title: Aberrant T-cell antigen expression in B lymphoblastic leukaemia.
abstract: B lymphoblastic leukaemia (B-ALL) cells are characterized by the expression of various B-cell antigens. Expression of T/Natural Killer-cell antigens, however, has rarely been reported in B-ALL (TAg+ B-ALL), and the significance of this aberrant antigen expression is unclear. We thus analysed the frequency of TAg+ B-ALL at our institution and investigated its significance in the context of immunophenotypes, cytogenetic/molecular findings, and prognosis. We reviewed 134 consecutive cases of B-ALL and found 18 cases (13·4%) of TAg+ B-ALL. The most common aberrant T-cell antigens expressed were CD2, CD5, and CD7 at equivalent rates (each in six cases), CD4 (two cases), and CD56 (three cases). Adverse cytogenetic abnormalities were seen in a significantly larger proportion of the TAg+ cases (72·2%) than the TAg- cases (32·2%; P = 0·003). Multivariate Cox-regression analysis showed that the risk of relapse over time was higher in the TAg+ cases, independent of high risk status (based on age and white blood cell count) and the presence of adverse cytogenetic abnormalities (hazard ratio = 2·256, P = 0·065). These findings suggest that T-cell antigen expression in B-ALL may be an independent predictor of poor prognosis, and a useful marker to identify patients at increased risk for relapse and for harbouring adverse cytogenetic abnormalities.
authors.affiliation: Department of Pathology, Columbia University Medical Center and New York Presbyterian Hospital, New York, NY, USA.
authors.forename: Shafinaz
authors.initials: S
authors.lastname: Hussein
authors.forename: Kamraan Z
authors.initials: KZ
authors.lastname: Gill
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Sireci
authors.forename: Adriana I
authors.initials: AI
authors.lastname: Colovai
authors.forename: Tania
authors.initials: T
authors.lastname: Small
authors.forename: Foxwell N
authors.initials: FN
authors.lastname: Emmons
authors.forename: Vundavalli V
authors.initials: VV
authors.lastname: Murty
authors.forename: Govind
authors.initials: G
authors.lastname: Bhagat
authors.forename: Bachir
authors.initials: B
authors.lastname: Alobeid
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000096:biosynthesis* / Q000276:immunology; D000957:Antigens, Viral, Tumor / Q000096:biosynthesis / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D015448:Leukemia, B-Cell / Q000276:immunology*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D055815:Young Adult
chemical_list: D015703:Antigens, CD; D000957:Antigens, Viral, Tumor