Association of Intravenous Immunoglobulins Plus Methylprednisolone vs Immunoglobulins Alone With Course of Fever in Multisystem Inflammatory Syndrome in Children

IMPORTANCE

Multisystem inflammatory syndrome in children (MIS-C) is the most severe pediatric disease associated with severe acute respiratory syndrome coronavirus 2 infection, potentially life-threatening, but the optimal therapeutic strategy remains unknown.

OBJECTIVE

To compare intravenous immunoglobulins (IVIG) plus methylprednisolone vs IVIG alone as initial therapy in MIS-C.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study drawn from a national surveillance system with propensity score-matched analysis. All cases with suspected MIS-C were reported to the French National Public Health Agency. Confirmed MIS-C cases fulfilling the World Health Organization definition were included. The study started on April 1, 2020, and follow-up ended on January 6, 2021.

EXPOSURES

IVIG and methylprednisolone vs IVIG alone.

MAIN OUTCOMES AND MEASURES

The primary outcome was persistence of fever 2 days after the introduction of initial therapy or recrudescence of fever within 7 days, which defined treatment failure. Secondary outcomes included a second-line therapy, hemodynamic support, acute left ventricular dysfunction after first-line therapy, and length of stay in the pediatric intensive care unit. The primary analysis involved propensity score matching with a minimum caliper of 0.1.

RESULTS

Among 181 children with suspected MIS-C, 111 fulfilled the World Health Organization definition (58 females [52%]; median age, 8.6 years [interquartile range, 4.7 to 12.1]). Five children did not receive either treatment. Overall, 3 of 34 children (9%) in the IVIG and methylprednisolone group and 37 of 72 (51%) in the IVIG alone group did not respond to treatment. Treatment with IVIG and methylprednisolone vs IVIG alone was associated with lower risk of treatment failure (absolute risk difference, -0.28 [95% CI, -0.48 to -0.08]; odds ratio [OR], 0.25 [95% CI, 0.09 to 0.70]; P = .008). IVIG and methylprednisolone therapy vs IVIG alone was also significantly associated with lower risk of use of second-line therapy (absolute risk difference, -0.22 [95% CI, -0.40 to -0.04]; OR, 0.19 [95% CI, 0.06 to 0.61]; P = .004), hemodynamic support (absolute risk difference, -0.17 [95% CI, -0.34 to -0.004]; OR, 0.21 [95% CI, 0.06 to 0.76]), acute left ventricular dysfunction occurring after initial therapy (absolute risk difference, -0.18 [95% CI, -0.35 to -0.01]; OR, 0.20 [95% CI, 0.06 to 0.66]), and duration of stay in the pediatric intensive care unit (median, 4 vs 6 days; difference in days, -2.4 [95% CI, -4.0 to -0.7]).

CONCLUSIONS AND RELEVANCE

Among children with MIS-C, treatment with IVIG and methylprednisolone vs IVIG alone was associated with a more favorable fever course. Study interpretation is limited by the observational design.

Infective Endocarditis Risk After Percutaneous Pulmonary Valve Implantation With the Melody and Sapien Valves

OBJECTIVES

This study compared the risk of infective endocarditis (IE) after percutaneous pulmonary valve implantation (PPVI) with the Sapien and Melody valves.

BACKGROUND

The incidence of IE after PPVI is estimated at 3% per year with the Melody valve. The Sapien valve is a more recently marketed valve used for PPVI.

METHODS

We retrospectively included consecutive patients who underwent PPVI at a single center between 2008 and 2016. IE was diagnosed using the modified DUKE criteria.

RESULTS

PPVI was performed in 79 patients (Melody valve, 40.5%; Sapien valve, 59.5%). Median age was 24.9 years (range 18.1 to 34.6). IE occurred in 8 patients (10.1%) at a median of 1.8 years (minimum: 1.0; maximum: 5.6) after surgery. Causative organisms were methicillin-sensitive Staphylococcus aureus (n = 3), Staphylococcus epidermidis (n = 1), Streptococcus mitis (n = 1), Aerococcus viridans (n = 1), Corynebacterium striatum (n = 1), and Haemophilus influenzae (n = 1). All 8 cases occurred after Melody PPVI (25.0% vs. 0.0%). The incidence of IE was 5.7% (95% confidence interval: 2.9% to 11.4%) per person-year after Melody PPVI. The Kaplan-Meier cumulative incidence of IE with Melody PPVI was 24.0% (95% confidence interval: 12.2% to 43.9%) after 4 years and 30.1% (95% confidence interval: 15.8% to 52.5%) after 6 years, compared with 0.0% with the Sapien PPVI after 4 years (p < 0.04 by log-rank test). There was a trend toward a higher incidence of IE in the first 20 patients with Melody PPVI (who received prophylactic antibiotics during the procedure only) and in patients who had percutaneous interventions, dental care, or noncardiac surgery after PPVI.

CONCLUSIONS

IE after PPVI may be less common with the Sapien compared with the Melody valve.

Synthetic active site analogues of heme-thiolate proteins. Characterization and identification of intermediates of the catalytic cycles of cytochrome P450cam and chloroperoxidase

In view of recent results from different sources, the reaction mechanisms of two heme-thiolate proteins, cytochrome P450cam and chloroperoxidase (CPO), are discussed. In this context a mechanism of CPO is proposed which includes H2O2 cleavage, subsequent formation of compound I and the identification of two elusive intermediates. The HOCl adduct of the iron(III)porpyhrin is the catalytically competent Cl+ donor chlorinating activated C-H bonds of substrates bound to the enzyme. Pulse-EPR characterization of an enzyme model of the resting state of P450cam suggests a role of the electric field of the protein for stabilizing the low-spin state of the cofactor of the enzyme. It is further suggested that the same effect of the protein may trigger the reactivity of compound I such that both concerted and two-step reactions are feasible within the concept of a Two-State-Reactivity. This review emphasizes the value of synthetic enzyme models complementing investigations of the native proteins.

Resident PW1+ Progenitor Cells Participate in Vascular Remodeling During Pulmonary Arterial Hypertension

RATIONALE

Pulmonary arterial hypertension is characterized by vascular remodeling and neomuscularization. PW1(+) progenitor cells can differentiate into smooth muscle cells (SMCs) in vitro.

OBJECTIVE

To determine the role of pulmonary PW1(+) progenitor cells in vascular remodeling characteristic of pulmonary arterial hypertension.

METHODS AND RESULTS

We investigated their contribution during chronic hypoxia-induced vascular remodeling in Pw1(nLacZ+/-) mouse expressing β-galactosidase in PW1(+) cells and in differentiated cells derived from PW1(+) cells. PW1(+) progenitor cells are present in the perivascular zone in rodent and human control lungs. Using progenitor markers, 3 distinct myogenic PW1(+) cell populations were isolated from the mouse lung of which 2 were significantly increased after 4 days of chronic hypoxia. The number of proliferating pulmonary PW1(+) cells and the proportion of β-gal(+) vascular SMC were increased, indicating a recruitment of PW1(+) cells and their differentiation into vascular SMC during early chronic hypoxia-induced neomuscularization. CXCR4 inhibition using AMD3100 prevented PW1(+) cells differentiation into SMC but did not inhibit their proliferation. Bone marrow transplantation experiments showed that the newly formed β-gal(+) SMC were not derived from circulating bone marrow-derived PW1(+) progenitor cells, confirming a resident origin of the recruited PW1(+) cells. The number of pulmonary PW1(+) cells was also increased in rats after monocrotaline injection. In lung from pulmonary arterial hypertension patients, PW1-expressing cells were observed in large numbers in remodeled vascular structures.

CONCLUSIONS

These results demonstrate the existence of a novel population of resident SMC progenitor cells expressing PW1 and participating in pulmonary hypertension-associated vascular remodeling.

Myeloid phenotypes in severe COVID-19 predict secondary infection and mortality: a pilot study

BACKGROUND

De-regulated host response to severe coronavirus disease 2019 (COVID-19), directly referring to the concept of sepsis-associated immunological dysregulation, seems to be a strong signature of severe COVID-19. Myeloid cells phenotyping is well recognized to diagnose critical illness-induced immunodepression in sepsis and has not been well characterized in COVID-19. The aim of this study is to review phenotypic characteristics of myeloid cells and evaluate their relations with the occurrence of secondary infection and mortality in patients with COVID-19 admitted in an intensive care unit.

METHODS

Retrospective analysis of the circulating myeloid cells phenotypes of adult COVID-19 critically ill patients. Phenotyping circulating immune cells was performed by flow cytometry daily for routine analysis and twice weekly for lymphocytes and monocytes subpopulations analysis, as well as monocyte human leukocyte antigen (mHLA)-DR expression.

RESULTS

Out of the 29 critically ill adult patients with severe COVID-19 analyzed, 12 (41.4%) developed secondary infection and six patients died during their stay. Monocyte HLA-DR kinetics was significantly different between patients developing secondary infection and those without, respectively, at day 5-7 and 8-10 following admission. The monocytes myeloid-derived suppressor cells to total monocytes ratio was associated with 28- and 60-day mortality. Those myeloid characteristics suggest three phenotypes: hyperactivated monocyte/macrophage is significantly associated with mortality, whereas persistent immunodepression is associated with secondary infection occurrence compared to transient immunodepression.

CONCLUSIONS

Myeloid phenotypes of critically ill COVID-19 patients may be associated with development of secondary infection, 28- and 60-day mortality.

Inhalable delivery of AAV-based MRP4/ABCC4 silencing RNA prevents monocrotaline-induced pulmonary hypertension

The ATP-binding cassette transporter MRP4 (encoded by ABCC4) regulates membrane cyclic nucleotides concentrations in arterial cells including smooth muscle cells. MRP4/ABCC4 deficient mice display a reduction in smooth muscle cells proliferation and a prevention of pulmonary hypertension in response to hypoxia. We aimed to study gene transfer of a MRP4/ABCC4 silencing RNA via intratracheal delivery of aerosolized adeno-associated virus 1 (AAV1.shMRP4 or AAV1.control) in a monocrotaline-induced model of pulmonary hypertension in rats. Gene transfer was performed at the time of monocrotaline administration and the effect on the development of pulmonary vascular remodeling was assessed 35 days later. AAV1.shMRP4 dose-dependently reduced right ventricular systolic pressure and hypertrophy with a significant reduction with the higher doses (i.e., >10¹¹ DRP/animal) as compared to AAV1.control. The higher dose of AAV1.shMRP4 was also associated with a significant reduction in distal pulmonary arteries remodeling. AAV1.shMRP4 was finally associated with a reduction in the expression of ANF, a marker of cardiac hypertrophy. Collectively, these results support a therapeutic potential for downregulation of MRP4 for the treatment of pulmonary artery hypertension.

Estimation of air-water gas exchange coefficient in a shallow lagoon based on 222Rn mass balance

The radon-222 mass balance is now commonly used to quantify water fluxes due to Submarine Groundwater Discharge (SGD) in coastal areas. One of the main loss terms of this mass balance, the radon evasion to the atmosphere, is based on empirical equations. This term is generally estimated using one among the many empirical equations describing the gas transfer velocity as a function of wind speed that have been proposed in the literature. These equations were, however, mainly obtained from areas of deep water and may be less appropriate for shallow areas. Here, we calculate the radon mass balance for a windy shallow coastal lagoon (mean depth of 6m and surface area of 1.55*10(8) m(2)) and use these data to estimate the radon loss to the atmosphere and the corresponding gas transfer velocity. We present new equations, adapted to our shallow water body, to express the gas transfer velocity as a function of wind speed at 10 m height (wind range from 2 to 12.5 m/s). When compared with those from the literature, these equations fit particularly well with the one of Kremer et al. (2003). Finally, we emphasize that some gas transfer exchange may always occur, even for conditions without wind.

Blood Purification with oXiris© in Critically Ill Children with Vasoplegic Shock

INTRODUCTION

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. As such, circulating cytokines and danger- and pathogen-associated molecular patterns (such as endotoxins) are recognized as central in the pathogenesis of sepsis and organ dysfunction. Removing these compounds by extracorporeal blood filtration, commonly considered blood purification, may improve the septic patients' condition. This study aimed to assess the vaso-inotropic support evolution over time in pediatric patients with vasoplegic shock treated with oXiris©.

METHODS

All patients aged below 18 years admitted at the Paris Saclay University Quaternary Pediatric Intensive Care Unit with vasoplegic shock and acute kidney injury and treated with oXiris© between October 2017 and January 2020 were included. The vaso-inotropic score and the 28-day mortality were assessed. Improvement under treatment was defined as a 50% decrease in the vaso-inotropic score following 24 h of oXiris© therapy.

RESULTS

Eleven pediatric patients aged 2-15 years and weighing 11-60 kg were admitted with vasoplegic shock and acute kidney injury. They received thirteen sessions of oXiris© therapy for septic shock (N = 7) and liver failure (N = 6). Eight patients did not improve their condition during the session, and five ultimately died (37.5% survival). Five patients improved, decreasing their inotropic support by &gt;50% in 24 h. Among them, four survived (80%).

CONCLUSION

Hemofiltration and extracorporeal blood purification with oXiris© can be used in pediatric patients with vasoplegic shock with rapid improvement in hemodynamics in selected patients.

Relationship between the cardiovascular effects and both plasma and myocardial levels of clentiazem, a new benzothiazepine calcium antagonist, in anesthetized dogs

We evaluated the relationship between the cardiovascular effects of clentiazem (TA-3090), a new 1,5-benzothiazepine calcium antagonist with high lipophilicity, and both its plasma and myocardial concentrations. Anesthetized, open-chest dogs, instrumented for hemodynamic data recording and blood sampling, were divided into three groups treated with 15, 50, or 200 micrograms/kg of clentiazem, respectively, as an intravenous bolus. At the end of the protocol (240 minutes), myocardial samples were tested for clentiazem. The results indicated that the peripheral and coronary vasodilatory effects of clentiazem were dose dependent and closely related to its plasma concentrations. It was also observed that the minimal effective plasma concentration was in the range of 15-20 ng/ml. Sustained negative chronotropic effects were recorded at the highest dose only and were best related to the amount of clentiazem detectable in the myocardium, suggesting that myocardial clentiazem retention is a major factor governing its depressant cardiac impact.

Nirsevimab prophylaxis on pediatric intensive care hospitalization for severe acute bronchiolitis: a clinical and economic analysis

BACKGROUND

Severe acute viral bronchiolitis is a common cause of admissions to pediatric intensive care units (PICUs), resulting in a significant organizational burden each winter. The recent introduction of generalized neonatal prophylactic therapies using Nirsevimab, a monoclonal antibody targeting the respiratory syncytial virus (RSV), has significantly reduced consultations and hospitalizations. However, its impact on the medico-economic aspects of the PICU remains poorly defined.

METHODS

We analyzed all infants admitted to our unit for severe acute bronchiolitis over six consecutive epidemic periods (September to March) and examined the effect of Nirsevimab generalized prophylaxis on PICU admissions during the 2023-2024 period.

RESULTS

Between 2018 and 2024, 572 out of, 3728 infants under 6 months of age were admitted to the PICU for severe acute bronchiolitis during six epidemic periods. The average percentage of infants with bronchiolitis admitted to the PICU was 15.3% (95% CI 14.2-16.5), with a net decrease during the 2023-2024 period (8.5%) compared to the 2022-2023 period (17.6%). Patients' characteristics were similar, as were the supporting therapies. The causes of bronchiolitis were identical, with 83% and 77% secondary to RSV. PICU duration was significantly reduced during the last period from 4.4 days (95% CI 3.8-5.9) to 3.3 days (95% CI 2.6-4). The medico-economic impact was significant, with a cost reduction for acute severe viral bronchiolitis PICU total stays from €210,105 to €121,044 per annual epidemic without a change in the return on investment.

CONCLUSIONS

The introduction of generalized neonatal prophylaxis with Nirsevimab significantly impacts the burden of severe acute bronchiolitis in the PICU.

[Treatment of malignant glioma. Apropos of 39 cases]

Thirty-nine patients with malignant gliomas (36 glioblastomas, 3 astrocytomas grade III; age median 52.5) were treated after surgery by combination chemotherapy followed by irradiation. The median survival on the actuarial curve is 7 months. An attempt is made to evaluate each therapeutic modality by analysis of clinical and CT parameters.