Expression of the immunoglobulin superfamily cell membrane adhesion molecule Cd146 in acute leukemia

Upregulation of CD146 in Pediatric B-Cell Acute Lymphocytic Leukemia and Its Implications on Treatment Outcomes

Background and Aim. We studied through flow cytometry the expression of CD146 on different T cells, and B-cell ALL blasts trying to correlate its expression with different prognostic factors of B-cell ALL and treatment outcomes. Patients and Methods. All pediatric patients with B-cell ALL were subjected to bone marrow examination and cytochemistry, flow cytometric immunophenotyping using monoclonal antibodies utilized for diagnosis of B-ALL including CD34, CD19, CD10, CD22, and intracellular IgM. The diagnosis was based on standard morphologic, cytochemical, and immunophenotypic followed by flow cytometric detection of CD146 expression on blast cells, CD4⁺, and CD8⁺ T cells.

CD146 (Cluster of Differentiation 146)

CD146 (cluster of differentiation 146) is an adhesion molecule that is expressed by different cells constituting vessels, particularly endothelial cells. The last 30 years of research in this field have shown that CD146 plays a key role in the control of several vessel functions. Three forms of CD146 have been described, including 2 transmembrane isoforms and a soluble protein that is detectable in the plasma. These CD146 forms mediate pleiotropic functions through homophilic and heterophilic interactions with proteins present on surrounding partners. Several studies used neutralizing antibodies, siRNA, or genetically modified mice to demonstrate the involvement of CD146 in the regulation of angiogenesis, vascular permeability, and leukocyte transmigration. In this review, we will focus on the current knowledge of the roles of CD146 in vascular homeostasis and diseases associated with endothelial dysfunction.

Routine interim disease assessment in patients undergoing induction chemotherapy for acute myeloid leukemia: Can we do better?

The presence of >5% blasts at "day 14" (D14), in patients undergoing induction chemotherapy for acute myeloid leukemia (AML) is problematic. It is unclear if a second course of chemotherapy for early persistent disease will alter outcome in these patients. We conducted a retrospective study of AML patients undergoing induction chemotherapy where diagnostic, interim (around day 14), and recovery (days 21-42) bone marrow (BM) evaluations were available for review. Of the 113 patients included in the final analysis, 99 (87.6%) achieved CR at hematologic recovery. At D14, 90 patients (79.6%) had <5% blasts and of these, 87 (96.7%) ultimately achieved CR. At D14, Twenty-three (20.4%) patients had residual leukemia (>5% blasts). Of these, 11 (47.8%) received a second course of chemotherapy (double induction [DI]) and 12 (52.2%) were observed until count recovery (single induction [SI]). No significant difference in CR rates was observed between these two groups (58.3% DI group vs. 45.5% SI group, P value = 0.684). In our analysis, D14 BM evaluation did not uniformly identify patients with primary induction failure. To unequivocally determine the value of a D14 marrow assessment in AML, prospective studies in the context of large cooperative group trials are required. Considering our findings and similar reports from others, we propose that D14 marrow assessment should be individualized, and that other factors, such as cytogenetics and early peripheral blood blast clearance should be considered, to identify patients most likely to benefit from interim disease assessment during AML induction therapy.