Effects of prednisolone on specifically expressed genes in pediatric acute B-lymphoblastic leukemia

MicroRNA-31 is a potential biomarker for screening B-lymphoblastic leukemia in children

The present study aimed to investigate the expression and significance of microRNA-31 (miR-31) in children with acute B-lymphoblastic leukemia (B-ALL). Bone marrow specimens and peripheral blood were collected from children with B-ALL (n=38) and healthy controls (n=18). Total RNA was extracted and the expression levels of miR-31 were measured using quantitative PCR. In addition, a receiver operating characteristic curve was generated, and the area under the curve (AUC) was calculated to evaluate the diagnostic value of miR-31 for the development of B-ALL. miR-31 expression was significantly lower in the B-ALL group compared with in the control group (P<0.05). Additionally, the expression levels of miR-31 in the B-ALL group before treatment were markedly lower than in the B-ALL group after treatment, and miR-31 expression was significantly lower after 30 days of treatment compared with after 12 weeks of treatment. Furthermore, miR-31 expression in the group of children ≥10 years of age was higher than that in the group of children <10 years of age. Furthermore, the expression levels of miR-31 were higher in the low-risk group compared with in the medium- and high-risk groups (P<0.05). When the cutoff value was set at 1.8, the AUC of miR-31 for B-ALL diagnosis was 0.915 (95% CI, 0.828-1.000; P<0.0001), with a sensitivity and specificity of 80.8 and 100%, respectively. In conclusion, miR-31 may exert an anticancer role in B-ALL in children and may be a potential marker to assist in diagnosis and prognostic prediction.

Minimal residual disease testing in acute leukemia

SUMMARY Predictive/prognostic factors in acute leukemia continue to be sought, in order to refine treatment strategies. Minimal residual disease (MRD) testing has been shown to be a statistically significant factor by multivariate analysis in both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia. Its utility in guiding therapy has been more extensively studied in pediatric ALL, with some protocols having instituted MRD testing into therapeutic algorithms. The clinical impact of MRD testing in ALL and acute myeloid leukemia will be presented, including both molecular and flow cytometric methodologies, with a more focused discussion of the strategy, methodology and interpretation of MRD testing by multiparametric flow cytometry.

The kaleidoscope of glucorticoid effects on immune system

Glucocorticoids (GCs) are potent anti-inflammatory and immunosuppressive agents which exert multiple effects on immune cell functions. Although their use dates back 60 years, their functions and mode of action have not been completely elucidated yet. GCs act through different genomic and non genomic mechanisms which are mediated by the binding to cytosolic glucocorticoid receptor as well as to cell membrane receptors, or by interacting directly with enzymes and other cell proteins. T cell subtypes have a different sensitivity and response to GCs; in fact, GCs have an immunosuppressive effect on pro-inflammatory T cells, while they stimulate regulatory T cell activity. The effect of GCs on B cells is less clear. Interestingly, treatment with GCs may determine apoptosis of autoreactive B cells by reducing the B cell activator factor (BAFF). Tolerogenic dendritic cells which express low levels of Major Histocompatibility Complex class II, co-stimulatory molecules and cytokines, such as IL-1β, IL-6, and IL-12, can be induced by GCs. GCs at low levels stimulate and at high levels inhibit macrophage activity; moreover, they reduce the number of basophils, stimulate the transcription of inhibitors of leukocyte proteinases and the apoptosis of neutrophils and eosinophils. Finally, GCs inhibit the synthesis and function of some cytokines, particularly T helper type 1 cytokines, and to a lesser extent the secretion of chemokines and co-stimulatory molecules from immune and endothelial cells.

Immaturity associated antigens are lost during induction for T cell lymphoblastic leukemia: implications for minimal residual disease detection

BACKGROUND

Induction chemotherapy for acute leukemia often leads to antigenic shifts in residual abnormal blast populations. Studies in precursor B cell ALL (B-ALL) have demonstrated that chemotherapy commonly results in the loss of antigens associated with immaturity, limiting their utility for minimal residual disease (MRD) detection. Little information is available about the stability of these antigens in precursor T cell ALL (T-ALL) though it is presumed that CD99 and terminal deoxynucleotidyl transferase (TdT) are highly informative based on limited studies.

METHODS

In a longitudinal investigation, we explored patterns of lineage specific and immaturity-associated antigens in T-ALL in a large cohort of patients treated under the multicenter Children's Oncology Group (COG) protocol. All samples were analyzed using multicolor flow cytometry in a standardized fashion at a single institution.

RESULTS

We report that markers of immaturity particularly, TdT and CD99, dramatically decline on leukemic blasts during therapy. CD34 and CD10 expression is confined to a minority of pretreatment samples and is also not stable. In contrast, lineage-associated markers including CD2, CD3, CD4, CD5, CD7, and CD8 failed to show significant trends.

CONCLUSIONS

Our study strongly argues for expansion of immunophenotyping panels for T-ALL MRD to decrease reliance on immature antigens. This study represents the first demonstration of consistent immunophenotypic shifts in T-ALL.