Lung Ultrasound Findings and Endothelial Perturbation in a COVID-19 Low-Intensity Care Unit

Hypercoagulability and endothelial dysfunction related to inflammation have been clearly demonstrated in COVID-19. However, their influence on thromboembolism, lung alterations and mortality in low-intensity-care patients with COVID-19 is not completely clarified. Our aims were to evaluate the prevalence of deep vein thrombosis (DVT) with compressive ultrasound (CUS); to describe lung ultrasound (LUS) features; and to study coagulation, inflammatory and endothelial perturbation biomarkers in COVID-19 patients at low-intensity care unit admission. The predictive value of these biomarkers on mortality, need for oxygen support and duration of hospitalization was also evaluated. Of the 65 patients included, 8 were non-survivors. CUS was negative for DVT in all patients. LUS Soldati and Vetrugno scores were strongly correlated (rho = 0.95) with each other, and both significantly differed in patients who needed oxygen therapy vs. those who did not (Soldati p = 0.017; Vetrugno p = 0.023), with coalescent B lines as the most prevalent pattern in patients with a worse prognosis. Mean (SD) levels of thrombomodulin and VCAM-1 were higher in non-survivors than in survivors (7283.9 pg/mL (3961.9 pg/mL) vs. 4800.7 pg/mL (1771.0 pg/mL), p = 0.004 and 2299 ng/mL (730.35 ng/mL) vs. 1451 ng/mL (456.2 ng/mL), p < 0.001, respectively). Finally, in a multivariate analysis model adjusted for age, sex and Charlson score, VCAM-1 level increase was independently associated with death [OR 1.31 (1.06, 1.81; p = 0.036)]. In conclusion, in a cohort of mild COVID-19 patients, we found no DVT events despite the highly abnormal inflammatory, endothelial and coagulation parameters. The presence of lung alterations at admission could not predict outcome. The endothelial perturbation biomarker VCAM-1 emerged as a promising prognostic tool for mortality in COVID-19

High prevalence of splenic marginal zone lymphoma among patients with acquired C1 inhibtor deficiency

Marginal zone lymphoma represents about 10% of all non-Hodgkin lymphomas (NHLs). 33% of patients with acquired angioedema (AAE) due to acquired C1-inhibitor (C1-INH) deficiency (C1-INH-AAE) have or will develop NHLs. C1-INH-AAE is a rare condition. We report the follow-up of 72 C1-INH-AAE patients, followed for a median of 15\uc2\ua0years (range 1-24). Median age was 71 (range 64-79) years; median age at onset of angioedema symptoms was 57\uc2\ub75 (range 50-66) years and it was 63 [range 45-80) years at diagnosis]. Twenty patients were diagnosed with low-grade non-follicular B-cell lymphomas (75% were splenic MZL), one with follicular and three with high-grade lymphomas (two diffuse large B-cell lymphomas and one mantle cell lymphoma). Fifteen NHLs were diagnosed at onset of AAE or thereafter (3\uc2\ua0months to 7\uc2\ua0years), eight had already been diagnosed at onset of angioedema. Two of 24 patients remain on watchful wait. Thirthen of 24 received chemotherapy, two received rituximab. Three underwent splenectomy. All 18 patients receiving therapy for NHL experienced post-treatment reduction in AAE symptoms. Our study suggests that clonal B-cell proliferation is the pathology underlying AAE leading to production of C1-INH-neutralizing autoantibodies and to NHLs. The post-germinal centre origin of NHL suggests that immune stimulation may contribute to lymphomagenesis

Ongoing contact activation in patients with hereditary angioedema

Hereditary angioedema (HAE) is predominantly caused by a deficiency in C1 esterase inhibitor (C1INH) (HAE-C1INH). C1INH inhibits activated factor XII (FXIIa), activated factor XI (FXIa), and kallikrein. In HAE-C1INH patients the thrombotic risk is not increased even though activation of the contact system is poorly regulated. Therefore, we hypothesized that contact activation preferentially leads to kallikrein formation and less to activation of the coagulation cascade in HAE-C1INH patients. We measured the levels of C1INH in complex with activated contact factors in plasma samples of HAE-C1INH patients (N=30, 17 during remission and 13 during acute attack) and healthy controls (N=10). We did not detect differences in enzyme-inhibitor complexes between samples of controls, patients during remission and patients during an acute attack. Reconstitution with C1INH did not change this result. Next, we determined the potential to form enzyme-inhibitory complexes after complete in vitro activation of the plasma samples with a FXII trigger. In all samples, enzyme-C1INH levels increased after activation even in patients during an acute attack. However, the levels of FXIIa-C1INH, FXIa-C1INH and kallikrein-C1INH were at least 52% lower in samples taken during remission and 70% lower in samples taken during attack compared to samples from controls (p<0.05). Addition of C1INH after activation led to an increase in levels of FXIIa-C1INH and FXIa-C1INH (p<0.05), which were still lower than in controls (p<0.05), while the levels of kallikrein-C1INH did not change. These results are consistent with constitutive activation and attenuated depletion of the contact system and show that the ongoing activation of the contact system, which is present in HAE-C1INH patients both during remission and during acute attacks, is not associated with preferential generation of kallikrein over FXIa

Diagnostic value of plasma p-tau181, NfL, and GFAP in a clinical setting cohort of prevalent neurodegenerative dementias

Background: Increasing evidence supports the use of plasma biomarkers of neurodegeneration and neuroinflammation to screen and diagnose patients with dementia. However, confirmatory studies are required to demonstrate their usefulness in the clinical setting. Methods: We evaluated plasma and cerebrospinal fluid (CSF) samples from consecutive patients with frontotemporal dementia (FTD) (n = 59), progressive supranuclear palsy (PSP) (n = 31), corticobasal syndrome (CBS) (n = 29), dementia with Lewy bodies (DLB) (n = 49), Alzheimer disease (AD) (n = 97), and suspected non-AD physiopathology (n = 51), as well as plasma samples from 60 healthy controls (HC). We measured neurofilament light chain (NfL), phospho-tau181 (p-tau181), and glial fibrillary acid protein (GFAP) using Simoa (all plasma biomarkers and CSF GFAP), CLEIA (CSF p-tau181), and ELISA (CSF NfL) assays. Additionally, we stratified patients according to the A/T/N classification scheme and the CSF α-synuclein real-time quaking-induced conversion assay (RT-QuIC) results. Results: We found good correlations between CSF and plasma biomarkers for NfL (rho = 0.668, p &lt; 0.001) and p-tau181 (rho = 0.619, p &lt; 0.001). Plasma NfL was significantly higher in disease groups than in HC and showed a greater increase in FTD than in AD [44.9 (28.1–68.6) vs. 21.9 (17.0–27.9) pg/ml, p &lt; 0.001]. Conversely, plasma p-tau181 and GFAP levels were significantly higher in AD than in FTD [3.2 (2.4–4.3) vs. 1.1 (0.7–1.6) pg/ml, p &lt; 0.001; 404.7 (279.7–503.0) vs. 198.2 (143.9–316.8) pg/ml, p &lt; 0.001]. GFAP also allowed discriminating disease groups from HC. In the distinction between FTD and AD, plasma p-tau181 showed better accuracy (AUC 0.964) than NfL (AUC 0.791) and GFAP (AUC 0.818). In DLB and CBS, CSF amyloid positive (A+) subjects had higher plasma p-tau181 and GFAP levels than A− individuals. CSF RT-QuIC showed positive α-synuclein seeding activity in 96% DLB and 15% AD patients with no differences in plasma biomarker levels in those stratified by RT-QuIC result. Conclusions: In a single-center clinical cohort, we confirm the high diagnostic value of plasma p-tau181 for distinguishing FTD from AD and plasma NfL for discriminating degenerative dementias from HC. Plasma GFAP alone differentiates AD from FTD and neurodegenerative dementias from HC but with lower accuracy than p-tau181 and NfL. In CBS and DLB, plasma p-tau181 and GFAP levels are significantly influenced by beta-amyloid pathology

Intermittent C1-Inhibitor Deficiency Associated with Recessive Inheritance: Functional and Structural Insight

C1-inhibitor is a serine protease inhibitor (serpin) controlling complement and contact system activation. Gene mutations result in reduced C1-inhibitor functional plasma level causing hereditary angioedema, a life-threatening disorder. Despite a stable defect, the clinical expression of hereditary angioedema is unpredictable, and the molecular mechanism underlying this variability remains undisclosed. Here we report functional and structural studies on the Arg378Cys C1-inhibitor mutant found in a patient presenting reduced C1-inhibitor levels, episodically undergoing normalization. Expression studies resulted in a drop in mutant C1-innhibitor secretion compared to wild-type. Notwithstanding, the purified proteins had similar features. Thermal denaturation experiments showed a comparable denaturation profile, but the mutant thermal stability decays when tested in conditions reproducing intracellular crowding.Our findings suggest that once correctly folded, the Arg378Cys C1-inhibitor is secreted as an active, although quite unstable, monomer. However, it could bear a folding defect, occasionally promoting protein oligomerization and interfering with the secretion process, thus accounting for its plasma level variability. This defect is exacerbated by the nature of the mutation since the acquired cysteine leads to the formation of non-functional homodimers through inter-molecular disulphide bonding. All the proposed phenomena could be modulated by specific environmental conditions, rendering this mutant exceptionally vulnerable to mild stress

Hereditary angioedema: Assessing the hypothesis for underlying autonomic dysfunction

Background Attacks of Hereditary Angioedema due to C1-inhibitor deficiency (Cl-INH-HAE) are often triggered by stressful events/hormonal changes. Objective Our study evaluates the relationship between autonomic nervous system (ANS) and contact/complement system activation. Methods Twenty-three HAE patients (6 males, mean age 47.5 +/- 11.4 years) during remission and 24 healthy controls (8 males, mean age 45.3 +/- 10.6 years) were studied. ECG, beat-by-beat blood pressure, respiratory activity were continuously recorded during rest (10') and 75degrees- head-up tilt (10'). C1-INH, C4, cleaved high molecular weight kininogen (cHK) were assessed; in 16 patients and 11 controls plasma catecholamines were also evaluated. Spectral analysis of heart rate variability allowed extraction of low-(LF) and high-(HF)frequency components, markers of sympathetic and vagal modulation respectively. Results HAE patients showed higher mean systolic arterial pressure (SAP) than controls during both rest and tilt. Tilt induced a significant increase in SAP and its variability only in controls. Although sympathetic modulation (LFnu) increased significantly with tilt in both groups, LF/HF ratio, index of sympathovagal balance, increased significantly only in controls. At rest HAE patients showed higher noradrenaline values (301.4 +/- 132.9 pg/ml vs 210.5 +/- 89.6 pg/ml, p = 0.05). Moreover, in patients tilt was associated with a significant increase in cHK, marker of contact system activation (49.5 +/- 7.5% after T vs 47.1 +/- 7.8% at R, p = 0.01). Conclusions Our data are consistent with altered ANS modulation in HAE patients, i.e. increased sympathetic activation at rest and blunted response to orthostatic challenge. Tilt test-induced increased HK cleavage suggests a link between stress and bradykinin production

Aspects of hereditary angioedema genotyping in the era of NGS: The case of F12 gene = Wybrane aspekty genotypowania wrodzonego obrzȩku naczynioruchowego w erze NGS: Gen F12

Objective. To screen a cohort of patients diagnosed with non-FXII angioedema for carriage of variants of F12 gene. Material and methods. DNA samples from 191 patients suffering from primary angioedema with normal C1-INH, 54 samples from non- -affected family members, and 161 samples from C1-INH-HAE (154 type I, 7 type II) patients were included in the study. The F12 gene was genotyped by targeted NGS (100% coverage of translated regions). Sanger sequencing was performed for the verification of all identified variants and family segregation studies. Results. The pathogenic F12 variant c.983C&gt;A was detected in three patients from two unrelated families initially diagnosed as U-HAE. Six additional mutations were identified, four of which were characterized as benign (c.41T&gt;C, c.418C&gt;G, c.1025C&gt;T, c.530C&gt;T) and two of uncertain significance (c.1530G&gt;C, c.1768T&gt;G). Two synonymous variants (c.756C&gt;T and c.711C&gt;T), the common polymorphism c.619G&gt;C, and the functional polymorphism c.-4T&gt;C were detected in allele frequencies similar to those presented in the ExAC database for the European population. One more not yet reported synonymous variant (c. 1599A&gt;G) was also found. Conclusion. Analyzing the entire translated region of F12 gene is important in order to identify new variants that possibly affect HAE expressivity. Interestingly, genetic analysis of F12 supports not only the diagnosis of FXII-HAE but also the correct exclusion diagnosis of U-HAE