Monocyte-driven atypical cytokine storm and aberrant neutrophil activation as key mediators of COVID-19 disease severity

Epidemiological and clinical reports indicate that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we perform cytokine and multiplex immune profiling in COVID-19 patients. We show that hypercytokinemia in COVID-19 differs from the interferon-gamma-driven cytokine storm in macrophage activation syndrome, and is more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling shows that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Antigen presenting machinery expression is also reduced in critical disease. Furthermore, we report that neutrophils contribute to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together our findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity.

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents

OBJECTIVES

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period.

METHODS

Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification.

RESULTS

1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10⁵ for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10⁵ (+126%; P<0.001) and for UC, from 1.6 to 4.1/10⁵ (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC.

CONCLUSIONS

In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

Extra-intestinal Manifestations at Diagnosis in Paediatric- and Elderly-onset Ulcerative Colitis are Associated With a More Severe Disease Outcome: A Population-based Study

BACKGROUND AND AIMS

Data on extra-intestinal manifestations [EIM] and their impact on the disease course of ulcerative colitis [UC] in population-based cohorts are scarce, particularly in paediatric- and elderly-onset UC patients. The aims of this population-based study were to assess: 1] the occurrence of EIM in paediatric- and elderly-onset UC; 2] the factors associated with EIM; and 3] their impact on long-term disease outcome.

METHODS

Paediatric-onset [< 17 years at diagnosis] and elderly-onset UC patients [> 60 years at diagnosis] from a French prospective population-based registry [EPIMAD] were included. Data on EIM and other clinical factors at diagnosis and at maximal follow-up were collected.

RESULTS

In all, 158 paediatric- and 470 elderly-onset patients were included [median age at diagnosis 14.5 and 68.8 years, median follow-up 11.2 and 6.2 years, respectively]. EIM occurred in 8.9% of childhood- and 3% of elderly-onset patients at diagnosis and in 16.7% and 2.2% of individuals during follow-up [p < 0.01], respectively. The most frequent EIM was joint involvement [15.8% of paediatric onset and 2.6% of elderly-onset]. Presence of EIM at diagnosis was associated with more severe disease course [need for immunosuppressants or biologic therapy or colectomy] in both paediatric- and elderly-onset UC (hazard ratio [HR] = 2.0, 95% confidence interval [CI]: 1.0-4.2; and HR = 2.8, 0.9-7.9, respectively). Extensive colitis was another independent risk factor in both age groups.

CONCLUSIONS

Elderly-onset UC patients had lower risk of EIM either at diagnosis or during follow-up than paediatric-onset individuals. EIM at diagnosis predicted more severe disease outcome, including need for immunosuppressive or biologic therapy or surgery, in both paediatric- and elderly-onset UC.

The study of the pseudo-polyrotaxane architecture as a route for mild surface functionalization by click chemistry of poly(ε-caprolactone)-based electrospun fibers

PCL fibers with pseudopolyrotaxanes at their surface are functionalized with bicyclononyne clickable groups making possible an easy bioconjugation in water and without copper catalysts for biomedical applications.

Mixed systems to assist enzymatic ring opening polymerization of lactide stereoisomers

Enzymatic ring opening polymerization of both enantiomers of lactide was performed in toluene. The eROP was kinetically improved by solvent assisted method (by TEA) and gave 6 time faster reaction.

Elaboration, morphology and properties of starch/polyester nano-biocomposites based on sepiolite clay

The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) blends has been investigated with the goal of improving the matrix properties. TPS/PBAT nano-biocomposites were elaborated with two different proportions of the polymeric phases. The influence of the sepiolite nanoclays on the mechanical, thermal and structural properties of the corresponding blends was evaluated. SEM images confirmed the good dispersion of the sepiolite clay, with a low occurrence of small aggregates in the polymeric matrix. Wide-angle X-ray diffraction showed no significant alteration of the crystalline structures of PBAT and starch induced by the sepiolite clay. The addition of sepiolite slightly affected the thermal degradation of the nano-biocomposites; however, the mechanical tests revealed an increase in some mechanical properties, demonstrating that sepiolite is a promising nanofiller for TPS-based materials.

Micromechanically-based formulation of the cooperative model for the yield behavior of starch-based nano-biocomposites

The tensile yield stress of plasticized starch filled with montmorillonite has been studied as a function of the temperature and the strain rate and has been compared to the yield behavior of the original matrix. Aggregated/intercalated and exfoliated nano-biocomposites, obtained from different nanofillers, have been produced and tested under uniaxial tension (tensile test). To model the nanocomposite tensile yield stress behavior, a preexisting micro-mechanically based cooperative model, which describes properly the yield of semi-crystalline polymers has been modified. According to our development, the yield behavior of nano-biocomposites is strongly dependant on the clay concentration and exfoliation ratio. Based on the thermodynamics properties, an effective activation volume and effective activation energy are computed through the Takayanagi homogenization model. The predicted results for the yield stress at low strain rates and at different temperatures are in agreement with our experimental results.

[Fifty-two cases of postoperative endophthalmitis treated with one protocol: anatomical and functional results]

PURPOSE

To evaluate our management of postoperative endophthalmitis and compare our protocol to the Endophthalmitis Vitrectomy Study's (EVS) recommended protocol.

PATIENTS AND METHODS

This study comprises 52 patients with postoperative endophthalmitis treated with the same protocol in 1996 and 1997. Patients were given an intravitreal injection of antibiotics (vancomycin-amikacin) and steroids (dexamethasone), systemic antibiotics (pefloxacin-piperracillin), and systemic steroids in bolus. Vitrectomy was not systematic. So as not to delay the treatment, cultures were obtained only from an anterior chamber paracentesis.

RESULTS

Visual acuity was measurable in 86.5% of the patients, with 20/100 in 63.4% and 20/40 in 44.2%. Our results are similar to those of the EVS even when initial visual acuity was Light Perception.

CONCLUSION

Our protocol is simple and easy to perform in all ophthalmology centers. It is based on intravitreal injection, which must be performed as quickly as possible.

Role of tryptophan oxidation in peroxynitrite-dependent protein chemiluminescence

Bovine serum albumin oxidation by peroxynitrite is accompanied by chemiluminescence (Watts et al., Arch. Biochem. Biophys. 317, 324-330, 1995). Peak chemiluminescence during the reaction between bovine serum albumin (with or without fatty acids) and peroxynitrite was not modified in the presence of D2O, suggesting that light emission arising from lipid or protein oxidation was not the result of singlet oxygen formation. Light emission from fatty acid-free albumin increased in the presence of diphenylanthracene (DPA), suggesting that it is a consequence of the fluorescent decay of excited species. Exposure of individual amino acids to peroxynitrite in 50 mM potassium phosphate at pH 8.0 showed that tryptophan is the one that emits most light during oxidation, followed by phenylalanine. Tryptophan chemiluminescence correlated with oxygen consumption. The spin trap N-t-butyl-alpha-phenylnitrone (PBN) inhibited both oxygen consumption and chemiluminescence during tryptophan oxidation, suggesting that the reactions leading to light emission start with the abstraction of a H atom, forming a C-centered radical which in turn adds oxygen. When the oxidation of tryptophan by peroxynitrite was carried out in Tris-HCl instead of potassium phosphate, there was a second oxidative reaction between the peroxide and Tris. Chemiluminescence and oxygen consumption during the oxidation of tryptophan by peroxynitrite was 50% lower in the presence of Tris and in this case PBN did not inhibit chemiluminescence, suggesting that the new radicals formed during the reaction of Tris with peroxynitrite reacted with the amino acyl radicals inhibiting the formation of excited intermediates. Exposure of Tris but not phosphate to peroxynitrite (in the absence of amino acids) also resulted in light emission. In summary, these results suggest that tryptophan is one of the amino acids responsible for light emission during protein oxidation. In addition, this study confirms that Tris buffer is a target for strong oxidants and shows that its oxidation also is accompanied by light emission.

[Iatrogenic arteriovenous fistula between the internal mammary artery and the innominate venous trunk. Contribution of digital arteriography in the positive and anatomic diagnosis]

The authors report the case of an arterio-venous fistula between the internal mammary artery and the trunk of the innominate vein following puncture of the internal jugular. The clinical signs of this unusual complication led the authors to list the differential diagnoses which should be considered and to draw attention to the importance of digitalized angiography in anatomical diagnosis.

[Differential analysis of mitral and tricuspid regurgitation by continuous Doppler]

The following parameters have been measured by continuous Doppler in 40 patients with both mitral failure (MF) and tricuspid failure (TF): effusion time (ET), peak time (PT), maximum effusion speed (S. max), maximum anterograde speed (S. ant), taking into account the cardiac rate and the ejection fraction. Only the S. max. and the S. ant. are significantly different and enable the determination of the effusion origin with a percentage error of about 4%. When a straight line is drawn to joint 3.7 m/s on the ordinate (S. ant) and 5 m/s on the abcissa (S. max), the TF lie below the line and the MF above it. The selection of the sub-groups with low ejection fraction (less or equal to 30%) or with arterial pulmonary hypertension (S. max MF higher or equal to 3 m/s) does not modify the precision of the discrimination. The graph suggested seems therefore to be a rapid and reliable means of characterizing TF in order to assess the arterial pulmonary hypertension of dilated hypokinetic cardiomyopathies.

[Comparative study of cibenzoline and flecainide administered via an intravenous route in reducing auricular arrhythmia]

The efficacy of intravenous flecainide and cibenzoline acetate in the reduction of atrial rhythm disorders was compared in two groups of 30 patients. These arrhythmias are divided in 31 atrial fibrillation, 11 tachy-systoles, 18 atrial flutters. Parenteral administration of the anti-arrhythmic drug over a 24 hour-period is preceded by a bolus injection of 1.5 mg/kg of flecainide acetate for group I, and a bolus of 1 mg/kg of cibenzoline for group II. The overall efficacy of the two molecules is comparable (53%) as well as the reduction of the atrial fibrillations (65% vs 57%). Flecainide acetate seems more effective in treating effectively atrial tachycardias (66.6% vs 40%), and cibenzoline is more effective in the treatment of atrial flutters (54% vs 14%). The functional, electrical and haemodynamic tolerance has always been good in both group, except in 2 patients, because of the indirect pro-arrhythmic effect of cibenzoline. We are concluding that the efficacy of both molecules is satisfactory and we advocate their use, as first intention, in recent and idiopathic atrial fibrillation; it seems that cibenzoline is more effective on ischemic cardiopathies and flecainide acetate is more effective on valvular cardiopathies. Nevertheless, the possible indirect pro-arrhythmic effect, sometimes poorly tolerated in the first minutes following administration of the bolus, only on organized atrial rhythm disorder, leads us to advocate the prescription of these two drugs when attempts of transesophageal or endocardiac atrial stimulation have failed.

[Natural course of type III traumatic chronic dissection in a patient with Marfan's syndrome]

Description of a traumatic dissection of the descending thoracic aorta, occurring in a female patient with Marfan's syndrome, the chronic course of which over more than three years was complicated by retrograde extension to the ascending thoracic aorta, resulting in death by massive aortic insufficiency and pleuro-pericardial effusion. Advantages of clinical and sonocardiographic monitoring of chronic dissections.

[Ultrasonic diagnosis of biventricular thrombus during the acute phase of myocardial infarction]

The occurrence of a left ventricular thrombus is a classic complication of acute myocardial infarction. On the contrary, this is much less frequent in the right ventricle. The authors report the case of a patient presenting a biventricular thrombus resulting as a complication of an anterior myocardial infarction, diagnosed by bidimensional ultrasonography. The course is characterized by the occurrence of a cerebral vascular accident. The sonogram following this neurological accident shows that the left ventricular thrombus has disappeared, confirming its migration. On the contrary, the right ventricular thrombus regressed under appropriate heparin treatment, without any embolic complication.

[Diagnostic, prognostic and therapeutic value of Doppler echocardiography in pulmonary embolism. Apropos of 41 cases]

In 41 patients with acute or recent pulmonary embolus (PE), a prospective study was conducted with cardiac Doppler sonography (CDS). The test is performed first in all patients, then immediately following a treatment fibrinolytics in 10 of them. The PE is confirmed by pulmonary angiography in 39 patients and embolectomy for the 2 patients who presented a mobile thrombus in the right atrium. A tricuspid insufficiency (TI) is almost always recorded by continuous Doppler: the systolic pulmonary artery pressure (sPAP) is calculated from the maximum velocity of the regurgitating tricuspid flow, using Bernouilli's equation. The correlation between Doppler sPAP and sPAP obtained by catheterization is: r = 0.95 (n = 34; p less than 0.001). A severe pulmonary hypertension, corresponding to a TI exceeding 3.5 m/s is related to a pulmonary migration occurring on a pathological heart. There is a satisfactory relationship between the elevation of the Doppler sPAP and the degree of pulmonary obstruction in the "Pe on healthy heart" population: r = 0.6 (n = 29; p less than 0.001). The dilated right ventricle observed on the sonogram (RV) is proportional to the severity of the angiographic image: correlation between the RV/LV ratio and the percentage of vascular obstruction is r = 0.73 (n = 27; p less than 0.001). The drop in the sPAP and the regression of the symptoms of pulmonary heart noted on CDS after fibrinolysis, correspond to a significant improvement of the pulmonary perfusion. The CDS seems to be absolutely necessary in PE because of the major and reliable informations it provides.

[Acute dysfunction of mitral bioprosthesis: Doppler expression of a musical holosystolic murmur. Apropos of 2 cases]

Two women who had been fitted with a porcine mitral valve seven years previously suddenly developed acute dysfunction of the bioprosthesis with regurgitation. In both patients physical examination revealed an intense, vibrating, musical holosystolic murmur sounding like a "goose cry" and located at the apex. Pulsed doppler showed major, jet-like, central orothetic mitral regurgitation. A harmonic graph was recorded when the doppler window was positioned upstream of the porcine valve leaflets. The finding of such a doppler signal in this clinical context suggests tearing or perforation of one cuspid and rules out the possibility of bioprosthesis degeneration.

[Postoperative hemopericardium compressing the left atrium. Apropos of a case]

We report a case of tamponade due to an effusion of blood which had occurred two weeks after an aorto-coronary bypass and was unusually located behind the left atrium. The effusion, with severe clinical symptoms, was diagnosed by echocardiography and computerized tomography of the chest. These examinations provided an accurate anatomical diagnosis on which the approach route of the emergency operation was based.

[Comparative study of pulsed and continuous Doppler in the quantification of aortic insufficiency]

31 patients whose mean age was 61 +/- 29 yrs. presenting with aortic regurgitation (AR) benefited from cardiac catheterization which was preceded by Doppler ultrasound examination in a prospective study to compare the diagnostic contributions made by continuous vs pulsed wave techniques respectively in the quantitative assessment of AR, with reference to semi-quantitative angiographic evaluation. Pulsed Doppler analysis involves mapping of the left ventricle in two projections as well as the investigation of blood flow in the aortic isthmus using a suprasternal approach. Collection of continuous wave signals from the cardiac apex makes it possible to measure circulatory deceleration and the half-time of decrease in signal velocity and the protodiastolic pressure gradient. Our results corroborate the reliability of data obtained using continuous-wave Doppler technique in finding significant correlations for each parameter respectively: r' = 0.88 (p less than 0.001); r' = -0.81 (p less than 0.001); r' = -0.75 (p less than 0.001). Values determined by pulsed wave Doppler mapping of the left ventricle appear to be less satisfactory but are significant: r' = 0.68 (p less than 0.001) while measurement of end-diastolic blood flow recorded in the isthmus of the aorta is more highly correlated: r' = 0.84 (p less than 0.01), with the main disadvantage being its limited applicability to a small number of our patients (48%). We thus concluded that continuous-wave Doppler ultrasound is a better technique in the quantitative evaluation of AR, while recalling the essential additional value of pulsed-wave Doppler technique to localize the leakage and of ultrasound to assess its impact on the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

[Validation of a method for measuring the area of aortic stenosis using only continuous Doppler. Value for the surveillance of transluminal aortic valvuloplasties]

Forty patients with aortic valve stenosis underwent continuous wave doppler-echocardiographic exploration followed by catheterization within 24 hours on average. Three methods of aortic functional area calculation, based on the continuity equation principle, were tried and compared with the haemodynamic data. The results of the reference equation (continuity through the whole systole) gave a correlation coefficient r = 0.77 with a standard error (SE) of 0.17 cm2. The continuity equation using only maximum velocity values was less satisfactory: r = 0.69; SE = 0.19 cm2. The simplified equation with an arbitrary 2 cm subaortic diameter and a subaortic velocity obtained by continuous wave doppler recording yielded results that were very similar to those of the reference equation: r = 0.78; SE = 0.16 cm2. It is suggested that this third equation should be used in the follow-up of transluminal aortic valvuloplasties, since its calculation is based only on aortic velocity, which reflects the degree of stenosis, and subaortic velocity, which indirectly reflects left ventricular function.

[Diagnostic and prognostic value of continuous Doppler in pulmonary embolism]

A prospective study of 18 patients admitted to hospital for acute pulmonary embolism confirmed the reliability of continuous wave cardiac doppler as a non-invasive method of evaluating systolic pulmonary artery pressures. These pressures were calculated by applying the simplified Bernoulli equation to the maximal velocity of regurgitant tricuspid flow and compared with the results of cardiac catheterisation and angiography, the percentage of vascular obstruction being assessed using Miller's index. The correlations between the two methods were good, r = 0.96; p less than 0.001, with a standard error of +/- 5.2 mmHg. The correlations between the velocity of tricuspid flow and the percentage of obstruction were less significant (r = 0.65; p less than 0.005) but improved when patients with pre-existing cardiopulmonary disease were excluded. This technique of non-invasive assessment of haemodynamic parameters also helps in evaluating the underlying pathology; tricuspid regurgitation with velocities greater than 3.5 m/s is associated with pre-existing chronic cor pulmonale, information of prognostic interest which would guide therapeutic management.

[Floating thrombus of the right atrium in acute pulmonary embolism. Clinical, echocardiographic aspects and therapeutic sequelae]

The performance of a systematic sonocardiography in all our patients hospitalized since January 1985 for pulmonary embolism, has enabled to discover five cases of floating thrombus of the right atrium. Three patients presented an abnormal auscultation, with one of them presenting a tricuspid wedge syndrome. On the sonogram, the aspect of the thrombus, "coil or ball-shaped", floating in the atrial cavity, sometimes prolapsed through the tricuspid valve, associated with the signs of a pulmonary heart, enables to rule out other right intraatrial masses. Pulmonary angiography seems contra-indicated because of the risk of embolus of this thrombus, the migration of which may be fatal. Embolectomy, under extra-corporeal circulation (heart-lung pump) with examination of the right cavities appears to be the treatment of choice.

[Treatment of giardiasis with tinidazole]

Fifty patients stricken by giardiosis were treated by a single dose administration of Tinidazole -- 50 mg./kg. for children and 2 g. for adults per os. Fifteen days after treatment, 84 0/0 of the patients had negative coprologic exams for giardiosis. The product was well-tolerated by the digestive tract as was demonstrated by a coprologic examination for digested food reside; however, minor digestive inconveniences were noted in 87 0/0 of the patients. There were no perturbations of hematologic or hepatic tests. This product would thus appear to be a treatment of choice in the management of giardiosis.