Elevated HScore is Associated with Poor Clinical Outcomes in COVID-19, Even in the Absence of Secondary Hemophagocytic Lymphohistiocytosis.

IntroductionPatients with Coronavirus Disease 2019 (COVID-19) frequently experience a hyperinflammatory syndrome, that leads to unfavorable outcomes. This condition resembles Secondary Hemophagocytic Lymphohistiocytosis (sHLH) described in neoplastic, rheumatic and other infectious diseases. However, it has not been prospectively studied on these patients. A scoring system (HScore) has been validated for sHLH, and recently proposed to evaluate hyperinflammation in COVID-19. Methods143 patients aged [≥]18 years admitted because of COVID-19 were enrolled in a prospective, single-center, cohort study. HScore was calculated within the 72 hours since admission. The incidence of sHLH during hospitalization was evaluated. Additionally, the relationship between HScore [≥]130 points and either the requirement of mechanical ventilation or 60-days mortality was explored. ResultsThe median age of enrolled patients was 57 (21-100), and 63.6% were male. The median HScore was 96 (33-169). One patient was diagnosed with sHLH (incidence 0,7%), due to a HScore of 169. After adjusting for age, sex, comorbidities and obesity, HScore [≥]130 was independently associated with the composite clinical outcome (HR 2.13, p=0.022). ConclusionsHLH is not frequent among COVID-19 patients. HScore can efficiently predict the risk for poor outcomes.

Ideal evolution of magnetohydrodynamic turbulence when imposing Taylor-Green symmetries.

We investigate the ideal and incompressible magnetohydrodynamic (MHD) equations in three space dimensions for the development of potentially singular structures. The methodology consists in implementing the fourfold symmetries of the Taylor-Green vortex generalized to MHD, leading to substantial computer time and memory savings at a given resolution; we also use a regridding method that allows for lower-resolution runs at early times, with no loss of spectral accuracy. One magnetic configuration is examined at an equivalent resolution of 6144(3) points and three different configurations on grids of 4096(3) points. At the highest resolution, two different current and vorticity sheet systems are found to collide, producing two successive accelerations in the development of small scales. At the latest time, a convergence of magnetic field lines to the location of maximum current is probably leading locally to a strong bending and directional variability of such lines. A novel analytical method, based on sharp analysis inequalities, is used to assess the validity of the finite-time singularity scenario. This method allows one to rule out spurious singularities by evaluating the rate at which the logarithmic decrement of the analyticity-strip method goes to zero. The result is that the finite-time singularity scenario cannot be ruled out, and the singularity time could be somewhere between t=2.33 and t=2.70. More robust conclusions will require higher resolution runs and grid-point interpolation measurements of maximum current and vorticity.