Chimeric antigen receptor T cells for acute myeloid leukemia.

The use of T cells expressing chimeric antigen receptors (CARs) that can target and eliminate cancer cells has revolutionized the treatment of B-cell malignancies. In contrast, CAR T cells have not yet become a routine treatment for myeloid malignancies such as acute myeloid leukemia (AML) or myeloproliferative neoplasms (MPNs). For these disease entities, allogeneic hematopoietic cell transplantation (allo-HCT) relying on polyclonal allo-reactive T cells is still the major cellular immunotherapy used in clinical routine. Here, we discuss major hurdles of CAR T-cell therapy for myeloid malignancies and novel approaches to enhance their efficacy and reduce toxicity. Heterogeneity of the malignant myeloid clone, CAR T-cell induced toxicity against normal hematopoietic cells, lack of long-term CAR T-cell persistence, and loss or downregulation of targetable antigens on myeloid cells are obstacles for successful CAR T cells therapy against AML and MPNs. Strategies to overcome these hurdles include pharmacological interventions, for example, demethylating therapy to increase target antigen expression, multi-targeted CAR T cells, and gene-therapy based approaches that delete the CAR target antigen in the hematopoietic cells of the recipient to protect them from CAR-induced myelotoxicity. Most of these approaches are still in preclinical testing but may reach the clinic in the coming years. In summary, we report on barriers to CAR T-cell use against AML and novel therapeutic strategies to overcome these challenges, with the goal of clinical treatment of myeloid malignancies with CAR T cells.

Administration mode matters for 5-fluorouracil therapy: Physiologically based pharmacokinetic evidence for avoidance of myelotoxicity by continuous infusion but not intravenous bolus.

AIMS: Pre-emptive prediction to avoid myelosuppression and harmful sequelae is difficult given the complex interplay among patients, drugs and treatment protocols. This study aimed to model plasma and bone marrow concentrations and the likelihood of myelotoxicity following administration of 5-fluorouracil (5-FU) by diverse intravenous (IV) bolus or continuous infusion (cIF) regimens. METHODS: Using physicochemical, in vitro and clinical data obtained from the literature consisting of various regimens and patient cohorts, a 5-FU physiologically based pharmacokinetic (PBPK) model was developed. The predicted and observed PK values were compared to assess model performance prior to examining myelotoxicity potential of IV bolus vs. cIF and DPYD wild type vs. genetic variant. RESULTS: The established model was verified by utilizing 5-FU concentration-time profiles of adequate heterogeneity contributed by 36 regimens from 15 studies. The study provided corroborative evidence to explain why cIF (vs. IV bolus) had lower myelotoxicity risk despite much higher total doses. The PBPK model was used to estimate the optimal dosage in patients heterozygous for the DPYD c.1905 + 1G > A allele and suggested that a dose reduction of at least 25% was needed (compared to the dose in wild-type subjects). CONCLUSION: A verified PBPK model was used to explain the lower myelotoxicity risk of cIF vs. IV bolus administration of 5-FU and to estimate the dose reduction needed in carriers of a DPYD variant. With appropriate data, expertise and resources, PBPK models have many potential uses in precision medicine application of oncology drugs.

Mercaptopurine induced myelosuppression in a child with a NUDT15 rs116855232 homozygous variant.

INTRODUCTION: Mercaptopurine (6-MP) is the backbone of the consolidation and maintenance therapy for paediatric acute lymphoblastic leukaemia (ALL). Nevertheless, it can cause critical myelosuppression. Predicting adverse reactions to 6-MP often involves the investigation of pharmacogenetic variants; in particular thiopurine S-methyltransferase (TPMT) and nudix hydrolase 15 (NUDT15). Lately, NUDT15 variants have been shown to play a significant pharmacogenetic role in predicting 6-MP intolerance in children of Asian descent. CASE REPORT: We present a six-year-old male child of Indian origin with persistent cytopenia after treatment. This prompted targeted sequencing of the genes TPMT and NUD15. The results revealed two copies of the variant of NUD15 rs116855232, that is, NUDT15*2 genotype. MANAGEMENT AND OUTCOME: Since the NUDT15*2 allele classified the patient as a poor metabolizer, he was restarted on a low dose of 6-MP, which he tolerated. DISCUSSION: Individuals with the NUDT15*2allele (*2/*2 genotype) are poor metabolizers of thiopurines which results in an adverse reaction to 6-MP. About 3.5% of Indians show variations in the TPMT gene as compared to 19.4% variations observed in NUDT15, which makes the latter a more reliable disease marker.

Temozolomide-induced myelotoxicity and single nucleotide polymorphisms in the MGMT gene in patients with adult diffuse glioma: a single-institutional pharmacogenetic study.

PURPOSE: Nearly 10% of patients with adult diffuse glioma develop clinically significant myelotoxicity while on temozolomide (TMZ) leading to treatment interruptions. This study aimed to assess single nucleotide polymorphisms (SNPs) in the O6-methylguanine-DNA methyltransferase (MGMT) gene in adults with biopsy-proven diffuse glioma who develop TMZ-induced myelotoxicity and correlate their presence with severity and duration of such toxicity. METHODS: This study assessed 33 adults treated with TMZ for diffuse glioma who developed ≥ grade 2 thrombocytopenia and/or ≥ grade 3 neutropenia. Genomic DNA was extracted from peripheral blood cells for MGMT SNP analysis after written informed consent. TMZ-induced severe myelotoxicity (≥ grade 3) was correlated with three specified SNPs commonly seen in the MGMT gene (L84F, I143V/K178R) using chi-square test or Fischer's exact test as appropriate. RESULTS: Of the 33 adults, 24 (72.7%) experienced ≥ grade 3 thrombocytopenia and/or neutropenia, while 9 (27.3%) developed grade 2 thrombocytopenia only. The variant T allele of L84F was expressed in 28.7% (19/66) of analyzed alleles, which was substantially higher than previously reported for South Asian ancestry. The variant G allele of I143V/K178R was expressed in 9.3% (6/64) of analyzed alleles. Of which 3 patients showed statistically significant association with prolonged myelosuppression for > 2 months (p = 0.03). No significant correlation was established between the mentioned SNPs and severe myelotoxicity. CONCLUSIONS: There is substantially higher frequency of variant T allele (L84F) in Indian patients than previously reported for South Asians. The presence of specific SNPs in the MGMT gene correlates with prolonged duration but not severity of TMZ-induced myelotoxicity.

Cytokinetic-driven myeloprotection after cytotoxic chemotherapy: from an old idea to a new clinical approach.

Chemotherapy is the backbone of the treatment of several solid tumours and lymphomas. Myelotoxicity is often a dose-limiting toxicity and myeloprotection has always been investigated. In fact, over the years, several approaches have been studied in order to reduce the incidence of haematological toxicities and allow patients to receive effective, full-dose, chemotherapy. After the use of stimulating factors, such as granulocyte colony-stimulating factors and erythropoiesis-stimulating agents, in the very last years, a new approach has emerged. Trilaciclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor, has been studied and it has been demonstrated in several clinical trials to reduce the incidence of myelotoxicity in small-cell lung cancer patients treated with chemotherapy or chemo-immunotherapy. Its potential role has not been fully studied yet, but it represents a highly effective tool to reduce myelotoxicity, widen the applicability of full-dose chemotherapy, even in frailer patients, and finally to increase the efficacy of chemotherapy in those tumours where relative dose intensity is a standard to achieve to get the best clinical results.

Influence of allopurinol on thiopurine associated toxicity: A retrospective population-based cohort study.

AIMS: Thiopurines are important for treating inflammatory bowel disease, but are often discontinued due to adverse effects. Concomitant use of allopurinol might lower the risk of these unwanted effects, but large studies in the general population are lacking. The aims of this study were to evaluate rates of hepatotoxicity, myelotoxicity, pancreas toxicity and therapy persistence in adult thiopurine users with or without allopurinol. METHODS: A retrospective population-based cohort study was conducted within current thiopurine users (Clinical Practice Research Datalink). Among these patients, co-use of allopurinol was compared to non-use. Hazard ratios (HRs) for hepatotoxicity, myelotoxicity and pancreatitis were derived using time-dependent Cox proportional hazards models, and were adjusted for potential confounders. Persistence of thiopurine use was evaluated using Log-rank statistics. RESULTS: Patients using thiopurines (n = 37 360) were identified of which 1077 were concomitantly taking allopurinol. A 58% decreased risk of hepatotoxicity was observed in those concomitantly taking allopurinol (HR 0.42; 95% CI 0.30-0.60; NNT 46). Rate of myelotoxicity (HR 0.96; 95% CI 0.89-1.03) was not influenced. Risk of pancreatitis was increased (HR 3.00; 95% CI 1.01-8.93; NNH 337), but was only seen in those with active gout (suggesting confounding by indication). Finally, allopurinol co-users were able to maintain thiopurine therapy over twice as long as those not on allopurinol (3.9 years vs. 1.8 years, P < 0.0001). CONCLUSION: In thiopurine users, allopurinol is associated with a 58% reduced risk of hepatotoxicity. In addition, thiopurine persistence was prolonged by 2.1 years in allopurinol users. These data support the use of allopurinol in individuals requiring thiopurine therapy.

Optimization of the IL-2 Luc assay for immunosuppressive drugs: a novel in vitro immunotoxicity test with high sensitivity and predictivity.

We have reported that the IL-2 Luc assay can detect the effects of chemicals on IL-2 promoter activity by using a dual reporter cell line, 2H4 cells that measure IL-2 promoter-driven luciferase activity (IL2LA) and GAPDH promoter-driven luciferase activity (GAPLA). Since the IL-2 Luc assay cannot detect immunosuppressive drugs that are antimitotic towards rapidly proliferating cells, we attempted to establish a new assay to detect these chemicals by taking advantage of the dual reporter cell properties of 2H4 cells. We first determined the optimal incubation time with drugs and the seeding cell density, and confirmed that the change in GAPLA and IL2LA levels reflects the change in cell count and IL-2 production of 2H4 cells after drug treatment. We designed the IL-2 luciferase lymphotoxicity test (IL-2 Luc LTT) to detect the antimitotic effects of chemicals by modifying the protocol and criteria of the IL-2 Luc assay. To determine the performance of the IL-2 Luc LTT and that of the combination of the IL-2 Luc LTT and the IL-2 Luc assay, we examined 46 drugs: 19 immunosuppressive drugs with different mechanisms of action, 12 anti-cancer drugs, and 15 non-immunosuppressive drugs. The performances of the IL-2 Luc LTT, the IL-2 Luc assay and their combination were 43.3%, 61.3%, and 93.3%, respectively, for sensitivity, 84.6%, 53.3%, and 50.0%, respectively, for specificity, and 55.8%, 58.7%, and 79.5%, respectively, for accuracy. These results demonstrated that the combination of these two assays is promising for the detection of immunosuppressive drugs with different mechanisms of action.

Daily Intravenous Infusion of Busulfan Impurity 5 for 4 Days Is Not Associated With Toxic Effects in the Rat.

The alkylating agent busulfan is used in conditioning treatment of chronic myelogenous or granulocytic leukemia prior to stem cell transplantations. Its cytotoxic activity results in primary damage or destruction of hematopoietic cells. While the toxicity of busulfan is well investigated, little is known about the toxic effects of its impurities. In this study, the effect of 4-day intravenous infusion (3 h/d) of 4.8 mg/kg/d busulfan and 0.49, 4.9, and 49 mg/kg/d busulfan impurity 5 (4-((methylsulfonyl)oxy)butyl acetate) was investigated in rats. Whereas busulfan elicited myelotoxic and hepatotoxic effects, no toxic effects were observed in animals receiving the impurity at dosages up to 10 times higher than busulfan. The highest impurity dose of 49 mg/kg/d is therefore considered the no-observed-adverse-effect level of busulfan impurity 5.

Cellular and Molecular Mechanisms of Environmental Pollutants on Hematopoiesis.

Hematopoiesis is a complex and intricate process that aims to replenish blood components in a constant fashion. It is orchestrated mostly by hematopoietic progenitor cells (hematopoietic stem cells (HSCs)) that are capable of self-renewal and differentiation. These cells can originate other cell subtypes that are responsible for maintaining vital functions, mediate innate and adaptive immune responses, provide tissues with oxygen, and control coagulation. Hematopoiesis in adults takes place in the bone marrow, which is endowed with an extensive vasculature conferring an intense flow of cells. A myriad of cell subtypes can be found in the bone marrow at different levels of activation, being also under constant action of an extensive amount of diverse chemical mediators and enzymatic systems. Bone marrow platelets, mature erythrocytes and leukocytes are delivered into the bloodstream readily available to meet body demands. Leukocytes circulate and reach different tissues, returning or not returning to the bloodstream. Senescent leukocytes, specially granulocytes, return to the bone marrow to be phagocytized by macrophages, restarting granulopoiesis. The constant high production and delivery of cells into the bloodstream, alongside the fact that blood cells can also circulate between tissues, makes the hematopoietic system a prime target for toxic agents to act upon, making the understanding of the bone marrow microenvironment vital for both toxicological sciences and risk assessment. Environmental and occupational pollutants, therapeutic molecules, drugs of abuse, and even nutritional status can directly affect progenitor cells at their differentiation and maturation stages, altering behavior and function of blood compounds and resulting in impaired immune responses, anemias, leukemias, and blood coagulation disturbances. This review aims to describe the most recently investigated molecular and cellular toxicity mechanisms of current major environmental pollutants on hematopoiesis in the bone marrow.

Use of Cardioprotective Dexrazoxane Is Associated with Increased Myelotoxicity in Anthracycline-Treated Soft-Tissue Sarcoma Patients.

BACKGROUND: Dexrazoxane (DEX) is indicated as a cardioprotective agent for breast cancer patients receiving the anthracycline doxorubicin. Two meta-analyses in metastatic breast cancer reported an apparent increase in the severity of myelosuppression when DEX was used. So far, no data in soft-tissue sarcoma (STS) patients are available. METHODS: We retrospectively analyzed hematological toxicity data from 133 consecutive STS patients who received a chemotherapy regimen containing an anthracycline and ifosfamide (AI) in the perioperative or metastatic settings between January 2006 and December 2017. Of these, 46 received off-label DEX concurrently with the AI treatment. The differences between incidence of any of the explored outcomes were assessed according to the Fisher exact test. RESULTS: Compared with the non-DEX group, DEX treatment was associated with significantly higher rates of grade 3/4 hematological toxicities: leukopenia (56.5 vs. 28.7%; p = 0.0014), neutropenia (69.6 vs. 24.1%; p = 0.0001), febrile neutropenia (52.2 vs. 20.7%; p = 0.0004), anemia (41.3 vs. 28.7%; p = 0.1758), and thrombocytopenia (54.3 vs. 32.1%; p = 0.0159). Similarly, in the DEX group dose reductions were more frequent compared to the non-DEX group (39.1 vs. 19.5%; p = 0.0221). CONCLUSION: Adding DEX to AI in STS patients leads to higher rates of bone marrow suppression in all blood components, as well as to more frequent events of febrile neutropenia and dose reductions.

Incidence and attributes of chemotherapy induced myelotoxicity, anemia and neutropenia in adults with cancer in Nepal: A cross-sectional observational study.

BACKGROUND: Myelosuppression remains a major toxicity in cancer patients receiving chemotherapy, and is associated with considerable morbidity, mortality and cost. OBJECTIVE: The present study aims to investigate the prevalence and incidence of myelotoxicity, anemia and neutropenia in the adult cancer population, and further to determine the factors influencing them. METHODS: This was a cross-sectional observational study conducted at National Academy of Medical Sciences, Bir Hospital, Kathmandu. A total of 170 subjects eligible for the study were enrolled for analysis. Prevalence and incidence of myelotoxicity anemia, neutropenia and myelotoxicity at enrollment and during study were investigated. Factors influencing development of myelotoxic event were determined. RESULTS: Of 170 enrolled patients, the prevalence of myelotoxicity, anemia and neutropenia at enrolment was 54 (31.8%), 20 (11.8%) and 28 (16.6%), respectively, with 27 (16%) mild and 12 (7.1%) moderate type of anemia. Incidence of myelotoxicity, anemia and neutropenia during treatment was 90 (52.94%), 44 (26%) and 53 (31.2%) respectively, with 70 (41.2%) mild, 39 (22.9%) moderate and 5 (2.9%) severe type of anemia. Age (OR: 0.49; p < 0.047), and baseline Hb (OR: 1.29; p < 0.01) were found to be independent predictors associated with anemia. Hb (OR: 2.42, CI: 1.79-3.28; p < 0.001) and smoking (OR: 0.49: p = 0.03) were found to be independent factors associated myelotoxicity. CONCLUSION: Our study confirmed a high incidence rate of myelotoxicity, neutropenia and anemia in a considerable number of Nepalese cancer patients receiving chemotherapy, and that baseline Hb, smoker and older adults are at more risk, these patients should be evaluated carefully and a prophylactic measure should be adopted accordingly so as to prevent toxicity and improve quality of life during cancer treatment.

Effect of Primary and Secondary Beads of Carbon Enterosorbent on Haematological Parameters and Oxidative Stress Development Caused by Melphalan in Rats.

Background and Objectives: Side effects of anti-cancer drugs are usually accompanied by oxidative stress, including myelotoxicity. We evaluated the potential of oral highly activated micro-/macroporous carbon adsorbents (bulk density of 0.16 g/cm3, surface area calculation by Brunauer-Emmett-Teller model (SBET) > 2200 m2/g, derived from proprietary phenolic resin beads) to alleviate oxidative stress and myelotoxicity in rats. Materials and Methods: A single injection of cytostatic melphalan (L-PAM) at a dose of 4 mg/kg was used for modelling. Two forms of activated carbon were used: AC1-primary beads with the particle size range of 125-250 µm, and AC2-micronized AC1 with a mean particle size of ~1 µm. We measured haematological parameters white blood cells, red blood cells, platelet count, and haemoglobin level. Oxidative stress intensity was evaluated using the following markers: total levels of reactive oxygen species (ROS) in blood plasma; catalase activity (CAT) and pro-oxidant/antioxidant ratio in blood haemolysate samples; level of reduced glutathione (GSH) in liver tissues; oxidative modification of proteins, OPM (APHD, aldehyde-dinitrophenylhydrazone derivatives and KPHD, ketone dinitrophenylhydrazone derivatives) and malonic dialdehyde (MDA) in blood plasma and liver samples. Results: AC2 administration promoted significant myeloprotective effect: 1.5-fold increase in leukocytes, 2-fold in neutrophils, 1.5-fold in lymphocytes, and 1.23-fold in platelet count compared to the experimental Melphalan Group. At the same time, AC1 administration resulted in a slight increase in haematological parameters. Both ACs positively corrected important, but diverse, components of oxidative stress. They significantly reduced oxidative modification of blood and liver proteins (especially the AC1 form), normalized the level of reduced glutathione, pro-oxidant/antioxidant ratio and other markers. For some markers, such as ROS production in blood plasma, the use of enterosorbents resulted in non-significant a shift towards normal parameters. Conclusions: Oral activated carbon adsorbents reduce oxidative stress intensity and myelotoxicity; they can be promising means to combat the adverse effects of chemotherapy in clinical practice.

Modification of the Myelotoxic and Antitumor Effects of Polychemotherapy by Polysaccharides from Tussilago farfara L.

The experiments on C57Bl/6 mice with Lewis lung carcinoma showed that addition of Tussilago farfara L. polysaccharides to conventional cisplatin/paclitaxel polychemotherapy moderated neutropenia caused by antitumor therapy and increased its efficiency. The stimulating effect of polysaccharides on the granulopoietic lineage cells is comparable with that of recombinant CSF Neupogen.

Acute and late toxicities of pirarubicin in the treatment of childhood acute lymphoblastic leukemia: results from a clinical trial by the Japan Association of Childhood Leukemia Study.

BACKGROUND: Anthracyclines are used to treat childhood acute lymphoblastic leukemia (ALL). Even when administered at low doses, these agents are reported to cause progressive cardiac dysfunction. We conducted a clinical trial comparing the toxicities of two anthracyclines, pirarubicin (THP) and daunorubicin (DNR), in the treatment of childhood ALL. The results from our study that relate to acute and late toxicities are reported here. METHODS: 276 children with B-ALL were enrolled in the trial from April 1997 to March 2002 and were randomly assigned to receive a regimen including either THP (25 mg/m2 × 11) or DNR (30 mg/m2 × 11). Acute toxicity was prospectively assessed based on the National Cancer Institute Common Toxicity Criteria. Acute hematological toxicity was also examined via some parameters. Patients with event-free survival of >5 years were retrospectively surveyed for cardiac function at 5 and 10 years and at the most recent assessment more than 10 years from the onset of ALL. RESULTS: Acute hematological toxicity in the early phase was more significant in the THP arm. Based on ultrasound cardiography, cardiac function was impaired in both groups during the follow-up period, but there was no significant difference between the groups except for a greater decline in fractional shortening on ultrasound cardiography in the DNR arm. CONCLUSIONS: While acute hematological toxicity was more significant in the THP arm, THP also appeared to be less cardiotoxic. However, the evaluation of late cardiotoxicity was limited because only a few subjects were followed beyond 10 years after ALL onset. Considering that the THP regimen produced an EFS rate comparable with that of the DNR regimen, the efficacy and toxicity of THP at reduced doses should be studied in order to identify potentially safer regimens.

Aqueous extract of Phragmitis rhizoma ameliorates myelotoxicity of docetaxel in vitro and in vivo.

BACKGROUND: A variety of anticancer chemotherapeutics induce adverse side effects including myelotoxicity. Dried roots of Phragmites communis Trinius, Phragmitis rhizoma, have been clinically used in traditional folk medicine to relieve various symptoms like fever. In this study, we evaluated the protective effect of the aqueous extract of Phragmitis rhizoma (EPR) against docetaxel-induced myelotoxicity in vitro and in vivo. METHODS: The in vitro myelo-protective effect of EPR was evaluated using the colony forming unit (CFU) assay with hematopoietic progenitor cells. The in vivo efficacy of EPR was evaluated in myelosuppressed C57BL/6 male mice which were induced by repeated intraperitoneal injections of 30 mg/kg docetaxel for 3 times. EPR was orally administered for 4 days to docetaxel-induced myelosuppressed C57BL/6 male mice which were induced by intraperitoneal injection of 30 mg/kg docetaxel for 3 times: Group 1 (vehicle control, n = 10), Group 2 (docetaxel plus vehicle, n = 10), Group 3 (docetaxel plus EPR 30 mg/kg, n = 10), Group 4 (docetaxel plus EPR 100 mg/kg, n = 10) and Group 5 (docetaxel plus EPR 300 mg/kg, n = 10). Whole blood counts were measured automatically, and immune organs were histologically examined. Expression of immunomodulatory cytokines was measured by quantitative real-time polymerase chain reaction or enzyme-linked immunosorbent assay. The toxicity of EPR itself was evaluated in normal human cell lines including IMR-90, foreskin fibroblast and human umbilical vein endothelial cells. The hepatotoxicity of EPR was predicted by multi-parametric assays involving cell viability, caspase 3/7 activity, GSH contents and LDH leakage using the HepaRG hepatic cell line. RESULTS: Co-treatment of EPR or its major component, p-hydroxycinnamic acid, increased the numbers of hematopoietic CFU counts in the docetaxel-induced in vitro myelotoxicity assay system. The in vitro protective effect of EPR against docetaxel toxicity was replicated in a myelosuppressed animal model: white blood cells, neutrophils, lymphocytes and red blood cells rebounded; bone marrow niche and structural integrity of the thymus were preserved; and the expression of immune-stimulating cytokines including IL3, IL6, SCF and GM-CSF was enhanced. Furthermore, EPR and p-hydroxycinnamic acid promoted the proliferation of primary splenocytes and thymocytes. In the toxicity assays, no remarkable signs related with toxicity were observed in all tested normal human cells and HepaRG. CONCLUSIONS: EPR has the potential to ameliorate docetaxel-mediated myelotoxicity in both in vitro and in vivo models. However, the identification of the responsible active components and the precise underlying myelo-protective mechanism of EPR need to be elucidated before novel drug development using EPR can precede.

In silico prediction of drug-induced myelotoxicity by using Naïve Bayes method.

Drug-induced myelotoxicity usually leads to decrease the production of platelets, red cells, and white cells. Thus, early identification and characterization of myelotoxicity hazard in drug development is very necessary. The purpose of this investigation was to develop a prediction model of drug-induced myelotoxicity by using a Naïve Bayes classifier. For comparison, other prediction models based on support vector machine and single-hidden-layer feed-forward neural network  methods were also established. Among all the prediction models, the Naïve Bayes classification model showed the best prediction performance, which offered an average overall prediction accuracy of [Formula: see text] for the training set and [Formula: see text] for the external test set. The significant contributions of this study are that we first developed a Naïve Bayes classification model of drug-induced myelotoxicity adverse effect using a larger scale dataset, which could be employed for the prediction of drug-induced myelotoxicity. In addition, several important molecular descriptors and substructures of myelotoxic compounds have been identified, which should be taken into consideration in the design of new candidate compounds to produce safer and more effective drugs, ultimately reducing the attrition rate in later stages of drug development.

Myeloperoxidase inhibition protects bone marrow mononuclear cells from DNA damage induced by the TOP2 poison anti-cancer drug etoposide.

Myeloperoxidase (MPO) is found almost exclusively in granulocytes and immature myeloid cells. It plays a key role in the innate immune system, catalysing the formation of reactive oxygen species that are important in anti-microbial action, but MPO also oxidatively transforms the topoisomerase II (TOP2) poison etoposide to chemical forms that have elevated DNA damaging properties. TOP2 poisons such as etoposide are widely used anti-cancer drugs, but they are linked to cases of secondary acute myeloid leukaemias through a mechanism that involves DNA damage and presumably erroneous repair leading to leukaemogenic chromosome translocations. This leads to the possibility that myeloperoxidase inhibitors could reduce the rate of therapy-related leukaemia by protecting haematopoietic cells from TOP2 poison-mediated genotoxic damage while preserving the anti-cancer efficacy of the treatment. We show here that myeloperoxidase inhibition reduces etoposide-induced TOP2B-DNA covalent complexes and resulting DNA double-strand break formation in primary ex vivo expanded CD34+ progenitor cells and unfractionated bone marrow mononuclear cells. Since MPO inhibitors are currently being developed as anti-inflammatory agents this raises the possibility that repurposing of these potential new drugs could provide a means of suppressing secondary acute myeloid leukaemias associated with therapies containing TOP2 poisons.

Cerebral toxoplasmosis in HIV-infected patients: a review.

Toxoplasma gondii infection in the central nervous system commonly occurs among immunodeficient patients. Its prevalence is high in countries with a high burden of HIV and low coverage of antiretroviral drugs. The brain is one of the predilections for T. gondii infection due to its low inflammatory reaction, and cerebral toxoplasmosis occurs solely due to the reactivation of a latent infection rather than a new infection. Several immune elements have recently been recognized to have an essential role in the immunopathogenesis of cerebral toxoplasmosis. Although real-time isothermal amplification, next-generation sequencing, and enzyme-linked aptamer assays from blood samples have been the recommended diagnostic tools in some in-vivo studies, a combination of clinical symptoms, serology examination, and neuroimaging are still the daily standard for the presumptive diagnosis of cerebral toxoplasmosis and early anti-toxoplasma administration. Clinical trials are needed to find a new therapy that is less likely to affect folate synthesis, have neuroprotective properties, or cure the latent phase of infection. The development of a vaccine is being extensively tested in animals, but its efficacy and safety for humans are still not proven.

Advancing CART therapy for acute myeloid leukemia: recent breakthroughs and strategies for future development.

Chimeric antigen receptor (CAR) T therapies are being developed for acute myeloid leukemia (AML) on the basis of the results obtained for other haematological malignancies and the need of new treatments for relapsed and refractory AML. The biggest challenge of CART therapy for AML is to identify a specific target antigen, since antigens expressed in AML cells are usually shared with healthy haematopoietic stem cells (HSC). The concomitant expression of the target antigen on both tumour and HSC may lead to on-target/off-tumour toxicity. In this review, we guide researchers to design, develop, and translate to the clinic CART therapies for the treatment of AML. Specifically, we describe what issues have to be considered to design these therapies; what in vitro and in vivo assays can be used to prove their efficacy and safety; and what expertise and facilities are needed to treat and manage patients at the hospital.

Azathioprine-Induced Marrow Suppression in Dermatology Patients - Analysis of 18 Patients.

Background: Azathioprine is an immunosuppressant used to treat several immunological disorders. As a purine analog, it inhibits DNA synthesis and cell multiplication. However, marrow suppression is a serious complication associated with azathioprine. Aim: To analyze the marrow suppression caused by azathioprine in dermatology patients. Material and Method: This is a retrospective analysis of the records of 18 patients who presented with marrow suppression secondary to azathioprine which was used for the treatment of various dermatological diseases. Results: The analysis includes 18 patients, 15 females and 3 males with the average age being 25.88 years. All except two patients received 1 mg/kg of oral azathioprine once daily. Leukopenia was seen in 13 patients (with severe leukopenia in 7 patients), thrombocytopenia in 8, and low hemoglobin in 14 patients. Isolated low hemoglobin was seen in four patients, isolated leukopenia in four patients, and only one patient presented with isolated thrombocytopenia. Six patients had pancytopenia. The duration from the starting dose to reporting of marrow suppression ranged from 10 days to 1 year. Eight out of 18 patients presented with anagen effluvium, 2 patients with oral ulcers, and 1 patient with an upper respiratory tract infection. All the patients recovered within 1 month. Conclusion: Marrow suppression due to azathioprine can occur with a low dose of 1 mg/kg. Hair loss and oral ulcers serve as early warning signs for marrow suppression.