First-in-Class Humanized Antibody against Alternatively Spliced Tissue Factor Augments Anti-Metastatic Efficacy of Chemotherapy in a Preclinical Model of Pancreatic Ductal Adenocarcinoma.

Alternatively spliced tissue factor (asTF) promotes the progression of pancreatic ductal adenocarcinoma (PDAC) by activating ß1-integrins on PDAC cell surfaces. hRabMab1, a first-in-class humanized inhibitory anti-asTF antibody we recently developed, can suppress PDAC primary tumor growth as a single agent. Whether hRabMab1 has the potential to suppress metastases in PDAC is unknown. Following in vivo screening of three asTF-proficient human PDAC cell lines, we chose to make use of KRAS G12V-mutant human PDAC cell line PaCa-44, which yields aggressive primary orthotopic tumors with spontaneous spread to PDAC-relevant anatomical sites, along with concomitant severe leukocytosis. The experimental design featured orthotopic tumors formed by luciferase labeled PaCa-44 cells; administration of hRabMab1 alone or in combination with gemcitabine/paclitaxel (gem/PTX); and the assessment of the treatment outcomes on the primary tumor tissue as well as systemic spread. When administered alone, hRabMab1 exhibited poor penetration of tumor tissue; however, hRabMab1 was abundant in tumor tissue when co-administered with gem/PTX, which resulted in a significant decrease in tumor cell proliferation; leukocyte infiltration; and neovascularization. Gem/PTX alone reduced primary tumor volume, but not metastatic spread; only the combination of hRabMab1 and gem/PTX significantly reduced metastatic spread. RNA-seq analysis of primary tumors showed that the addition of hRabMab1 to gem/PTX enhanced the downregulation of tubulin binding and microtubule motor activity. In the liver, hRabMab1 reduced liver metastasis as a single agent. Only the combination of hRabMab1 and gem/PTX eliminated tumor cell-induced leukocytosis. We here demonstrate for the first time that hRabMab1 may help suppress metastasis in PDAC. hRabMab1's ability to improve the efficacy of chemotherapy is significant and warrants further investigation.

Polycythemia vera: 2024 update on diagnosis, risk-stratification, and management.

DISEASE OVERVIEW: Polycythemia vera (PV) is a JAK2-mutated myeloproliferative neoplasm characterized by clonal erythrocytosis; other features include leukocytosis, thrombocytosis, splenomegaly, pruritus, constitutional symptoms, microcirculatory disturbances, and increased risk of thrombosis and progression into myelofibrosis (post-PV MF) or acute myeloid leukemia (AML). DIAGNOSIS: A working diagnosis is considered in the presence of a JAK2 mutation associated with hemoglobin/hematocrit levels of >16.5 g/dL/49% in men or 16 g/dL/48% in women; morphologic confirmation by bone marrow examination is advised but not mandated. CYTOGENETICS: Abnormal karyotype is seen in 15%-20% of patients with the most frequent sole abnormalities being +9 (5%), loss of chromosome Y (4%), +8 (3%), and 20q- (3%). MUTATIONS: Over 50% of patients harbor DNA sequence variants/mutations other than JAK2, with the most frequent being TET2 (18%) and ASXL1 (15%). Prognostically adverse mutations include SRSF2, IDH2, RUNX1, and U2AF1, with a combined incidence of 5%-10%. SURVIVAL AND PROGNOSIS: Median survival is ⁓15 years but exceeds 35 years for patients aged ≤40 years. Risk factors for survival include older age, leukocytosis, abnormal karyotype, and the presence of adverse mutations. Twenty-year risk for thrombosis, post-PV MF, or AML are ⁓26%, 16% and 4%, respectively. RISK FACTORS FOR THROMBOSIS: Two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). Additional predictors for arterial thrombosis include cardiovascular risk factors and for venous thrombosis higher absolute neutrophil count and JAK2V617F allele burden. TREATMENT: Current goal of therapy is to prevent thrombosis. Periodic phlebotomy, with a hematocrit target of <45%, combined with once- or twice-daily aspirin (81 mg) therapy, absent contraindications, is the backbone of treatment in all patients, regardless of risk category. Cytoreductive therapy is reserved for high-risk disease with first-line drugs of choice being hydroxyurea and pegylated interferon-α and second-line busulfan and ruxolitinib. In addition, systemic anticoagulation is advised in patients with venous thrombosis history. ADDITIONAL TREATMENT CONSIDERATIONS: At the present time, we do not consider a drug-induced reduction in JAK2V617F allele burden, which is often incomplete and seen not only with peg-IFN but also with ruxolitinib and busulfan, as an indicator of disease-modifying activity, unless accompanied by cytogenetic and independently-verified morphologic remission. Accordingly, we do not use the specific parameter to influence treatment choices. The current review also includes specific treatment strategies in the context of pregnancy, splanchnic vein thrombosis, pruritus, perioperative care, and post-PV MF.

Neuroleptic malignant syndrome associated with atypical antipsychotics: A case report.

INTRODUCTION: Neuroleptic malignant syndrome (NMS) is uncommon, with an incidence of 0.01%-3.23%, and is associated with the use of drugs that intervene with dopamine, causing hyperthermia, muscular rigidity, confusion, autonomic instability and death. CASE REPORT: A 35-year-old man with a history of catatonia, refractory epilepsy and functional impairment, required frequent changes in his anticonvulsant and antipsychotic treatment, due to adverse effects. During 2019, in the month of July, clozapine was changed to amisulpride, in September he developed fever, muscle stiffness, stupor, diaphoresis and tachypnea over a two-week period; paraclinical tests showed elevated creatine phosphokinase (CPK) and leukocytosis, so NMS was considered. The antipsychotic was withdrawn and he was treated with bromocriptine and biperiden, with a good response. Ten days after discharge, he began treatment with olanzapine, which generated a similar episode to the one described in December, with subsequent management and resolution. DISCUSSION: The diagnosis is based on the use of drugs that alter dopamine levels, plus altered state of consciousness, fever, autonomic instability and paraclinical tests showing leukocytosis and elevated CPK. Differential diagnoses must be ruled out. Early diagnosis generally leads to total remission, although some patients will suffer complications, long-term sequelae or recurrences. The recurrence in this case derived from the early reintroduction of the neuroleptic after the first episode. Treatment should be individualised according to severity to avoid mortality. CONCLUSIONS: Atypical antipsychotics are rarely suspected of generating NMS. Moreover, the time to reintroduction after an episode must also be taken into account.

Phage therapy in a lung transplant recipient with cystic fibrosis infected with multidrug-resistant Burkholderia multivorans.

BACKGROUND: There is increased interest in bacteriophage (phage) therapy to treat infections caused by antibiotic-resistant bacteria. A lung transplant recipient with cystic fibrosis and Burkholderia multivorans infection was treated with inhaled phage therapy for 7 days before she died. METHODS: Phages were given via nebulization through the mechanical ventilation circuit. Remnant respiratory specimens and serum were collected. We quantified phage and bacterial deoxyribonucleic acid (DNA) using quantitative polymerase chain reaction, and tested phage neutralization in the presence of patient serum. We performed whole genome sequencing and antibiotic and phage susceptibility testing on 15 B. multivorans isolates. Finally, we extracted lipopolysaccharide (LPS) from two isolates and visualized their LPS using gel electrophoresis. RESULTS: Phage therapy was temporally followed by a temporary improvement in leukocytosis and hemodynamics, followed by worsening leukocytosis on day 5, deterioration on day 7, and death on day 8. We detected phage DNA in respiratory samples after 6 days of nebulized phage therapy. Bacterial DNA in respiratory samples decreased over time, and no serum neutralization was detected. Isolates collected between 2001 and 2020 were closely related but differed in their antibiotic and phage susceptibility profiles. Early isolates were not susceptible to the phage used for therapy, while later isolates, including two isolates collected during phage therapy, were susceptible. Susceptibility to the phage used for therapy was correlated with differences in O-antigen profiles of an early versus a late isolate. CONCLUSIONS: This case of clinical failure of nebulized phage therapy highlights the limitations, unknowns, and challenges of phage therapy for resistant infections.

Clinical outcomes of therapeutic leukapheresis in acute promyelocytic leukemia: A single-center retrospective cohort study.

BACKGROUND: In acute promyelocytic leukemia (APL), increased cell burden in the peripheral blood due to either the disease itself or early treatment with all-trans retinoic acid could cause hyperleukocytosis (HL) before induction chemotherapy. However, therapeutic leukapheresis has seldom been used because of concerns of subsequent coagulopathy after this invasive procedure. The aim of this study was to evaluate the effects of leukapheresis in APL, especially for efficacy and safety. METHODS: We retrospectively analyzed newly diagnosed patients with APL from January 2009 to March 2022. Among 323 patients, 85 had white blood cell count above 40 × 109/L before induction chemotherapy. Thirty-nine patients were initially treated with leukapheresis, whereas the other 46 were not. Clinical and laboratory parameters between these groups were compared. RESULTS: There was a trend toward favorable 30-day survival rate for the leukapheresis group compared with the non-leukapheresis group (76.9% and 67.4%; P = 0.24). The complications including subsequent intensive unit care (P = 0.23), severe hemorrhagic events (P = 0.13) showed no significant differences between the two groups. The patients were divided into subcohorts, and the survival rates of the leukapheresis and non-leukapheresis groups were 92.3% (95% confidence interval [CI], 77.8%-100.0%) versus 58.3% (95% CI, 38.6%-78.1%) (P = 0.03) in "sequential HL" and 76.7% (95% CI, 61.5%-91.8%) versus 54.8% (95% CI, 37.3%-72.4%) (P = 0.03) in "symptomatic HL," respectively. Moreover, in the "sequential HL" subcohort, the cumulative incidence of differentiation syndrome and following adverse events were significantly lower in the leukapheresis group. CONCLUSIONS: In APL with "sequential HL" or "symptomatic HL" from either the disease itself or the effect of all-trans retinoic acid, therapeutic leukapheresis could be applied to reduce leukemic cell burden without significant risks.

Benefits of dexamethasone on early outcomes in patients with acute myeloid leukemia with hyperleukocytosis: a propensity score matched analysis.

Hyperleukocytosis is associated with a significant early mortality rate in patients with acute myeloid leukemia (AML). To date, no controlled trial has ever evaluated a strategy to reduce this risk, and the initial management of these patients remains heterogeneous worldwide. The aim of the present study was to evaluate the influence of a short course of intravenous dexamethasone on the early outcomes of patients with hyperleukocytic AML with white blood cell (WBC) count above 50 × 109/L. Clinical and biological data of all consecutive patients (1997-2017) eligible for intensive chemotherapy from a single center were retrospectively collected. A total of 251 patients with a median age of 51 years and a median WBC count of 120 × 109/L were included, 95 of whom received dexamethasone. Patients treated with dexamethasone had higher WBC count and a more severe disease compared with those who did not, and they presented more often with leukostasis and hypoxemia, resulting in a more frequent need for life-sustaining therapies (p < 0.001). To account for these imbalances, patients were compared after adjusting for a propensity score, which included all variables with a prognostic influence in the overall cohort. In the matched cohort, dexamethasone was associated with lower early death (OR = 0.34, p = 0.0026) and induction failure rate (OR = 0.44, p = 0.02) and better overall survival (HR = 0.60, p = 0.011), with no impact on relapse risk (cHR = 0.73, p = 0.39). The overall survival benefit was confirmed among all tested subgroups. This study suggests that dexamethasone administration is safe and associated with a lower risk of induction mortality in patients with hyperleukocytic AML and deserves prospective evaluation.

Prognostic impact of neutrophilia and lymphopenia on survival in anal cancer treated with definitive concurrent chemoradiotherapy: a retrospective multicenter study.

PURPOSE: This study evaluated the prognostic value of leukocyte, lymphocyte, and neutrophil counts in anal cancer patients undergoing concurrent chemoradiotherapy (CCRT). METHODS: Multi-institutional retrospective data review included 148 non-metastatic anal cancer patients treated with definitive CCRT with 5-fluorouracil plus mitomycin C between the year 2001 and 2019. The median radiation dose to the primary tumor was 54 Gy with a median pelvic dose of 45 Gy. Median follow-up duration was 56 months, and complete blood cell counts were analyzed from baseline to 1 year after the completion of radiotherapy. RESULTS: Although most patients showed a normal number of blood cells before treatment, 6.1% and 4.1% of patients showed leukocytosis (> 10,000/µl) and neutrophilia (> 7500/µl), respectively. After the initiation of treatment, seven patients (4.7%) displayed grade 4 lymphopenia (< 200/µl) at 1 month. Patients with initial leukocytosis showed inferior progression- and locoregional progression-free survival, and neutrophilia was a prognostic factor in all survival outcomes. Grade 4 lymphopenia at 1 month was also significantly associated with overall, progression-, and distant metastasis-free survival. On multivariate analyses, baseline neutrophilia was associated with 56.8-, 22.6-, 10.7-, and 23.0-fold increased risks of death, disease relapse, locoregional progression, and distant metastasis, respectively. Furthermore, lymphocytes < 200/µl at 1 month was linked to 6.8-, 5.4-, and 6.3-fold increased risks for death, disease relapse, and distant metastasis, respectively. CONCLUSION: The number of leukocytes, lymphocytes, and neutrophils readily acquired from routine blood tests before and during treatment could be an independent prognostic factor of survival in patients with anal cancer.

Pharmacological targeting of host chaperones protects from pertussis toxin in vitro and in vivo.

Whooping cough is caused by Bordetella pertussis that releases pertussis toxin (PT) which comprises enzyme A-subunit PTS1 and binding/transport B-subunit. After receptor-mediated endocytosis, PT reaches the endoplasmic reticulum from where unfolded PTS1 is transported to the cytosol. PTS1 ADP-ribosylates G-protein α-subunits resulting in increased cAMP signaling. Here, a role of target cell chaperones Hsp90, Hsp70, cyclophilins and FK506-binding proteins for cytosolic PTS1-uptake is demonstrated. PTS1 specifically and directly interacts with chaperones in vitro and in cells. Specific pharmacological chaperone inhibition protects CHO-K1, human primary airway basal cells and a fully differentiated airway epithelium from PT-intoxication by reducing intracellular PTS1-amounts without affecting cell binding or enzyme activity. PT is internalized by human airway epithelium secretory but not ciliated cells and leads to increase of apical surface liquid. Cyclophilin-inhibitors reduced leukocytosis in infant mouse model of pertussis, indicating their promising potential for developing novel therapeutic strategies against whooping cough.

The Effect of TLR4 Blockade on Some Indicators of Systemic Inflammatory Response to Proteus mirabilis LPS in Rats.

The effects of TLR4 blocker on blood cell morphology, concentrations proinflammatory cytokines, and functional state of the liver and kidneys were studied in outbred male rats (n=60) after intravenous injection of 20 mg/kg LPS isolated from opportunistic Proteus mirabilis strain ATCC 51393. TLR4 blocker TLR4-IN-C34 was injected intravenously in a dose of 1 mg/kg/day over 3 days. Systemic inflammatory reaction induced by LPS was characterized by elevation of serum TNFα, IL-1ß, IL-6, erythrocyte sedimentation rate, leukocytosis, and thrombocytosis. Increased activity of hepatocyte enzymes (ALT, alkaline phosphatase, and lactate dehydrogenase), retention of nitrogen metabolites (urea and creatinine), elevated content of protein oxidation products, and enhanced protein catabolism were also observed. Administration of TLR4 blocker reduced parameters of inflammatory reaction and prevented the development of hypercatabolic syndrome; endotoxicosis and kidney function indicators approached the normal levels.

Delayed Granulocyte Colony-Stimulating Factor (G-CSF) Administration after Chemotherapy Reduces Total G-CSF Doses without Affecting Neutrophil Recovery in a Randomized Clinical Study in Children with Solid Tumors.

The use of G-CSF after myelotoxic chemotherapy accelerates neutrophil recovery reducing the risk of febrile neutropenia. Current guidelines recommend initiating G-CSF 24 hours after myelotoxic chemotherapy. However, the optimal timing of post-chemotherapy G-CSF administration has not been elucidated. Our previous work in murine models demonstrated that the reappearance of myeloid progenitors does not occur in bone marrow until 3-4 days after completion of chemotherapy suggesting that delayed G-CSF administration may be equally efficacious compared to current practice. We conducted a prospective, randomized, crossover study to compare the absolute neutrophil count (ANC) recovery after chemotherapy and a delayed G-CSF administration to a standard G-CSF administration schedule with early G-CSF start. A total of 21 children with solid tumors who received 2 identical cycles of myelotoxic chemotherapy were randomized to start receiving G-CSF either 24 hours after completion of chemotherapy or on the day that their ANC dropped below 1,000/mm3. There was no significant difference in the time to neutrophil recovery (ANC > 1,000/mm3 post nadir) between the two G-CSF administration schedules: 16.0 ± 0.5 days in the standard group compared to 16.7 ± 0.4 days in the delayed group (p = 0.36). The total number of G-CSF doses given, however, was significantly less in the delayed group: 6.7 ± 0.6 compared to 10.5 ± 0.6 doses in the standard group (p < 0.0001). Our data show that a delayed administration of post chemotherapy G-CSF resulted in a significant reduction in the number of G-CSF injections without compromising the G-CSF effects on neutrophil recovery.

Follicular lymphoma presenting as hyperleucocytosis.

Follicular lymphoma is the second most common subtype of non-Hodgkin's lymphoma affecting adults. Clinically, follicular lymphoma is generally indolent, most often presenting as a painless peripheral lymphadenopathy; however, a leucocytosis at presentation is exceedingly rare. We present the case of a 63-year-old woman with follicular lymphoma with a presenting hyperleucocytosis at diagnosis of 1 327 000/µL demonstrated on laboratory analysis work while hospitalised for progressive weakness. fluorescence in situ hybridization (FISH) panel was consistent with follicular lymphoma, which was positive for B-cell leukaemia/lymphoma 2 and negative for MYC Proto-Oncogene. Cytoreduction with rituximab-containing therapy was initiated, with the patient ultimately expiring. A leukaemic phase at presentation appears to be associated with poor outcome. The findings from our case, in addition to others, have potential implications in regard to prognostic utility. The current prognostic tool used to estimate overall survival for follicular lymphoma, Follicular Lymphoma International Prognostic Index, does not take leucocytosis into account.

When leucocytosis is not leukaemia.

A female aged 84 years with a history of Clostridium difficile-associated diarrhoea presented from an extended care facility with altered mental status and respiratory distress. She was haemodynamically unstable and initial laboratory results revealed hyperleucocytosis (110.3×109/L). The presence of immature myeloid precursors, thrombocytopenia and respiratory distress, raised concern for an acute leukaemic process requiring emergent leucapheresis. However, on evaluation of the peripheral smear, prominent left shift and toxic granulation were noted, along with absence of blast cells. Considering her history of C. difficile infection, a CT scan of the abdomen and pelvis was obtained, which was suggestive of toxic megacolon. She was taken to the operating room for emergent colectomy. The pathology specimen showed pseudomembrane formation consistent with fulminant C. difficile infection. She was treated with oral vancomycin and intravenous metronidazole, followed by clinical improvement and resolution of leucocytosis and thrombocytopenia.

[What is neutrophilic urticaria?] / Qu'est-ce que l'urticaire neutrophilique ?

Some debate continues to surround the existence of neutrophilic urticaria (NU) as a nosological entity. Certain authors consider NU as a banal form of urticaria since an infiltrate predominantly made up of polynuclear neutrophils (PNN) is seen in certain cases of chronic and acute urticaria. Moreover, it has been stated that the histological appearance of chronic urticaria varies according to the time between appearance of the plaque and the performance of biopsy: the presence of PNN may occur later. According to the literature, there appear to be no specific clinical characteristics associated with the presence of PNN at histology. Most cases exhibit moderate laboratory inflammatory syndrome. Data concerning therapeutic response are contradictory: some studies have shown no significant difference in terms of therapeutic response in relation to banal urticaria, while only one study has demonstrated superior response to dapsone in the case of histologically demonstrated neutrophilic infiltrate. There does not appear to be any disease more frequently associated in the event of NU. In conclusion, the available data concerning NU are insufficient to confirm the existence of this condition. A prospective study comparing routine acute and chronic urticaria biopsies would be extremely useful to better characterise the relationships between cellular infiltrate and therapeutic response.

Dose-related mucositis with hydroxyurea for cytoreduction in acute myeloid leukemia.

Hyperleukocytosis occurs in 15-20% of all newly diagnosed acute myeloid leukemia patients and requires emergent treatment with leukapheresis or hydroxyurea when accompanied by signs or symptoms of leukostasis. Currently, there is no standardized hydroxyurea dosing strategy, although usual dosing ranges from 50 to 150 mg/kg/day, and prescribing patterns vary significantly among oncologists and institutions. In addition to other hematologic and dermatologic toxicities, the use of hydroxyurea may be associated with significant mucositis and mucositis-related pain. The purpose of this study was to compare mucositis-related pain between two different hydroxyurea dosing strategies in patients who received hydroxyurea for cytoreduction during induction. A retrospective chart review of adult patients with acute myeloid leukemia treated with chemotherapy at UNC Medical Center from April 2014 to April 2016 who received at least one dose of hydroxyurea for cytoreduction was conducted. This study compared the safety and toxicity profiles of hydroxyurea in patients who received high-dose hydroxyurea (≥75 mg/kg/day) versus low-dose hydroxyurea (<75 mg/kg/day). Safety and toxicity were evaluated based on indicators of mucositis and cumulative intravenous narcotic requirements following induction chemotherapy. Data collection included baseline demographics, mucositis risk factors, baseline laboratory values, hydroxyurea dosing, mucositis indicators, and pain indicators. A total of 55 patients were included in the study, 21 patients (38.2%) received the high-dose hydroxyurea dosing strategy. The high-dose hydroxyurea dosing strategy had a significantly higher white blood cell count at diagnosis, increased duration of hydroxyurea, and received a higher cumulative dose of hydroxyurea. Additionally, the high-dose hydroxyurea dosing strategy patients were associated with significantly more grade 3 or 4 mucositis requiring a formulation change (0% versus 28.6%, p = 0.002) and significantly higher cumulative intravenous narcotic requirements during induction (p = 0.019). No significant differences in baseline demographics or mucositis risk factors between dosing strategies were identified. The high-dose hydroxyurea dosing strategy patients had a significant increase in cumulative intravenous narcotic requirements and formulation changes, both common interventions made for the treatment of mucositis. Additional studies are needed to further elucidate the safety and toxicity profiles of hydroxyurea dosing strategies and to explore the correlation between total cumulative hydroxyurea dose and total cumulative narcotic requirements.