Cytophagic histiocytic panniculitis leading to a diagnosis of acute myeloid leukemia with monocytic differentiation: A case report and literature review.

Cytophagic histiocytic panniculitis (CHP) is associated with a number of systemic conditions and is characterized by the presence of benign phagocytic histiocytes ("bean bag cells"), including phagocytosed erythrocytes, leukocytes, and platelets. We describe a case of a 72-year-old female who presented with a papular eruption that clinically mimicked pityriasis lichenoides et varioliformis acuta (PLEVA). Given that her skin biopsy had multiple features concerning PLEVA, this diagnosis was classified as a superficial pityriasis lichenoides-like variant of CHP. The histopathologic presence of cytophagic histiocytosis prompted workup for a systemic malignancy, leading to a diagnosis of underlying acute monocytic leukemia of myeloid lineage.

Selective eradication of venetoclax-resistant monocytic acute myeloid leukemia with iron oxide nanozymes.

The clinical treatment of human acute myeloid leukemia (AML) is rapidly progressing from chemotherapy to targeted therapies led by the BCL-2 inhibitor venetoclax (VEN). Despite its unprecedented success, VEN still encounters clinical resistance. Thus, uncovering the biological vulnerability of VEN-resistant AML disease and identifying effective therapies to treat them are urgently needed. We have previously demonstrated that iron oxide nanozymes (IONE) are capable of overcoming chemoresistance in AML. The current study reports a new activity of IONE in overcoming VEN resistance. Specifically, we revealed an aberrant redox balance with excessive intracellular reactive oxygen species (ROS) in VEN-resistant monocytic AML. Treatment with IONE potently induced ROS-dependent cell death in monocytic AML in both cell lines and primary AML models. In primary AML with developmental heterogeneity containing primitive and monocytic subpopulations, IONE selectively eradicated the VEN-resistant ROS-high monocytic subpopulation, successfully resolving the challenge of developmental heterogeneity faced by VEN. Overall, our study revealed an aberrant redox balance as a therapeutic target for monocytic AML and identified a candidate IONE that could selectively and potently eradicate VEN-resistant monocytic disease.

On the mechanism of wogonin against acute monocytic leukemia using network pharmacology and experimental validation.

Wogonin is a natural flavone compound from the plant Scutellaria baicalensis, which has a variety of pharmacological activities such as anti-cancer, anti-virus, anti-inflammatory, and immune regulation. However, the potential mechanism of wogonin remains unknown. This study was to confirm the molecular mechanism of wogonin for acute monocytic leukemia treatment, known as AML-M5. The potential action targets between wogonin and acute monocytic leukemia were predicted from databases. The compound-target-pathway network and protein-protein interaction network (PPI) were constructed. The enrichment analysis of related targets and molecular docking were performed. The network pharmacological results of wogonin for AML-M5 treatment were verified using the THP-1 cell line. 71 target genes of wogonin associated with AML-M5 were found. The key genes TP53, SRC, AKT1, RELA, HSP90AA1, JUN, PIK3R1, and CCND1 were preliminarily found to be the potential central targets of wogonin for AML-M5 treatment. The PPI network analysis, GO analysis and KEGG pathway enrichment analysis demonstrated that the PI3K/AKT signaling pathway was the significant pathway in the wogonin for AML-M5 treatment. The antiproliferative effects of wogonin on THP-1 cells of AML-M5 presented a dose-dependent and time-dependent manner, inducing apoptosis, blocking the cell cycle at the G2/M phase, decreasing the expressions of CCND1, CDK2, and CyclinA2 mRNA, as well as AKT and p-AKT proteins. The mechanisms of wogonin on AML-M5 treatment may be associated with inhibiting cell proliferation and regulating the cell cycle via the PI3K/AKT signaling pathway.

A rare KMT2A::CBL transcript in an acute monoblastic leukemia patient with an unfavorable outcome.

BACKGROUND: Lysine [K] methyltransferase 2A (KMT2A, previously known as MLL) gene rearrangements are common in acute leukemias of various lineages and are associated with features such as chemotherapy resistance and rapid relapse. KMT2A::CBL is a rare fusion of unknown pathogenesis generated by a unique interstitial deletion of chromosome 11 that has been reported across a wide age range in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients. The leukemogenic effect of the KMT2A::CBL rearrangement and its association with clinical prognosis have not been well clarified. METHODS AND RESULTS: We report the case of a 64-year-old female who was diagnosed with acute monoblastic leukemia (M5a) and who acquired the rare KMT2A::CBL fusion. The patient received multiple cycles of therapy but did not achieve remission and eventually succumbed to severe infection and disease progression. Additionally, we characterized the predicted KMT2A-CBL protein structure in this case to reveal the underlying leukemogenic mechanisms and summarized reported cases of hematological malignancies with KMT2A::CBL fusion to investigate the correlation of gene rearrangements with clinical outcomes. CONCLUSIONS: This report provides novel insights into the leukemogenic potential of the KMT2A::CBL rearrangement and the correlation between gene rearrangements and clinical outcomes.

Organomegalies as a predictive indicator of leukemia cutis in patients with acute myeloid leukemia.

BACKGROUND: Leukemia cutis (LC) is an extramedullary acute myeloid leukemia (AML) infiltrate. No previous study has described the clinical characteristics and outcomes of Thai patients diagnosed with AML with LC. MATERIALS AND METHODS: We conducted a 7-year retrospective case-control study on Thai AML patients at Siriraj Hospital from November 2013 to July 2020. Patients were divided into LC and non-LC groups. Initial clinical presentations and laboratory findings were examined to identify LC-associated factors. Overall survival (OS) and relapse-free survival (RFS) were assessed. Pathological tissues underwent re-evaluation to validate the LC diagnoses. RESULTS: The study included 159 patients in a 2:1 ratio (106 non-LC and 53 LC). The LC group had a mean ± SD age of 54.3 ± 15.5 years; females were predominant. Three-fifths of the LC patients had intermediate-risk cytogenetics; 20.4% had an adverse risk, and 10.2% had a favorable risk. Most were classified as AML-M4 and AML-M5. Leukemic nodules were the primary finding in 58.5% of the cases, mainly on the legs. In the multivariate analysis of predictive factors associated with LC, organomegalies, specifically hepatomegaly, and lymphadenopathy, remained significant factors associated with LC [OR 4.45 (95%CI 1.20, 16.50); p = 0.026 and OR 5.48 (95%CI 1.65, 18.20); p = 0.005], respectively. The LC group demonstrated a significantly reduced OS (log-rank test p = 0.002) (median OS of 8.6 months vs. 32.4 months). RFS was considerably lower in the LC group (log-rank test p = 0.001) (median duration of 10.3 months vs. 24.4 months in the non-LC). CONCLUSIONS: AML patients who developed LC tended to experience notably poorer prognoses. Therefore, it is imperative to consider aggressive treatment options for such individuals. The presence of organomegalies in AML patients serves as a strong predictor of the possible occurrence of LC when accompanied by skin lesions.

Red cell exchange for rapid leukoreduction in adults with hyperleukocytosis and leukostasis.

ABSTRACT: We show that red cell exchange (RCE) treats hyperleukocytosis in acute leukemia. RCE provided similar leukoreduction to standard therapeutic leukoreduction and could be superior in patients with severe anemia or monocytic leukemias or when requiring rapid treatment.

Real-world genomic profiling of acute myeloid leukemia and the impact of European LeukemiaNet risk stratification 2022 update

Backgroung Acute myeloid leukemia (AML) is a myeloid neoplasm associated with a high morbidity and mortality. The diagnosis, risk stratification and therapy selection in AML have changed substantially in the last decade with the progressive incorporation of clinically relevant molecular markers. Methods In this work, our aim was to describe a real-world genomic profiling experience in AML and to demonstrate the impact of the European Leukemia Net 2022 update on risk stratification in AML. Results and Discussion One hundred and forty-one patients were evaluated with an amplicon-based multi-gene next-generation sequencing (NGS) panel. The most commonly mutated genes were FLT3, DNMT3A, RUNX1, IDH2, NPM1, ASXL1, SRSF2, NRAS, TP53 and TET2. Detection of FLT3 ITD with NGS had a sensitivity of 96.3% when compared to capillary electrophoresis. According to ELN 2017, 26.6%, 20.1%, and 53.3% of patients were classified as having a good, moderate, or unfavorable risk. When ELN 2022 was used, 15.6%, 27.8%, and 56.6% of patients were classified as favorable, moderate, or unfavorable risk, respectively. When ELN 2022 was compared to ELN 2017, thirteen patients (14.4%) exhibited a different risk classification, with a significant decrease in the number of favorable risk patients, what has immediate clinical impact. Conclusions In conclusion, we have described a real-world genomic profiling experience in AML and the impact of the 2022 ELN update on risk stratification (AU)

Influence of Microbiota-Related Metabolites Associated with Inflammation and Sepsis on the Peroxidase Activity of Cyclooxygenase in Healthy Human Monocytes and Acute Monocytic Leukemia Cells.

The human microbiota produces metabolites that can enter the bloodstream and exert systemic effects on various functions in both healthy and pathological states. We have studied the participation of microbiota-related metabolites in bacterial infection by examining their influence on the activity of cyclooxygenase (COX) as a key enzyme of inflammation. The influence of aromatic microbial metabolites, derivatives of phenylalanine (phenylpropionic acid, PPA), tyrosine (4-hydroxyphenyllactic acid, HPLA), and tryptophan (indolacetic acids, IAA), the concentrations of which in the blood change notably during sepsis, was evaluated. Also, the effect of itaconic acid (ITA) was studied, which is formed in macrophages under the action of bacterial lipopolysaccharides (LPS) and appears in the blood in the early stages of infection. Metabiotic acetyl phosphate (AcP) as a strong acetylating agent was also tested. The activity of COX was measured via the TMPD oxidation colorimetric assay using the commercial pure enzyme, cultured healthy monocytes, and the human acute monocytic leukemia cell line THP-1. All metabolites in the concentration range of 100-500 µM lowered the activity of COX. The most pronounced inhibition was observed on the commercial pure enzyme, reaching up to 40% in the presence of AcP and 20-30% in the presence of the other metabolites. On cell lysates, the effect of metabolites was preserved, although it significantly decreased, probably due to their interaction with other targets subject to redox-dependent and acetylation processes. The possible contribution of the redox-dependent action of microbial metabolites was confirmed by assessing the activity of the enzyme in the presence of thiol reagents and in model conditions, when the COX-formed peroxy intermediate was replaced with tert-butyl hydroperoxide (TBH). The data show the involvement of the microbial metabolites in the regulation of COX activity, probably due to their influence on the peroxidase activity of the enzyme.

Anti-inflammatory effects of cold atmospheric plasma irradiation on the THP-1 human acute monocytic leukemia cell line.

Cold atmospheric plasma (CAP) has been studied and clinically applied to treat chronic wounds, cancer, periodontitis, and other diseases. CAP exerts cytotoxic, bactericidal, cell-proliferative, and anti-inflammatory effects on living tissues by generating reactive species. Therefore, CAP holds promise as a treatment for diseases involving chronic inflammation and bacterial infections. However, the cellular mechanisms underlying these anti-inflammatory effects of CAP are still unclear. Thus, this study aimed to elucidate the anti-inflammatory mechanisms of CAP in vitro. The human acute monocytic leukemia cell line, THP-1, was stimulated with lipopolysaccharide and irradiated with CAP, and the cytotoxic effects of CAP were evaluated. Time-course differentiation of gene expression was analyzed, and key transcription factors were identified via transcriptome analysis. Additionally, the nuclear localization of the CAP-induced transcription factor was examined using western blotting. The results indicated that CAP showed no cytotoxic effects after less than 70 s of irradiation and significantly inhibited interleukin 6 (IL6) expression after more than 40 s of irradiation. Transcriptome analysis revealed many differentially expressed genes (DEGs) following CAP irradiation at all time points. Cluster analysis classified the DEGs into four distinct groups, each with time-dependent characteristics. Gene ontology and gene set enrichment analyses revealed CAP-induced suppression of IL6 production, other inflammatory responses, and the expression of genes related to major histocompatibility complex (MHC) class II. Transcription factor analysis suggested that nuclear factor erythroid 2-related factor 2 (NRF2), which suppresses intracellular oxidative stress, is the most activated transcription factor. Contrarily, regulatory factor X5, which regulates MHC class II expression, is the most suppressed transcription factor. Western blotting revealed the nuclear localization of NRF2 following CAP irradiation. These data suggest that CAP suppresses the inflammatory response, possibly by promoting NRF2 nuclear translocation.

The Potential Use of THP-1, a Monocytic Leukemia Cell Line, to Predict Immune-Suppressive Potency of Human Bone-Marrow Stromal Cells (BMSCs) In Vitro: A Pilot Study.

Adoptive transfer of cultured BMSCs was shown to be immune-suppressive in various inflammatory settings. Many factors play a role in the process, but no master regulator of BMSC-driven immunomodulation was identified. Consequently, an assay that might predict BMSC product efficacy is still unavailable. Below, we show that BMSC donor variability can be monitored by IL-10 production of monocytes/macrophages using THP-1 cells (immortalized monocytic leukemia cells) co-cultured with BMSCs. Using a mixed lymphocyte reaction (MLR) assay, we also compared the ability of the different donor BMSCs to suppress T-cell proliferation, another measure of their immune-suppressive ability. We found that the BMSCs from a donor that induced the most IL-10 production were also the most efficient in suppressing T-cell proliferation. Transcriptome studies showed that the most potent BMSC batch also had higher expression of several known key immunomodulatory molecules such as hepatocyte growth factor (HGF), PDL1, and numerous members of the PGE2 pathway, including PTGS1 and TLR4. Multiplex ELISA experiments revealed higher expression of HGF and IL6 by the most potent BMSC donor. Based on these findings, we propose that THP-1 cells may be used to assess BMSC immunosuppressive activity as a product characterization assay.

Pediatric acute myeloid leukemia and hyperleukocytosis with WBC count greater than 50 × 109/L.

BACKGROUND: Acute myeloid leukemia (AML) and hyperleukocytosis have an unfavorable prognosis, but the impact of hyperleukocytosis on the prognosis of pediatric AML remains uncertain. We investigated the clinical characteristics and prognosis of pediatric AML with hyperleukocytosis, defined as WBC ≥ 50 × 109/L. METHODS: A total of 132 patients with newly diagnosed childhood AML with hyperleukocytosis were consecutively enrolled at our center from September 2009 to August 2021 to investigate prognostic factors and clinical outcomes. RESULTS: Hyperleukocytosis occurred in 27.4% of AML patients. Pediatric patients with hyperleukocytosis had similar CR and OS rates to those without hyperleukocytosis, but had a lower EFS rate. In our study, rates of CR1, mortality, relapsed/refractory disease, and HSCT were comparable between AML patients with WBC counts of 50-100 × 109/L and ≥ 100 × 109/L. AML patients with a WBC count of 50-100 × 109/L had a similar 5-year OS rate to patients with a WBC count ≥ 100 × 109/L (74.6% vs. 75.4%, P = 0.921). Among all patients with hyperleukocytosis, the FAB M5 subtype was associated with significantly inferior survival, and the prognosis of CBF-AML was good. CONCLUSIONS: Pediatric AML patients with hyperleukocytosis have the similar prognosis regardless of whether their WBC count is 50-100 × 109/L or ≥ 100 × 109/L.

Leukemia cutis - A case of cutaneous manifestation of acute monoblastic leukemia.

Leukemia cutis is a comprehensive terminology for dermal manifestations of any type of leukemia either with accompanied or antecedent blood or bone marrow involvement. Although both myeloid and lymphoid neoplastic leukocytes can infiltrate the skin, the frequency is higher among children with congenital myeloid leukemia. However, the underlying pathogenesis of dermal tropism is not yet established. Clinical manifestation varies regarding appearance, site, and numbers. Skin biopsy is essential for the early establishment of the diagnosis and to guide for further testing and categorical management. We report the case of acute myeloid leukemia-cutis in a 22-year-old female where cutaneous manifestation preceded the hematological diagnosis of systemic leukemia.

Rare Case of Refractory Hypokalemia in a Patient with Acute Monocytic Leukemia.

BACKGROUND Refractory hypokalemia has been rarely demonstrated in patients with acute monocytic leukemia (AMoL). Hypokalemia develops in these patients owing to renal tubular dysfunction, secondary to lysozyme enzymes that are released by monocytes in AMoL. Additionally, renin-like substances are produced from monocytes and can lead to hypokalemia and metabolic alkalosis. There is also an entity called spurious hypokalemia, in which high numbers of metabolically active cells in blood samples increase sodium-potassium ATPase activity, resulting in influx of potassium. Additional research is warranted regarding this specific demographic to create standardized treatment approaches to electrolyte repletion. CASE REPORT In this case report, we demonstrate a rare case of an 82-year-old woman with AMoL, complicated by refractory hypokalemia, who presented with concerns of fatigue. The patient's initial laboratory results were significant for leukocytosis with monocytosis and severe hypokalemia. Refractory hypokalemia was noted, despite administration of aggressive repletions. During her hospitalization, AMoL was diagnosed and an extensive workup was performed to evaluate the underlying cause of hypokalemia. Ultimately, the patient died on day 4 of hospitalization. We describe the correlation between severe refractory hypokalemia and leukocytosis and provide a literature review of multiple etiologies of refractory hypokalemia in patients with AMoL. CONCLUSIONS We evaluated the numerous pathophysiologic mechanisms responsible for refractory hypokalemia in patients with AMoL. Our therapeutic outcomes were limited owing to the patient's early death. It is of high importance to evaluate the underlying cause of hypokalemia in these patients and to treat accordingly with caution.

Acute monocytic leukemia with KMT2A::LASP1 developed 9 months after diagnosis of acute megakaryoblastic leukemia in a 2-year-old boy.

Acute myeloid leukemia (AML) is known as one of the subsequent malignant neoplasms that can develop after cancer treatment, but it is difficult to distinguish from relapse when the preceding cancer is leukemia. We report a 2-year-old boy who developed acute megakaryoblastic leukemia (AMKL, French-American-British classification [FAB]: M7) at 18 months of age and achieved complete remission with multi-agent chemotherapy without hematopoietic stem cell transplantation. Nine months after diagnosis and 4 months after completing treatment for AMKL, he developed acute monocytic leukemia (AMoL) with the KMT2A::LASP1 chimeric gene (FAB: M5b). The second complete remission was achieved using multi-agent chemotherapy and he underwent cord blood transplantation 4 months after AMoL was diagnosed. He is currently alive and disease free at 39 and 48 months since his AMoL and AMKL diagnoses, respectively. Retrospective analysis revealed that the KMT2A::LASP1 chimeric gene was detected 4 months after diagnosis of AMKL. Common somatic mutations were not detected in AMKL or AMoL and no germline pathogenic variants were detected. Since the patient's AMoL was different from his primary leukemia of AMKL in terms of morphological, genomic, and molecular analysis, we concluded that he developed a subsequent leukemia rather than a relapse of his primary leukemia.

Antiproliferative Potential of Olneya tesota PF2 Lectin in Human Acute Monocytic Leukemia Cells.

Acute monocytic leukemia is a type of myeloid leukemia that develops in monocytes. The current clinical therapies for leukemia are unsatisfactory due to their side effects and nonspecificity toward target cells. Some lectins display antitumor activity and may specifically recognize cancer cells by binding to carbohydrate structures on their surface. Therefore, this study evaluated the response of the human monocytic leukemia cell lines THP-1 to the Olneya tesota PF2 lectin. The induction of apoptosis and reactive oxygen species production in PF2-treated cells was evaluated by flow cytometry, and the lectin-THP-1 cell interaction and mitochondrial membrane potential were evaluated by confocal fluorescence microscopy. PF2 genotoxicity was evaluated by DNA fragmentation analysis via gel electrophoresis. The results showed that PF2 binds to THP-1 cells, triggers apoptosis and DNA degradation, changes the mitochondrial membrane potential, and increases reactive oxygen species levels in PF2-treated THP-1 cells. These results suggest the potential use of PF2 for developing alternative anticancer treatments with enhanced specificity.

Isofraxidin enhances hyperthermia­induced apoptosis via redox modification in acute monocytic leukemia U937 cells.

The cell­killing potential of most chemotherapeutic agents is enhanced by a temperature elevation. Isofraxidin (IF) is a coumarin compound widely found in plants, such as the Umbelliferae or Chloranthaceae families. IF induces anticancer effects in lung and colorectal cancer. To the best of our knowledge, the combined effects of hyperthermia (HT) and IF on heat­induced apoptosis have not been reported. Acute monocytic leukemia U937 cells were exposed to HT with or without IF pre­treatment. Apoptosis was measured by Annexin V­FITC/PI double staining assay using flow cytometry and cell viability was observed by cell counting kit assay, DNA fragmentation. The mechanism involved in the combination was explored by measuring changes in the mitochondrial membrane potential, (MMP), intracellular ROS generation, expression of apoptosis related protein, and intracellular calcium ion level. It was demonstrated that IF enhanced HT­induced apoptosis in U937 cells. The results demonstrated that combined treatment enhanced mitochondrial membrane potential loss and transient superoxide generation increased protein expression levels of caspase­3, caspase­8 and phosphorylated­JNK and intracellular calcium levels. Moreover, the role of caspases and JNK was confirmed using a pan caspase inhibitor (zVAD­FMK) and JNK inhibitor (SP600125) in U937 cells. Collectively, the data demonstrated that IF enhanced HT­induced apoptosis via a reactive oxygen species mediated mitochondria/caspase­dependent pathway in U937 cells.

Leukemic retinopathy presenting as concurrent bilateral subhyaloid hemorrhage and subarachnoid hemorrhage in a patient with acute monocytic leukemia: a case report.

BACKGROUND: Ophthalmic manifestations are common in patients with leukemia, developing in nearly 50% of cases. Intracranial hemorrhage is another potentially fatal complication of leukemia. In this case report, we aim to present a challenging case that involves both ophthalmic and intracranial manifestations in an individual with acute monocytic leukemia. CASE PRESENTATION: A 36-year-old Persian male presented to the emergency room with complaints of fever, headache, and bilateral blurred vision. The patient had been diagnosed with acute monocytic leukemia 3 months prior and had undergone four sessions of induction chemotherapy, the last of which was 10 days prior to admission. The patient was admitted to the internal medicine service, and initial lab studies confirmed pancytopenia, including severe neutropenia, anemia, and thrombocytopenia. Subarachnoid hemorrhage in the left frontal lobe was detected through spiral brain computed tomography scan. Ophthalmic examination revealed visual acuity of light perception in the right eye and 3-m finger count in the left eye. Fundus examination revealed bilateral peripapillary subhyaloid and intraretinal hemorrhages, confirming leukemic retinopathy. The patient showed significant improvement in visual acuity and hemorrhage resolution through conservative treatment and regular follow-ups after 3 months. CONCLUSION: Simultaneous subarachnoid hemorrhage and bilateral subhyaloid hemorrhages seemed to have occurred as a result of pancytopenia. Management approach of ophthalmic manifestations of leukemia involves interdisciplinary cooperation and should be individualized on the basis of the patients' underlying medical condition.