Chronic Lymphocytic Research Articles

Genetic Profiling in Chronic Lymphocytic Leukemia: The Role of TP53 Mutations and IGHV Status in Treatment Decision-Making – A Case Report

Introduction. The TP53 gene encodes the p53 protein, crucial for DNA damage response, apoptosis, and cell cycle regulation. In chronic lymphocytic leukemia (CLL), TP53 loss due to 17p deletion or mutation leads to poor chemoimmunotherapy response and shorter survival. Patients with unmutated immunoglobulin heavy chain variable (IGHV) status exhibit a more aggressive disease course, poorer outcomes, and reduced response to standard chemoimmunotherapy. These genetic variations significantly affect disease progression, treatment choice, and response to therapy. Case Report. In November 2023, a 61-year-old man presented to our clinic with complaints of generalized weakness and rapid fatigue since October 2023. CLL was diagnosed in 2018 through pathohistological and immunohistochemical analysis of the bone marrow. The patient received no therapy until 2023 due to the absence of active disease signs. From March 28, 2023, to July 25, 2023, the patient received chemoimmunotherapy with the bendamustine and rituximab (BR) regimen. Five courses of therapy were administered; however, further treatment was discontinued due to side effects that occurred during the fifth course of bendamustine administration. A subsequent diagnostic evaluation aimed at assessing treatment efficacy, prognosis, and genetic profiling included a cytomorphological analysis, which revealed that lymphocytes comprised 80% of the cellular composition. Immunocytological analysis confirmed the presence of monoclonal atypical lymphocytes, accounting for 70% of the cell population. Next-generation sequencing identified a pathogenic TP53 mutation, and fragment analysis confirmed an unmutated IGHV status. The presence of the TP53 mutation and unmutated IGHV status categorizes the patient as being in the very high-risk group, for which the use of Bruton’s tyrosine kinase inhibitors (BTKIs) and/or B-cell lymphoma-2 (BCL-2) inhibitors is recommended. Conclusions. This case highlights the significance of comprehensive genetic profiling in CLL patients using techniques such as fluorescence in situ hybridization, polymerase chain reaction, and next-generation sequencing. Such profiling detects molecular genetic alterations, facilitating personalized and effective treatment.

TRIP13 is Critical for the Survival of B-cell Lymphomas and Myeloid Leukemias In Vitro

Hematologic malignancies represent a diverse group of blood tumors accounting for approximately 10% of all cancer cases in the US. Based on the site of manifestation, presumed cell of origin, genetic abnormalities, and clinical features, we recognize more than 100 clinically important subtypes of hematologic malignancies broadly categorized into three main groups: leukemia, lymphoma, and multiple myeloma. While the prognosis for patients with specific subtypes of hematologic malignancies, such as Hodgkin lymphomas or chronic lymphocytic leukemia has significantly improved over the last several years, other subtypes such as acute myeloid leukemia or non-Hodgkin lymphomas still present with significant treatment challenges. A better understanding of molecular drivers of tumor maintenance is needed to improve existing therapies. Thyroid hormone receptor interactor 13 (TRIP13) is an AAA + ATPase that plays an important yet poorly understood role in the regulation of the mammalian cell cycle. The TRIP13 gene is highly expressed in various human tumors including colorectal carcinoma and glioblastoma, and it seems to promote tumorigenesis. Recently, we identified TRIP13 as a gene overexpressed in Peripheral T-cell lymphomas where it plays a critical role in tumor maintenance by regulating the G2-M phase of the cell cycle. However, the biological activities of TRIP13 in non-T cell hematologic malignancies have not been investigated to date. Here we used shRNA-mediated knockdown and a small molecule inhibitor to downregulate TRIP13 in B-cell lymphoid and myeloid lineages. We found genetic downregulation inhibited the proliferation of both B-cell lymphomas and acute myeloid leukemia cell lines in vitro. The pharmacologic inhibition of TRIP13 effectively induced the G0/G1 cell cycle arrest and apoptosis of B-cell lymphomas. Altogether these data demonstrate that TRIP13 is critical for the maintenance of hematologic malignancies of B-cell and myeloid malignancies in vitro. Thus, TRIP13 might be a good target in the treatment of various types of hematologic malignancies.

Corynebacterium striatum

Abstract Corynebacterium striatum (C. striatum) is a rapidly emerging multidrug-resistant organism commonly found as a skin and respiratory tract commensal. The first case of C. striatum infection was published in 1980 in a patient with chronic lymphocytic leukemia who had a pleuropulmonary infection. The chemotherapeutic agents used in hematologic malignancies completely deplete neutrophils, making them susceptible to various pathogens such as C. striatum, which are rarely pathogenic. The spectrum of presentation due to C. striatum includes severe bloodstream infections, pneumonia, meningitis, and infective endocarditis. Some of the most common risk factors are prolonged neutropenia with various invasive devices and numerous prophylactic antibiotics. This article aims to present three cases of C. striatum infections in immunocompromised patients at H. Lee Moffitt Cancer Centre. In such rare cases, infection prevention and appropriate antibiotic coverage are the key to preventing such infections.

The chromosomal translocation t(1;6)(p35.3;p25.2), recurrent in chronic lymphocytic leukaemia, leads to RCC1::IRF4 fusion.

The chromosomal translocation t(1;6)(p35.3;p25.2) is a rare but recurrent aberration in chronic lymphocytic leukaemia (CLL). We report molecular characterization of 10 cases and show that this translocation juxtaposes interferon regulatory factor 4 (IRF4) on 6p25 with regulator of chromosome condensation 1 (RCC1) on 1p35. The breakpoints fell within the 5' untranslated regions of both genes, resulting in RCC1::IRF4 fusion transcripts without alterations of the protein-coding sequences. Levels of expression of both RCC1 and IRF4 proteins were not obviously deregulated. The cases showed other mutations typical of CLL and we confirm previously reported skewing towards the IGHV-unmutated subtype. RCC1::IRF4 fusion characterizes a rare subset of CLL.

Therapeutic strategies targeting aberrant RNA splicing in myeloid malignancies.

In recent years, large-scale sequencing efforts have identified targetable driver mutations in haematopoietic stem cells. These efforts have led to the development and approval of nine novel agents for relapsed or refractory acute myelogenous leukaemia (R/R AML). However, despite an expansion in targeted therapies, achieving a durable remission in AML and high-risk myelodysplastic syndrome (HR-MDS) remains a significant challenge, and there is an urgent need for new effective treatments. Modulation of aberrant RNA splicing has emerged as a novel therapeutic approach in myeloid diseases. Aberrant splicing drives dysregulated gene expression that promotes tumourigenesis through increased proliferation and metastatic potential, immune evasion, decreased apoptosis, and chemotherapy resistance. Mutations in spliceosomal components have been identified in numerous cancer subtypes, with mutations in RNA binding proteins SF3B1, SRSF2, U2AF1, and ZRSR2 occurring frequently in AML and in up to 60% of patients with MDS, as well as in chronic myelomonocytic leukaemia and in 10% of patients with chronic lymphocytic leukaemia. In this review, we explore therapeutic strategies targeting aberrant splicing and the potential of these approaches to drive clinical responses.

The discovery of the RCC1::IRF4 Fusion in CLL patients with t(1;6)(p35.3;p25.2) chromosomal translocation.

Jayne etal. provide a molecular characterization of the t(1;6)(p35.3;p25.2) chromosomal translocation in patients with chronic lymphocytic leukaemia. They indicate that this translocation involves the gene encoding interferon regulatory factor 4 (IRF4) on chromosome 6p25.2 with the regulator of chromosome condensation 1 (RCC1) gene on chromosome 1p35.3. This translocations may have important prognostic value. Commentary on: Jayne etal. The chromosomal translocation t(1;6)(p35.3;p25.2), recurrent in chronic lymphocytic leukaemia leads to RCC1::IRF4 fusion. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19790.

The Value of Sysmex White Precursor Cell Channel in Distinguishing Circulating Large Blastoid Lymphoma Cells from Blasts

Abstract Background There are rare cases of lymphoma presenting with circulating large blastoid cells mimicking blasts. These abnormal cells usually are medium to large in size with high nucleus-to-cytoplasmic ratio, fine to slightly condensed chromatin, prominent nucleoli, and scant to moderate amount of cytoplasm. Distinguishing them from real blasts is challenging, and although flow cytometry provides a definitive answer, pathologists may feel compelled to offer a quick preliminary assessment to the clinical team, particularly during weekends when flow cytometry is not accessible. We have recently replaced the old CBC instrument with Sysmex XN-9100 which incorporates a new white precursor cell channel (WPC). WPC channel is triggered only when Sysmex differential channels (WDF+WNR) produce a combined flag of “blasts/abnormal lymphocytes?”. The WPC will then separate this into a specific flag for either cell type or remove the flag if it is normal. Our study aims to explore the effectiveness of the WPC Channel in distinguishing blastoid lymphoma cells from true blasts. Method Between October 2023 and January 2024, we identified four lymphoma cases exhibiting circulating large blastoid cells. For comparative analysis, we included the most recent seven cases of acute myeloid leukemia (AML) and one case of acute lymphoblastic leukemia (ALL), all featuring medium to large-sized blasts. We collected results from initial testing (WDF+WNR) and WPC reflex testing. The reference for our analysis included manual differentials assisted by CellaVision, pathologist reviews, and immunophenotyping results. Results Within four blastoid lymphoma cases, two were diagnosed as blastoid high-grade B-cell lymphomas, one as diffuse large B-cell lymphoma, and another as chronic lymphocytic leukemia with many blast-like cells observed on the cytospin slide (no smear available). Pathologists reviewed the smears and slides of all four cases, categorizing them as blasts or blast-like cells before flow was run. All cases were initially flagged with “Blasts/Abnormal Lymphocyte?” on Sysmex differential channels but were subsequently flagged only with abnormal lymphocytes after the WPC reflex. For comparison, in 7 AML and 1 ALL cases, the WPC channel flagged blasts in 7 out of the 8 cases following the reflex of initial “Blasts/Abnormal Lymphocyte?” flag. The only case flagged with abnormal lymphocytes but not blasts was a case of AML with monocytic differentiation, characterized by many promonocytes and rare blasts. Conclusion The WPC channel accurately characterized the challenging large blastoid lymphoma cells as abnormal lymphocytes in all four cases, where morphology characterization was difficult. The study’s limitation lies in its small sample size. We are actively accumulating additional cases with circulating blastoid lymphoma cells, alongside control leukemia cases, to further assess the efficacy of the WPC channel.

A Rare Case of Diffuse Large B Cell Lymphoma Co-occurring with Small Lymphocytic Leukemia: De Novo Process or Richter’s Syndrome?

Abstract Introduction/Objective Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of lymphoma and can arise either de novo or through transformation from indolent lymphomas, such as Chronic Lymphocytic Leukemia (CLL), known as Richter syndrome (RS). DLBCL derived from RS tends to exhibit more aggressive behavior compared to de novo DLBCL. Methods/Case Report We present a case of a 57-year-old female with no significant medical history, who initially presented with antibiotic and prednisone-resistant sinusitis, progressing to bilateral neck pain and eye congestion. Computed tomography (CT) imaging revealed a 3 cm mass in the right nasal cavity extending to the right maxillary sinus and medial right orbit. Histopathological examination showed diffuse sheets of intermediate to large cells with irregular nuclear contours, dispersed chromatin, variably conspicuous nucleoli, and moderate cytoplasm. Additionally, scattered foci of monotonous, atypical lymphoid cells with lower grade morphology, including small size and condensed chromatin, were also present. Immunohistochemical analysis revealed differential staining patterns between the two cell populations. The larger atypical cells expressed CD20, PAX5, CD10, BCL-6, MUM1, BCL-2, MYC, CD19 (dim), and exhibited a high Ki-67 proliferation index (>80%). In contrast, the smaller atypical cells were positive for CD5, CD19, CD20, PAX5, BCL-2, and CD23 (subset), with a lower Ki-67 proliferation index (<5%). Flow cytometry analysis of tissue samples revealed two distinct clones: Surface Kappa-restricted CD19 dim B cells (38.9%) with CD5- CD10 dim CD20+ and surface Lambda-restricted CD19+ B cells (58.7%) with CD5+ CD10- CD20+. FISH analysis revealed no gene rearrangements. The final diagnosis was Diffuse large B-cell lymphoma, germinal center B- cell phenotype, with aggressive features and focal involvement by small lymphocytic lymphoma/chronic lymphocytic leukemia. Results (if a Case Study enter NA) NA Conclusion The relationship between the large B-cell lymphoma and SLL/CLL remains uncertain; however, given the different immunophenotype and light chain expression observed by flow cytometry, they are likely to represent separate processes.

Subclonal Populations Detected by Flow Cytometry in Chronic Lymphocytic Leukemia

Abstract Introduction Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a mature, small B-cell lymphoma that typically co-expresses CD5 and CD23. Molecular-targeted therapies have produced remarkable therapeutic benefits in CLL, yet many patients are resistant to treatment. This study aims to identify subpopulations in CLL by conventional flow cytometry and clustering analysis. Methods One-hundred-and-forty-one CLL cases were taken from a public database and analyzed by uniform manifold approximation and projection (UMAP). Differences in size, granularity, and intensities of CD19, CD20, CD79a, CD5, CD23, CD10, and FMC7 were plotted with BD FACSDiva Software. Eighteen cases with a new diagnosis of CLL at our institution between January 1, 2021 to December 31, 2022 were analyzed. Only peripheral blood samples were included. Markers including forward scatter, side scatter, and fluorescent intensities of CD19, CD20, CD5, CD23, CD10, surface kappa, and surface lambda were used to identify discrete CLL clusters in UMAP plots. Results: Public Dataset Clustering analysis of conventional flow cytometry data from 141 cases from a public database reveals discrete populations of cells exhibiting varying sizes, granularity and fluorescent intensities. Among the 141 cases, 33 (23.4%) had 1 cluster, 64 (45.4%) with 2 clusters, 42 (29.8%) with 3 clusters and 2 (1.4%) with 4 clusters. Among the cases with 2 clusters, a smaller population of cells deviated from the main neoplastic population. This smaller population had a higher forward and side scatter, and brighter intensities in CD45 and CD19, consistent with prolymphocytes. Among the cases with 3 clusters, a third population recurrently had a smaller size by forward scatter. A few cases additionally had varying intensities by CD23 and CD19. Among the 2 cases with 4 clusters, only slight deviations by UMAP were seen and may be artifactual. Institutional Dataset Clustering analysis of 18 cases at our institution revealed complex patterns of cell clusters exhibiting varying sizes, granularity and surface receptor expression intensity. Among the 18 cases, 1 (5.6%) had 1 cluster, 1 (5.6%) with 2 clusters, 10 (55.6%) with 3 clusters, 3 (16.7%) with 4 clusters, and 3 (16.7%) with 5 clusters. Similar to the public dataset, the third population, in addition to the predominant population and prolymphocytes, consistently varied by lower forward scatter. Additional clusters, such as a population with varying CD23 signal intensities, were identified in some cases. Conclusions In our study, multiple clonal subsets in CLL/SLL are detected by conventional flow cytometry analysis. These subclonal populations may result in therapy resistance for these patients, and identifying them by flow cytometry analysis may provide additional prognostic information in the clinical setting. Furthermore, the ability to detect these subclonal populations may allow for isolation of specific clones for future investigation in research settings.

MALTomas of the lung: A Clinicopathologic Review

Abstract Introduction/Objective MALTomas of the lung are the most common primary lymphoma of the lung. They are rare in clinical practice and have an indolent nature with a good prognosis and are often asymptomatic upon diagnosis. We undertook a retrospective study to assess the clinical and pathologic features of primary MALTomas of the lung. Methods/Case Report A search for lymphomas of the lung was done in our institutional archive of pathology from 1993-2023. The clinical and pathological data were reviewed in detail. Results (if a Case Study enter NA) There were a total of 51 cases of MALTomas recorded. Ages ranged from 35-88 years with an average age of 65 years old. 32 of the patients were female and 19 were male. Twenty eight of these cases involved the right lung, 18 affected the left lung, 5 cases had synchronoous involvement bilaterally. Thirteen (13/51) cases had extrapulmonary involvement, including the bone marrow, stomach, lymph nodes, thyroid, endometrium, eye, small bowel and pleura. 1/51 had synchronous follicular lymphoma and 2/51 had metachronous lymphoma (one large cell and one small lymphocytic lymphoma). 15/51 patients had bone marow biopsies, one of which developed multiple myeloma 7 years later. 10/51 patients had synchronous gastrointestinal epithelial lesions (9 tubular adenomas and 1 carcinoid tumor). 1/51 patients had a synchronous adenocarcinoma of the lung. 18 of the cases showed plasmacytic differentiation (8 kappa restricted and 10 lambda restricted). Conclusion Primary MALTomas of the lung are low grade malignancies that can have a more complex clinical scenario, such as multifocality or synchronous/metachronous lesions which can complicate clinical management.

Global chromatin reorganization and regulation of genes with specific evolutionary ages during differentiation and cancer.

Cancer cells are highly plastic, allowing them to adapt to changing conditions. Genes related to basic cellular processes evolved in ancient species, while more specialized genes appeared later with multicellularity (metazoan genes) or even after mammals evolved. Transcriptomic analyses have shown that ancient genes are up-regulated in cancer, while metazoan-origin genes are inactivated. Despite the importance of these observations, the underlying mechanisms remain unexplored. Here, we study local and global epigenomic mechanisms that may regulate genes from specific evolutionary periods. Using evolutionary gene age data, we characterize the epigenomic landscape, gene expression regulation, and chromatin organization in three cell types: human embryonic stem cells, normal B-cells, and primary cells from Chronic Lymphocytic Leukemia, a B-cell malignancy. We identify topological changes in chromatin organization during differentiation observing patterns in Polycomb repression and RNA Polymerase II pausing, which are reversed during oncogenesis. Beyond the non-random organization of genes and chromatin features in the 3D epigenome, we suggest that these patterns lead to preferential interactions among ancient, intermediate, and recent genes, mediated by RNA Polymerase II, Polycomb, and the lamina, respectively. Our findings shed light on gene regulation according to evolutionary age and suggest this organization changes across differentiation and oncogenesis.

Hesperidin as a bioactive compound in citrus fruits reduces N-ethyl-N-nitrosourea-induced mortality and toxicity in mice: as a model for chronic lymphocytic leukemia.

The current study is aimed at determining the preventive effects of hesperidin against death, weight changes, cellular damage, and oxidative stress in mice induced by n-ethyl-n-nitrosourea as a chronic lymphocytic leukemia (CLL) model. Female mice were pretreated with hesperidin (20 mg/kg, intraperitoneally, daily for 30 days). Next, the animals received a single intraperitoneal injection of 80 mg/kg ENU on the 30th. Changes in weight and mortality were monitored for 120 days, and then the animals were sacrificed and parameters such as reactive oxygen species (ROS), mitochondrial dysfunction, lysosomal membrane integrity, oxidized/reduced glutathione (GSH/GSSG), and malondialdehyde (MDA) were analyzed in isolated lymphocytes. Hesperidin significantly increases the survival of mice up to 86% and delay in death time and prevents weight changes after exposure to ENU. Also, hesperidin improved cellular toxicity parameters such as ROS formation, MMP collapse, lysosomal membrane destabilization, and lipid peroxidation in isolated lymphocytes. These results promisingly showed that pretreatment with hesperidin increases delay in death time and reduces mortality cellular toxicities consistent with the carcinogenicity of alkylating compounds. This study confirms that the consumption of hesperidin and citrus most likely inhibits alkylating agents-induced carcinogenicity and toxicity.

A 47-Year-old Asian female with tracheobronchial space-occupying lesions caused by chronic lymphocytic leukemia

Case presentationA 47-year-old Asian woman was admitted with worsening chest tightness and dyspnea for 10 days. Computed tomography (CT) showed changes in the trachea and segmental bronchi. Pulmonary function results suggestive of severe obstructive ventilatory dysfunction. Bronchoscopic findings showed the presence of multiple nodular lesions in the patient’s trachea and left and right main bronchi. Bronchoscopic biopsy, lymph node biopsy and bone marrow aspiration flow cytometry test results led to a definitive diagnosis of chronic lymphocytic leukemia (CLL), staged as Binet stage B and Rai stage 2.

Recent Advances in the Molecular Biology of Chronic Lymphocytic Leukemia: How to Define Prognosis and Guide Treatment

Chronic Lymphocytic Leukemia (CLL) is the most frequent type of leukemia in Western countries. In recent years, there have been important advances in the knowledge of molecular alterations that underlie the disease’s pathogenesis. Very heterogeneous prognostic subgroups have been identified by the mutational status of immunoglobulin heavy variable genes (IGVH), FISH analysis and molecular evaluation of TP53 mutations. Next-generation sequencing (NGS) technologies have provided a deeper characterization of the genomic and epigenomic landscape of CLL. New therapeutic targets have led to a progressive reduction of traditional chemoimmunotherapy in favor of specific biological agents. Furthermore, in the latest clinical trials, the minimal residual disease (MRD) has emerged as a potent marker of outcome and a guide to treatment duration. This review focuses on recent insights into the understanding of CLL biology. We also consider the translation of these findings into the development of risk-adapted and targeted therapeutic approaches.

Eosinophilic dermatosis of haematologic malignancy treated with ibrutinib: A case report

AbstractEosinophilic dermatosis of haematologic malignancy is an infrequent skin disorder characterised by severe pruritus and skin lesions resembling arthropod bites. It primarily affects individuals with underlying haematological conditions, most commonly chronic lymphocytic leukaemia (CLL). While it does not correlate with a worse prognosis for the haematological disease itself, it significantly impacts patients' quality of life due to the distressing pruritus and recurring nature. Clinical presentation typically shows erythematous papules resembling arthropod bites, with less frequent occurrences of urticarial plaques or bullous lesions. Histologically, an intense and polymorphous inflammatory infiltrate is found both in the superficial and deep dermis, marked by an abundance of eosinophils and the absence of atypical cells. Treatment of this disease remains uncertain, with corticosteroids often being the only effective therapy. Here, we present the case of an 80‐year‐old patient with a history of CLL, who experienced a widespread, itchy eruption of papules and plaques over 2 months. Despite various therapeutic attempts, the lesions only responded to high‐dose corticosteroids. Following the initiation of ibrutinib at a daily dose of 420 mg, both the skin lesions and pruritus resolved within 3 months. Ibrutinib, a tyrosine kinase inhibitor, is approved as a first‐line treatment for CLL. However, its potential as a remedy for refractory eosinophilic dermatosis has not been reported thus far.

The NOTCH1 and miR-34a signaling network is affected by TP53 alterations in CLL

In chronic lymphocytic leukemia (CLL), TP53 mutations or deletions on chromosome 17p lead to adverse prognosis and reduced levels of miR-34a, which targets NOTCH1. Also, hyperactivated NOTCH1 signaling is crucial for CLL progression. Here we explored the interaction between p53, miR-34a, and NOTCH1 in CLL. We investigated the effect of p53 and miR-34a on NOTCH1 signaling and expression in CLL cells with altered TP53. Our results indicate that miR-34a reduces NOTCH1 3’ UTR activity but might not be a mediator between p53 signaling and NOTCH1. p53 activation increases miR-34a expression and NOTCH1 protein levels, correlating with decreased NOTCH1 and miR-34a levels in primary CLL cells with TP53 alterations. Some samples with high NOTCH1 levels presented increased BCL-2, suggesting an anti-apoptotic mechanism of a potentially direct p53-NOTCH1 relation in CLL. This study deepens the understanding of the p53-miR-34a-NOTCH1 signaling network, providing insights that could guide future therapeutic strategies for CLL.

Comparing the Efficacy and Safety of First-Line Treatments for Chronic Lymphocytic Leukemia: A Network Meta-Analysis.

The Chronic Lymphocytic Leukemia (CLL) treatment strategies have transitioned from chemotherapy and chemoimmunotherapy to chemo-free regimens. Frequentist network meta-analysis allows for both direct and indirect comparisons between different treatments. Randomized controlled trials assessing first-line treatments were included. Outcomes were progression-free survival (PFS), overall survival, undetectable minimal residual disease (MRD), objective response rate, and adverse events. Studies with comparable characteristics also underwent subgroup analysis, stratifying by age, comorbidities, IGHV status, and cytogenetic abnormalities. 30 eligible trials involved 12,818 patients and 30 treatments were included. Acalabrutinib demonstrated a PFS advantage over ibrutinib and obinutuzumab-venetoclax (OV) in patients over 65 years old or with unmutated IGHV. In younger patients with comorbidities, Acalabrutinib-Obinutuzumab (AO) had superior PFS compared to Ibrutinib-Obinutuzumab (IO), Ibrutinib-Venetoclax (IV), and OV. For older patients with comorbidities, Acalabrutinib and AO both outperformed OV without significant difference between them. MRD-guided IV surpassed OV in patients without comorbidities. IO exhibited extended PFS benefits compared to OV in patients with mutated IGHV or with del(17p) and/or TP53 mutations. IV and IO have lower neutropenia rates than OV. IV have fewer infections than Acalabrutinib and AO. AO causes less diarrhea than IV but more headaches than IO and OV. OV has lower hypertension rates than IO. IV has fewer arthralgia than AO. For any grade secondary primary neoplasms, IV and OV is less than AO. Tailored chemo-free regimens can be selected based on age, comorbidities, IGHV status, and cytogenetic abnormalities to optimize treatment outcomes while considering different response spectra.

Impact of the clinically approved BTK inhibitors on the conformation of full-length BTK and analysis of the development of BTK resistance mutations in chronic lymphocytic leukemia.

Inhibition of Bruton's tyrosine kinase (BTK) has proven to be highly effective in the treatment of B-cell malignancies such as chronic lymphocytic leukemia (CLL), autoimmune disorders and multiple sclerosis. Since the approval of the first BTK inhibitor (BTKi), Ibrutinib, several other inhibitors including Acalabrutinib, Zanubrutinib, Tirabrutinib and Pirtobrutinib have been clinically approved. All are covalent active site inhibitors, with the exception of the reversible active site inhibitor Pirtobrutinib. The large number of available inhibitors for the BTK target creates challenges in choosing the most appropriate BTKi for treatment. Side-by-side comparisons in CLL have shown that different inhibitors may differ in their treatment efficacy. Moreover, the nature of the resistance mutations that arise in patients appears to depend on the specific BTKi administered. We have previously shown that Ibrutinib binding to the kinase active site causes unanticipated long-range effects on the global conformation of BTK (Joseph, R.E., et al., 2020, https://doi.org/10.7554/eLife.60470 ). Here we show that binding of each of the five approved BTKi to the kinase active site brings about distinct allosteric changes that alter the conformational equilibrium of full-length BTK. Additionally, we provide an explanation for the resistance mutation bias observed in CLL patients treated with different BTKi and characterize the mechanism of action of two common resistance mutations: BTK T474I and L528W.

Patient-Specific Nanoparticle Targeting in Human Leukemia Blood.

Antibody-directed targeting of chemotherapeutic nanoparticles to primary human cancers holds promise for improving efficacy and reducing off-target toxicity. However, clinical responses to targeted nanomedicines are highly variable. Herein, we prepared and examined a matrix of 9 particles (organic and inorganic particles of three surface chemistries with and without antibody functionalization) and developed an ex vivo model to study the person-specific targeting of nanoparticles in whole blood of 15 patients with chronic lymphocytic leukemia (CLL). Generally, anti-CD20-functionalized poly(ethylene glycol) (PEG) nanoparticles efficiently targeted CLL cells, leading to low off-target phagocytosis by granulocytes and monocytes in the blood. However, there was up to 164-fold patient-to-patient variability in the CLL targeting. This was further exemplified through using clinically relevant PEGylated doxorubicin-encapsulated liposomes, which showed high interpersonal differences in CLL targeting (up to 234-fold differences) and off-target phagocytosis (up to 65- and 112-fold differences in granulocytes and monocytes, respectively). Off-target phagocytosis led to almost all monocytes being killed within 24 h of treatment. Variance of the off-target association of PEGylated liposomes with granulocytes and monocytes significantly correlated to anti-PEG immunoglobulin G levels in the blood of CLL patients. A negative correlation between CLL targeting of PEG particles and anti-PEG immunoglobulin M levels was found in the blood. Taken together, our study identifies anti-PEG antibodies as key proteins in modulating patient-specific targeting of PEGylated nanoparticles in human leukemia blood. Other factors, such as the antigen expression of targeted cells and fouling properties of nanoparticles, also play an important role in patient-specific targeting. The human leukemia blood assay we developed provides an ex vivo model to evaluate interpersonal variances in response to targeted nanomedicines.

Manual flagging failed to identify pseudohyperkalemia in acute myeloid leukemia: case report

BackgroundPseudohyperkalemia is well known in acute or chronic lymphocytic leukemia, but it is very rare in acute myeloid leukemia (AML). The lab flagging system for leukocytosis to prevent pseudohyperkalemia may not work.Case presentationA 55 year-old white man with AML was sent to emergency department for transfusion due to severe anemia. Blood test showed severe leukocytosis and elevated potassium. Repeated blood test showed his potassium was even higher. Anti-hyperkalemic medical treatment was given. He was then diagnosed with pseudohyperkalema.InvestigationI was repeatedly reassured that the lab’s manual flagging system for leukocytosis was the key in reaching the correct diagnosis. My persistent inquiries, however, revealed that the flagging system was not functioning in the care of this patient. It was clinicians’ suspicion of pseudohyperkalema that led to the correct diagnosis, although the clinicians’ recommendation of obtaining a heparinized plasma for test did not play a role because all blood samples were already heparinized. The cause of pseudohyperkalemia was pneumatic tube transport. After this incident, our laboratory is investigating the options of using the Laboratory Information System to automatically flag the results and Clinical Laboratory Scientists to make the chemistry team more aware of potentially erroneous potassium results due to pseudohyperkalemia.ConclusionsPseudohyperkalemia associated with leukocytosis still occurs. This is the first case of pneumatic tube transport causing pseudohyperkalemia associated with AML. When significant leukocytosis, thrombocytosis, hyperproteinemia, or hyperlipidemia is present, whole blood should be utilized for potassium measurements and walked to the lab instead of sent by pneumatic tube transport. Even in a lab with a manual flagging system, there is still room to improve by implementing an automatic flagging system.