Leukemia’s Clonal Evolution in Development, Progression, and Relapse

Acute Kidney Injury after Bone Marrow Transplantation in Patients with Lymphomas and Leukemias

Introduction: Hematologic malignancies, including lymphomas and leukemias, may be treated with autologous or allogeneic bone marrow transplantation. However, these approaches can increase the risk of infection, sepsis, graft-versus-host disease, and nephrotoxicity, possibly resulting in acute kidney injury (AKI). Objective: To evaluate AKI in patients with lymphomas or leukemia submitted to bone marrow transplantation (BMT). Method: Retrospective, observational cohort study of cases from a database of 256 patients (53.9% males) hospitalized for BMT between 2012 and 2014 at a cancer hospital in Sao Paulo, Brazil. Of these, 79 were selected randomly for analysis. Demographic data, length of hospitalization, and associated morbidities were recorded. AKI was identified according to Kidney Diseases Improving Global Outcomes (KDIGO) criteria. Results: The most frequent diagnoses for the 79 cases were non-Hodgkin’s lymphoma (30.4%), acute myeloid leukemia (26.6%), and Hodgkin’s lymphoma (24.1%). The probability of 100 days-survival after BMT was 81%, and three years after BMT was 61%. In-hospital mortality was significantly higher among patients who presented AKI during hospitalization (p<0.001). However, there was no difference in overall life expectancy (p=0.770). Conclusion: A significant prevalence of AKI was found in patients with leukemia or lymphoma while they were hospitalized for BMT, resulting in significantly increased rates of in-hospital mortality. The presence of AKI during hospitalization was not associated with a subsequent reduction in life expectancy.

Preleukemic and leukemic evolution at the stem cell level

Hematological malignancies are an aggregate of diverse populations of cells that arise following a complex process of clonal evolution and selection. Recent approaches have facilitated the study of clonal populations and their evolution over time across multiple phenotypic cell populations. In this review, we present current concepts on the role of clonal evolution in leukemic initiation, disease progression, and relapse. We highlight recent advances and unanswered questions about the contribution of the hematopoietic stem cell population to these processes.

All-FIT: allele-frequency-based imputation of tumor purity from high-depth sequencing data

SUMMARY

Clinical sequencing aims to identify somatic mutations in cancer cells for accurate diagnosis and treatment. However, most widely used clinical assays lack patient-matched control DNA and additional analysis is needed to distinguish somatic and unfiltered germline variants. Such computational analyses require accurate assessment of tumor cell content in individual specimens. Histological estimates often do not corroborate with results from computational methods that are primarily designed for normal-tumor matched data and can be confounded by genomic heterogeneity and presence of sub-clonal mutations. Allele-frequency-based imputation of tumor (All-FIT) is an iterative weighted least square method to estimate specimen tumor purity based on the allele frequencies of variants detected in high-depth, targeted, clinical sequencing data. Using simulated and clinical data, we demonstrate All-FIT's accuracy and improved performance against leading computational approaches, highlighting the importance of interpreting purity estimates based on expected biology of tumors.

AVAILABILITY AND IMPLEMENTATION

Freely available at http://software.khiabanian-lab.org.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.