Treatment with Mesenchymal Stromal Cells Overexpressing Fas-Ligand Ameliorates Acute Graft-versus-Host Disease in Mice

Allogeneic hematopoietic cell transplantation (allo-HCT) has the potential to cure malignant and non-malignant hematological disorders, but because of the serious side effects of this intervention its applications are limited to a restricted number of diseases. Graft-versus-host disease (GvHD) is the most frequent complication and the leading cause of mortality and morbidity following allo-HCT. It results from the attack of the transplanted T cells from the graft against the cells of the recipient. There is no clear treatment for this severe complication. Due to their immunomodulatory properties, mesenchymal stromal cells (MSC) have been proposed to treat GvHD, but the results did not meet expectations. We have previously showed that the immunomodulatory effect of the MSC was significantly enhanced through adenoviral-mediated overexpression of FasL. In this study, we have tested the properties of FasL-overexpressing MSC in vivo, in a mouse model for acute GvHD. We found that treatment with FasL-overexpressing MSC delayed the onset of the disease and increased survival of the mice.

Lack of Adverse Effects of Cold Physical Plasma-Treated Blood from Leukemia Patients: A Proof-of-Concept Study

Chronic lymphocytic leukemia (CLL) is the most common blood malignancy with multiple therapeutic challenges. Cold physical plasma has been considered a promising approach in cancer therapy in recent years. In this study, we aimed to evaluate the cytotoxic effect of cold plasma or plasma-treated solutions (PTS) on hematologic parameters in the whole blood of CLL patients. The mean red blood cell count, white blood cell (WBC) count, platelet and hemoglobin counts, and peripheral blood smear images did not significantly differ between treated and untreated samples in either CLL or healthy individuals. However, both direct plasma and indirect PTS treatment increased lipid peroxidation and RNS deposition in the whole blood of CLL patients and in healthy subjects. In addition, the metabolic activity of WBCs was decreased with 120 s of cold plasma or PTS treatment after 24 h and 48 h. However, cold plasma and PTS treatment did not affect the prothrombin time, partial thromboplastin time, nor hemolysis in either CLL patients or in healthy individuals. The present study identifies the components of cold plasma to reach the blood without disturbing the basic parameters important in hematology, confirming the idea that the effect of cold plasma may not be limited to solid tumors and possibly extends to hematological disorders. Further cellular and molecular studies are needed to determine which cells in CLL patients are targeted by cold plasma or PTS.

Management of Vascular Thrombosis in Patients with Thrombocytopenia

Platelets play critical roles in hemostasis and thrombosis. While low platelet counts increase the risk of bleeding, antithrombotic drugs, including anticoagulants and antiplatelet agents, are used to treat thromboembolic events. Thus, the management of thrombosis in patients with low platelet counts is challenging with hardly any evidence available to guide treatment. Recognition of the underlying cause of thrombocytopenia is essential for assessing the bleeding risk and tailoring therapeutic options. A typical clinical scenario is the occurrence of venous thromboembolism (VTE) in cancer patients experiencing transient thrombocytopenia during myelosuppressive chemotherapy. In such patients, the severity of thrombocytopenia, thrombus burden, clinical symptoms, and the timing of VTE relative to thrombocytopenia must be considered. In clinical practice, distinct hematological disorders characterized by low platelet counts and a thrombogenic state require specific diagnostics and treatment. These include the antiphospholipid syndrome, heparin-induced thrombocytopenia (HIT) and (spontaneous) HIT syndromes, disseminated intravascular coagulation, and paroxysmal nocturnal hemoglobinuria.

Clonal hematopoiesis is associated with protection from Alzheimer's disease

Clonal hematopoiesis of indeterminate potential (CHIP) is a pre-malignant expansion of mutated blood stem cells that also associates with non-hematological disorders. Here, we tested whether CHIP was associated with Alzheimer's disease (AD). Surprisingly, we found that CHIP carriers had reduced risk of AD dementia or AD neuropathologic features in multiple cohorts. The same mutations found in blood were also detected in the microglia-enriched fraction of brain in 7 out of 8 CHIP carriers. Single-cell chromatin accessibility profiling of brain-derived nuclei in two CHIP carriers revealed that the mutated cells were indistinguishable from microglia and comprised between 42-77% of the total microglial pool. These results suggest a role for mutant, marrow-derived cells in attenuating risk of AD, possibly by supplementing a failing microglial system during aging.

Effect of CD34+ cell dose on neutrophil and platelet engraftment kinetics in haematopoietic stem cell transplantation – A single-centre experience

Objectives: Haematopoietic stem cell transplantation (SCT) is curative for a number of benign and malignant hematological disorders. CD34 expression on haematopoietic progenitor cells is used to assess stem cell content in peripheral blood stem cell and bone marrow grafts. This study evaluated the relationship between numbers of CD34+ cells infused per kg and the timing of neutrophil and platelet engraftment. Materials and Methods: The effect of cell dose was studied in consecutive HSCT patients transplanted between November 2008 and December 2017. Neutrophil engraftment was defined as the first of 2 consecutive days with an absolute neutrophil count >0.5 × 109/L and platelet engraftment as unsupported platelet count >20 × 109/L for 7 days. Results: Of a total of 131 patients, 26 (19.8%) underwent an autologous SCT, while 105 (80.2%) underwent an allogeneic SCT. The median CD34 dose infused in the auto-SCT group was 5.29 × 106 CD34+cells/kg (IQR = 2.95–10.98) and 6.42 × 106 CD34+cells/kg (IQR = 4.20–9.20) in the allo-SCT group (P = 0.773). The median time to neutrophil engraftment in the auto-SCT group was 11 days (range 9.5–12) and in the allo-SCT group was 15 days (range 13–17), P ≤ 0.001. The median time to platelet engraftment in both groups was similar (12 days). When patients were divided into three groups based on CD34 dose (<5, 5–8 and >8), no difference was observed in the time to ANC or platelet engraftment. Similarly, no differences in time to engraftment were noted in each quartile of CD34 dosage in auto- and allo-SCT. Conclusion: Thus, it was concluded that a cell dose of approximately 5 × 106/kg provides reasonably rapid engraftment, with no advantage seen for a higher cell dose of >5.

Hippo Pathway-related Genes Expression Is Deregulated in Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPN) are hematological disorders characterized by increased proliferation of precursor and mature myeloid cells. MPN patients may present driver mutations in JAK2, MPL, and CALR genes, which are essential to describe the molecular mechanisms of MPN pathogenesis. Despite all the new knowledge on MPN pathogenesis, many questions remain to be answered to develop effective therapies to cure MPN or impair its progression to acute myeloid leukemia. The present study examined the expression levels of the Hippo signaling pathway members in patients with polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), as well as the role that they play in disease pathogenesis. The Hippo pathway is a tumor suppressor pathway that participates in the regulation of cell proliferation, differentiation, and death. Our main findings were: (i) expression of tumor suppressor genes from Hippo pathway were downregulated and seemed to be associated with cell resistance to apoptosis and increased proliferation rate; and (ii) Hippo pathway-related gene expression was associated with mutation status in ET and PMF patients. Therefore, the decreased expression of Hippo pathway-related genes may contribute to the malignant phenotype, apoptosis resistance, and cell proliferation in MPN pathogenesis.

New insights on severe clinical manifestations and deaths from visceral leishmaniasis in free-living crab-eating foxes (Cerdocyon thous) in Brazil

Visceral leishmaniasis (VL) is a zoonotic and severe neglected tropical disease, with worldwide distribution, that still cause many deaths among dogs and humans. Brazil is the country responsible for about 97% of the cases of leishmaniasis in the Americas and the disease is still considered a serious public health concern. Among wild mammalians, studies demonstrate the involvement of Cerdocyon thous in the biological cycle of Leishmania. Nevertheless, several authors consider the clinical manifestation of the disease to be rare or mild in free-living animals. Herein, we demonstrate the occurrence of severe clinical sings and deaths caused by VL in free-living crab-eating foxes. Three specimens of foxes collected from periurban areas were diagnosed with VL. The animals presented cutaneous, ophthalmological, gastrointestinal, locomotor and hematological alterations, and died after clinical progression. We identified the presence of anti-Leishmania antibodies by immunochromatographic test in all specimens. We also observed intra and extracellular amastigotes in skin cytology and lymph node aspirate. Furthermore, Leishmania infantum DNA was identified in all samples by the polymer chain reaction technique. Additionally, we performed blood count and stool parasitological tests and observed hematological disorders common to VL, such as anemia and lymphopenia. Taken together, our data demonstrate that VL can induce clinical complications and even cause death in C. thous and corroborate that this crab-eating fox is an adequate host for L. infantum.

COVID-19–induced acute kidney injury in critically ill patients: epidemiology, risk factors, and outcome

Background: The kidney represents a potential target for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Acute kidney injury (AKI) can occur through several mechanisms and includes intrinsic tissue injury by direct viral invasion. Clinical data about the clinical course of AKI are lacking. We aimed to investigate the proportion, risk factors, and prognosis of AKI in critical patients affected with coronavirus disease 2019 (COVID-19).Methods: A case/control study conducted in two intensive care units of a tertiary teaching hospital from September to December 2020.Results: Among 109 patients, 75 were male (69%), and the median age was 64 years (interquartile range [IQR], 57–71 years); 48 (44%) developed AKI within 4 days (IQR, 1–9). Of these 48 patients, 11 (23%), 9 (19%), and 28 (58%) were classified as stage 1, 2, and 3, respectively. Eight patients received renal replacement therapy. AKI patients were older and had more frequent sepsis, acute respiratory distress syndrome, and rhabdomyolysis; higher initial urea and creatinine; more marked inflammatory syndrome and hematological disorders; and required more frequent mechanical ventilation and vasopressors. An elevated level of D-dimers (odds ratio [OR], 12.83; 95% confidence interval [CI], 1.9–85) was an independent factor of AKI. Sepsis was near to significance (OR, 5.22; 95% CI, 0.94–28; P=0.058). Renal recovery was identified in three patients. AKI, hypoxemia with the ratio of the arterial partial pressure of oxygen and the inspiratory concentration of oxygen <70, and vasopressors were identified as mortality factors.Conclusions: AKI occurred in almost half the patients with critical COVID-19. A high level of D-dimers and sepsis contributed significantly to its development. AKI significantly worsened the prognosis in these patients.

Respiratory, Hepatic, Renal and Hematological Disorders Among Adolescent Females Environmentally Exposed To Pesticides, Menoufia Governorate, Egypt

Adolescent females are often environmentally exposed to pesticides by living near agricultural fields, by using pesticides at home, or by having contact with contaminated clothes and pesticide application work tools. This study assessed respiratory, hepatic, renal and hematological health disorders that might arise due to environmental exposure to pesticides among adolescent females. A cross-sectional study was conducted with 100 adolescent females environmentally exposed to pesticides who had one or more of their family members working as seasonal pesticides' applicators and 50 non- exposed (control) adolescent females from Menoufia governorate, Egypt. The studied period of pesticide application season of cotton crop was from May 1st to the end of September 2017. Participants completed a self-administered questionnaire about pesticide exposure and respiratory, hepatic, renal and hematological disorders. In addition, serum acetyl cholinesterase (AChE), spirometry, complete blood count, liver and kidney functions' tests were measured pre and post pesticide application season. The control adolescent females had a higher AChE activity, a lower prevalence of respiratory symptoms and higher means of spirometric measurements than the exposed group. During the pre and postseason, the exposed group presented a prevalence of (6%, 24%) for cough, (4%, 11%) for rhinitis, and (6%, 26%) for dyspnea during the pre and postseason; respectively. In addition, there was a decrease in means of spirometric measurements (FEV1%, FEV1/FVC%, FEF 25-75% and PEF%) in post season compared to preseason among the exposed group. Also, there were significant associations between (AChE) activity and both the prevalence of respiratory manifestations and spirometric measurements among the exposed females. On the other hand, there were significantly increased red blood corpuscles (RBCs) and lymphocytes counts, and a significantly lower mean hemoglobin level among the exposed group (post season) than each of their pre-season values and the control group (P<0.05). AChE level, total protein, albumin and albumin/globulin (A/G) ratio levels were significantly lower, while SGPT, SGOT, and globulin, blood urea and serum creatinine mean levels were significantly higher among the exposed group (post season) than either of their pre-season or the control group (P<0.05). There was a positive correlation between AChE level and all studied CBC parameters for the exposed group reaching a significant level with basophils (P<0.05). Also, there was a negative correlation between AChE level and each of SGPT, SGOT, ALP, globulin, blood urea and serum creatinine for the exposed group reaching a significant level with each of SGPT and SGOT (P<0.05). At the same time, a non-significant positive correlation was found between AChE level and each of total protein, albumin and A/G ratio (P>0.05). So, environmental exposure to organophosphorus pesticides has a detrimental impact on respiratory, hepatic, renal and hematological systems of adolescent females living in rural districts at Menoufia governorate. Educational and training intervention programs on pesticide handling and safety precautions are recommended for protecting both pesticides' workers and their family members who might be exposed.

Unexpected High Frequency of Pathogenic Germline Variants in Older Adults with Primary Myelodysplastic Syndrome

Background: Germline predisposition is increasingly being recognised in myeloid neoplasms (MN) including primary myelodysplastic syndrome. An unequivocal diagnosis of germline predisposition carries actionable considerations for patient management including donor stem cell source for allogeneic transplantation, dose-reduction of conditioning regimes and screening for extra-hematological disease (such as pulmonary abnormalities in patients with telomere biology disorders). In addition, the identification of MDS predisposition syndromes can avoid misdiagnosis (for example, distinguishing idiopathic thrombocytopenic purpura from thrombocytopenia due to RUNX1 germline variant). However, the prevalence of pathogenic germline variants (PGVs) in unselected pMDS patients presenting at older age remains unknown. Aim: This study assesses frequency and type of pathogenic germline variants in MDS patients and compares with age matched healthy controls and patients with other cancers. Method: We analysed 68 known cancer predisposition genes in germline samples of 146 samples from myeloid neoplasms. Study included primary MDS (n=51) and MDS diagnosed in cancer survivors with (n=77) or without prior exposure to cytotoxic therapy (n=18). Using uniform American College of Medical Genetics and Genomics (ACMG) guidelines for annotating germline mutation, we also compared the frequency of pathogenic germline variants in the same genes with patients with single cancer and age-match healthy controls (&gt;70 years). Results: Pathogenic germline variants (PGVs) were identified in 19% (28/146) patients compared to 4% and 3% patients with single cancer and age-matched controls respectively (P&lt;0.0001) (Fig. 1A). Median age at diagnosis was similar between MN patients with or without PGVs [66 years (19-81) vs. 70 years (33-87); P=0.06]. PGVs were most frequent in DDX41 (n=7, 33%) followed by BRCA1 (n=2, 10%), GATA2 (n=2; 10%) and TP53 (n=2; 10%) (Fig.1B). We also identified pathogenic copy number variations (CNV) in 4 patients. The distribution of PGVs was also different, with DDX41 PGVs absent in single cancers and more prevalent in MN than age-matched controls (35% vs. 4%, P&lt;0.001). The frequency of PGV was not significantly different between P-MN and T-MN/ MC-MN (17% versus 10%, P = 0.32 (Fig.1C). The frequency of PGV was 30%, 6%, 19%, 15% and 18% in patients ≤50, 51-59, 60-69, 70-79 and &gt;80 years of age (Fig. 1D). Phenotypic features such as monocytopenia and mycobacterium infections (MonoMAC; SA460) and personal and family history of pulmonary fibrosis (SA918) were present in only two cases with PGVs. Family history of MDS/AML was present in only in four cases with PGVs, in which PGVs were found in typical myeloid malignancy genes (DDX41, GATA2). Importantly, some patients with family history of solid cancers carried PGVs in genes traditionally associated with solid cancers (e.g. MSH6, NF1, TP53 and BRCA1). SA927 had a PGV in MSH6 and multiple first-degree relatives with solid cancers including colon, renal and brain cancers. Moreover, 41% of adults with hematological disorders and a personal and/or family history of interstitial lung disease had PGVs in telomere biology disorder genes. Hence, family history should not be restricted to hematological disorders, but also solid cancers and non-malignant phenotypes (e.g. hepatic and pulmonary fibrosis). The frequency of PGVs was not different in patients with and without family history of cancer (23% vs. 13%, P=0.32). Conclusion: The frequency of PGVs is significantly high in MN compared to age matched healthy control and other cancer patients. Our observation of a high frequency of PGVs in the older MDS population warrants standardization of germline testing at diagnosis to guide optimal management of patients and their families. Figure 1 Figure 1. Disclosures Hiwase: Novartis: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees.