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• A qPCR assay was developed for the quantification of a new mt-tRNA-derived fragment. • i-tRF-PheGAA can distinguish between CLL patients and normal controls. • An association was observed between i-tRF-PheGAA expression and CLL clinical stage. • Patients overexpressing i-tRF-PheGAA show significantly poorer overall survival. • The prognostic power of i-tRF-PheGAA is independent of established prognosticators. Chronic lymphocytic leukemia (CLL) is the most common leukemia among adults. The prognosis of CLL patients varies considerably. Transfer RNA-derived RNA fragments (tRFs) constitute a class of small non-coding RNA fragments excised from mature tRNAs and pre-tRNAs located in nuclei as well as in mitochondria. In this study, the clinical utility of i-tRF-PheGAA, a novel mitochondrial tRF, was investigated in CLL. Peripheral blood mononuclear cells (PBMCs) were isolated from 91 CLL patients and 43 non-leukemic controls. Total RNA was isolated from each sample, polyadenylated at the 3′ end and reversely transcribed. An in-house developed real-time quantitative PCR assay was developed and applied, and the results were biostatistically analyzed. For the normalization of the i-tRF-PheGAA expression levels, the expression of a small nucleolar RNA (RNU48) was used as reference. Mann-Whitney U test showed that i-tRF-PheGAA can distinguish between CLL samples and normal controls (p < 0.001). As determined by Kaplan-Meier survival analysis, overexpression of i-tRF-PheGAA was related to poor overall survival of the CLL patients (p < 0.001). Univariate bootstrap Cox regression analysis exhibited a higher hazard ratio of 7.95 (95% CI = 2.37–26.72, p < 0.001) for patients with positive i-tRF-PheGAA expression status. Multivariate bootstrap Cox regression analysis showed that the prognostic value of this tRF is independent of clinical stage, mutational status of the immunoglobulin heavy chain variable (IGHV) genetic locus, and CD38 expression status (p = 0.010). Our results show that i-tRF-PheGAA can serve as a molecular biomarker of poor prognosis in CLL, alongside with the existing factors for CLL prognosis. [ABSTRACT FROM AUTHOR]

MicroRNA-20b-5p (miR-20b-5p) is part of the miR-106a/363 cluster and a member of the cancer-related miR-17 family. miR-20b-5p regulates important transcription factors, including hypoxia-inducible factor 1 (HIF1) and signal transducer and activator of transcription 3 (STAT3). Recently, the dysregulation of miR-20b-5p expression has been observed in many B-cell lymphomas and T-cell leukemias. In this research study, we examined the putative prognostic value of miR-20b-5p in CLL. Therefore, total RNA was isolated from peripheral blood mononuclear cells (PBMCs) collected from 88 CLL patients; next, total RNA was polyadenylated and first-strand cDNA was synthesized, using an oligo-dT–adapter primer. miR-20b-5p expression was quantified using an in-house–developed real-time quantitative PCR assay. Kaplan-Meier OS analysis and bootstrap univariate Cox regression showed that high miR-20b-5p expression predicts better OS for CLL patients ( p <  0.001). Interestingly, miR-20b-5p overexpression retains its favorable prognostic role in CLL patients of intermediate risk or stratified according to established prognostic factors [CD38 expression and mutational status of the immunoglobulin heavy chain variable ( IGHV ) region]. In conclusion, miR-20b-5p is a potential independent molecular biomarker of favorable prognosis in CLL. [ABSTRACT FROM AUTHOR]

Accumulated data indicate a significant role of T cell dysfunction in the pathogenesis of chronic lymphocytic leukemia. In CLL, regulatory T cells are significantly higher and show lower apoptotic levels compared to healthy donors. We demonstrate that CLL derived CD4 + CD25 − CD127 − and CD4 + CD25 low CD127 − subpopulations share a common immunophenotypic profile with conventional Tregs and are associated with advanced stage disease. We further provide evidence that the increased number of Tregs contributes indirectly to the proliferation of the CLL clone, by suppressing the proliferation of Teffs which in turn suppress CLL cells. These data are further supported by our observations that CLL derived Tregs appear rather incapable of inducing apoptosis of both normal B cells and CLL cells, in contrast to normal Tregs, suggesting an immunoediting effect of CLL cells on Tregs which negatively affects the functionality of the latter and contributes to the failure of Tregs in CLL to efficiently eliminate the abnormal clone. [ABSTRACT FROM AUTHOR]

Anti-CD20-based chemo-immunotherapeutic regimens have been suggested to assist in the management of Epstein-Barr virus (EBV)-induced hemophagocytic lymphohistiocytosis (HLH) and EBV-associated post-transplant lymphoproliferative disorders (EBV-PTLD), by reducing EBV viral load and EBV-induced inflammation. Herein we report a fatal EBV-related HLH in the context of Hodgkin lymphoma (HL)-like Richter’s transformation of B chronic lymphocytic leukemia (B-CLL), two months after rituximab treatment. The complex balance between EBV driven T-cell stimulation and immunosuppressive therapy in the context of multiple immune deficits is discussed. [ABSTRACT FROM AUTHOR]

• An innovative qPCR method for quantification of i-tRF-GlyCCC levels was developed. • High i-tRF-GlyCCC expression predicts poor overall survival in CLL patients. • Prognostic significance of i-tRF-GlyCCC is independent of other prognostic factors. • i-tRF-GlyCCC is an unfavorable prognosticator in distinct subgroups of CLL patients Chronic lymphocytic leukemia (CLL) is one of the most common types of leukemia in adults. Several studies have identified various prognostic biomarkers in CLL. In this study, we investigated the potential value of an internal fragment of the tRNAs bearing the Glycine anticodon CCC (i-tRF-GlyCCC), which is a small non-coding RNA, as a prognostic and screening biomarker in CLL. For this purpose, blood samples were collected from 90 CLL patients and 43 non-leukemic blood donors. Peripheral blood mononuclear cells (PBMCs) were isolated, total RNA was extracted and in-vitro polyadenylated, and first-strand cDNA was synthesized using an oligo-dT–adaptor primer. A real-time quantitative PCR assay was developed and applied for the quantification of i-tRF-GlyCCC in our samples. The biostatistical analysis revealed that i-tRF-GlyCCC levels are significantly lower in PBMCs of CLL patients, compared to PBMCs of non-leukemic controls, and that i-tRF-GlyCCC could be considered as a screening biomarker. Kaplan-Meier overall survival (OS) analysis revealed reduced OS for CLL patients with positive i-tRF-GlyCCC expression (P = 0.001). Multivariate Cox regression confirmed its independent unfavorable prognostic power with regard to OS. In conclusion, i-tRF-GlyCCC may constitute a promising molecular biomarker in CLL, for screening and prognostic purposes. [ABSTRACT FROM AUTHOR]