Deletion of Tissue Factor Pathway Inhibitor Isoform Beta or Gamma, but not Alpha, Improves Clotting in Hemophilia Mice.

BACKGROUND: Tissue factor pathway inhibitor (TFPI) regulates tissue factor (TF)-triggered coagulation. Humans and mice express transcripts encoding for multi-distributed (endothelial, platelet, and plasma) 3-Kunitz domain TFPIα and endothelial membrane-anchored 2-Kunitz TFPIß. Mice express a third transcript, γ, that encodes plasma lipoprotein-associated 2-Kunitz TFPI. In humans, proteolysis of α and/or ß produces plasma lipoprotein-associated 2-Kunitz TFPI at lower levels. In clinical trials, monoclonal antibodies that target all TFPI isoforms extend coagulation and correct bleeding in hemophilia patients but with some thrombosis risks. OBJECTIVES: Determine the impact of TFPI isoform-specific deletions on promoting clotting in hemophilia mice. METHODS: Engineered TFPI isoform-specific, hemophilia (FVIII-null) mice were evaluated for clotting. RESULTS: Mice expressing any single TFPI isoform are healthy. Thrombin generation assays identified TFPIγ as the dominant anticoagulation isoform in mouse plasma. Hemostasis was assessed by serial bleeding times from a tail vein laceration. Repeatedly, after a clot forms, it is manually disrupted; the number of clots/disruptions occurring over a 15-minute period is reported. C57BL/6 and hemophilia mice clot on average 25.6 versus 5.4 times, respectively. On a hemophilia background, TFPIß or TFPIγ-specific deletion improves clotting to 14.6 and 15.2 times, respectively (p<0.0001). TFPIα-specific deletion is without impact, clotting 5.1 times. Heterozygous deletion of TFPIß is effective, clotting 11.8 times (p<0.0001). Heterozygous deletion of TFPIα or TFPIγ alone is ineffective clotting 3.0 and 6.1 times, respectively; but heterozygous TFPIαγ deletion improves clotting to 11.2 times (p<0.001). CONCLUSION: In hemophilia mice, endothelial TFPIß and plasma γ-derived 2-Kunitz TFPI individually contribute more to bleeding than total TFPIα.

Red blood cell distribution width as a potential inflammatory marker in pediatric osteomyelitis.

Background: Red cell distribution width (RDW) has been used in the differential diagnosis of anemia and revealed to be a potential marker of inflammation. Method: We conducted a retrospective study of acute-phase reactant changes in correlation with RDW among pediatric patients with osteomyelitis. Results: We identified 82 patients whose mean RDW increased on average by 1% during antibiotic therapy (mean 13.9% on admission, 95% CI 13.4-14.3, and 14.9% at the end of antibiotic therapy, 95% CI 14.5-15.4). Overall, the RDW was weakly correlated with absolute neutrophil count (r = -0.21, P = 0.001), erythrocyte sedimentation rate (r = -0.17, P = 0.007), and C-reactive protein (r = -0.21, P = 0.001). The generalized estimating equation model showed a weak negative correlation between RDW and C-reactive protein during the therapy duration (B= -0.03, P = 0.008). Conclusions: The mild increase in RDW, and its weak negative correlation with other acute-phase reactants during the study course, limits its utility as a therapy response marker in pediatric osteomyelitis.

Treatment and outcomes of symptomatic hyperammonemia following asparaginase therapy in children with acute lymphoblastic leukemia.

Hyperammonemia has been reported following asparaginase administration, consistent with the mechanisms of asparaginase, which catabolizes asparagine to aspartic acid and ammonia, and secondarily converts glutamine to glutamate and ammonia. However, there are only a few reports on the treatment of these patients, which varies widely from watchful waiting to treatment with lactulose, protein restriction, sodium benzoate, and phenylbutyrate to dialysis. While many patients with reported asparaginase-induced hyperammonemia (AIH) are asymptomatic, some have severe complications and even fatal outcomes despite medical intervention. Here, we present a cohort of five pediatric patients with symptomatic AIH, which occurred after switching patients from polyethylene glycolated (PEG)- asparaginase to recombinant Crisantaspase Pseudomonas fluorescens (4 patients) or Erwinia (1 patient) asparaginase, and discuss their subsequent management, metabolic workup, and genetic testing. We developed an institutional management plan, which gradually evolved based on our local experience and previous treatment modalities. Because of the significant reduction in glutamine levels after asparaginase administration, sodium benzoate should be used as a first-line ammonia scavenger for symptomatic AIH instead of sodium phenylacetate or phenylbutyrate. This approach facilitated continuation of asparaginase doses, which is known to improve cancer outcomes. We also discuss the potential contribution of genetic modifiers to AIH. Our data highlights the need for increased awareness of symptomatic AIH, especially when an asparaginase with higher glutaminase activity is used, and its prompt management. The utility and efficacy of this management approach should be systematically investigated in a larger cohort of patients.

Peripheral blood mononuclear cell tissue factor (F3 gene) transcript levels and circulating extracellular vesicles are elevated in severe coronavirus 2019 (COVID-19) disease.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with excessive coagulation, thrombosis, and mortality. OBJECTIVE: To provide insight into mechanisms that contribute to excessive coagulation in coronavirus 2019 (COVID-19) disease. PATIENTS/METHODS: Blood from COVID-19 patients was investigated for coagulation-related gene expression and functional activities. RESULTS: Single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells from severe COVID-19 patients revealed a 5.2-fold increase in tissue factor (TF [F3 gene]) transcript expression levels (P < .05), the trigger of extrinsic coagulation; a 7.7-fold increase in C1-inhibitor (SERPING1 gene; P < .01) transcript expression levels, an inhibitor of intrinsic coagulation; and a 4.4-fold increase in anticoagulant thrombomodulin (TM [THBD gene]) transcript expression levels (P < .001). Bulk RNA-seq analysis of sorted CD14+ monocytes on an independent cohort of COVID-19 patients confirmed these findings (P < .05). Indicative of excessive coagulation, 41% of COVID-19 patients' plasma samples contained high D-dimer levels (P < .0001); of these, 19% demonstrated extracellular vesicle TF activity (P = .109). COVID-19 patients' ex vivo plasma-based thrombin generation correlated positively with D-dimer levels (P < .01). Plasma procoagulant extracellular vesicles were elevated ∼9-fold in COVID-19 patients (P < .01). Public scRNA-seq data sets from bronchoalveolar lung fluid and our peripheral blood mononuclear cell scRNA-seq data show CD14+ monocytes/macrophages TF transcript expression levels are elevated in severe but not mild or moderate COVID-19 patients. CONCLUSIONS: Beyond local lung injury, SARS-CoV-2 infection increases systemic TF (F3) transcript levels and elevates circulating extracellular vesicles that likely contribute to disease-associated coagulation, thrombosis, and related mortality.

Screening Awareness of HPV-Related Oropharyngeal Cancers and Attitudes and Concerns towards HPV Vaccination Among Parents : HPV and Oropharyngeal Cancer.

Baseline population opinions on human papillomavirus (HPV) and HPV vaccination must be understood before physicians can address knowledge gaps in that population and encourage timely vaccination. To determine the opinions of parents of children age 9 to 18 on HPV-related oropharyngeal cancers (OPC); the associations with education level, socioeconomic status, and having a family member/friend with OPC; and the main concerns against having a vaccination., An anonymous survey was created and administered. Parents were asked to complete the survey if they met the inclusion criteria. After the survey, results were tabulated, and the answers for each question were analyzed. The target population was surveyed in the clinic. The target population was parents with children between 9 and 18 years old: the background knowledge and awareness of HPV-related OPC and associations with education level, socioeconomic status, having a family member/friend with OPC, and concerns about vaccination. Our study results showed that the age of parents, education level, marital status, personal vaccination status, and gender of the child are significant factors for background knowledge about HPV-related diseases. Similarly, the education level, the gender of the child, and personal vaccination status are significant factors towards attitudes against having children vaccinated. There is a strong correlation between background knowledge and attitudes. The main issues about vaccination are concerns about effectiveness and side effects, concerns about safe sex experiences, and the cost of vaccination. This is the first study designed to provide information on parents' knowledge of HPV-related cancers, prevalence of HPV vaccination, and attitudes and concerns about HPV vaccination in the USA. The lack of awareness of HPV-related cancers is a significant factor in attitudes against HPV vaccination.

Evaluation of Pediatric Hematology Referrals at a Tertiary University Hospital in West Texas.

One in 40 pediatric office visits in the United States result in referral to subspecialty care, mostly for secondary opinion. The aim of this study was to evaluate the necessity of pediatric hematology referrals from Eastern New Mexico and West Texas to a tertiary university hospital. Retrospective data was obtained from chart review based on referrals made to the Southwest Cancer Center in Lubbock, TX for abnormal complete blood count or coagulation tests. Necessity of referrals were assessed according to patient laboratory values before referral, at initial visit, and whether therapy was started by the primary care physician (PCP). One hundred one patients met the study criteria during the period in review. The most common reasons of referral were iron deficiency anemia, leukopenia or leukocytosis and other types of anemia. About 33% of the referrals were determined to be manageable by a PCP as either the correct therapy had been already started before referral and/or the laboratory values were back to normal at the time of the first subspecialty visit. The total estimated cost of unnecessary referrals, including clinic visits and laboratories were $82,888 excluding mileage costs, days of work-school missed, and child care. Incorporation of referral guidelines, improving communication between PCP and subspecialties, and utilizing age-sex appropriate values in the interpretation of results could prevent excessive subspecialty referrals.

A novel de novo mutation at the ABCC8 gene in a newborn with transient diabetes mellitus.

Neonatal diabetes mellitus is a monogenic disease that can present with hyperglycemia, dehydration, failure to thrive, and ketoacidosis within the first six months of life. Neonatal diabetes mellitus can be transient or permanent. Here, we describe a 10-week-old infant with transient neonatal diabetes mellitus who presented with diabetic ketoacidosis and was found to have heterozygous a de novo mutation, p.Thr1381Asn in the ABCC8 gene, which encodes the SUR1 protein. There was no family history of diabetes mellitus and the parents were negative for the mutation at ABCC8. The patient started on insulin therapy and remission of diabetes occurred at 4 months of age. The patient remained euglycemic over a 2-year follow-up period without necessitating any medicine.

How to Treat Cytomegalovirus-induced Hemophagocytic Lymphohistiocytosis in a Child With Leukemia.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by a hyperinflammatory state due to an aberrant activation of the immune cells. It can be familial or secondary to malignancy, autoimmune or metabolic diseases. Most HLH cases are triggered by infection. Histiocyte society suggested HLH-2004 protocol for diagnosis and treatment of both forms. Here, we present a three-year-old girl with B-cell acute lymphoblastic leukemia who developed HLH secondary to cytomegalovirus infection during maintenance therapy. She was successfully treated without needing full HLH protocol therapy. We discuss modified therapy for this specific group of HLH, summarizing 5 other similar cases in the literature.

SLCO1B1 Polymorphisms are Associated With Drug Intolerance in Childhood Leukemia Maintenance Therapy.

BACKGROUND: Therapy discontinuations and toxicities occur because of significant interindividual variations in 6-mercaptopurine (6-MP) and methotrexate (MTX) response during maintenance therapy of childhood acute lymphoblastic leukemia (ALL). 6-MP/MTX intolerance in some of the patients cannot be explained by thiopurine S-methyl transferase (TPMT) gene variants. In this study, we aimed to investigate candidate pharmacogenetic determinants of 6-MP and MTX intolerance in Turkish ALL children. METHODS: In total, 48 children with ALL who had completed or were receiving maintenance therapy according to Children's Oncology Group (COG) protocols were enrolled. Fifteen single-nucleotide polymorphisms in 8 candidate genes that were related to drug toxicity or had a role in the 6-MP/MTX metabolism (TPMT, ITPA, MTHFR, IMPDH2, PACSIN2, SLCO1B1, ABCC4, and PYGL) were genotyped by competitive allele-specific PCR (KASP). Drug doses during maintenance therapy were modified according to the protocol. RESULTS: The median drug dose intensity was 50% (28% to 92%) for 6-MP and 58% (27% to 99%) for MTX in the first year of maintenance therapy, which were lower than that scheduled in all patients. Among the analyzed polymorphisms, variant alleles in SLCO1B1 rs4149056 and rs11045879 were found to be associated with lower 6-MP/MTX tolerance. CONCLUSIONS: SLCO1B1 rs4149056 and rs11045879 polymorphisms may be important genetic markers to individualize 6-MP/MTX doses.

Venlafaxine intoxication in an adolescent presenting with severe lactic acidosis.

Venlafaxine is a selective serotonin noradrenaline reuptake inhibitor and commonly prescribed antidepressant in adults. Most patients overdosing with venlafaxine develop only mild symptoms. Severe toxicity is reported with the most common symptoms being CNS depression, serotonin toxicity, seizure, or cardiac conduction abnormalities. However, lactic acidosis is an uncommon adverse effect. Here, we present the first case in the literature reporting lactic acidosis due to venlafaxine overuse in an adolescent.

Idiopathic Pulmonary Hemosiderosis With Allergic Asthma Diagnosis in a Pediatric Patient.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disorder with unknown pathogenesis that usually presents in the first decade of life. As a result of diffuse alveolar hemorrhage, respiratory symptoms such as cough attacks, hemoptysis, dyspnea, and recurrent and refractory iron-deficiency anemia (IDA) are observed. We present an 8-year-old girl who was followed up with recurrent IDA and allergic asthma and later diagnosed with IPH. IPH was confirmed by the presence of hemosiderin-laden macrophages in bronchoalveolar lavage obtained by bronchoscopy and exclusion of the secondary causes of pulmonary hemosiderosis. Glucocorticoids and iron supplementation were started. Clinical and laboratory improvement was observed with therapy. Our case illustrates that refractory/recurrent IDA with any pulmonary symptoms may be the only presenting feature of IPH.