The clinicopathologic significance of lymphocyte subsets in acute myeloid leukemia.

INTRODUCTION: While the role of the immune system in altering and modulating the progression of solid tumors is well studied, the impact of the immune system on the outcome and progression of hematolymphoid neoplasms is still poorly understood. METHODS: Here, we report a retrospective study detailing our analysis of 130 patients with acute myeloid leukemia (AML), with flow cytometry immunophenotypic evaluation of major lymphocyte subsets including B cells, T cells, and NK cells. RESULTS: Our study identifies differential signatures of lymphocyte subsets pertaining to distinct subcategories of AML, and prognostic correlations in patients. In multivariate analysis, NK cells (specifically CD56+/CD16+ NK cells at a cutoff of ≥5%) were found to be an independent indicator of improved overall and disease-free survival; cytogenetic risk was also shown to be critical in stratifying patients with AML. CONCLUSIONS: In total, we demonstrate that in AML, the subset distribution of immune system lymphocytes is nonrandom, and suggest an important role for distinct lymphocyte subsets, particularly NK cells, in this disease.

A study of disseminated intravascular coagulation in acute leukemia reveals markedly elevated D-dimer levels are a sensitive indicator of acute promyelocytic leukemia.

INTRODUCTION: While the presence of disseminated intravascular coagulation (DIC) has been implicated in worse clinical outcome in acute leukemia, the relationship between different subtypes of acute leukemia and the clinicopathologic features of DIC has not been systematically well studied. METHODS: In this study, we retrospectively reviewed 149 cases of newly diagnosed acute leukemia and assessed the utility of evaluating red blood cell morphologic features, and coagulation parameters in determining the presence of DIC as well as differentiating subtypes of acute leukemia. RESULTS: Review of our cohort demonstrates a novel finding, that elevated D-dimer concentrations ≥19 000 ng/mL fibrinogen equivalent units (FEU) are a sensitive diagnostic indicator of acute promyelocytic leukemia (APL) with moderate specificity, sensitivity 96%, specificity 92% in acute leukemia subtyping. Similar to other studies, APL showed an increased incidence of DIC (P < 0.01) compared to other subtypes of acute leukemia. Surprisingly, the presence of schistocytes on the peripheral blood smear was not a statistically significant indicator of DIC, sensitivity of 36% and specificity of 89%. Finally, the presence of DIC was not a significant indicator of poorer prognosis amongst all patients with AML. CONCLUSION: Overall we identify elevated D-dimer concentrations ≥19 000 ng/mL FEU are a sensitive indicator of acute promyelocytic leukemia (APL), with a sensitivity of 96% and specificity of 92% in the subtyping of acute leukemias, and that the presence of schistocytes in peripheral blood smears is not a diagnostically sensitive screening test for DIC with a sensitivity of 36%.

The diagnostic and clinical impact of genetics and epigenetics in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a complex disease, for which our understanding of the role of genetic and epigenetic changes has undergone significant advancements. Newer diagnostic and prognostic classifications have increasingly incorporated such information, and novel therapies have been developed to target specific genes, processes, and pathways based on this growing understanding. Given the rapid evolution of this field, it is critical for physicians and translational researchers to have a more in-depth understanding of this evolving landscape. Here, we review both genetics and epigenetics in acute myeloid leukemia from a practical standpoint.

Refining the diagnosis of T-cell large granular lymphocytic leukemia by combining distinct patterns of antigen expression with T-cell clonality studies.

T-cell large granular lymphocytic (LGL) leukemia is a complex diagnosis, requiring persistent clonal expansions of LGLs, and cytopenias. Often the diagnosis is unclear as non-clonal expansions of LGLs commonly occur in reactive conditions. To better understand T-LGL leukemia, we performed a comprehensive clinicopathologic analysis of 85 patients with LGL expansions. Interestingly, distinct CD8+(dim)/CD57+ populations, seen by flow cytometry, were significantly associated with clonal T-LGL leukemia (P < 0.001) as well as neutropenia (median absolute neutrophil count (ANC) 1.45 vs 3.19 × 10(9)/l; P = 0.0017). Furthermore, cases with distinct CD8+(dim)/CD57+ populations and monoclonal T cells had even lower ANCs (median ANC 1.41 × 10(9)/l; P = 0.001) compared with cases without these dual criteria. Additionally, complete or partial loss of CD5 expression was independently associated with clonal T-LGL leukemia (P<0.001) and neutropenia (median ANC 1.41 vs 2.70 × 10(9)/l; P = 0.002). This study describes specific immunophenotypic parameters to better define clonal cases of T-LGL leukemia associated with significant neutropenia.