface. (ii) ETP-ALL patients may be pre-T-ALL if CD2(+) ; CD2(+) , conversely, CD5(-) /CD1a(-) /CD8(-) pre-T ALL patients are ETP-ALL. (iii) Immunophenotypic workup of T-ALL must not omit CD1a, CD5, CD8 and CD2, and positivity of antigens should preferably be defined as recommended for ETP-ALL, so that this entity can be better evaluated in future studies of immature T-ALL, a group to which ETP-ALL belongs. (iv) ETP-ALL has poor prognosis.
authors: Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India.
authors: Anita
authors: A
authors: Chopra
authors: Sameer
authors: S
authors: Bakhshi
authors: Suman Kumar
authors: SK
authors: Pramanik
authors: Ravindra Mohan
authors: RM
authors: Pandey
authors: Saroj
authors: S
authors: Singh
authors: Smeeta
authors: S
authors: Gajendra
authors: Ajay
authors: A
authors: Gogia
authors: Jagan
authors: J
authors: Chandramohan
authors: Atul
authors: A
authors: Sharma
authors: Lalit
authors: L
authors: Kumar
authors: Rachna
authors: R
authors: Seth
authors: Sandeep
authors: S
authors: Rai
authors: Rajive
authors: R
authors: Kumar
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D018956:CD5 Antigens / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology*; D054504:Precursor Cells, T-Lymphoid / Q000166:cytology; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology*; D011379:Prognosis; D013234:Stem Cells / Q000166:cytology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018956:CD5 Antigens
keywords: CD5; EGIL and WHO classification of T-ALL; early T-cell precursor acute lymphoblastic leukemia