[Clinical characteristics of 37 antiphospholipid syndrome patients complicated by autoimmune hemolytic anemia]

Objective: We sought to investigate the clinical characteristics and risk factors of antiphospholipid syndrome (APS) complicated by autoimmune hemolytic anemia (AIHA). Methods: Retrospective anaysis.Three hundred fifteen consecutive patients with APS were enrolled at the Department of Rheumatology of Peking Union Medical College Hospital between May 2017 to May 2021, and their clinical manifestations[including initial symptoms, time interval between APS onset and diagnosis, systemic lupus erythematosus(SLE), thrombotic events, obstetric morbidity, and extra-criteria manifestations] and laboratory test results[including blood routine, antiphospholipid antibodies(aPLs), blood lipid profile, homocysteine, anti-nuclear antibody profile, immunoglobulin levels, and complement levels] were collected. Then, univariate and multivariate logistic regression analyses were performed. Clinical features and risk factors were analyzed using univariable and multivariable logistic regression analysis. Results: Among 315 APS patients, 37 cases (11.7%) were complicated by AIHA, and AIHA was the first manifestation or co-occurrence. The median time interval between APS onset and diagnosis was 12 months. The proportion of SLE in APS patients combined with AIHA was higher than that in APS patients without AIHA[62.2%(23/37) vs. 19.4%(54/278), P<0.001]. There was no significant difference in the proportions of thrombosis and pregnancy morbidity between the two groups. In terms of extra-criteria manifestations, APS patients with AIHA had a significantly (P<0.05) greater risk of thrombocytopenia (OR=6.19, 95%CI 2.81-13.65) and higher proportions of hypocomplementemia, a positive lupus anticoagulant (LA) result, double aPLs positivity[i.e., any two of the following antibodies were positive: LA, anticardilolipin antibody(aCL), and anti-β2 glycoprotein Ⅰ(β2GPⅠ)], and triple aPLs positivity (i.e., LA, aCL, and anti-β2GPⅠ antibodies were all positive). Multivariate logistic regression analysis showed that SLE (OR=3.46,95%CI 1.60-7.48), thrombocytopenia (OR=2.56,95%CI 1.15-5.67), and hypocomplementemia (OR=4.29,95%CI 2.03-9.04) were independent risk factors for the complication of APS. In the primary APS subgroup, multivariate logistic regression analysis showed that livedo reticularis (OR=10.51,95%CI 1.06-103.78), thrombocytopenia (OR=3.77, 95%CI 1.23-11.57), and hypocomplementemia (OR=5.92,95%CI 1.95-17.95) were independent risk factors for the complication of APS. Conclusions: AIHA is not rare in APS patients; moreover, it occurs more frequently in APS secondary to SLE and is more likely to present with a variety of extra-criteria manifestations. Patients with AIHA should be promptly tested for antiphospholipid antibody profiles and alerted to the possibility of thrombotic events.

[Role of functional hydrogel in promoting wound healing]

Cutaneous wounds are one of the commonest clinical diseases. At present, there are still many challenges in how to repair wounds quickly with high quality. With the rapid development and cross-integration of materials science and biomedicine, hydrogels that can integrate various excellent properties through flexible structural modification and combination of different functional components are widely applied in wound management and research. This paper attempted to summarize the role of hydrogel in promoting wound repair from the respects of matrix materials, special structures, and diverse functions of hydrogel.

Identification and characterization of an unexpected isomerization motif in CDRH2 that affects antibody activity

Aspartic acid (Asp) isomerization is a spontaneous non-enzymatic post-translation modification causing a change in the structure of the protein backbone, which is commonly observed in therapeutic antibodies during manufacturing and storage. The Asps in Asp-Gly (DG), Asp-Ser (DS), and Asp-Thr (DT) motifs in the structurally flexible regions, such as complementarity-determining regions (CDRs) in antibodies, are often found to have high rate of isomerization, and they are considered "hot spots" in antibodies. In contrast, the Asp-His (DH) motif is usually considered a silent spot with low isomerization propensity. However, in monoclonal antibody mAb-a, the isomerization rate of an Asp residue, Asp55, in the aspartic acid-histidine-lysine (DHK) motif present in CDRH2 was found to be unexpectedly high. By determining the conformation of DHK motif in the crystal structure of mAb-a, we found that the Cgamma of the Asp side chain carbonyl group and the back bone amide nitrogen of successor His were in proximal contact, which facilitates the formation of succinimide intermediate, and the +2 Lys played an important role in stabilizing such conformation. The contributing roles of the His and Lys residues in DHK motif were also verified using a series of synthetic peptides. This study identified a novel Asp isomerization hot spot, DHK, and the structural-based molecular mechanism was revealed. When 20% Asp55 isomerization in this DHK motif occurred in mAb-a, antigen binding activity reduced to 54%, but the pharmacokinetics in rat was not affected significantly. Although Asp isomerization of DHK motif in CDR does not appear to have a negative impact on PK, DHK motifs in the CDRs of antibody therapeutics should be removed, considering the high propensity of isomerization and impact on antibody activity and stability.

"Stapling" scFv for multispecific biotherapeutics of superior properties

Single-chain fragment variable (scFv) domains play an important role in antibody-based therapeutic modalities, such as bispecifics, multispecifics and chimeric antigen receptor T cells or natural killer cells. However, scFv domains exhibit lower stability and increased risk of aggregation due to transient dissociation ("breathing") and inter-molecular reassociation of the two domains (VL and VH). We designed a novel strategy, referred to as stapling, that introduces two disulfide bonds between the scFv linker and the two variable domains to minimize scFv breathing. We named the resulting molecules stapled scFv (spFv). Stapling increased thermal stability (Tm) by an average of 10°C. In multiple scFv/spFv multispecifics, the spFv molecules display significantly improved stability, minimal aggregation and superior product quality. These spFv multispecifics retain binding affinity and functionality. Our stapling design was compatible with all antibody variable regions we evaluated and may be widely applicable to stabilize scFv molecules for designing biotherapeutics with superior biophysical properties.

Accelerating the speed of innovative anti-tumor drugs to first-in-human trials incorporating key de-risk strategies

Pharmaceutical companies have recently focused on accelerating the timeline for initiating first-in-human (FIH) trials to allow quick assessment of biologic drugs. For example, a stable cell pool can be used to produce materials for the toxicology (Tox) study, reducing time to the clinic by 4-5 months. During the coronavirus disease 2019 (COVID-19) pandemic, the anti-COVID drugs timeline from DNA transfection to the clinical stage was decreased to 6 months using a stable pool to generate a clinical drug substrate (DS) with limited stability, virus clearance, and Tox study package. However, a lean chemistry, manufacturing, and controls (CMC) package raises safety and comparability risks and may leave extra work in the late-stage development and commercialization phase. In addition, whether these accelerated COVID-19 drug development strategies can be applied to non-COVID projects and established as a standard practice in biologics development is uncertain. Here, we present a case study of a novel anti-tumor drug in which application of "fast-to-FIH" approaches in combination with BeiGene's de-risk strategy achieved successful delivery of a complete CMC package within 10 months. A comprehensive comparability study demonstrated that the DS generated from a stable pool and a single-cell-derived master cell bank were highly comparable with regards to process performance, product quality, and potency. This accomplishment can be a blueprint for non-COVID drug programs that approach the pace of drug development during the pandemic, with no adverse impact on the safety, quality, and late-stage development of biologics.

The effects of natural active substances in food on the toxicity of patulin

Patulin (PAT) is a mycotoxin, a secondary metabolite mainly produced by fungi of the genera Aspergillus, Byssochlamys, and Penicillium. Many studies have looked into the potential impacts of this mycotoxin due to its high risk. Researchers are currently doing a more in-depth investigation of and employing physical, chemical, and biological ways to remove PAT. However, existing technology cannot completely remove it, and the residual PAT will continue to pose a threat to human health. As a result, substances capable of reducing PAT toxicity need be discovered. According to previous studies, natural components in food could reduce the toxicity of PAT. This article will review the different types of active compounds and discus the detoxification processes, as well as give recommendations for decreasing the toxicity of PAT and future research directions.

Functional hybrid factor regression model for handling heterogeneity in imaging studies

This paper develops a functional hybrid factor regression modelling framework to handle the heterogeneity of many large-scale imaging studies, such as the Alzheimer's disease neuroimaging initiative study. Despite the numerous successes of those imaging studies, such heterogeneity may be caused by the differences in study environment, population, design, protocols or other hidden factors, and it has posed major challenges in integrative analysis of imaging data collected from multicentres or multistudies. We propose both estimation and inference procedures for estimating unknown parameters and detecting unknown factors under our new model. The asymptotic properties of both estimation and inference procedures are systematically investigated. The finite-sample performance of our proposed procedures is assessed by using Monte Carlo simulations and a real data example on hippocampal surface data from the Alzheimer's disease study.

Liposomal docosahexaenoic acid halts atherosclerosis progression

Background

Atherosclerosis is the main cause underlying cardiovascular disease (CVD). Docosahexaenoic acid (DHA, 22:6n-3) is a hydrophobic polyunsaturated fatty acid that exerts anti-inflammatory and antioxidant activities. However, the beneficial effects of DHA on CVD have been controversial likely due to variations in bioavailability after oral intake.

Purpose

In this study, we aim to investigate the potential inhibiting properties of liposomal DHA on atherosclerosis progression upon intravenous administration.

Methods

Four weeks old ApoE−/− and LDLr−/− mice were fed on athero-inducing high fat diet for 4 weeks and then randomly divided into two groups. The mice received either control liposomes (control group) or liposomes containing DHA (liposomal DHA treatment group) via intravenous injection, twice a week for 8 weeks while still being fed on high fat diet. At the experiment endpoint, whole aortas were collected for Oil Red O staining to quantify plaque area or for biochemical analysis. Plasma was collected for total cholesterol measurement and lipidomic analysis. Aortic roots were used for histological analysis.

Results

Upon intravenous injection, as shown by IVIS imaging, DHA-containing liposomes accumulated preferentially in the atherosclerotic plaques. Compared to control liposomes, liposomal DHA treatment reduced the atherosclerotic plaque area in both atherosclerosis animal models, with the total plaque area decreased by 35.8% in ApoE−/− mice, (p&lt;0.001) and by 22.4% in LDLr−/− mice (p&lt;0.05). Plaque composition analysis revealed that liposomal DHA treatment increased collagen content and reduced the number of macrophages and neutral lipid within the plaques, resulting in a lower plaque vulnerability index (1.095 for liposomal DHA treated group vs. 1.692 for control group, p&lt;0.05). Among those plaque macrophages, as demonstrated by immunohistology, M2 (anti-inflammatory) macrophages accounted for 4.44% in liposomal DHA treated mice and 2.24% in control liposomes treated mice (p&lt;0.05). In agreement with the histology results, higher mRNA expression levels of anti-inflammatory markers (IL-10, CD206 and CD163) and collagen type 1 were determined in aortic tissue after liposomal DHA treatment. Moreover, liposomal DHA did not change total cholesterol level in the blood but significantly lowered plasma levels of several species of triglycerides. In vitro experiment with bone marrow derived macrophages showed that liposomal DHA was able to suppress lipopolysaccharide-induced inflammatory response and oxidative stress.

Conclusions

Our findings demonstrate that incorporation of DHA in injectable liposomes is an effective way to increase the inhibitory effects of DHA on halting the progression of atherosclerosis via lowering circulating triglycerides, reducing plaque inflammation, and enhancing plaque stability. Intravenous administration of liposomal DHA may become an efficacious strategy for the treatment of atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): NUSMed Seed Fund

Spatial-temporal lipidomics profile of acute myocardial injury

Background

Lipidome disturbance has long been recognized to occur after myocardial infarction (MI). Accumulation of excessive fatty acids induces production of reactive oxygen species and consequently deteriorates cardiac injury in MI. However, the spatial and temporal lipid profile in the heart following ischemic injury remains unknown.

Purpose

We aim to uncover the temporal-spatial lipidome profile of the heart following ischemia reperfusion (I/R) injury and identify circulating lipids released from injured myocardium that are potentially useful for diagnosis of ischemic heart disease.

Methods

C57/BL6 mice were subjected to 30 min myocardial ischemia followed by removal of the ligature to establish reperfusion injury. Porcine I/R injury was induced by 105 min myocardial ischemia followed by reperfusion. Human plasma was obtained from 143 post-MI patients. Myocardial lipid profiles were generated by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MALDI-MSI) in different regions (infarct, remote and peri-infarct) at different time points. Moreover, the lipids in the heart and plasma were analysed by LC-MS/MS.

Results

We observed a drastic alteration in the lipidome with distinct spatial-temporal features in the injured heart by both MALDI-MSI and LC-MS/MS. In the infarct heart tissue, as revealed by LC-MS/MS, we observed an elevation of glycerolipids that peaked at 3 hours after I/R, and a sustained elevation of phospholipids and sphingolipids up to 3 days. Similar alternations in lipid profile was observed but much weaker in the remote and peri-infarct heart tissue compared to the infarct tissue. Among those lipids, PC 32:0 detected by MALDI-MSI highly overlapped CD68 staining at a single-cell level, showing a strong correlation of PC 32:0 with macrophage infiltration in mouse hearts (R2=0.93, p&lt;0.0001). A similar increase of PC 32:0 in the infarct area was also observed in porcine hearts following I/R injury. Surprisingly, plasma levels of PC 32:0 in the mice decreased after I/R injury. In humans, plasma levels of PC 32:0 in post-MI patients were lower than that in healthy individuals (p=0.03). Further analysis demonstrated that plasma levels of PC 32:0 determined within 72 hours after percutaneous coronary intervention were negatively correlated with the 6-month post-MI cardiac ejection fraction in patients (R2=0.08, p&lt;0.001).

Conclusions

A temporal-spatial lipidome profile was established in heart injury by synergizing LC-MS/MS and mass spectrometry imaging. PC 32:0 levels are positively correlated with myocardial macrophage infiltration but negatively correlated with cardiac function in cardiac I/R injury. Our findings indicate that PC 32:0 is a potential biomarker for cardiac injury and the inflammatory status in the injured heart.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Singapore Ministry of Health's National Medical Research Council

Unsupervised machine learning improves risk stratification of patients with visual normal SPECT myocardial perfusion imaging assessments

Background

Unsupervised machine learning has the potential to identify new cardiovascular phenotypes and more accurately assess individual risk in an unbiased fashion.

Purpose

We aimed to use unsupervised learning to identify, analyze, and risk-stratify subgroups of patients with normal perfusion by visual interpretation on single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

Methods

We included consecutive patients with visual normal clinical assessment (summed stress score of 0) from the multicenter (9 sites), REFINE SPECT registry. We considered 23 clinical, 17 image-acquisition, and 26 imaging variables. Optimal dimensionality reduction (Uniform Manifold Approximation and Projection), clustering (Gaussian Mixture Model), and number of clusters were selected to maximize the silhouette coefficient (how similar a patient is to those in their own cluster compared to other clusters). Risk stratification for all-cause mortality (ACM) and major adverse cardiac events (MACE) was assessed within these clusters and compared to risk stratification by quantitative ischemia (&lt;5%, 5–10%, &gt;10%) using Kaplan-Meier curves and Cox Proportional-Hazards analysis.

Results

In total, 17,527 (of 30,351) patients in the registry had visually normal perfusion, 49.7% female, median age of 64 [55, 72] years. There were 1,138 ACM events and 2,091 MACE events with a median follow-up of 4.1 [2.9, 5.7] years. Unsupervised learning provided better risk stratification for both ACM and MACE compared to quantitative ischemia (Figure). Notably, the high-risk cluster by unsupervised learning had a hazard ratio (HR) of 9.5 (95% confidence interval [CI]: 7.7–11.7) compared to 1.4 (95% CI: 1.1–1.9) for quantitative ischemia &gt;10%. The high-risk cluster had proportionally more women (45% [low-risk], 51% [medium-risk], 57% [high-risk], all p&lt;0.001), higher body mass indices (26.9, 27.4, 29.6, all p&lt;0.001), prevalence of diabetes (17%, 22%, 33%, all p&lt;0.001), and abnormal rest ECGs (30%, 43%, 64%, p&lt;0.001); with lower rates of family history of coronary artery disease (40%, 33%, 24%, p&lt;0.001). Patients in the low-risk cluster were more likely to undergo exercise stress (100%, 38%, 0%, all p&lt;0.001), had lower rest peak systolic blood pressure (130, 131, 140 mmHg, all p&lt;0.001), and higher stress peak systolic blood pressure (164, 150, 131 mmHg, all p&lt;0.001). Patients in the high-risk cluster had higher left ventricular mass (129, 135.45, 143.9 g, all p&lt;0.001) and stress volume (57, 59, 66 ml, all p&lt;0.001).

Conclusion

Unsupervised learning identified new phenotypic clusters for SPECT MPI patients with visual normal assessments which provided improved risk stratification for ACM and MACE compared to SPECT ischemia. Such individualized risk assessment may allow better targeted management of patients with visually normal perfusion.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Research reported in this publication was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R01HL089765. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Long-term exposure to air pollution increases hip fracture incidence rate and related mortality: analysis of National Hip Fracture Database

To explore the association of air pollution and hip fracture and related mortality in the UK. The average levels of PM2.5, PM10, and NO2 exhibited a positive association with hip fracture and short-term mortality while O₃ did not. Our study highlights the association of air pollution and hip fracture.

INTRODUCTION

Until now, the influence of air pollution on bone mineral density and associated fractures has drawn little attention, and the consequences are controversial. To investigate the association between air pollution and hip fracture incidence and related short-term mortality.

METHODS

We constructed a cohort of all the National Hip Fracture Database beneficiaries (513,540 patients) in the UK from 2013 to 2018. Per year averages of PM_2.5, PM₁₀, O₃, NO₂, and SO₂ were estimated according to the person's residence. The incidence rate ratio with 95% confidence interval and all-cause mortality within 30-day post-fracture (ACM30D) rate ratios were estimated using generalized additive models.

RESULTS

The average levels of PM_2.5, PM₁₀, and NO₂ exhibited a positive association with the incidence rate of hip fracture (IHF) and ACM30D. Whereas, this association was negative for O₃ levels. Each increase of 5 μg per cubic meter in PM_2.5, PM₁₀, and NO₂ leads to 9.5%, 9.2%, and 4.1% higher hip fracture rate, respectively, and also 9.3%, 8.3%, and 2.9% higher ACM30D, respectively. When we restricted the analysis to low-level exposure of air pollutants, similar results were obtained.

CONCLUSION

Our study found a moderate, positive association between IHF, ACM30D, and the levels of specific air pollutants in the entire National Hip Fracture Database population. A reduction in the levels of PM_2.5, PM₁₀, and NO₂ may decrease the hip fracture incidence rate and associated short-term mortality in older adults. Our study highlights the influence of air pollution on hip fracture.

[Retrospective analysis of clinical characteristics of patients with metabolic-associated fatty liver disease at high and low altitude areas]

Objective: To explore differences in clinical characteristics and hemoglobin levels between different age groups in patients with metabolic-associated fatty liver disease (MAFLD) at high and low altitude areas, so as to provide a basis for further research on the effect of chronic hypoxia on MAFLD. Methods: Liver function indexes, non-invasive fibrosis indexes, metabolic indexes, and routine blood test of 1 458 (Xining area of Qinghai province) and 1 633 cases (Huzhou area, Zhejiang province) with MAFLD who underwent physical examination were retrospectively analyzed. The total population of the two places were compared and analyzed with the hemoglobin reference limit of 180 g/L. The population of Xining was divided into high and low hemoglobin groups for comparative analysis. The population of the two places was divided into five groups according to age stratification (≤30 years old, 31-40 years old, 41-50 years old, 51-60 years old, ≥61 years old). After multivariate adjustment, the characteristics of high and low hemoglobin groups and MAFLD were compared between the two groups. Statistical analysis was performed with t-test or χ² test. Results: The detected indexes values observed were higher in Xining than Huzhou area population [fibrosis indexes (FIB4, 1.08±0.02 vs. 1.19±0.02), erythrocyte (5.14±0.13 vs. 5.30±0.13), hemoglobin (156.82±0.37 vs. 164.19± 0.39), alanine aminotransferase (ALT, 33.70±0.66 vs. 43.68±0.70), aspartate aminotransferase (AST, 24.34±0.28 vs. 29.23±0.30), γ-glutamyltransferase (42.40±1.02 vs. 51.82±1.53), alkaline phosphatase (77.92±0.56 vs. 84.63±0.85), triglyceride (TG, 2.07±0.04 vs. 2.74±0.05), uric acid (UA, 383.42±2.15 vs. 406.44±2.36)]. The detected indexes values observed were higher in Huzhou than Xining area population [platelet count (220.54±1.32 vs. 181.62±1.40), total cholesterol (TC, 5.10±0.02 vs. 5.04±0.03), fasting blood glucose (FBG, 5.67±0.04 vs. 5.29±0.04)]. The differences were statistically significant (P<0.01). Xining population UA and body mass index were increased in high hemoglobin group than low hemoglobin group, and the other parameters difference were not statistically significant. After the population in Xining was grouped by age, high and low FIB4, ALT, and AST and UA levels were detected in the age group of 31-40 and 51-60 years old, >61 years old, 31-40 years old, and the difference between hemoglobin groups were statistically significant (P<0.01). Conclusion: Patients with MAFLD are more likely to develop fibrosis, liver function impairment, metabolic disorders and so on under high-altitude hypoxic environment. Additionally, there is certain correlation with disease severity and age changes, suggesting that chronic hypoxia can accelerate MAFLD progression.