Genetic alterations in chronic lymphocytic leukaemia

Relapsed Chronic Lymphocytic Leukaemia with Concomitant Extensive Chronic Graft versus Host Disease after Allogeneic Haematopoietic Stem Cell Transplantation Successfully Treated with Oral Venetoclax

A middle-aged gentleman who was diagnosed with high-risk chronic lymphocytic leukaemia (CLL), Rai stage IV, Binet C with del(17p) and del(13q) underwent allogeneic haematopoeitic stem cell transplantation (allo-HSCT) from a human leukocyte antigen (HLA) identical sister. The patient developed extensive skin, oral, and liver chronic graft versus host disease (GVHD) required tacrolimus, mycophenolate mofetil (MMF), and prednisolone. At seventh month after allo-HSCT, the patient presented with systemic symptoms, right cervical lymphadenopathy, splenomegaly, marked pancytopaenia, and elevated lactate dehydrogenase (LDH). Bone marrow study, immunophenotyping (IP), chromosome analysis, and PET-CT scan confirmed relapsed CLL with no evidence of Richter's transformation or posttransplant lymphoproliferative disease (PTLD). Withdrawal of immunosuppressant (IS) worsened cutaneous and liver GVHD. Chemotherapy was not a suitable treatment option in view of immunodeficiency. The patient underwent extracorporeal photopheresis (ECP) therapy eventually for extensive chronic GVHD, and the IS were gradually tapered to the minimal effective dose. The relapsed CLL was treated successfully with oral venetoclax accessible via a compassionate drug program. This case highlights challenges in managing relapsed CLL and loss of graft-versus-leukaemia (GVL) effect despite extensive chronic GVHD. Venetoclax is an effective and well-tolerated oral novel agent for relapsed CLL after allo-HSCT.

Blockage of autophagic flux is associated with lymphocytosis and higher percentage of tumoral cells in chronic lymphocytic leukemia of B cells

PURPOSE

Autophagy has lately emerged as an important biological process with implications in several hematological pathologies. Recently, a growing body of evidence supports a putative role of autophagy in chronic lymphocytic leukemia; however, no definitive clue has been established so far. To elucidate this issue, we have developed a pilot study to measure autophagic flux in peripheral blood mononuclear cells from chronic lymphocytic leukemia patients, and explored its correlation with classical clinical/analytical parameters.

METHODS/PATIENTS

Thirty-three chronic lymphocytic leukemia patients participated in the study. Autophagic flux in peripheral blood mononuclear cells was determined by western blot measuring the levels of the proteins p62 and lipidated LC3. Moreover, p62 mRNA levels were analyzed by RT-qPCR.

RESULTS

Lymphocytosis and the percentage of tumoral lymphocytes in chronic lymphocytic leukemia patients statistically correlate with a blocked autophagic flux.

CONCLUSION

Alterations in autophagic flux could play an important role in the physiopathology of chronic lymphocytic leukemia.

The tumorigenic potential of pluripotent stem cells: What can we do to minimize it?

Human pluripotent stem cells (hPSCs) have the potential to fundamentally change the way that we go about treating and understanding human disease. Despite this extraordinary potential, these cells also have an innate capability to form tumors in immunocompromised individuals when they are introduced in their pluripotent state. Although current therapeutic strategies involve transplantation of only differentiated hPSC derivatives, there is still a concern that transplanted cell populations could contain a small percentage of cells that are not fully differentiated. In addition, these cells have been frequently reported to acquire genetic alterations that, in some cases, are associated with certain types of human cancers. Here, we try to separate the panic from reality and rationally evaluate the true tumorigenic potential of these cells. We also discuss a recent study examining the effect of culture conditions on the genetic integrity of hPSCs. Finally, we present a set of sensible guidelines for minimizing the tumorigenic potential of hPSC-derived cells. © 2016 The Authors. Inside the Cell published by Wiley Periodicals, Inc.

Contribution of MLPA to routine diagnostic testing of recurrent genomic aberrations in chronic lymphocytic leukemia

To better define the place of multiplex ligation-dependent probe amplification (MLPA) in routine cytogenetic diagnosis in chronic lymphocytic leukemia (CLL), we compared MLPA and fluorescence in situ hybridization (iFISH) data obtained in 77 CLL patients. Although MLPA detected most recurrent copy number genomic aberrations (90.9%), false-negative results were found in cases with small-size abnormal clones and false-positive MLPA findings resulting from point mutations (TP53) or an apparent lack of probe specificity (chromosome 19) were observed. Thus, MLPA may be a useful complementary but not alternative approach for iFISH testing of genomic aberration in CLL.

Multiplex ligation-dependent probe amplification and fluorescence in situ hybridization to detect chromosomal abnormalities in chronic lymphocytic leukemia: a comparative study

Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease characterized by recurrent chromosomal aberrations of prognostic significance. We aimed to evaluate the potential of the multiplex ligation-dependent probe amplification (MLPA) assay to detect genomic alterations in CLL. Highly purified (>90%) peripheral mononuclear CD19+ cell populations from 100 untreated CLL patients (pts) in early stage disease (Binet stage A) were included in this study. All samples were investigated by fluorescence in situ hybridization (FISH) for the presence of trisomy 12 and 17p13.1, 11q22.3, and 13q14.3 deletions. For MPLA analysis, DNA was amplified by means of two commercially available probes sets allowing the simultaneous screening of 56 genomic sequences. Overall, a high degree of concordance (95%) between MPLA and FISH results was found, if the abnormal clone was present in more than 30% of the leukemic cell population. The use of multiple MPLA probes allowed the fine-mapping of the 13q14 deletion and the identification of intragenic or small alterations undetected by FISH. Moreover, additional alterations in 2p24 (MYCN) (3 pts), 8q24 (MYC) (1 pt), 9p21 (CDKN2A2B) (1 pt), 1q21 (LMNA) (1 pt), and 6q25-26 (1 pt) regions not covered by a standard FISH assay were detected and all confirmed by FISH. Our data extend previously limited evidence that MLPA may represent a useful technique for the characterization of well-known lesions as well as the investigation of additional genomic changes in CLL.