Aberrant T‐cell antigen expression in B lymphoblastic leukaemia

Abstract

Summary 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.

Clinical Significance of Co-expression of Aberrant Antigens in Acute Leukemia: A Retrospective Cohort Study in Makah Al Mukaramah, Saudi Arabia

“…In this work, CD56 was detected in 9% in ALL, mildly lower frequency of CD56 expression were reported earlier; 5% (Seegmiller et al, 2009), 3% (Paietta et al, 2001) and 2.2% (Hussein et al, 2011). We reported 4 cases with hyperdiploidy all were expressing CD34 and two of them lost CD45 in agreement with others who found higher CD34 expression in B-ALL with hyperdipolidy and under expression or loss of CD45 (Behm et al, 1992;Seegmiller et al, 2009).…”

Aberrant Immunophenotypic Expression of CD5 in a Case of B Acute Lymphoblastic Leukemia: A Case Report

“…It is also reported in some other B-CLPDs, including diffuse large B-cell lymphoma (DLBCL), splenic marginal zone lymphoma (SMZL), lymphoplasmacytic lymphoma and even in some cases of follicular lymphoma [1]. Aberrant expression of CD5 in B-ALL is uncommon, seen in 2 % in a series of 200 cases of B-ALL cases [5] and 4.5 % cases in a series of 134 cases [6]. Blastoid variant of MCLs was considered in the differential diagnosis as both entities are CD19?, CD5?…”

“…Thus, a diagnosis of B-ALL with aberrant expression of CD5 was established. Conventional cytogenetics showed karyotype of 47,XY,?mar [6]/46,XY, [14]. Patient was treated with broad spectrum antibiotics, antifungals and transfusion support with partial improvement in his general condition.…”

“…CD5 expression in B-ALL is very uncommon with only few case reports and small series reported in literature [2][3][4]. Aberrant T-cell antigen expression is said to be associated with poor prognosis, and as a useful marker to identify patients at increased risk for relapse and for harbouring adverse cytogenetic abnormalities [5,6]. In this report we present a case of 20 year old male with CD5?…”

Immunophenotypic Profile in Adult Patients with Acute Leukemia Association with Clinical Feature: Fluorescence Cytometry Quantitative Analysis

“…In the vast majority of cases, leukemic B-cells express CD19, cytoplasm (cyt) CD79a, cyt CD22, and PAX5, while expression of CD20 is variable [28]. A diagnosis of ALL of B-cell lineage requires the use of a panel of B-cell markers, commonly including CD19, CD20, and CD22 [29].…”