Antigen Expression Varies Significantly between Molecular Subgroups of Acute Myeloid Leukemia Patients: Clinical Applicability Is Hampered by Establishment of Relevant Cutoffs.

Introduction: In this single-center study of 268 acute myeloid leukemia (AML) patients, we have tested if a subset of 4 routinely employed immunophenotypic stem cell-associated markers correlated with the presence of recurrently mutated genes and if the markers were predictive for mutational status.

Methods: Immunophenotypic data from 268 diagnostic AML samples obtained in 2009-2018 were analyzed retrospectively for the antigens CD34, CD117, CD123, and CLEC12A. Correlation between immunophenotypes and mutations was analyzed by Fischer's exact test.

Monoclonal B-cell lymphocytosis; not the same as B-cell chronic lymphocytic leukaemia.

Introduction: Depending on the location and the extent of disease, mature B-cell disorders can be divided into 
benign monoclonal B-cell lymphocytosis (MBL), chronic 
lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL). Whereas SLL is characterised by its location outside the blood stream, MBL is distinguished from CLL by a monoclonal B-cell count below 5 × 109/l. Due to its low tendency to transform into CLL, correct diagnosis of MBL is essential.

Combination of RNA- and exome sequencing: Increasing specificity for identification of somatic point mutations and indels in acute leukaemia.

Handling of large data sets from whole exome sequencing is a challenge, not the least because of the high risk of detecting false positive variants. Furthermore, there is still no consensus regarding what stage filtering of variants is performed in the bioinformatics pipeline to produce consistent result sets, the extent of filtering and how this is most optimal performed. We hypothesized that combination of coding transcriptome and exomes enables precise identification of both somatic single nucleotide and indel variants early in the bioinformatics process, superseding the need for extensive annotation and validation from external databases.

Kinetics of del(7q) driven leukemogenesis in a patient with JAK2 V617F and TET2 mutated chronic myeloproliferative neoplasm.

Chronic myeloid neoplasms have susceptibility to transform into acute myeloid leukemia due to attainment of additional molecular lesions. We here describe the kinetics of a del(7q) driven leukemogenesis in a patient with multiple TET2 mutations and JAK2 V617F mutated chronic myeloproliferative neoplasm. The del(7q) emerged in the accelerated phase of disease, which was preceded by a lag phase of almost three years with normalized peripheral blood cell counts.