Impact of Folinic Acid Dosing on Efficacy and Toxicity of High-Dose Methotrexate in Central Nervous System Lymphoma.

INTRODUCTION: High-dose methotrexate (HDMTX)-based regimens are the treatment of choice in primary central nervous system lymphoma (PCNSL). Folinic acid (FA) rescue is used to mitigate the toxic effects of MTX on normal cells. However, the optimal dosing of FA in PCNSL remains uncertain. METHODS: We analyzed the relationship between FA dosing and treatment efficacy and toxicity in a cohort of 36 PCNSL patients treated at our institute between the years 2014 and 2022. A combination of univariate and multivariate analyses using known prognostic factors were used to determine the association between FA dosing and treatment outcomes. RESULTS: We found that higher per-treatment cumulative FA doses were associated with inferior progression-free survival (PFS), with a hazard ratio (HR) of 2.2 for each 100 mg/m2 increase in FA dose. We identified a threshold of 350 mg/m2/treatment, above which there was a significant reduction in PFS. Notably, lower FA doses did not result in increased toxicity. CONCLUSION: Our findings suggest that optimizing FA dosing to avoid very high rescue doses may improve treatment outcomes in PCNSL patients receiving HDMTX. Further prospective studies are warranted to validate these findings.

Peripheral Blood Cell Mitochondrial Dysfunction in Myelodysplastic Syndrome Can Be Improved by a Combination of Coenzyme Q10 and Carnitine.

Structural mitochondrial abnormalities and genetic aberrations in mitochondrial proteins have been known in Myelodysplastic syndrome (MDS), yet there is currently little data regarding MDS's metabolic properties and energy production cells. In the current study, we used state-of-the-art methods to assess OXPHOS in peripheral blood cells obtained from MDS patients and healthy controls. We then assessed the effect of food supplements-Coenzyme Q10 and carnitine on mitochondrial function and hematological response. We show here for the first time that there is a significant impairment of mitochondrial respiration in peripheral blood cells in low-risk MDS, which can be improved with food supplements. We also show that these supplements may improve the cytopenia and quality of life.

[THE ROLE OF THE PLANT ARTEMISIA IN SURVIVAL AND INDUCTION OF APOPTOSIS OF B CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL)].

BACKGROUND: The cytotoxic effect of plants such as green tea and turmeric (curcumin) on B chronic lymphocytic leukemia (CLL) cells has been established. The plant Artemisia has been used in China for anti-cancer and anti-malaria applications. In Israel, Artemisia absinthium ("the Chiba") is used to release abdominal pain. In attempts to evaluate the cytotoxic effect of this plant in CLL cells, we prepared a decoction of Artemisia leaves and after filtration used it as an inducer of apoptosis of B CLL cells. METHODS: CLL cells were collected from 7 patients in different stages of the disease. Apoptosis was measured using an annexin based flow cytometry assay. RESULTS: First a viability test showed that 100µl/106 cells was the most effective dilution for killing up to 70% cells after 48 hours of incubation. In these conditions Artemisia induced approximately 75% apoptosis in comparison to 32% in the cultures without Artemisia. CONCLUSIONS: We concluded that decoction of Artemisia absinthium is a potent inducer of in vitro apoptosis of CLL cells. Our results provide a laboratory basis for further clinical application.

Loss of Muscle MTCH2 Increases Whole-Body Energy Utilization and Protects from Diet-Induced Obesity.

Mitochondrial carrier homolog 2 (MTCH2) is a repressor of mitochondrial oxidative phosphorylation (OXPHOS), and its locus is associated with increased BMI in humans. Here, we demonstrate that mice deficient in muscle MTCH2 are protected from diet-induced obesity and hyperinsulinemia and that they demonstrate increased energy expenditure. Deletion of muscle MTCH2 also increases mitochondrial OXPHOS and mass, triggers conversion from glycolytic to oxidative fibers, increases capacity for endurance exercise, and increases heart function. Moreover, metabolic profiling of mice deficient in muscle MTCH2 reveals a preference for carbohydrate utilization and an increase in mitochondria and glycolytic flux in muscles. Thus, MTCH2 is a critical player in muscle biology, modulating metabolism and mitochondria mass as well as impacting whole-body energy homeostasis.

Balancing glycolysis and mitochondrial OXPHOS: lessons from the hematopoietic system and exercising muscles.

Living organisms require a constant supply of safe and efficient energy to maintain homeostasis and to allow locomotion of single cells, tissues and the entire organism. The source of energy can be glycolysis, a simple series of enzymatic reactions in the cytosol, or a much more complex process in the mitochondria, oxidative phosphorylation (OXPHOS). In this review we will examine how does the organism balance its source of energy in two seemingly distinct and unrelated processes: hematopoiesis and exercise. In both processes we will show the importance of the metabolic program and its regulation. We will also discuss the importance of oxygen availability not as a sole determinant, but in the context of the nutrient and cellular state, and address the emerging role of lactate as an energy source and signaling molecule in health and disease.

Can a rare form of myasthenia gravis shed additional light on disease mechanisms?

A healthy 43-year-old physician developed gradually progressive and fluctuating fatigable muscle weakness involving ocular, limb, bulbar and respiratory muscles, with episodic acute respiratory failure, eventually necessitating intermittent non-invasive respiratory support (NIV). A mild short episode occurred 15 years earlier with complete resolution. Electromyography (EMG) studies and acetylcholine receptor (AchR) antibodies were repeatedly non-diagnostic. The diagnosis of myasthenia gravis (MG) was finally confirmed by direct measurement of diaphragmatic strength using magnetic nerve stimulation providing clear cut evidence of significant fatigable weakness and the demonstration of muscle-specific kinase (MuSK) serum antibodies using a novel cell-based assay. The cluster of several atypical features and lack of response to commonly used treatment modalities prompted a search for a unifying mechanism and better understanding of the underlying pathophysiology. Review of the literature suggested a possible impairment of excitation-contraction coupling with malfunction of a signaling protein downstream to the AchR, without an accompanying impairment of electrical transmission. This postulated mechanism, resulting in a disturbance of calcium signaling, explained the unusual features in this patient's illness and led to treatment with salbutamol and ephedrine and to significant symptomatic improvement not achieved by any other treatment.

Benefits versus risks of pharmacological prophylaxis to prevent symptomatic venous thromboembolism in unselected medical patients revisited. Meta-analysis of the medical literature.

A significant proportion of the outcomes reported in trials assessing venous thromboembolism (VTE) prophylaxis in medical patients are related to asymptomatic events found on routine imaging studies. The implications of these events are controversial. Moreover, such trials did not always reflect the patient mix in today's internal medicine departments. We summarized the evidence assessing the rate of symptomatic VTE events and the benefit of pharmacological prophylaxis in unselected medical patients, and formally evaluated the benefit versus risk of this intervention. We searched MEDLINE, EMBASE and CENTRAL until June 2011 for studies that prospectively followed cohorts of medical patients and assessed the rates of VTE, and randomized controlled trials reporting the effect of prophylaxis on these events, at 3 weeks and 3 months. Eight trials were included. The rates of symptomatic VTE were 0.69 and 3.7 % for short term and long term follow-up periods, respectively. In the interventional meta-analysis, the odds ratio (OR) for overall mortality and for symptomatic VTE at 3 weeks were 0.93 and 0.59, favouring intervention. The OR for major bleeding at 3 weeks was 2.0, favouring no intervention. None of these results were statistically significant. The number needed to treat to prevent one overt VTE event was 292, while the number needed to treat for an additional major bleeding was 336. In unselected medical patients, the rate of symptomatic VTE is lower than the reported overall VTE rate, and the benefit to risk ratio of pharmacological intervention for alleviating this condition in at-risk medical inpatient is questionable. Further specifying the population at risk for an overt VTE, and the clinical significance of asymptomatic events, is warranted.

Venous thromboembolism prophylaxis of acutely ill hospitalized medical patients. Are we over-treating our patients?

Venous thromboembolism (VTE) is prevalent and is associated with dire consequences. Many VTE events are related to medical hospitalization, and some of these events are avoidable when appropriate measures are taken. Despite the current knowledge of the prevalence and burden of this disease, many internists are reluctant to prescribe pharmacological prophylaxis to "at-risk" medical inpatients. The purpose of this review is to analyze the reasons for deferring such treatment, in view of the facts as presented in the medical literature. We believe that while the literature supports further emphasis on education and support systems, Internists are deficient of validated tools to decide upon their patient's true risk of clinically overt disease.

Attitudes towards and practice of venous thromboembolism prevention in general internal medicine wards: a multinational survey from member countries of the European Federation of Internal Medicine.

INTRODUCTION: Hospitalised patients in Internal Medicine departments are at risk of venous thromboembolism (VTE). Adherence to risk stratification methods is poor. We conducted a survey among Internists from member countries of the European Federation of Internal Medicine (EFIM) to assess current knowledge and attitude towards VTE prevention. METHODS: A multinational survey of Internists affiliated to EFIM. RESULTS: 226 physicians from 30 countries were included. Seventy nine percent of the physicians were aware of clinical guidelines to prevent VTE. Most considered their knowledge of the guidelines to be moderate. Many had not updated their knowledge recently. The magnitude of the clinical problem was over- and underestimated by many (12.2% and 40.1%, respectively). Only 46.7% thought their patients were mostly receiving proper prophylaxis. Sixty four percent worked in departments without a formal VTE prophylaxis program. Risk of bleeding, lack of awareness and lack of decision support systems were the three most common reasons for deferring treatment (88.6%, 32.3% and 27.9%, respectively). Most of the participants stated that they strongly believe in VTE prophylaxis as an intervention that prevents morbidity and mortality. CONCLUSIONS: Despite general awareness of clinical guidelines, many medical wards do not have formal risk assessment methodologies incorporated into their operative workflow. This gap, as well as fear of complications, may be one of the reasons for the low rates of adherence reported by physicians. We speculate that perhaps current guidelines have not been accepted by Internists due to paucity of well defined and validated risk assessment tools.

The cytokine midkine and its receptor RPTPζ regulate B cell survival in a pathway induced by CD74.

Lasting B cell persistence depends on survival signals that are transduced by cell surface receptors. In this study, we describe a novel biological mechanism essential for survival and homeostasis of normal peripheral mature B cells and chronic lymphocytic leukemia cells, regulated by the heparin-binding cytokine, midkine (MK), and its proteoglycan receptor, the receptor-type tyrosine phosphatase ζ (RPTPζ). We demonstrate that MK initiates a signaling cascade leading to B cell survival by binding to RPTPζ. In mice lacking PTPRZ, the proportion and number of the mature B cell population are reduced. Our results emphasize a unique and critical function for MK signaling in the previously described MIF/CD74-induced survival pathway. Stimulation of CD74 with MIF leads to c-Met activation, resulting in elevation of MK expression in both normal mouse splenic B and chronic lymphocytic leukemia cells. Our results indicate that MK and RPTPζ are important regulators of the B cell repertoire. These findings could pave the way toward understanding the mechanisms shaping B cell survival and suggest novel therapeutic strategies based on the blockade of the MK/RPTPζ-dependent survival pathway.

On the clinical encounter with 'zebras' - the science and art of rare diseases.

Taught since medical school to concentrate on the more common disease entities, physicians may become insensitive to the possibility of encountering a rare disease ("zebra") or even an unusual presentation of one. The personal experience of one of the authors prompted this article, presenting an alternative view. We stress the need to carefully consider at times even rare diagnostic entities and their potentially unusual presentations. We discuss practical approaches to the special problems of these patients who are under-represented in the literature. In particular, using computerized searches when facing patients with unexplained symptoms, and adopting an honest, supportive attitude when uncertainty persists, seems important.

The secret second life of an innocent chaperone: the story of CD74 and B cell/chronic lymphocytic leukemia cell survival.

This review deals with the cytokine macrophage migration inhibitory factor (MIF) and its receptor, CD74. MIF and CD74 have been shown to regulate peripheral B cell survival and were associated with tumor progression and metastasis. CD74 expression has been suggested to serve as a prognostic factor in many cancers, with higher relative expression of CD74 behaving as a marker of tumor progression. In chronic lymphocytic leukemia (CLL) cells, binding of MIF to CD74 induces nuclear factor-κB (NF-κB) activation and up-regulation of TAp63 expression, resulting in the secretion of interleukin 8 (IL-8), which in turn promotes cell survival. In addition, TAp63 expression elevates expression of the integrin VLA-4, particularly during the advanced stage of the disease. Blocking of CD74, TAp63, or VLA-4 inhibits the in vivo homing of CLL cells to the BM. Thus, CD74 and its target genes, TAp63 and VLA-4, facilitate migration of CLL cells back to the BM, where they interact with the supportive BM environment that helps rescue them from apoptosis. These results are expected to pave the way toward novel therapeutic strategies aimed at interrupting this survival pathway. One such agent, the monocolonal antibody milatuzumab directed at CD74, is already being studied in early clinical trials.

TAp63 regulates VLA-4 expression and chronic lymphocytic leukemia cell migration to the bone marrow in a CD74-dependent manner.

The hallmark of chronic lymphocytic leukemia (CLL) is the relentless accumulation of mature lymphocytes, mostly due to their decreased apoptosis. CD74 was recently shown to serve as a survival receptor on CLL cells. In this study, we show that stimulation of CD74 with its natural ligand, migration inhibitory factor, initiates a signaling cascade that results in upregulation of TAp63, which directly regulates CLL survival. In addition, TAp63 expression elevates the expression of the integrin VLA-4, particularly during the advanced stage of the disease. Blocking of CD74, TAp63, or VLA-4 inhibits the in vivo homing of CLL cells to the bone marrow (BM). Thus, CD74 and its target genes TAp63 and VLA-4 facilitate migration of CLL cells back to the BM, where they interact with the supportive BM environment that rescues them from apoptosis. These results could form the basis of novel therapeutic strategies aimed at blocking homing of CLL cells in their return to the BM and attenuating their survival.