Single-cell transcriptomics reveals the intra-tumoral heterogeneity and SQSTM1/P62 and Wnt/β-catenin mediated epithelial to mesenchymal transition and stemness of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is characterized by the complex tumor microenvironment (TME) consisting of an abundance of mesenchymal stem cells (MSCs), which is known to facilitate epithelial-to-mesenchymal transition (EMT). The development of single-cell genomics is a powerful method for defining the intricate genetic landscapes of malignancies. In this study, we have employed single-cell RNA sequencing (scRNA-seq) to dissect the intra-tumoral heterogeneity and analyze the single-cell transcriptomic landscape to detect rare consequential cell subpopulations of significance. The scRNA-seq analysis of TNBC and Normal patient derived samples revealed that EMT markers and transcription factors were most upregulated in MSC population. Further, exploration of gene expression analysis among TNBC and Normal patient-derived MSCs ascertained the role of SQSTM1/P62 and Wnt/β-catenin in TNBC progression. Wnt/β-catenin and Wnt/PCP signaling pathways are prominent contributors of EMT, stemness, and cancer stem cell (CSC) properties of TNBC. SQSTM1/P62 cooperates with the components of the Wnt/PCP signaling pathway and is critically involved at the interface of autophagy and EMT. Moreover, siRNA targeting SQSTM1/P62 and inhibitor of Wnt/β-catenin (FH535) in conjunction was used to explore molecular modification of EMT and stemness markers. Although SQSTM1/P62 is not crucial for cell survival, cytotoxicity assay revealed synergistic interaction between the siRNA/inhibitor. Modulation of these important pathways helped in reduction of expression of genes and proteins contributing to CSC properties. Gene and protein expression analysis revealed the induction of EMT to MET. Moreover, co-treatment resulted in inactivation of non-canonical Wnt VANGL2-JNK signaling axis. The synergistic impact of inhibition of SQSTM1/P62 and Wnt/β-catenin signaling facilitates the development of a potential therapeutic regimen for TNBC.

Targeting AR-positive breast cancer cells via drug repurposing approach

Androgen Receptor (AR) is overexpressed in almost all the molecular subtypes of breast cancer. Besides aiding the tumorigenic environment of cancer by abnormal cell proliferation, AR also takes part in promoting cancer signaling pathways, thereby promoting aggressiveness. In this study, AR was selected as the target protein in breast cancer cells. Following this, a library of 1293 FDA-approved drugs was screened via molecular docking, MD simulation, and MMPBSA binding energy. Amongst the library of compounds, Adapalene exhibited the least binding energy of (-10.2 kCal/mol) in comparison to that of the chosen reference compound, Nilutamide (-8.6 kCal/mol). Furthermore, the in vitro efficacy of Adapalene was also determined in two different breast cancer cell lines such as MCF7 (AR-positive/ER-positive) and MDA-MB-231 (AR negative/TNBC). Initially, the cell viability assay (MTT) was performed, which endowed us with a lesser IC50 value of Adapalene in comparison to Nilutamide in both cell lines. The IC50 of Adapalene was found to be 12 μM and 39.4 μM in MCF7 and MDA-MB-231 cells, respectively. Furthermore, Adapalene also induced cellular ROS and apoptosis by 3.5-fold and 26.58% in MCF7 cells. However, the overall effect of Adapalene was significantly lower in the case of MDA-MB-231 cell lines, which could be attributed to its inherent nature of the absence of hormone receptors. Conclusively, Adapalene possesses greater therapeutic efficacy in comparison to the control drug, thereby hinting towards the potential use of Adapalene in the treatment of AR-positive breast cancer.

An in-silico approach to understand the potential role of Wnt inhibitory factor-1 (WIF-1) in the inhibition of the Wnt signalling pathway

WIF1 (Wnt inhibitory factor 1) is a potent tumour suppressor gene which is epigenetically silenced in numerous malignancies. The associations of WIF1 protein with the Wnt pathway molecules have not been fully explored, despite their involvement in the downregulation of several malignancies. In the present study, a computational approach encompassing the expression, gene ontology analysis and pathway analysis is employed to obtain an insight into the role of the WIF1 protein. Moreover, the interaction of the WIF1 domain with the Wnt pathway molecules was carried out to ascertain the tumour-suppressive role of the domain, along with the determination of their plausible interactions. Initially, the protein-protein interaction network analysis endowed us with the Wnt ligands (such as Wnt1, Wnt3a, Wnt4, Wnt5a, Wnt8a and Wnt9a), along with the Frizzled receptors (Fzd1 and Fzd2) and the low-density lipoprotein complex (Lrp5/6) as the foremost interactors of the protein. Further, the expression analysis of the aforementioned genes and proteins was determined using The Cancer Genome Atlas to comprehend the significance of the signalling molecules in the major cancer subtypes. Moreover, the associations of the aforementioned macromolecular entities with the WIF1 domain were explored using the molecular docking studies, whereas the dynamics and stability of the assemblage were investigated using 100 ns molecular dynamics simulations. Therefore, providing us insights into the plausible roles of WIF1 in inhibiting the Wnt pathways in various malignancies.Communicated by Ramaswamy H. Sarma.

Biological activity of recombinant human PDX1 protein produced from Escherichia coli

Pancreatic and duodenum homeobox 1 (PDX1) is considered as a pivotal transcription factor that acts as a "master regulator" in pancreatogenesis and maintenance of β-cells. Earlier study has reported that PDX1 also functions as a tumor suppressor in human gastric cancer cells by inhibiting cell growth. Here, we report the bioactivity of the purified human PDX1 fusion protein using various assays like cell migration, proliferation, cell cycle analysis, and gene expression. In cancer cells, recombinant PDX1 protein reduced cell migration and proliferation, and arrested cell growth by inducing apoptosis in gastric cancer cells. In pancreatic ductal cancer cells, the application of the PDX1 protein resulted in the induction of insulin gene expression. The results of these experiments demonstrate the biological activity imparted by recombinant human PDX1 fusion protein on gastric and pancreatic cancer cells and its usefulness as a biological tool to elucidate its function in various cellular processes.

Production of Bioactive Human PAX4 Protein from E. coli

Paired box 4 (PAX4) is a pivotal transcription factor involved in pancreatogenesis during embryogenesis, and in adults, it is key for β-cell proliferation and survival. Additionally, PAX4 also functions as a tumor suppressor protein in human melanomas. The present study demonstrates the production of bioactive recombinant human PAX4 transcription factor. At first, the inserts (PAX4 protein-coding sequence having tags at either ends) were cloned in an expression vector to give rise to pET28a(+)-HTN-PAX4 and pET28a(+)-PAX4-NTH genetic constructs, and these were then transformed into Escherichia coli (E. coli) for their expression. The HTN-PAX4 and PAX4-NTH fusion proteins produced were purified with a yield of ~ 3.15 mg and ~ 0.83 mg, respectively, from 1.2 L E. coli culture. Further, the secondary structure retention of the PAX4 fusion proteins and their potential to internalize the mammalian cell and its nucleus was demonstrated. The bioactivity of these fusion proteins was investigated using various assays (cell migration, cell proliferation and cell cycle assays), demonstrating it to function as a tumor suppressor protein. Thus, this macromolecule can prospectively help understand the function of human PAX4 in cellular processes, disease-specific investigations and direct cellular reprogramming.

γ-Secretase Inhibitor Potentiates the Activity of Suberoylanilide Hydroxamic Acid by Inhibiting Its Ability to Induce Epithelial to Mesenchymal Transition and Stemness via Notch Pathway Activation in Triple-Negative Breast Cancer Cells

Histone deacetylase inhibitors, such as suberoylanilide hydroxamic acid (SAHA), possess great therapeutic value for triple-negative breast cancer patients. However, their inherent ability to induce epithelial to mesenchymal transition in various malignancies has been of greater concern. Herein, we hypothesize that SAHA facilitates epithelial to mesenchymal transition (EMT) via activation of the Notch pathway. From the literature survey, it is evident that histone deacetylase mediates the formation of the co-repressor complex upon interacting with the DNA binding domain, thereby inhibiting the transcription of the Notch downstream genes. Hence, we hypothesize that the use of SAHA facilitates the transcriptional activation of the Notch target genes, by disrupting the co-repressor complex and recruiting the coactivator complex, thereby facilitating EMT. In this study, we have observed that SAHA upregulates the expression profile of the Notch downstream proteins (such as Notch intracellular domain, Hes-1, c-Myc, etc.) and the Notch ligands (such as Jagged-1 and Jagged-2), thereby aberrantly activating the signaling pathway. Therefore, we have focused on combination therapy using a γ-secretase inhibitor LY411575 that would enhance the efficacy of SAHA by blocking the canonical Notch pathway mediated via its intracellular domain. It was observed that co-treatment significantly mediates apoptosis, generates cellular reactive oxygen species, depolarizes mitochondria, and diminishes the stemness properties. Besides, it also mediates autophagy-independent cell death and diminishes the expression of inflammatory cytokines, along with the downregulation in the expression of the Notch downstream genes and mesenchymal markers. Altogether, our study provides a mechanistic basis for combating EMT potentiated by SAHA, which could be utilized as a rational strategy for the treatment of solid tumors, especially triple-negative breast cancer.

The Intricate Notch Signaling Dynamics in Therapeutic Realms of Cancer

The Notch pathway is remarkably simple without the interventions of secondary messengers. It possesses a unique receptor-ligand interaction that imparts signaling upon cleavage of the receptor followed by the nuclear localization of its cleaved intracellular domain. It is found that the transcriptional regulator of the Notch pathway lies at the intersection of multiple signaling pathways that enhance the aggressiveness of cancer. The preclinical and clinical evidence supports the pro-oncogenic function of Notch signaling in various tumor subtypes. Owing to its oncogenic role, the Notch signaling pathway assists in enhanced tumorigenesis by facilitating angiogenesis, drug resistance, epithelial to mesenchymal transition, etc., which is also attributed to the poor outcome in patients. Therefore, it is extremely vital to discover a suitable inhibitor to downregulate the signal-transducing ability of Notch. The Notch inhibitory agents, such as receptor decoys, protease (ADAM and γ-secretase) inhibitors, and monoclonal/bispecific antibodies, are being investigated as candidate therapeutic agents. Studies conducted by our group exemplify the promising results in ablating tumorigenic aggressiveness by inhibiting the constituents of the Notch pathway. This review deals with the detailed mechanism of the Notch pathways and their implications in various malignancies. It also bestows us with the recent therapeutic advances concerning Notch signaling in the context of monotherapy and combination therapy.

Multi-targeting TACE/ADAM17 and gamma-secretase of notch signalling pathway in TNBC via drug repurposing approach using Lomitapide

The aberrant expression of the Notch signalling pathway genes aids in potentiating the belligerent characteristics of numerous malignancies. Besides imparting abnormal proliferation and metastasis, the Notch also aids in the metabolic reprogramming of tumor cells. Since the activation of the Notch pathway is mediated via TACE/ADAM protease and the γ-secretase complex, hence it is crucial in determining a multi-targeted therapeutic approach to target these major proteases to downregulate the aberrant Notch signalling pathway. In this study, Lomitapide was chosen based on its binding score (-305.108 kJ/mol and - 173.174 kJ/mol) against the crucial proteases, TACE and γ-secretase, respectively. Further, the remarkable antitumor properties of Lomitapide were established on the TNBC cell lines (MDA-MB-231 and MDA-MB-468), along with the EMT-induced MDA-MB-468 cells. Apart from inducing ∼2 to 2.5-fold increase in the cellular ROS levels, Lomitapide treatment induced significant apoptosis, arrested cell cycle progression and reduced sphere and colony forming abilities of the TNBC cells. Differentiated epithelial phenotype with diminished CD44-stem cell marker was also observed upon treatment. Furthermore, reduction of migration potential, decrease in the gene expression profile of the EMT markers, along with downregulation of the Notch signalling genes were evident in the treated TNBC cells. Altogether, the present study attributes the repurposing of Lomitapide as an effective therapeutic agent against the major proteases of the Notch pathway to combat TNBC progression and dissemination.

In-silico evidence of ADAM metalloproteinase pathology in cancer signaling networks

Lack of effective targeted therapies often contributes to poor clinical outcomes of aggressive malignancies associated with drug resistance, angiogenesis and metastasis. Literature mining portrays the major role of ADAM17 in cancer and inflammatory diseases. However, it is quite challenging to design a candidate drug for targeting ADAM17 due to its structural similarity with the catalytic domain of the matrix metalloproteases (MMPs). The present study reports the protein-protein interaction analysis of ADAM17, along with the molecular docking and MD simulation studies for the screened compounds. Our analysis confirms the association of ADAM17 with numerous oncogenes that facilitates cancer progression and inflammation, especially the members of the Notch, receptor tyrosine kinase (RTK) and TNFα pathways. The outcome provides evidence that the prevalent protease ADAM17 could attribute to cancer signaling regulation though the shedding of various inflammatory and oncogenic molecules. We have also exploited the analogues of the existing inhibitors, with an aim at discovering a potent molecule, which could be repurposed as a drug against ADAM17 inflicted cancer progression. Upon stringent screening, we delineated our choice into two specific compounds (I6 and I9; analogues of IK862, a type of y-lactam hydroxamates), possessing the lowest binding energy (-9.1 Kcal/mol), stable MD-simulation studies and superior pharmacodynamic properties. The current information illustrates the avenue to persuade further research on targeting ADAM17 with small molecular compounds (I6 and I9) in cancer therapeutics.Communicated by Ramaswamy H. Sarma.

A photo-responsive fluorescent amphiphile for target-specific and image-guided drug delivery applications

Multifunctional drug delivery systems are the centerpiece of effective chemotherapeutic strategies. Herein, we report the synthesis of an acetazolamide-linked cyanine-3-based NIR-responsive fluorescent macrocyclic amphiphile that self-assembled into spherical nanostructures in the aqueous medium via a J-aggregation pattern. The amphiphile shows various favorable properties of lipids. The photocleavage of the strained dioxacycloundecine ring induces spherical to nanotubular self-assembly with concomitant release of an encapsulated anticancer drug, doxorubicin (Dox), in a controlled manner. The CA-IX targeted amphiphile also showed lower cytotoxicity, effective cellular uptake, and Dox delivery to the model carcinoma cells.

POS0855 IMPAIRED PROMIS PHYSICAL FUNCTION IN IDIOPATHIC INFLAMMATORY MYOPATHY PATIENTS: RESULTS FROM THE MULTICENTER COVAD PATIENT REPORTED E-SURVEY

Background

Evaluation of physical function is fundamental in the management of idiopathic inflammatory myopathies (IIMs). Patient-Reported Outcome Measurement Information System (PROMIS) is a National Institute of Health initiative established in 2004 to develop patient-reported outcome measures (PROMs) with improved validity and efficacy. PROMIS Physical Function (PF) short forms have been validated for use in IIMs [1].

Objectives

To investigate the physical function status of IIM patients compared to those with non-IIM autoimmune diseases (AIDs) and healthy controls (HCs) utilizing PROMIS PF data obtained in the coronavirus disease-2019 (COVID-19) Vaccination in Autoimmune Diseases (COVAD) study, a large-scale, international self-reported e-survey assessing the safety of COVID-19 vaccines in AID patients [2].

Methods

The survey data regarding demographics, IIM and AID diagnosis, disease activity, and PROMIS PF short form-10a scores were extracted from the COVAD study database. The disease activity (active vs inactive) of each patient was assessed in 3 different ways: (1) physician’s assessment (active if there was an increased immunosuppression), (2) patient’s assessment (active vs inactive as per patient), and (3) current steroid use. These 3 definitions of disease activity were applied independently to each patient. PROMIS PF-10a scores were compared between each disease category (IIMs vs non-IIM AIDs vs HCs), stratified by disease activity based on the 3 definitions stated above, employing negative binominal regression model. Multivariable regression analysis adjusted for age, gender, and ethnicity was performed clustering countries, and the predicted PROMIS PF-10a score was calculated based on the regression result. Factors affecting PROMIS PF-10a scores other than disease activity were identified by another multivariable regression analysis in the patients with inactive disease (IIMs or non-IIM AIDs).

Results

1057 IIM patients, 3635 non-IIM AID patients, and 3981 HCs responded to the COVAD survey until August 2021. The median age of the respondents was 43 [IQR 30-56] years old, and 74.8% were female. Among IIM patients, dermatomyositis was the most prevalent diagnosis (34.8%), followed by inclusion body myositis (IBM) (23.6%), polymyositis (PM) (16.2%), anti-synthetase syndrome (11.8%), overlap myositis (7.9%), and immune-mediated necrotizing myopathy (IMNM) (4.6%). The predicted mean of PROMIS PF-10a scores was significantly lower in IIMs compared to non-IIM AIDs or HCs (36.3 [95% (CI) 35.5-37.1] vs 41.3 [95% CI 40.2-42.5] vs 46.2 [95% CI 45.8-46.6], P < 0.001), irrespective of disease activity or the definitions of disease activity used (physician’s assessment, patient’s assessment, or steroid use) (Figure 1). The largest difference between active IIMs and non-IIM AIDs was observed when the disease activity was defined by patient’s assessment (35.0 [95% CI 34.1-35.9] vs 40.1 [95% CI 38.7-41.5]). Considering the subgroups of IIMs, the scores were significantly lower in IBM in comparison with non-IBM IIMs (P < 0.001). The independent factors associated with low PROMIS PF-10a scores in the patients with inactive disease were older age, female gender, and the disease category being IBM, PM, or IMNM.

Conclusion

Physical function is significantly impaired in IIMs compared to non-IIM AIDs or HCs, even in patients with inactive disease. The elderly, women, and IBM groups are the worst affected, suggesting that developing targeted strategies to minimize functional disability in certain groups may improve patient reported physical function and disease outcomes.

References

[1]Saygin D, Oddis CV, Dzanko S, et al. Utility of patient-reported outcomes measurement information system (PROMIS) physical function form in inflammatory myopathy. Semin Arthritis Rheum. 2021; 51: 539-46.

[2]Sen P, Gupta L, Lilleker JB, et al. COVID-19 vaccination in autoimmune disease (COVAD) survey protocol. Rheumatol Int. 2022; 42: 23-9.

Acknowledgements

The authors thank all respondents for filling the questionnaire. The authors thank The Myositis Association, Myositis India, Myositis UK, the Myositis Global Network, Cure JM, Cure IBM, Sjögren’s India Foundation, EULAR PARE, and various other patient support groups and organizations for their invaluable contribution in the dissemination of this survey among patients which made the data collection possible. The authors also thank all members of the COVAD study group.

Disclosure of Interests

None declared

POS0899 HIGH FATIGUE SCORES IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES: A MULTIGROUP COMPARATIVE STUDY FROM THE COVAD E-SURVEY

Background

Idiopathic inflammatory myopathies (IIM) are a rare, multisystem, heterogeneous diseases, and contribute to high psychological burden. The patients’ perception of physical health, deteriorating independence and social and environmental relationships may not always be a direct function of disease activity. To face with these aspects, several worldwide specialized organization have recommended the use of patient reported outcome measures (PROMs) both in clinical trials and observational studies to highlight patient’s perception of the disease (1). Unfortunately, data on fatigue scores in IIM is limited.

Objectives

We compared fatigue VAS scores in patients with IIM, autoimmune diseases (AIDs) and healthy controls (HCs) and triangulated them with PROMIS physical function in a large international cohort made up of answers from the e-survey regarding the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study.

Methods

Data of 16327 respondents was extracted from the COVAD database on August 31th 2021. VAS fatigue scores were compared between AID, HC and IIM using univariate followed by multivariate analysis after adjusting for baseline differences. We further performed a propensity score matched analysis on 1827 subjects after adjusting for age, gender and ethnicity. The Kruskal-Wallis test was used for continuous variables and chi-square test for categorical variables, and Bonferroni’s correction was applied for the post hoc analyses considering IIMs as a reference group.

Results

We analyzed answers from 6988 patients, with a mean age of 43.8 years (SD 16.2). The overall percentage of female was 72% and the population ethnicity was mainly composed of White (55.1%), followed by Asian (24.6%), and Hispanic (13.8%). The overall fatigue VAS was 3.6 mm (SD 2.7). IIMs VAS was 4.8 mm (SD 2.6), AIDs 4.5 mm (SD 2.6), and HC 2.8 mm (SD 2.6) (P <0,001). VAS fatigue scores of IIMs were comparable with AIDs (P 0.084), albeit significantly higher than the HCs (P <0,001). Notably, fatigue VAS was lower in IIMs than AIDs in two distinct subsets: inactive disease as defined by the patient’s perception and the “excellent” general health condition group, where IIMs had worse scores (P <0,05). Interestingly, fatigue VAS was comparable in active disease defined by physician assessment, patient perception, based on general functional status, or when defined by steroid dose being prescribed. Notably, after propensity matched analysis of patients adjusting for gender, age and ethnicity (1.827 answers, i.e. 609 subjects per group, P =1) the differences disappeared and IIMs and AIDs had comparable fatigue levels across all levels of disease activity, although the fatigue discrepancies with HCs were substantially confirmed.

After application of a multivariate linear regression analysis we found that lower fatigue VAS scores were related to HC (P <0,001), male gender (P <0,001), Asian and Hispanic ethnicities (P <0,001 and 0,003).

Conclusion

Our study confirms that there is a higher prevalence of fatigue in all the AIDs patients, with comparable VAS scores between IIMs and other AIDs. We can also read our data commenting that females and/or Caucasians patients suffer a higher impact of this manifestation of chronic autoimmune diseases upon their lives. This is why these subjects, to our judgement, should be carefully evaluated during outpatients visits and to whom we should spend some extra time to discuss health related issues and how to improve them.

References

[1]Regardt, M. et al. OMERACT 2018 Modified Patient-reported Outcome Domain Core Set in the Life Impact Area for Adult Idiopathic Inflammatory Myopathies. J. Rheumatol.46, 1351–1354 (2019).

Figure 1.

distribution of Fatigue VAS scores in the three population evaluated. IIM idiopathic inflammatory myositis; AID autoimmune diseases; HC healthy controls; * P < 0,05.

Disclosure of Interests

None declared

POS1260 COVID-19 VACCINATION-RELATED ADVERSE EVENTS AMONG AUTOIMMUNE DISEASE PATIENTS: RESULTS FROM THE COVID-19 VACCINATION IN AUTOIMMUNE DISEASES (COVAD) STUDY

Background

COVID-19 vaccines have been proven to be safe and effective in the healthy population at large. However, significant gaps remain in the evidence of their safety in patients with systemic autoimmune and inflammatory disorders (SAIDs). Patients and rheumatologists have expressed concerns regarding vaccination triggered allergic reactions, thrombogenic events, and other adverse events (ADEs) contributing to vaccine hesitancy (1)

Objectives

This study aimed to assess and compare short term COVID-19 vaccination associated ADEs in patients with SAIDs and healthy controls (HC) seven days post-vaccination, as well as between patients with SAIDs receiving different vaccines.

Methods

We developed an comprehensive, patient self-reporting electronic-survey to collect respondent demographics, SAID details, COVID-19 infection history, COVID-19 vaccination details, 7-day post vaccination adverse events and patient reported outcome measures using the PROMIS tool. After pilot testing, validation, translation into 18 languages on the online platform surveymonkey.com, and vetting by international experts, the survey was circulated in early 2021 by a multicenter study group of >110 collaborators in 94 countries. ADEs were categorized as injection site pain, minor ADEs, major ADEs, and hospitalizations. We analyzed data from the baseline survey for descriptive and intergroup comparative statistics based on data distribution and variable type (data as median, IQR).

Results

10900 respondents [42 (30-55) years, 74% females and 45% Caucasians] were analyzed. 5,867 patients (54%) with SAIDs were compared with 5033 HCs. All respondents included in the final analysis had received a single dose of the vaccine and 69% had received 2 primary doses. Pfizer (39.8%) was the most common vaccine received, followed by Oxford/AstraZeneca (13.4%), and Covishield (10.9%). Baseline demographics differed by an older SAID population (mean age 42 vs. 33 years) and a greater female predominance (M:F= 1:4.7 vs. 1:1.8) compared to HCs.

79% had minor and only 3% had major vaccine ADEs requiring urgent medical attention overall. In adjusted analysis, among minor ADEs, abdominal pain [multivariate OR 1.6 (1.14-2.3)], dizziness [multivariate OR 1.3 (1.2-1.5)], and headache [multivariate OR 1.67 (1.3-2.2)], were more frequent in SAIDs than HCs. Overall major ADEs [multivariate OR 1.9 (1.6-2.2)], and throat closure [multivariate OR 5.7 (2.9-11.3)] were more frequent in SAIDs though absolute risk was small (0-4%) and rates of hospitalization were similarly small in both groups, with a small absolute risk (0-4%). Specific minor ADEs frequencies were different among different vaccine types, however, major ADEs and hospitalizations overall were rare (0-4%) and comparable across vaccine types in patients with SAIDs (Figure 1).

Figure 1.

A. Post Vaccination ADEs in SAIDs compared to HCs. B. Proportions of post COVID-19 vaccination ADEs in SAIDs by vaccine type.

Conclusion

Vaccination against COVID-19 is relatively safe and tolerable in patients with SAIDs. Certain minor vaccine ADEs are more frequent in SAIDs than HCs in this study, though are not severe and do not require urgent medical attention. SAIDs were at a higher risk of major ADEs than HCs, though absolute risk was small, and did not lead to increased hospitalizations. There are small differences in minor ADEs between vaccine types in patients with SAIDs.

References

[1]Boekel L, Kummer LY, van Dam KPJ, Hooijberg F, van Kempen Z, Vogelzang EH, et al. Adverse events after first COVID-19 vaccination in patients with autoimmune diseases. Lancet Rheumatol. 2021 Aug;3(8):e542–5.

Acknowledgements

The authors thank all members of the COVAD study group for their invaluable role in the collection of data. The authors thank all respondents for filling the questionnaire. The authors thank The Myositis Association, Myositis India, Myositis UK, the Myositis Global Network, Cure JM, Cure IBM, Sjögren’s India Foundation, EULAR PARE, and various other patient support groups and organizations for their invaluable contribution in the dissemination of this survey among patients which made the data collection possible. The authors also thank all members of the COVAD study group.

Disclosure of Interests

Parikshit Sen: None declared, Naveen R: None declared, Arvind Nune: None declared, James B. Lilleker: None declared, Vishwesh Agarwal: None declared, Sinan Kardes: None declared, Minchul Kim: None declared, Jessica Day Grant/research support from: JD has received research funding from CSL Limited., Marcin Milchert: None declared, Tamer A Gheita: None declared, Babur Salim: None declared, Tsvetelina Velikova: None declared, Abraham Edgar Gracia-Ramos: None declared, Ioannis Parodis Speakers bureau: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Consultant of: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Grant/research support from: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Albert Selva-O’Callaghan: None declared, Elena Nikiphorou Speakers bureau: EN has received speaker honoraria/participated in advisory boards for Celltrion, Pfizer, Sanofi, Gilead, Galapagos, AbbVie, Lilly, Consultant of: EN has received speaker honoraria/participated in advisory boards for Celltrion, Pfizer, Sanofi, Gilead, Galapagos, AbbVie, Lilly, Grant/research support from: EN has received speaker honoraria/participated in advisory boards for Celltrion, Pfizer, Sanofi, Gilead, Galapagos, AbbVie, Lilly, and holds research grants from Pfizer and Lilly., Tulika Chatterjee: None declared, Ai Lyn Tan Speakers bureau: ALT has received honoraria for advisory boards and speaking for Abbvie, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB., Consultant of: ALT has received honoraria for advisory boards and speaking for Abbvie, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB., Grant/research support from: ALT has received honoraria for advisory boards and speaking for Abbvie, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB., Lorenzo Cavagna: None declared, Miguel A Saavedra: None declared, Samuel Katsuyuki Shinjo: None declared, Nelly Ziade Speakers bureau: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript., Consultant of: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript., Grant/research support from: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript., Johannes Knitza: None declared, Masataka Kuwana: None declared, Oliver Distler Speakers bureau: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Consultant of: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Hector Chinoy Speakers bureau: HC has served as a speaker for UCB, Biogen., Consultant of: HC has received consulting fees from Novartis, Eli Lilly, Orphazyme, Astra Zeneca, Grant/research support from: HC has received grant support from Eli Lilly and UCB, Vikas Agarwal: None declared, Rohit Aggarwal Consultant of: RA has/had a consultancy relationship with and/or has received research funding from for the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, Kyverna, Janssen, Roivant, Boehringer Ingelheim, Argenx, Q32, Alexion, EMD Serono, Jubliant, Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant., Grant/research support from: RA has/had a consultancy relationship with and/or has received research funding from for the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, Kyverna, Janssen, Roivant, Boehringer Ingelheim, Argenx, Q32, Alexion, EMD Serono, Jubliant, Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant., Latika Gupta: None declared

POS0198 COVID-19 OUTCOMES IN PATIENTS WITH DERMATOMYOSITIS: A REGISTRY-BASED COHORT ANALYSIS

Background

Dermatomyositis (DM) patients have fewer risks of COVID-19 infection compared to the general population, however, certain subgroups with DM have worse outcomes. Men. African Americans, those with interstitial lung disease, exhibited higher risks of severe COVID-19. DMARD and glucocorticoid use was associated with frequent hospitalisations and severe sepsis.

Objectives

Rheumatic diseases (RDs) like DM, are previously known to be vulnerable towards various types of infections due to its aggressive activity mandating high dose immunosuppressive therapy. The severity of COVID-19 in RDs is limited in literature due to the heterogeneous nature of the condition. Therefore, specific details on mortality is essential to navigate any precautions required in the treatment.

Methods

Retrospective data of individuals with DM and COVID-19 and the general population with COVID-19 between January 2020 to August 2020 was retrieved from the TriNetX database. A one-to-one matched COVID-19 positive control was selected using propensity score (PS) matching. We assessed COVID-19 outcomes such as mortality, hospitalisation, ICU admission, severe COVID-19, mechanical ventilation (MV), acute kidney injury (AKI), venous thromboembolism (VTE), ischemic stroke, acute respiratory distress syndrome (ARDS), renal replacement therapy (RRT) and sepsis. Subgroup analyses included gender, race, ILD, cancer patients, disease-modifying rheumatic drugs (DMARDs) use, and glucocorticoids (GC) use (Figure 1).

Figure 1.

Overview of study

Results

We identified 5,574 DM patients with COVID-19, and 5,574 general population with COVID-19 (controls). DM with COVID-19 had a lower risk of mortality in comparison to controls [RR 0.76], hospitalisation [RR 0.8], severe COVID-19 [RR 0.76], AKI [RR 0.83], and sepsis [RR 0.73]. Males and African Americans were more likely to develop AKI [RR 1.35, 1.65], while African Americans had higher odds for severe COVID-19 [RR 1.62] and VTE [RR 1.54]. DM with ILD group also experienced higher odds for severe COVID-19 infection [RR 1.64], and VTE [RR 2.06] (Figure 1).

DM patients receiving DMARDs and glucocorticoids had higher odds for hospitalisation [RR 1.46, 2.12], and sepsis [RR 3.25] Subgroup analysis of neoplasms amongst DM patients with COVID-19 was inadequate for meaningful comparison (Figure 1).

Conclusion

DM patients are protected for certain aspects of COVID-19 disease, including severe COVID-19, hospitalization, and mortality. The African American race, male gender, ILD, DMARDS and glucocorticoid users, are associated with poor outcomes.

Disclosure of Interests

Latika Gupta: None declared, Haig Pakhchanian: None declared, Hiba Khan: None declared, Rahul Raiker: None declared, Maryam Abbasi: None declared, Charles DeYoung: None declared, Sinan Kardes Grant/research support from: SK has received congress travel, accommodation, and participation fee support (12th Anatolian Rheumatology Days) from Abbvie, Sakir Ahmed Speakers bureau: SA has received honorarium as speaker for Pfizer, Chengappa Kavadichanda: None declared, Parikshit Sen: None declared, Rohit Aggarwal Consultant of: RA has/had a consultancy relationship with and/or has received research funding from the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, and Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant., Grant/research support from: RA has/had a consultancy relationship with and/or has received research funding from the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, and Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant.

Designing of disruptor molecules to restrain the protein-protein interaction network of VANG1/SCRIB/NOS1AP using fragment-based drug discovery techniques

Governing protein-protein interaction networks are the cynosure of cell signaling and oncogenic networks. Multifarious processes when aligned with one another can result in a dysregulated output which can result in cancer progression. In the current research, one such network of proteins comprising VANG1/SCRIB/NOS1AP, which is responsible for cell migration, is targeted. The proteins are modeled using in-silico approaches, and the interaction is visualized utilizing protein-protein docking. Designing drugs for the convoluted protein network can serve as a challenging task that can be overcome by fragment-based drug designing, a recent game-changer in the computational drug discovery strategy for protein interaction networks. The model is exposed to the extraction of hotspots, also known as the restrained regions for small molecular hits. The hotspot regions are subjected to a library of generated fragments, which are then recombined and rejoined to develop small molecular disruptors of the macromolecular assemblage. Rapid screening methods using pharmacokinetic tools and 2D interaction studies resulted in four molecules that could serve the purpose of a disruptor. The final validation is executed by long-range simulations of 100 ns and exploring the stability of the complex using several parameters leading to the emergence of two novel molecules VNS003 and VNS005 that could be used as the disruptors of the protein assembly VANG1/SCRIB/NOS1AP. Also, the molecules were explored as single protein targets approbated via molecular docking and 100 ns molecular dynamics simulation. This concluded VNS003 as the most suitable inhibitor module capable of acting as a disruptor of a macromolecular assembly as well as acting on individual protein chains, thus leading to the primary hindrance in the formation of the protein interaction complex.

POS0201 COVID-19 SEVERITY AND VACCINE BREAKTHROUGH INFECTIONS IN IDIOPATHIC INFLAMMATORY MYOPATHIES, OTHER SYSTEMIC AUTOIMMUNE AND INFLAMMATORY DISEASES, AND HEALTHY INDIVIDUALS: RESULTS FROM THE COVID-19 VACCINATION IN AUTOIMMUNE DISEASES (COVAD) STUDY

Background

Significant gaps are present in the evidence of the spectrum and severity of COVID-19 infection in idiopathic inflammatory myopathies (IIM). IIM patients typically require immunosuppressive therapy, may have multiple disease sequelae, and frequent comorbidities, and thus may be more susceptible to severe COVID-19 infection and complications (1). The possibility of attenuated immunogenicity and reduced efficacy of COVID-19 vaccines due to concomitant immunosuppressive medication is a major concern in these patients, and there is little data available on COVID-19 vaccine breakthrough infections (BI) in IIM (2).

Objectives

This study aimed to compare disease spectrum and severity and COVID-19 BI in patients with IIM, other systemic autoimmune and inflammatory diseases (SAIDs) and healthy controls (HCs).

Methods

We developed an extensive self-reporting electronic-survey (COVAD survey) featuring 36 questions to collect respondent demographics, SAID details, COVID-19 infection history, COVID-19 vaccination details, 7-day post vaccination adverse events and patient reported outcome measures using the PROMIS tool. After pilot testing, validation, translation into 18 languages on the online platform surveymonkey.com, and vetting by international experts, the COVAD survey was circulated in early 2021 by a multicenter study group of >110 collaborators in 94 countries. BI was defined as COVID-19 infection occurring more than 2 weeks after receiving 1st or 2nd dose of a COVID-19 vaccine. We analyzed data from the baseline survey for descriptive and intergroup comparative statistics based on data distribution and variable type.

Results

10900 respondents [mean age 42 (30-55) years, 74% females and 45% Caucasians] were analyzed. 1,227 (11.2%) had IIM, 4,640 (42.6%) had other SAIDs, and 5,033 (46.2%) were HC. All respondents included in the final analysis had received a single dose of the vaccine and 69% had received 2 primary doses. Pfizer (39.8%) was the most common vaccine received, followed by Oxford/AstraZeneca (13.4%), and Covishield (10.9%). IIM patients were older, had a higher Caucasian representation and higher Pfizer uptake than other SAIDs, and HC. A higher proportion of IIM patients received immunosuppressants than other SAIDs.

IIMs were at a lower risk of symptomatic pre-vaccination COVID-19 infection compared to SAIDs [multivariate OR 0.6 (0.4-0.8)] and HCs [multivariate OR 0.39 (0.28-0.54)], yet at a higher risk of hospitalization due to COVID-19 compared to SAIDs [univariate OR 2.3 (1.2-3.5)] and HCs [multivariate OR 2.5 (1.1-5.8)]. BIs were very uncommon in IIM patients, with only 17 (1.4%) reporting BI. IIM patients were at a higher risk of contracting COVID-19 prior to vaccination than ≤2 weeks of vaccination [univariate OR 8 (4.1-15)] or BI [univariate OR 4.6 (2.7-8.0)]. BIs were equally severe compared to when they occurred prior to vaccination in IIMs, and were comparable between IIM, SAIDs, and HC (Figure 1), though BI disease duration was shorter in IIMs than SAIDs (7 vs 11 days, p 0.027). 13/17 IIM patients with BI were on immunosuppressants.

Conclusion

IIM patients experienced COVID-19 infection less frequently prior to vaccination but were at a higher risk of hospitalization and requirement for oxygen therapy compared with patients with HC. Breakthrough COVID-19 infections were rare (1.4%) in vaccinated IIM patients, and were similar to HC and SAIDs, except for shorter disease duration in IIM.

References

[1]Brito-Zerón P, Sisó-Almirall A, Flores-Chavez A, Retamozo S, Ramos-Casals M. SARS-CoV-2 infection in patients with systemic autoimmune diseases. Clin Exp Rheumatol. 2021 Jun;39(3):676–87.

[2]Wack S, Patton T, Ferris LK. COVID-19 vaccine safety and efficacy in patients with immune-mediated inflammatory disease: Review of available evidence. J Am Acad Dermatol. 2021 Nov;85(5):1274–84.

Acknowledgements

The authors thank all members of the COVAD study group for their invaluable role in the collection of data. The authors thank all respondents for filling the questionnaire. The authors thank The Myositis Association, Myositis India, Myositis UK, the Myositis Global Network, Cure JM, Cure IBM, Sjögren’s India Foundation, EULAR PARE, and various other patient support groups and organizations for their invaluable contribution in the dissemination of this survey among patients which made the data collection possible. The authors also thank all members of the COVAD study group.

Disclosure of Interests

Latika Gupta: None declared, Leonardo Santos Hoff: None declared, Naveen R: None declared, Parikshit Sen: None declared, Samuel Katsuyuki Shinjo: None declared, Jessica Day Grant/research support from: JD has received research funding from CSL Limited, James B. Lilleker: None declared, Vishwesh Agarwal: None declared, Sinan Kardes: None declared, Minchul Kim: None declared, Ashima Makol: None declared, Marcin Milchert: None declared, Tamer A Gheita: None declared, Babur Salim: None declared, Tsvetelina Velikova: None declared, Abraham Edgar Gracia-Ramos: None declared, Ioannis Parodis Speakers bureau: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Consultant of: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Grant/research support from: IP has received research funding and/or honoraria from Amgen, AstraZeneca, Aurinia Pharmaceuticals, Elli Lilly and Company, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Novartis and F. Hoffmann-La Roche AG., Albert Selva-O’Callaghan: None declared, Elena Nikiphorou Speakers bureau: EN has received speaker honoraria/participated in advisory boards for Celltrion, Pfizer, Sanofi, Gilead, Galapagos, AbbVie, Lilly, Consultant of: EN has received speaker honoraria/participated in advisory boards for Celltrion, Pfizer, Sanofi, Gilead, Galapagos, AbbVie, Lilly, Grant/research support from: EN holds research grants from Pfizer and Lilly., Tulika Chatterjee: None declared, Ai Lyn Tan Speakers bureau: ALT has received honoraria for advisory boards and speaking for Abbvie, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB., Consultant of: ALT has received honoraria for advisory boards and speaking for Abbvie, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB., Arvind Nune: None declared, Lorenzo Cavagna: None declared, Miguel A Saavedra: None declared, Nelly Ziade Speakers bureau: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript, Consultant of: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript, Grant/research support from: NZ has received speaker fees, advisory board fees and research grants from Pfizer, Roche, Abbvie, Eli Lilly, NewBridge, Sanofi-Aventis, Boehringer Ingelheim, Janssen, Pierre Fabre; none is related to this manuscript, Johannes Knitza: None declared, Masataka Kuwana: None declared, Oliver Distler Speakers bureau: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Consultant of: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: OD has/had consultancy relationship with and/or has received research funding from or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon (Curzion), Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Mitsubishi Tanabe, Novartis, Roche, Roivant, Sanofi, Serodapharm, Topadur and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Hector Chinoy Speakers bureau: HC has been a speaker for UCB, Biogen., Consultant of: HC has received consulting fees from Novartis, Eli Lilly, Orphazyme, Astra Zeneca, Grant/research support from: HC has received grant support from Eli Lilly and UCB, Vikas Agarwal: None declared, Rohit Aggarwal Consultant of: RA has/had a consultancy relationship with and/or has received research funding from the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, and Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant., Grant/research support from: RA has/had a consultancy relationship with and/or has received research funding from the following companies-Bristol Myers-Squibb, Pfizer, Genentech, Octapharma, CSL Behring, Mallinckrodt, AstraZeneca, Corbus, Kezar, and Abbvie, Janssen, Alexion, Argenx, Q32, EMD-Serono, Boehringer Ingelheim, Roivant.

OP0161 TREATMENT PATTERNS OF IDIOPATHIC INFLAMMATORY MYOPATHIES: RESULTS FROM AN INTERNATIONAL COHORT OF OVER 1,400 PATIENTS

Background

Idiopathic inflammatory myopathies (IIM) are a group of heterogeneous autoimmune disorders with limited standardization of treatment protocols.

Objectives

To evaluate frequency and patterns of various treatments used for IIM based on disease subtype, world region, and organ involvement.

Methods

Cross-sectional data from the international CoVAD self-report e-survey1 was extracted on Sep 14th, 2021. Patient details included demographics, IIM subtypes (dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM), antisynthetase syndrome (ASSD), necrotizing myositis (NM) and overlap myositis (OM)), clinical symptoms, disease duration and activity, and current treatments. Treatments were categorized in corticosteroids (CS), antimalarials, immunosuppressants (IS), intravenous immunoglobulins (IVIG), biologics, and others. Typical clinical symptoms (dyspnea, dysphagia) were used as surrogate for organ involvement. Factors associated with IS were analyzed using multivariable logistic regression, adjusting for IIM subtype, demographics, world region, disease activity, and prevalent clinical symptoms (>10%).

Results

In 1418 patients with IIM, median age was 61 years [IQR 49-70], 62.5% were females, median disease duration was 6 years [IQR 3-11], most common subset was DM (32.4%).

The most used treatments were IS (49.4%, including Methotrexate 19.6%, Mycophenolate Mofetil 18.2%, Azathioprine 8.8%, Cyclosporine 2.7%, Tacrolimus 2%, Leflunomide 1.6%, Sulfasalazine 1%, and Cyclophosphamide 0.6%), followed by CS (40.8%), antimalarials (13.8%) and IVIG (9.4%). Biologics were used in 4.3% of patients.

Treatment patterns differed significantly by IIM subtypes with a higher frequency of IS (77.7%) and CS (63.4%) use in ASSD; antimalarials (28.6%) and biologics (9.8%) use in OM and IVIG use in NM (24.6%) (Table 1). Also, treatment patterns were different in regions of the world (Figure 1), with a higher frequency of CS use in Europe (60.5%) and IS use in South America (77.2%). Antimalarials were most used in Asia (19.4%), while IVIG use was most common in Oceania (16.9%). Dyspnea was associated with higher use of IS (69.9%) and CS (65.8%) (p<0.001), whereas dysphagia was negatively associated with IS (39.7%) and CS (32.7%) likely due to a higher proportion in IBM patients reporting dysphagia.

Table 1.

Current Treatments for IIM, Stratified by Disease Subtypes

DermatomyositisPolymyositisInclusion Body MyositisAnti-synthetase syndromeNecrotizing myositisOverlap syndromeAll IIMp-valueNumber of patients459182348148572241418Immunosuppressants*269 (58.6)107 (58.8)39 (11.2)115 (77.7)40 (70.2)130 (58.0)700 (49.4)<0.001Corticosteroids208 (48.0)81 (46.8)32 (9.7)90 (63.4)32 (59.3)103 (50.0)546 (40.8)<0.001Antimalarials99 (21.6)7 (3.8)0 (0.0)25 (16.9)1 (1.8)64 (28.6)196 (13.8)<0.001Intravenous Immunoglobulins54 (11.8)16 (8.8)19 (5.5)10 (6.8)14 (24.6)20 (8.9)133 (9.4)<0.001Biologics**17 (3.7)7 (3.8)0 (0.0)13 (8.8)2 (3.5)22 (9.8)61 (4.3)<0.001Others***6 (1.3)0 (0.0)0 (0.0)1 (0.7)0 (0.0)5 (2,2)12 (0.8)0.098

*Methotrexate (278), Mycophenolate Mofetil (258), Azathioprine (125), Cyclosporine (38), Tacrolimus (28), Leflunomide (23), Sulfasalazine (14), Cyclophosphamide (9)

. **Rituximab (44), Abatacept (5), TNF inhibitors (4), Tocilizumab (3), Belimumab (3), Secukinumab (1)

. ***JAK(10) and PDE4 inhibitors (2)

Multivariable logistic regression analysis showed an association of IS with the IIM subtype (least used in IBM (OR 0.07 [95%CI 0.04-0.13] compared to DM), world region (most used in South America (OR 2.35 [1.12-4.91] compared to North America), active and worsening disease activity (OR 3.49 [1.76-6.91] compared to remission), and some clinical features (dyspnea, fatigue, and muscle weakness).

Conclusion

IIM treatment patterns differ significantly by disease subtypes, world regions and organ involvement, highlighting the need for unified international consensus-driven guidelines.

References

[1]Parikshit S. et al. Rheumatol Int. 2022 Jan;42(1):23–9.

Disclosure of Interests

None declared

Multi-targeted drug repurposing approach for breast cancer via integrated functional network analysis

The present study focuses on the interconnected functional network of altered metabolism and EMT (epithelial to mesenchymal transition) signaling in breast cancer. We have interlinked the metabolic and EMT signaling circuits and selected Insulin receptor (IR), Integrin beta 1 (ITGB1), and CD36 as target proteins based on network analysis. Extensive computational approaches discerned the potential drug molecules from the library of 1293 FDA-approved drugs to block all three target proteins. Using molecular docking, molecular dynamics simulation, and MMPBSA binding free energy studies, Capmatinib, Ponatinib, Naldemedine, and Pimozide were identified as potential repurposed drugs to block the function of all three target proteins. Among in silico selected candidate drugs, Pimozide, a known anti-psychotic drug, was further validated using in-vitro studies for its anti-cell proliferative potential on breast cancer cell lines (namely, MCF7, MDAMB231 and MDAMB468). The inhibitory concentration (IC50) values of MCF7, MDAMB231 and MDAMB468 was found to be 16.26 µM, 20.82 µM and 13.10 µM, respectively. The effect of Pimozide on EMT-induced MDAMB231 and MDAMB468 cells was evident from their IC50 values of 7.85 µM and 6.83 µM, respectively. The potent anti-cancer property of Pimozide has opened up avenues for drug repurposing towards 'multi-targeted therapy' in EMT dynamics.

Genome-wide association studies for agronomical traits in winter rice accessions of Assam

The 297 winter rice accessions of Assam, North East India were genotyped by sequencing (GBS). The 50,985 high-quality SNPs were filtered and assigned to 12 rice chromosomes. The population structure analysis revealed three major subgroups SG1, SG2, and SG3 consisting of 30, 8, and 143 accessions respectively. The remaining 116 accessions were grouped as admixture population. Phenotypic data were recorded on13 agronomical traits for genome-wide association studies (GWAS). The 60 significant marker-trait associations (MTAs) were identified for 11 agronomical traits, which explained 0 to 15% of phenotypic variance (PV). A QTL 'hot spot' was detected near the centromeric region on chromosome 6. The identified QTLs may be validated and utilized in 'genomics assisted breeding' for improvement of existing rice cultivars of Assam and North East India.

Alcohol functionality in the fatty acid backbone of sphingomyelin guides the inhibition of blood coagulation

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation by an unknown mechanism. Here we show the OH functionality of SM contributes in forming the close assembly through intermolecular H-bond and through Ca²⁺ chelation, which restricts the protein–lipid/protein–protein interactions and thus inhibits the coagulation procedure.

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation.

Utilization of absolute monocyte counts to predict cardiovascular events in people living with HIV

OBJECTIVES

Cardiovascular risk is increased in people living with HIV (PLWH). In HIV-uninfected populations, total absolute monocyte count (AMC) has been shown to be predictive of future cardiovascular events (CVEs). We sought to determine whether AMC predicts CVEs in PLWH independent of established and HIV-related cardiovascular risk factors.

METHODS

We identified all PLWH within the Partners HIV Cohort without factors that could confound the monocyte count. CVE was defined as fatal or non-fatal acute myocardial infarction or ischaemic stroke. Baseline-measured AMC was defined as the average of all outpatient AMC counts a year before and after the baseline date. Multivariable Cox proportional hazards models were used to assess the association of baseline AMC with CVEs.

RESULTS

Our cohort consisted of 1980 patients, with median follow-up of 10.9 years and 182 CVEs. Mean (± SD) age was 41.9 ± 9.3 years; 73.0% were male. Mean CD4 count was 506.3 ± 307.1 cells/µL, 48% had HIV viral load (VL) < 400 copies/mL, and 87% were on antiretroviral therapy. Mean AMC was 0.38 × 10³  ± 0.13 cells/µL. In multivariable modelling adjusted for traditional CV risk factors, CD4 cell count, and HIV VL, AMC quartile 2 (Q2) (HR = 1.01, P = 0.98), Q3 (HR = 1.07, P = 0.76), and Q4 (HR = 0.97, P = 0.89) were not significantly predictive of CVE compared with Q1.

DISCUSSION

Baseline AMC was not associated with long-term CVEs in PLWH. AMC obtained in routine clinical encounters does not appear to enhance CV risk stratification in PLWH.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Kidney injury enhances renal G-CSF expression and modulates granulopoiesis and human neutrophil CD177 in vivo

Kidney injury significantly increases overall mortality. Neutrophilic granulocytes (neutrophils) are the most abundant human blood leukocytes. They are characterized by a high turnover rate, chiefly controlled by granulocyte colony stimulating factor (G‐CSF). The role of kidney injury and uremia in regulation of granulopoiesis has not been reported. Kidney transplantation, which inherently causes ischemia–reperfusion injury of the graft, elevated human neutrophil expression of the surface glycoprotein CD177. CD177 is among the most G‐CSF‐responsive neutrophil genes and reversibly increased on neutrophils of healthy donors who received recombinant G‐CSF. In kidney graft recipients, a transient rise in neutrophil CD177 correlated with renal tubular epithelial G‐CSF expression. In contrast, CD177 was unaltered in patients with chronic renal impairment and independent of renal replacement therapy. Under controlled conditions of experimental ischemia–reperfusion and unilateral ureteral obstruction injuries in mice, renal G‐CSF mRNA and protein expression significantly increased and systemic neutrophilia developed. Human renal tubular epithelial cell G‐CSF expression was promoted by hypoxia and proinflammatory cytokine interleukin 17A in vitro. Clinically, recipients of ABO blood group‐incompatible kidney grafts developed a larger rise in neutrophil CD177. Their grafts are characterized by complement C4d deposition on the renal endothelium, even in the absence of rejection. Indeed, complement activation, but not hypoxia, induced primary human endothelial cell G‐CSF expression. Our data demonstrate that kidney injury induces renal G‐CSF expression and modulates granulopoiesis. They delineate differential G‐CSF regulation in renal epithelium and endothelium. Altered granulopoiesis may contribute to the systemic impact of kidney injury.

Gold Nanoparticle-Based Detection of Low Molecular Weight AGEs from In Vitro Glycated Haemoglobin A0 Samples

Protein glycation is a major biochemical event that takes place in the plasma of diabetic patients due to increased sugar levels. Extensive glycation leads to the formation of advanced glycation end products (AGEs) that is well known for having detrimental effects on diabetic patients. In the current work, we have glycated the physiologically important protein Haemoglobin A0 in vitro to study AGE formation and activity by using them as a template for gold nanoparticle (GNPs) synthesis. It was found that the surface plasmon resonance of synthesised GNPs showed high correlation with the extent of glycation. On fractionation, the glycated Haemoglobin A0 segregated into two distinct population of products, one consisting of proteinaceous, cross-linked larger fragments of Haemoglobin A0 and a second population of non-proteinaceous low molecular weight AGEs. Only low molecular weight AGEs contributed to synthesis of GNPs upon using the fractions as a template, substantiating the principle of proposed GNP-based assay. Owing to its physiological importance, AGEs can be used as a diagnostic means for diabetes and its associated complications. In this study, we have employed the high reactivity of AGEs for the development of a GNP-based novel colorimetric sensor to enable their detection. Our proposed GNP-based sensing could have high clinical significance in detecting diabetes and its associated complexities.

Intrinsic coincident linear polarimetry using stacked organic photovoltaics

Polarimetry has widespread applications within atmospheric sensing, telecommunications, biomedical imaging, and target detection. Several existing methods of imaging polarimetry trade off the sensor's spatial resolution for polarimetric resolution, and often have some form of spatial registration error. To mitigate these issues, we have developed a system using oriented polymer-based organic photovoltaics (OPVs) that can preferentially absorb linearly polarized light. Additionally, the OPV cells can be made semitransparent, enabling multiple detectors to be cascaded along the same optical axis. Since each device performs a partial polarization measurement of the same incident beam, high temporal resolution is maintained with the potential for inherent spatial registration. In this paper, a Mueller matrix model of the stacked OPV design is provided. Based on this model, a calibration technique is developed and presented. This calibration technique and model are validated with experimental data, taken with a cascaded three cell OPV Stokes polarimeter, capable of measuring incident linear polarization states. Our results indicate polarization measurement error of 1.2% RMS and an average absolute radiometric accuracy of 2.2% for the demonstrated polarimeter.

Next-generation sequencing confirms the implication of SLC24A1 in autosomal-recessive congenital stationary night blindness

Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder which represents rod photoreceptor dysfunction or signal transmission defect from photoreceptors to adjacent bipolar cells. Patients displaying photoreceptor dysfunction show a Riggs-electroretinogram (ERG) while patients with a signal transmission defect show a Schubert-Bornschein ERG. The latter group is subdivided into complete or incomplete (ic) CSNB. Only few CSNB cases with Riggs-ERG and only one family with a disease-causing variant in SLC24A1 have been reported. Whole-exome sequencing (WES) in a previously diagnosed icCSNB patient identified a homozygous nonsense variant in SLC24A1. Indeed, re-investigation of the clinical data corrected the diagnosis to Riggs-form of CSNB. Targeted next-generation sequencing (NGS) identified compound heterozygous deletions and a homozygous missense variant in SLC24A1 in two other patients, respectively. ERG abnormalities varied in these three cases but all patients had normal visual acuity, no myopia or nystagmus, unlike in Schubert-Bornschein-type of CSNB. This confirms that SLC24A1 defects lead to CSNB and outlines phenotype/genotype correlations in CSNB subtypes. In case of unclear clinical characteristics, NGS techniques are helpful to clarify the diagnosis.

A rare case of a myofibroma presenting on the tongue

Myofibromas are benign neoplasms of myofibroblastic origin, rarely encountered in the oral cavity. Limited awareness of the clinical features of these lesions risks misdiagnosis of more sinister pathology. The objective of this report is to highlight the potential diversity of oral lesions by describing an uncommon presentation of a myofibroma. The case reveals the diagnostic difficulties encountered, along with postoperative complications, which exemplify the remarkable healing capacity of the oral cavity.

Mutation spectrum in BBS genes guided by homozygosity mapping in an Indian cohort

Bardet-Biedl syndrome (BBS), a ciliopathy disorder with pleiotropic effect manifests primarily as retinal degeneration along with renal insufficiency, polydactyly and obesity. In this study, we have performed homozygosity mapping using NspI 250K affymetrix gene chip followed by mutation screening of the candidate genes located in the homozygous blocks. These regions are prioritized based on the block length and candidature of the genes in BBS and other ciliopathies. Gene alterations in known BBS (22) and other ciliopathy genes such as ALMS1 (2) were seen in 24 of 30 families (80%). Mutations in BBS3 gene, inclusive of a novel recurrent mutation (p.I91T) accounted for 18% of the identified variations. Disease associated polymorphisms p.S70N (BBS2), rs1545 and rs1547 (BBS6) were also observed. This is the first study in Indian BBS patients and homozygosity mapping has proved to be an effective tool in prioritizing the candidate genes in consanguineous pedigrees. The study reveals a different mutation profile in the ciliopathy genes in Indian population and implication of novel loci/genes in 20% of the study group.

Polarization sensitive optical low-coherence reflectometry for blood glucose monitoring in human subjects

A device based on polarization sensitive optical low-coherence reflectometry is developed to monitor blood glucose levels in human subjects. The device was initially tested with tissue phantom. The measurements with human subjects for various glucose concentration levels are found to be linearly dependent on the ellipticity obtainable from the home-made phase-sensitive optical low-coherence reflectometry device. The linearity obtained between glucose concentration and ellipticity are explained with theoretical calculations using Mie theory. A comparison of results with standard clinical methods establishes the utility of the present device for non-invasive glucose monitoring.

Arsenic(III) sorption on nanostructured cerium incorporated manganese oxide (NCMO): a physical insight into the mechanistic pathway

Arsenic(III) sorption was investigated with nanostructured cerium incorporated manganese oxide (NCMO). The pH between 6.0 and 8.0 was optimized for the arsenic(III) sorption. Kinetics and equilibrium data (pH=7.0±0.2, T=303±1.6 K, and I=0.01 M) of arsenic(III) sorption by NCMO described, respectively, the pseudo-second order and the Freundlich isotherm equations well. The sorption process was somewhat complicated in nature and divided into two different segments, initially very fast sorption followed by slow intraparticle diffusion process. Sorption reaction of arsenic(III) on NCMO was endothermic (ΔH°=+13.46 kJ mol(-1)) and spontaneous (ΔG°=-24.75 to -30.15 kJ mol(-1) at T=283-323 K), which took place with increasing entropy (ΔS°=+0.14 kJ mol(-1)K(-1)) at solid-liquid interface. Energy of arsenic(III) sorption estimated by analyzing the equilibrium data using the D-R isotherm model was 15.4 kJ mol(-1), indicating the ion-exchange type mechanism. Raman, FT-IR, pH effect, desorption, etc. studies indicated that arsenic(III) was oxidized to arsenic(V) during the sorption process.

Patients' perception of health services for sexually transmitted infections in Singapore

INTRODUCTION

The Department of Sexually Transmitted Infections (STI) Control (DSC) Clinic is the only public STI clinic in Singapore. This study aimed to determine patients' perception of the clinic as well as the factors that may influence their choice of DSC Clinic over other medical facilities. The concerns of certain risk groups were also assessed.

METHODS

Self-administered anonymous questionnaires were offered to Singaporeans and Permanent Residents over 18 years of age who were seeking treatment at the DSC Clinic. 1,000 responses were collected over a period of four weeks in May 2009.

RESULTS

More than two-thirds of the patients had a positive experience at the DSC Clinic and would recommend the clinic to their family and friends. Positive attributes included competence of staff and the convenience of a one-stop treatment facility. The patients' visits to the DSC Clinic also prompted them to engage in safer sexual practices. Stigma was surprisingly not an issue among more than three-quarters of the patients. Confidentiality of medical records was a major concern, with more than half of the patients unwilling to share their records with other healthcare providers, employers or insurance companies. The majority of patients would like to see the provision of clinics catering to special groups such as young people, women as well as men-who-have-sex-with-men.

CONCLUSION

The majority of patients were satisfied with the health services provided at the DSC Clinic. Confidentiality in consultation was of prime importance to patients.

Tumour-like presentations of anogenital herpes simplex in HIV-positive patients

Genital and perianal ulcers seen in patients with HIV are commonly due to herpes simplex virus (HSV) infection. While it is well known that the characteristic presentation of HSV is a vesicular rash or crops of erosions, the clinical presentation of genital HSV infection in HIV is varied and can assume vegetative, hypertrophic, condyloma-like, nodular, ulcerative and tumour-like nodules or plaques. These unusual presentations often lead to a delayed diagnosis. We describe five immunocompromised HIV-positive patients with CD4 counts ranging from 114 to 326 cells/μL with unusual presentations of anogenital herpes.

Plasminogen activator inhibitor-1 inhibits factor VIIa bound to tissue factor

BACKGROUND AND OBJECTIVE

A growing body of experimental evidence supports broad inhibitory and regulatory activity of plasminogen activator inhibitor 1 (PAI-1). The present study was designed to investigate whether PAI-1 inhibits factor (F) VIIa complexed with tissue factor (TF), a well-known procoagulant risk factor.

METHODS AND RESULTS

The ability of PAI-1 to inhibit FVIIa-TF activity was evaluated in both clotting and factor X (FX) activation assays. PAI-1 and its complex with vitronectin inhibit: (i) clotting activity of FVIIa-TF (PAI-1(IC50) , 817 and 125 nm, respectively); (ii) FVIIa-TF-mediated FX activation (PAI-1(IC50) , 260 and 50 nm, respectively); and (iii) FVIIa bound to TF expressed on the surface of stimulated endothelial cells (PAI-1(IC50) , 260 and 120 nm, respectively). The association rate constant (k(a)) for PAI-1 inhibition of FVIIa-TF was determined using a chromogenic assay. K(a) for PAI-1 inhibition of FVIIa bound to relipidated TF is 3.3-fold higher than that for FVIIa bound to soluble TF (k(a) = 0.09 ± 0.01 and 0.027 ± 0.03 μm(-1) min(-1), respectively). Vitronectin increases k(a) for both soluble and relipidated TF by 3.5- and 30-fold, respectively (to 0.094 ± 0.020 and 2.7 ± 0.2 μm(-1) min(-1)). However, only a 3.5- to 5.0-fold increase in the acylated FVIIa was observed on SDS PAGE in the presence of vitronectin for both relipidated and soluble TF, indicating fast formation of PAI-1/vitronectin/FVIIa/relipidated TF non-covalent complex.

CONCLUSIONS

Our results demonstrate potential anticoagulant activity of PAI-1 in the presence of vitronectin, which could contribute to regulation of hemostasis under pathological conditions such as severe sepsis, acute lung injury and pleural injury, where PAI-1 and TF are overexpressed.

Effect of glycoPEGylation on factor VIIa binding and internalization

SUMMARY

Recombinant coagulation factor VIIa (rFVIIa), which is widely used for treatment of bleeding episodes in haemophilia patients with inhibitors, is cleared from the circulation relatively fast with a plasma half-life of 2-4 h. PEGylation is an established and clinically proven strategy for prolonging the circulatory life-time of bio-therapeutic proteins. The aim of this study was to investigate the effect of glycoPEGylation of rFVIIa on rFVIIa binding to its cellular receptors and its subsequent internalization. rFVIIa and glycoPEGylated rFVIIa were labeled with (125)I and the radio-iodinated proteins were used to monitor rFVIIa binding and uptake in endothelial cells and fibroblasts. FVIIa-TF activity at the cell surface was analyzed by a factor X activation assay. Modification of rFVIIa with PEG impaired rFVIIa binding to both endothelial cell protein C receptor and tissue factor (TF) on cell surfaces. The internalization of PEGylated rFVIIa in endothelial cells and fibroblasts was markedly lower compared to the internalization of rFVIIa in these cells. PEGylated rFVIIa was able to activate factor X on TF expressing cell surfaces at a rate similar to that of unmodified rFVIIa when the cells were not subjected to multiple washings to remove the free ligand. General effects such as steric hindrance or changes in electrostatic binding properties of the modified rFVIIa to its receptors are probably responsible for this impairment rather than a loss of specific recognition of the receptors, which could explain near normal activation of factor X by glycoPEGylated rFVIIa on TF expressing cells while its uptake is reduced.

Activity and regulation of glycoPEGylated factor VIIa analogs

BACKGROUND

Recombinant coagulation factor VIIa (rFVIIa) has proven to be a safe and effective drug for treatment of bleeding episodes in hemophilic patients with inhibitors. However, rFVIIa is cleared from the circulation relatively quickly. Protein modification with poly(ethylene glycol) (PEG) can prolong the circulatory lifetime of proteins but it could also impair protein function by molecular shielding of the protein surface.

OBJECTIVES

To characterize the interaction of glycoPEGylated rFVIIa - rFVIIa-10K PEG and rFVIIa-40K PEG - with tissue factor (TF), factor X (FX) and plasma inhibitors, tissue factor pathway inhibitor (TFPI) and antithrombin (AT).

METHODS

The amidolytic and FX activation assays were employed to investigate the interaction of glycoPEGylated rFVIIa with its macromolecular substrate and inhibitors.

RESULTS

Both the glycoPEGylated rFVIIa analogs exhibited similar amidolytic activity as that of rFVIIa in the absence or the presence of relipidated TF. The analogs were as effective as rFVIIa in activating FX in the absence of TF. In the presence of TF, the glycoPEGylated rFVIIa variants, relative to rFVIIa, were slightly less effective at lower concentrations, but no significant differences were found among them in activating FX at saturating concentrations. Both AT/heparin and TFPI effectively inhibited the glycoPEGylated rFVIIa bound to relipidated TF or TF on stimulated endothelial cells. In contrast to their normal interaction with TF, the glycoPEGylated rFVIIa variants appeared to interact poorly with phospholipids.

CONCLUSIONS

The glycoPEGylated rFVIIa variants retained their catalytic activity and interacted efficiently with TF, FX and the plasma inhibitors. Further work with appropriate in vitro and in vivo model systems is needed to determine the feasibility of using glycoPEGylated rFVIIa to improve therapeutic options for bleeding disorders.